metal adhesives being applied on car underbody

All you need to know about metal adhesive systems

Where fasteners and welded bonds used to be of paramount importance, metal adhesive systems are becoming more and more popular. Metal glue and tapes bring along many benefits and cancel the disadvantages of mechanical bonds and seals. However, as there are different types of metals, also many types of metal bonding adhesive are available including machinery and structural adhesives.

Bonding metal with glues and tapes is highly possible, even recommended. However, the choice of the right metal adhesive may be a challenge due to the wide variety of different kinds of products which each have unique properties. Here you find the benefits of metal adhesives, the different types of metal glue and the suitable solutions for various types of metals, metal on metal glue options and how to glue metal to metal and to other materials.

Why you should choose for metal glue

Metal adhesives create chemical bonds which, in many cases, are preferred to mechanical fasteners, soldering and welds, especially when bonding metal to metal. Not only is metal glue often the more cost efficient option, but it also reduces the steps in assembly lines and so speeds up the process as a whole. The main reason for reducing the assembly steps is that adhesives not only bond but also seal. Thus the metal adhesive and sealant allow for application in one go. The bond (or seal) can also be flexible allowing for relative movement of the parts without affecting the bond. That is why metal adhesives are a go-to solution for products that are subject to vibration, temperature fluctuation and weather, such as trucks and other vehicles.

Metal adhesive vs. fasteners

Fasteners such as bolts and screws are very common methods of bonding for temporary joints. Fasteners are also suitable for semi temporary joints such as those in automotive assemblies. Nevertheless, problems may occur as fasteners require carefully placed holes, are prone to corrosion and may loosen over time.

This is where metal adhesives come into picture: removable glues and tapes are suitable for temporary bonding, and they do not leave traces behind after removal. Adhesives are also suitable for semi temporary joints as they seal from corrosion, are generally lighter and cheaper than mechanical fasteners, and distribute the stress throughout the bond making the assembly stronger. Some metal bonding adhesives come with special properties such as chemical resistance and heat resistance. Heat resistant glue for metal is common in public transport vehicles, automotive industry and general industrial applications. Metal glue can also be used for supporting fasteners: threadlocking and thread sealing are common applications where a metal glue makes sure the fastener does not loosen over time.

Gluing metal to metal vs. welding

Welding is a common method of bonding metal to metal in assembly operations. In a way, welds resemble adhesive bonds: both bonds are uniform and allow for equal stress distribution. They also do not require holes unlike fasteners. However, in applications that make use of welds, the labor costs are likely to be higher as the application requires special training and certificates. The welds also require inspection afterwards, bringing along more costs. With metal to metal adhesive this is not the case as most applications require only basic training and inspection is not necessary.

In bonding metal to metal, adhesives protect from corrosion whereas welds might even encourage it. Using adhesives also eliminates the rapid heating and cooling in a welding process. The drastic temperature fluctuations can cause the metal to weaken or discolor. Metal to metal glue applications usually do not involve as high heat as welding leaving the metal unharmed.

4 types of metal adhesive systems

Generally, metal adhesives can be divided into two groups: machinery adhesive and structural adhesive metal bonding. The latter refer to adhesives that are capable of bearing structural loads. These include epoxy glue for metal and acrylic metal adhesives. The other group is machinery adhesives which include those suitable for threadlocking and thread sealing as well as some special application which do not have to carry structural loads.

4 most common adhesives for gluing metal to metal and metal to other materials

threadlocking of screws with anaerobic metal adhesives
Anaerobic metal adhesives are used only for metal to metal bonding for applications like threadlocking.
  1. Epoxy is one of the strongest adhesives for metal. It exists in different types which have unique properties such as chemical resistance and heat resistance. Epoxies come as one or two component systems. Single component epoxy glue for metal cures as a result of additional heat. A 2K system is a mixture of two parts with react with each other starting the curing process. When looking for the strongest glue for metal, a 2K epoxy for metal should be considered.
  2. Acrylic metal glue exists as two types: surface activated and and bead on bead acrylics. The latter refers to applying a bead of adhesive on both substrates before connecting them. The bonding starts when the parts comne in contact with each other and become subject to pressure. Surface activated acrylics, in turn, require a water thin initiator applied to one substrate and the resin to the other.
  3. Cyanoacrylate, also known as instant adhesive, is the super glue for metal to metal bonding. Cyanoacrylate adhesives is suitable for most metals as long as they are reactive. Therefore, the super glue for metal works better on brass and copper than on steel. Due to the excellent performance as metal glue, commercial cyanoacrylate adhesives are very popular among miniature and modeling hobbyists.
  4. Anaerobic metal adhesives are only used for gluing metal to metal as they require presence of metal and absence of oxygen to be able to cure. Anaerobic adhesives are ideal for securing fasteners in terms of threadlocking and thread sealing as well as gasketing and retaining.

Other metal adhesives

Metal bonding can additionally, be realized by using MS (modified silane) polymers which are common when bonding metal sheets in vehicles like trains and buses. When invisible bonds are required, UV curable transparent systems should be considered. In case you are curious for more metal bonding solutions, contact us and let our experts guide you through the possibilities.

Bonding solutions for different types of metals

Not only are there many types of metal glue, but the range of different types of metals is also broad. Therefore, before choosing an adhesive system, you must know the metal that requires bonding: its properties have a great impact on the choice. Here you will find some common types of metal and suitable metal adhesive systems for different metal bonding applications.

Bonding aluminum with metal glue

When working with aluminum, it should be kept in mind that the metal is prone to corrosion and often has a thin oxide layer on it. The oxide layer forms a good surface for adhesives to adhere, however, the layer does not have a strong bond with the aluminum. Thus, to create strong bonds between aluminum and other materials, the adhesive should not be applied on the oxide layer, the layer should rather be removed. The best method to remove aluminum oxide is using solvent wipes, such as acetone or isopropanol, and abrading or grit blasting the surface.

After the surface preparation by abrasion or grit blasting, and appropriate cleaning, the surface is ready for the metal adhesive. Let’s look at the types of adhesives:

ANAEROBIC ADHESIVES – Even though aluminum is a passive metal, some anaerobic systems can be used for close-fitting concentric parts of threaded components. For softer aluminum alloys, anaerobic glues are suitable for gasketing and flange sealing.

EPOXY SYSTEMS – One component epoxy glues are ideal for aluminum bonding. They are easy to apply and cure fast when heated. Also 2K epoxy glues are suitable for aluminum. They generally form the strongest bonds.

CYANOACRYLATE GLUES – All grades of cyanoacrylate adhesive, instant glue, bond aluminum extremely well. Special formulations of super glue for metal form a considerable option when bonding aluminum to dissimilar surfaces with different coefficients of thermal expansion.

ACRYLICS – Structural acrylic adhesives are very suitable for aluminum. Both types, surface activated and bead to bead acrylics, are suitable for aluminum.

As many types of adhesives meet the needs of aluminum, the choice should be based on the adhesives suitability to your process, desired curing method and the required resistance.

Which metal adhesives bond brass?

Brass is an alloy which consists of zinc and copper. Brass is non-magnetic and resists corrosion: therefore, it is common in pipe joints, hydraulic fittings, heat exchangers, musical instruments and door locks and knobs.

For bonding brass, the options are open as the metal is rather easy to bond and many metal glues adhere well to it. The options include:

CYANOACRYLATE SYSTEMS – When bonding pads to musical instruments cyanoacrylate super glue is a preferred option. The strongest glue for metal often is methyl cyanoacrylates. However, when the bond needs resistance to impact or polar solvents, structural adhesive for metal bonding should be considered.

ANAEROBIC ADHESIVES – Brass is among the most reactive metals which causes anaerobic adhesives to cure much faster than when applied to, for instance, steel. On brass, anaerobic glues are used for threadlocking, thread sealing, form in place gaskets, retaining and weld sealing. These metal bonding adhesives exist as permanent and removable systems depending on the application. The applications also include pipe connections for oxygen and potable water pipelines.

STRUCTURAL ADHESIVES – Both epoxy and acrylic adhesives are highly suitable for bonding brass. Similarly to aluminum, all types are applicable: heat curing 1K epoxy, reactive 2K epoxy, and acrylic glue all do the job depending on the application.

Due to the wide variety of possible metal adhesives for brass, the choice should be based on the needs of the application, the adhesive´s compatibility with existing processes and the environment´s requirements.

Metal adhesives for copper

Copper and its alloys are readily bonded with a wide variety of different metal adhesives. For copper, adhesives are often the preferred option as they do not cause heat damage on the metal unlike soldering.

The most commonly used metal glues for copper include:

ANAEROBIC GLUES – As anaerobic adhesives require the presence of a metal and absence of oxygen to be able to cure fast, copper offers a perfect substrate due to the fact that it is one of the most reactive metals. That is why anaerobic systems cure much faster on copper than many other metals as steel. The uses include threadlocking, thread sealing, weld sealing, gasketing and munitions sealing.

EPOXY GLUE FOR METAL- Both one part, heat curing epoxies and 2K reactive epoxy glues are suitable for bonding copper. Epoxy glue for metal is ideal for forming strong metal to metal and metal to other material bonds.

CYANOACRYLATE ADHESIVES – Instant adhesive for metal offers the fastest curing time and results in increased efficiency. It is also highly compatible with copper. Nonetheless, when polar solvent resistance and impact resistance are the requirements, an epoxy or acrylic adhesive offers the right solution.

ACRYLIC SOLUTIONS – When it comes to acrylics, both surface activated and bead to bead systems support copper bonding. Both result in strong structural bonds.

Stainless steel adhesive systems

Stainless steel is generally an easy metal to bond, however the mirror-finish stainless steel may be a tricky metal to apply adhesives to as it usually has a very low texture surface which prevents adhesion. A Stainless steel surface without mirror-finish requires little to no surface preparation and can be bonded with the following systems:

ANAEROBIC SYSTEMS – threadlockers, thread sealants, gaskets and retaining compounds all work well as glue for stainless steel. However, the curing time of anaerobic adhesives is rather long due to the fact that stainless steel is a passive metal.

CYANOACRYLATE ADHESIVES – All grades bond stainless steel rather well. The strongest bonds form when using special products designed for metals like steel.

STRUCTURAL GLUES – Structural adhesives such as epoxy and acrylics provide heat and chemical resistance. Generally, epoxy is the tougher option, yet it always depends on the application and the environment.

If you are working with mirror-finish stainless steel, before applying any steel adhesives, you should create more texture on the surface. The surface must be roughened, but methods like sandpaper, steel wool or scotch brite are likely to fail due to the hard surface of the material. On the other hand, automated roughening methods may generate heat, which can alter the metal´s surface properties and prevent adhesion. The best way to abrade mirror-finish stainless steel is sandblasting: it is efficient enough and involves no heat.

The strongest metal bonding glue for mild steel

Mild steel, sometimes called carbon steel, is a common material used throughout industries such as automotive and machine building. The key to successful steel bonding lies in proper surface preparation. The surface preparation includes appropriate cleaning and abrasion where needed.

Note that mild steel is often powder coated or otherwise painted prior to adhesive application. Then the metal adhesive forms a bond with the coating layer, not the steel itself.

Cyanoacrylate adhesive tub
Cyanoacrylate adhesive is also known as super glue or instant adhesive as it sets faster than other metal adhesives.

ANAEROBIC SYSTEMS – Threadlockers, thread sealants, gaskets and retaining compounds all work well on mild steel. These result from the use of anaerobic steel adhesive systems.

CYANOACRYLATE GLUES – When strong, fast bonds are a must cyanoacrylate systems are a considerable option. For applications that require polar solvent and impact resistance, structural steel glue systems may offer a more suitable solution. For example retention dressings for bolts and nuts can be realized using cyanoacrylate metal glue.

STRUCTURAL SOLUTIONS – Structural adhesive for metal bonding such as epoxy and acrylics are famous for their heat and chemical resistance. Generally, epoxy is the tougher solution, yet it always depends on the application and the environment.

Several steel adhesive systems are suitable for bonding mild steel: to determine the right one, it is important to consider the correct chemical, weather and temperature resistance.

Metal adhesives for magnets

Strong, even permanent magnets are present in many assemblies, the most important ones being electric motors and speakers. Magnet types differ from each other by strength, cost as well as temperature and corrosion resistance. Some types of magnets include neodymium, rare-earth, AlNiCo, samarium cobalt and ferrites. Usually, magnets allow for bonding without surface preparation. However, to achieve the strongest bonds, isopropanol can be used for cleaning the surface.

There are many metal adhesives that bond magnets more than well. Here are some of the most common metal adhesives for magnets:

CYANOACRYLATE ADHESIVES – These instant adhesives create strong bonds at high speed as their curing time is very short. When the bond must be resistant to polar solvents, high temperatures or impact, structural adhesives should be considered.

EPOXY SOLUTIONS – One and two component epoxies are both suitable for bonding most magnets. One should always confirm the compatibility of the adhesive and the specific magnet by checking with the metal adhesive manufacturer.

ACRYLIC GLUES – Due to the fact that structural surface activated acrylic metal glue systems have a fast set time, they are often a preferred solution for high speed motor assemblies. External 2K mix systems are the alternative.

Looking for the perfect metal bonding adhesive for your application?

The range of metal adhesives and types of metals is broad making the choice of an adhesive extremely tricky. Our experts are always willing to share their expertise and guide you towards the ideal solution. Hit the button below and find the perfect metal glue for your application.

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EXTRA: the best metal glue for DIYers

Metal adhesives not only are industrial systems, but they also often come in handy for small fixes in and around the house. The types of metal glue that are the most suitable for do-it-yourself applications include epoxy, polyurethane and cyanoacrylate (super glue).

EPOXY – epoxy metal glue can be rigid or flexible, transparent or opaque and fast or slow setting. They are predominantly two part systems and are suitable for applications such as door handles, handrails, table legs and jewellery. Like industrial epoxy adhesive, also the one for home use is heat and chemical resistant as well as suitable for rebuilding, filling and repairing applications.

POLYURETHANE – Polyurethane adheres well to most metals and is water and UV resistant making it ideal for outdoor applications. There are many jobs in and around the house that can benefit from polyurethane metal adhesive. Especially moisture curing polyurethane is often referred to as the best exterior metal adhesive.

CYANOACRYLATE – super glue is perfect for almost any household fix: it is easy to apply and cures in the matter of seconds. Common applications of super glue for metal include car parts, ornaments, appliances and numerous other everyday items. Also miniatures and models as well as prototype electronics can benefit from super glue thanks to its excellent performance in gluing metal.

biomass resulting from composting biodegradable adhesive

Biodegradable polymers driven by demand, and necessity

The need for sustainable, even biodegradable polymers – in particular for biodegradable adhesives and compostable glues – has never been greater. The world’s population is growing, living standards are rising and an increasing number of industries are facing the harsh reality of environmental concerns and a demand for sustainability.

Biodegradable adhesive systems now serve a wide variety of industries, from general packaging to the specialized medical sector. With the adhesive systems under continuous development, new applications are frequently introduced. The invention and further improvement of biodegradable glue allow for greener bonding solutions and reduced environmental impact.

Compostable adhesive – a type of biodegradable glue

The terms compostable and biodegradable are often considered synonyms. However, they are not. Biodegradable adhesives refer to glues that break down naturally, eventually. Compostable adhesives are also biodegradable, but they only deserve the title if they comply to a specific break-down process, and do such within a restricted period of time.

Compostable adhesives may break down in domestic or industrial conditions, depending on the adhesive formulation. They take much less time to break down into useful or harmless components than biodegradable materials generally do.

Benefits of biodegradable and compostable adhesive technology

Biodegradable adhesives, including compostable glue, first were available for a very few applications. However, their extremely green approach towards bonding encouraged the development of new systems, suiting an ever-increasing range of applications. General sustainability aside, biodegradable glues come with more benefits:

  • No microplastic pollution: biodegradable adhesives consist of natural materials that do not lead to microplastic pollution at any stage of their lifecycle.
  • Reduced waste processing costs: biodegradable glue breaks down into natural gases and biomass, which reduces waste processing costs. Waste processing does not involve hazardous chemicals. Compostable glue waste is especially economical to process. The breaking down is generally faster than with other biodegradable glue systems.
  • Soil enrichment through waste: the products of breaking down compostable adhesive are suitable for enriching soil and so stimulate growth of plants. Other biodegradable solutions may not be harmful to the environment; however, they do not enrich the soil as effectively as compostable waste.
  • Workplace safety: as biodegradable adhesives are free of hazardous substances, applying the adhesives is safer than when working with other adhesives.
  • Accordance with environmental planning: for example, the UK Plastics Pact requires all plastic packaging to be reusable, recyclable or compostable by 2025. Other similar acts exist and their number is constantly on the rise.

Next to the benefits that lead to reduced environmental impact, biodegradable and compostable adhesives also offer great business opportunities. This especially for adhesive manufacturers and users. Green products are an ever-growing trend, and demand increases by the day. This leads to greater need for both the adhesives and products which use the adhesives to be biodegradable or even compostable.

Examples of biodegradable glue and compostable adhesive systems

In continuous development, biodegradable glue systems become available for more and more applications. The hottest topics of the moment that involve biodegradable glue or even compostable adhesive systems include the following.

  • Hot melt adhesives: especially the packaging industry currently benefits from biodegradable hot melt systems which guarantee an efficient process and a 100% green solution. 
  • Heat seal adhesive: again beneficial to the packaging industry, heat seal adhesives ideal for paper and biofilm applications can be biodegradable.
  • PSA adhesive: compostability can be integrated into pressure sensitive adhesives which allow for applications on tape and labels.

If you are looking to switch to biodegradable bonding, do not hesitate to contact us. Our experts are happy to deliver a greener solution tailored for your product.

compostable adhesive and biodegradable glue in a bag of potato chips
Biodegradable adhesive allows for food packaging material to be converted into biomass and CO2.

How biodegradable glue works

The molecular structure of biodegradable adhesive systems resembles that of natural polymers. However, micro-organisms – such as bacteria – break down the biodegradable materials, hence the name biodegradable. These adhesives exist as liquid solutions and hot melt solutions. Micro-organisms use enzymes to break down the adhesive into carbon dioxide, water and biomass.

As mentioned, to deserve the title ‘compostable’, the adhesive must break down within a specific period of time and under specific conditions, in either domestic or industrial processes. Unsurprisingly, of the two, the industrial one is far more common among compostable glues. Either way, the resulting products of both processes are beneficial, as they can be used for enriching soil, i.e. as compost.

EN 13432 – the European standard for biodegradable materials

Adhesives that are wished to be classified as biodegradable (or compostable) according to EN 13432, must pass four tests. These are biodegradation, disintegration, ecotoxicity and heavy metals test.

According to EN 13432, an adhesive is biodegradable if:

  • 90% of the total mass of the adhesive is converted to CO2 within 180 days;
  • The heavy metals in the product do not exceed the strict limits set in the standard;
  • The products of broken-down adhesive can be used to enrich soil or are not harmful to plant growth in the area;
  • The germination rate and plant biomass in the compost are more than 90% of those in the corresponding blank compost.

Looking for biodegradable adhesive or compostable glue?

As organizations and individuals take social and environmental responsibility more and more seriously, the demand for biodegradable adhesives is increasing. If you need a more sustainable and environmentally-friendly adhesive for your application, contact us. We will go the extra mile to deliver the most eco friendly solution for your application.

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hot melt as a solvent free adhesive

Solvent free adhesives grow in popularity

The growing interest and consciousness towards environmental responsibility is resulting in new technologies also in the adhesives industry. Solvent free adhesives are becoming more and more popular as they contribute to a greener future, user safety and reduced environmental impact.

But what is solvent free adhesive? For adhesives to be called solvent free, they must not contain more than 5% solvents. Therefore, several different technologies have been developed to reduce or eliminate the solvent content of the systems. The technologies include solvent free glue, hot melt and high solids adhesives as well as waterborne systems. All these systems are considered low VOC adhesives.

Ever increasing uses of solvent free adhesive solutions

First solvent free adhesives were a solution for low demand applications. However, as the technology is continuously improving, non solvent adhesives are becoming a desired solution in many industries. The industries that already rely on these low VOC adhesive solutions include the following.

solvent free adhesives and sealants for shoes drying
Solvent free adhesives are used in many industries including shoe making.
  • Automotive: interior fittings such as headlinings and dashboards
  • Packaging: especially lamination systems for flexible packaging
  • Furniture: bonding and sealing upholstery
  • Mattress: bonding mattress layers together
  • Paper: envelopes, bookbinding etc.
  • Textile and shoes: apparel and footwear, bonding upper to the sole
  • Hygiene: for example napkins, sanitary diapers and other non woven materials
  • Medical: solvent free adhesive pand-aids, surgical glues and cements for bones
  • Construction: non solvent based construction adhesive systems as multi purpose solutions

Non solvent adhesive systems beat solvent solutions

The main reason for choosing for solvent free adhesives is the reduced environmental impact they have. The nearly or completely solvent free adhesive systems are safer for the environment and for people due to the fact that they do not emit nor contain much VOC (volatile organic compound). These non solvent, low VOC adhesive systems have, nevertheless, more advantages than just that.

  • Lighter weight: bonding products that do not contain solvents tend to be lighter in weight both during the production and in finished products.
  • Fewer product requirements: many countries set high requirements for chemical products that are allowed to be imported, especially regarding VOC. As solvent free adhesives have close to zero VOC, export is also easier.
  • Fewer occupational safety requirements: in regards of occupational safety, non solvent adhesives have less requirements since processing them does not involve the possibility to inhale VOC emissions.
  • Reduced health risk: The absence of VOC means safer end products since no hazardous chemicals have been used in the no solvents adhesive systems.

Low VOC adhesive systems by different technologies

As solvent free adhesive systems are increasing in demand, there are several ways to realize them. The technologies resulting in non solvent adhesive solutions include hot melts, high solids, solventless and waterborne solutions which we will take a closer look at below.

Hot melt and high solid non solvent adhesive solutions

One of the newer non solven glue technologies is hot melt adhesive. Generally, hot melts are 100% solids formulations leaving no space for solvents – the perfect solution when one is looking for a water and solvent free adhesive. They are thermoplastics which appear in a solid phase in room temperature. However, when the temperature is elevated, they become liquid with a good flow. After application, it only takes seconds before the non solvent glue solutions are back to solid phase forming strong bonds and seals – all without the use of solvents.

The hot melt adhesives are traditionally applied by spraying due to their reaction to temperature. However, they can be made rollable by reducing the solid share (usually to about 75%) making them liquid also at room temperature. This, however, means that some solvent will be involved but as long as it does not exceed 5%, they still can be classified as non solvent adhesives. Hot melts also exist as biodegradable systems currently used in the packaging industry.

Do not hesitate to contact us in case you require any additional information on the hot melt adhesive technologies.

Solventless adhesives

Solventless adhesives traditionally do not contain any solvent and were first developed for the packaging industry, more specifically as lamination for flexible packaging. Solventless adhesives were first used for low demand applications only. Due to continuous development, they are now good for any lamination application, even when high temperatures or chemicals are involved.

These solvent free adhesives carry the benefit of lower machinery costs. Even though machinery made for solvent based products cannot be used for this non solvent glue, the initial investment of new machinery is remarkably lower.

Water based dispersions as solvent free glue

The most traditional no solvents adhesive solution is water based. These adhesives use water instead of solvent as the carrier agent. They cure through water evaporation. Despite the fact that these adhesives are very traditional, they still know several innovative applications, for example, solvent-free adhesive tapes.

Please find more information on waterborne adhesive and sealant solutions in our article dedicated to the topic.

Take a step towards greener future with solvent free adhesive solutions

An increasing number of organizations take their environmental responsibilities more seriously and aim at altering their production means to contribute to a greener future. If you are also looking for solvent free adhesives for your product, do not hesitate to contact us. Our specialists are happy to assist you in finding you the best possible solution.

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water based adhesive applied for food packaging

Water based adhesives for more sustainable bonding

The market share of water based adhesives is becoming ever greater since the development has taken a shift towards more and more sustainable solutions which support health and safety as well as reduce environmental impact. Waterborne adhesives are a great alternative for solvent based systems, as they do not contain any Volatile Organic Compounds (VOC), are lighter in weight and often require less product for forming durable bonds.

Being environmentally friendly and low VOC, water based adhesive systems are also user friendlier compared to alternative solutions. Applying waterborne adhesives does not require as many safety measures as systems that contain solvents, which can improve efficiency depending on the nature of the project. Additionally, the finished products that are bonded using aqueous adhesives are user friendly: water based adhesives do not bring along great health risk, nor do they release toxic or odorous fumes.

Types of water based adhesive systems

The trend in adhesives is strongly water based. In Europe and America water-based adhesives are preferred systems, whereas in markets such as China they only cover about 20% of the market. Waterborne glue systems can be roughly divided into two groups: emulsion and dispersion adhesives and solution adhesives.

Type 1: aqueous solution adhesives

Solution adhesives are the most traditional form of aqueous adhesive systems. They use water as the carrier substance and cure as the water evaporates. These waterborne adhesives are created using natural and synthetic polymers which dissolve in water. The uses of these water based glue systems include paper bonding and moistable glues such as those found in envelopes, stamps and labels.

Application methods: roller, spray and beads
Bonding: wet bonding
Examples: starch/dextrin adhesives for paper applications such as bookbinding, and protein/casein adhesives for food packaging industry.

Type 2: waterborne emulsions and dispersion adhesives

Water based adhesives are mainly used in food packaging lamination but gain more and more share in other applications, too.

The waterborne adhesive emulsions and dispersion systems are heterogenous mixtures which consist of dispersed liquid or solid polymer phase in an aqueous phase. These waterborne adhesives can be made by using a wide range of polymers including PVA (vinyl acetate polymers), PVAC (vinyl acetate copolymers) and acrylic as well as synthetic elastomers such as PUR (polyurethane).

As with other water based adhesives, also dispersion adhesives and emulsions can be cleaned with water. However, after the water based glue has dried, it is no longer water dispersible and cleaning residue may require use of solvents and detergents. More information on waterborne adhesives is available by contacting us.

Application methods: spray, brush, roller or beads.
Bonding: wet bonding or dry bonding (water based contact adhesive)
Examples: vinyl acetate adhesives for bonding paper, wood and cardboard, rubber latex waterborne adhesives for fabric and wood. Polyacrylate emulsions as water based construction adhesives, laminating adhesives, pressure sensitive waterborne adhesives, and waterborne polyurethane adhesive as dispersions and emulsions for packaging and shoe making industries.

Waterborne adhesive bonding in 2 ways

Another way to categorize water based adhesives is by the manner in which they form bonds. The two groups are wet bonding and dry bonding (water based contact adhesives).

1. Wet bonding waterborne adhesives

Wet bonding water-based adhesives are those that cure through evaporation, and include both dispersion and emulsion systems, and waterborne solution adhesives which are predominantly wet bonding. In this bonding process the waterborne adhesive is applied either to one adherent or both of them. The adherents meet each other while the adhesive is not dry, hence the name wet bonding. As curing takes place as a result of evaporation, it is extremely important that at least one of the adherents is porous, absorbing the water, and allowing it to leave the waterborne adhesive system faster. If none of the adherents is porous, curing and hardening may take a long time. Wet bonding aqueous adhesive systems are used mainly in the paper and packaging laminating processes as well as furniture and mattress industries.

2. Water based contact adhesives

Contact adhesives, also known as dry bonding waterborne adhesives, are predominantly emulsions and dispersion adhesives. Similar to solvent based dispersions, the water based adhesives are applied to both adherents, hence the substrates that require bonding, and the water is allowed to evaporate before the bond between the adherents is formed. When the parts coated with the water based glue come into contact with each other, the bonding takes place.

Water based contact adhesives are used more widely than the wet bonding systems since they are generally stronger, allow for greater variety of substrates and have better heat resistance. In these waterborne adhesive mixtures, ingredients can be added to enhance and create properties including fire resistance, chemical resistance and anti static properties.

Personalized advice – best waterborne adhesives

Moving towards more sustainable products is a trend that has reached the adhesives market. Water based adhesives not only are environmentally friendly but also contribute to the safety of finished products and possibly improve process efficiency. In case you are curious about waterborne adhesives for your production, contact us and let our experts guide you through the sustainable, greener possibilities.

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modified silane adhesives and sealant bein applied on window

Elasticity with silyl modified polymer adhesive and sealant systems

Silyl modified polymer adhesive and sealant solutions were first introduced in Japan in the late 80s. Today, there is a high demand for elastic bonding and sealing in industrial applications. These silane modified polymer-based systems have successfully entered the European and American markets. They are widely used in industries such as automotive, transportation, construction and many more.

Adhesives and sealants that rely on silane modified polymer combine the advantages of polyurethanes and silicones, and cancel all their disadvantages. Silane modified polymers can be applied to almost any surface, making modified silanes a perfect choice.

What is silane modified polymer?

MS polymer being applied in concrete crack
Silan modified adhesive and sealant systems with a polyether backbone are also called MS polymers and are mostly used in sealing applications.

Silane modified polymer (SMP), also known as silyl terminated polymer or silyl modified polymer, consists of a polymer backbone which is terminated by silane groups. The silane groups can be independent or supported by urethane groups. This gives us two main types of SMP adhesive and sealant systems: silyl modified polyethers (MS polymers) and silyl modified polyurethanes (SPUR polymers). The former are often preferred as sealants as they are more elastic and slightly less resistant than SPUR polymers. Both types of silane modified polymers are, however, also suitable for silyl modified polymer adhesive solutions.

Curing process of silane modified polymer adhesives and sealants

Modified silane polymer systems cure through polycondensation, also known as moisture curing, in room temperature. This means that the products use moisture in either the material or in the ambient to harden. With some products the curing starts from the outside and reaches the inside as last. Therefore, one must be careful not to apply too thick layers, as this may lead to poor curing and system failure.

Advantages of silyl modified polymer adhesive and sealant systems

Modified silane adhesives and sealants are the preferred option for many applications in a wide variety of industries. They are used for example for:

  • fixing solar panels
  • bonding side panels of trailers and vehicles such as trucks
  • assembly parts
  • container constructions
  • doors and windows (also in vehicles)
  • in sealing joints wherever elasticity is needed, for example in parking lots.

It is no wonder SMP adhesive and sealant systems are widely used, since they come with a great spectrum of advantages.

Advantages of silane modified polymers:

  • Elastic bonds and seams: SMP adhesive and sealant systems remain flexible also after complete cure. The elasticity of the seams and bonds is not affected even by harsh environments.
  • Easy to modify: silane modified polymer adhesives and sealants can have different polymer backbones which partially define their set of properties. However, the properties can also be modified with help of additives and so-called boosters.
  • Minimum surface preparation: in most cases through cleaning and degreasing of the surface is sufficient. Usually, these systems do not require a primer, thus the process is sped up. Note that some silyl modified sealant systems do not cure in the presence of polyols: therefore, the cleaning substance should not contain these.
  • Silicone and isocyanate free: most silane modified polymer solutions are environmentally friendly as they do not contain silicone or isocyanates. Some products may emit methanol during the hardening process, but also ethanol emitting, safer systems exist.
  • Good adhesion to most materials: silyl modified polymer adhesive and sealant products adhere to most substrates such as concrete, plastic and metal allowing for a wider variety of possible applications.

Adhesives and sealants based on silane modified polymer

Due to the fact that the modified silane systems are easy to further modify, they exist as adhesives and sealants. The MSP adhesives have excellent adhesion to many substrates whereas the sealants provide watertight and chemical resistant seals.

Silyl modified polymer adhesive systems

Silyl modified polymer adhesive systems are various and versatile. As the formulations are many, so are the application possibilities. For example POR adhesives, based on silane modified polyolefin, are rather common in the automotive industry, where they are used instead of polyurethane adhesives.

Silyl modified polymer sealant systems

The silyl modified polymer sealant systems are known for their extreme elasticity and abrasion resistance. Although these sealants are not extraordinarily chemical resistant, they are strong and economical sealing solutions for example for airports. Especially the sealants´ ability to adhere to different substrates makes them a go-to solution in many cases. 

Silane modified polymer vs. silicone

When it comes to silane modified polymer sealants, they are most often compared with silicone sealants. The main difference between the two is that silyl modified polymer sealant does not contain silicone which is sometimes considered harmful. The MSP sealants are also paintable unlike silicone.

Looking for the perfect SMP adhesive or sealant for your project?

In case you are curious about what modified silane polymers can do to your project or product, or you would like to enquire about a silyl modified adhesive or sealant, do not hesitate to contact us. Our experts make sure your application gets the SMP system it deserves. Note that the silane modified polymers market is under continuous development and the systems are generally easy to modify. Therefore, manufacturers within the silane modified polymers industry usually are willing to collaborate with their customers to enable more uses of SMP systems.

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silicone sealants applied on glass

Industrial silicone sealant suits many applications

ndustrial silicone sealant systems are the most widely used solutions in many sealing applications. They are easy to process and apply, as well as come with multiple other benefits. Additionally, they are versatile and cure into tough, rubber-like, watertight seals. The applications vary from marine work and general construction to engine gasketing in the automotive industry and industrial maintenance applications.

Silicone sealants are generally resistant to chemicals, moisture and weathering, making them suitable for indoor and outdoor applications. But what is the best silicone sealant? That depends on the specific needs of the project. Here you will find the different types of silicone sealant. Note that it is possible to modify silicone sealants to match the needs of a specific application.

Benefits of industrial silicone sealant systems

Next to being resistant to weathering, moisture and some chemicals, silicone sealants can have other properties which benefit specific applications. Generally, industrial silicone sealant systems have the following properties.

aquarium with silicone sealants
When a watertight solution is needed, industrial silicone sealant is a considerable option.
  • Watertightness: the most important benefit of silicone sealants is that they are a 100% watertight. Therefore, they are ideal for sealing aluminum roofing and creating water seals between glass and aluminum.
  • Flexibility: industrial silicone sealant systems are very flexible, and they remain flexible even after curing. Low temperature silicone sealants retain their flexibility even in lower temperatures.
  • Good adhesion to dissimilar materials: like many industrial sealants, also silicone sealants have exceptionally strong adhesion. However, industrial silicone is also suitable for sealing joints between dissimilar materials.
  • Heat resistance: general purpose silicone sealants are somewhat heat resistant – more than moist comparable systems. However, when continuous exposure to high temperatures is involved, it is good to opt for a heat resistant silicone sealant. These can withstand up to 315ºC (600ºF).
  • Electric protection and insulation: when electric and electronic materials such as silver, brass and copper need sealing, an industrial silicone sealant can be a good option. As long as one chooses for a silicone which protects seals and insulates them from electric discharge.
  • Resistance to microorganisms: silicones are watertight and common as sealing solutions in humid environments such as industrial kitchens. In hummus areas, a basic silicone sealant is prone to fungus forming. Therefore, for these applications the best silicone sealant is a system which resists mold and mildew as well as other harmful microorganisms.
  • Chemical resistance: silicone sealant is generally resistant to some chemicals. It is also possible to make special chemical resistant silicone sealants that resist a range of specified chemicals and acids.

The 2 types: acetoxy and neutral silicone sealant

Most of the industrial silicone sealant systems are ambient curing, meaning that they harden in room temperature. The process can take up to 24 hours depending on the product and the thickness of the seal.

Even though silicone sealant may seem like a simple product, it exists in two different types: acetoxy (or acetic) and neutral silicone sealant systems. For any enquiries regarding silicones sealants, contact us for the best possible solution tailored for your application

1. Neutral curing silicone sealant

A neutral curing silicone sealant cures through evaporation of alcohol or another non-acidic substance. These systems are ideal when there is a need for an odorless silicone sealant. 

The neutral silicone sealant is an ideal choice especially for sensitive surfaces such as stone and bitumen. These silicone sealants are generally more expensive than acetic silicones, but they do provide better adhesion and watertightness than the alternative solutions. Therefore, they are the preferred industrial silicone sealant types also for outdoor applications.

2. Acetic silicone sealant

Acetoxy or acetic silicone sealant cures in room temperature releasing acetic acid. The acetic acid is what causes the strong, vinegar-like smell, these sealants are often recognized for.

Acetoxy silicone sealant is the less expensive and faster curing alternative to neutral silicone sealants making them the most common type of industrial silicone sealants. However, one must consider the substrate when working with acetoxy silicones, since the acid in them may bring harm to sensitive materials. For example, when applied on bitumen substrates, bleeding may occur. On natural stone, silicone may cause discoloration, and on some metals the risk of corrosion increases. Acetic silicone sealant is, nonetheless, the go to solution for industrial applications unless a neutral cure silicone is necessary.

What is the best silicone sealant? – Types of silicone sealant

Industrial silicone sealant systems can be roughly divided into two groups: acetic silicone and neutral curing silicone sealant. Additionally, modifications of the formulas are possible in order to guarantee the system all necessary properties. 

Next to the two types of silicone sealant, the industrial systems can be divided into types by their properties. The most common industrial silicone sealants include the following.

  • Chemical resistant silicone sealant: industrial silicone is chemical resistant to a certain extent by nature. However, there are also systems that are designed for environments where chemical exposure is likely. These chemical resistant silicone sealant systems are common for example in industrial maintenance applications. Chemical resistant sealants are also common in silos and tanks
  • Acid resistant silicone sealant: a sub-group of chemical resistant sealants, acid resistant silicone sealants resist a specific set of acidic chemicals. 
  • Odorless silicone sealant: usually neutral curing silicones, the odorless systems are safe to use and preferred in many interior applications as well as on delicate substrates. 
  • Low temperature silicone sealant: silicone is not usually very cold resistant. Nevertheless, special low temperature silicone sealants exist, and they are often preferred due to their ability to retain flexibility even in low temperatures.
  • Antimicrobial silicone sealant: fungus, mold and mildew are common problems with silicone, mainly because the sealants are a preferred solution in humid areas. 

The best silicone sealant is the one that meets all the requirements set for the sealant. Choosing the sealant should be based on an assessment of the environment, application method and the finished product.

Find the best sealing solution for your project

Looking for an industrial silicone sealant for your project? Do not hesitate to contact us for more information, advice on products or quotes for solutions. Our experts are happy to help you find the best possible solution for sealing your project.

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thoughts of sustainable adhesives

The need for Sustainable Adhesives for greener future

While the world’s growing population and increasing living standards boost the need for adhesives, environmental concerns encourage the development of greener, sustainable adhesives. Therefore, the need for sustainable adhesives has reached a completely new level. Innovative sustainable glue solutions are being developed based on ever-improving technologies. Additionally, more and more industries opt for sustainable adhesive products, which is no wonder as sustainability of adhesives is a hot topic for many reasons.

  • Improved health and safety throughout the product’s lifecycle: sustainable adhesives contain little to no solvents. This means that less or no VOC (volatile organic compounds) are released during the application and curing. Neither do the finished product release VOC.
  • Decreased environmental impact and carbon footprint: the absence of solvents results in less impact on the environment. This is due to lighter weight, less product needed and VOC emissions reduced to the minimum.
  • Rules and regulations towards more sustainable products: sustainability has become a priority in development of new products and systems. Therefore, also governments strive towards the trend by setting rules and regulations for products. For example, the VOC emissions of chemical products have long been strictly controlled in the USA and EU. They also gain more and more importance in other markets such as Asia and South America.

Are adhesives sustainable?

Yes and no: many adhesives use fuel based raw materials which are harmful for the environment. However, it is possible to replace those raw materials completely or partially with materials derived from natural resources. The use of natural raw materials defines the sustainability of adhesives.

Innovation leads the development of sustainable adhesives

Sustainability of adhesives has many advantages, but achieving them requires modification of existing products and inventing new innovative technologies. Sustainable adhesives generally belong to one of three groups:

  • Solventless adhesives: nowadays many adhesives are made with less solvents by increasing the solid share. However, among other methods, 100% solid adhesives such as hot melt contain no solvents at all. Hot melts are common throughout industries including the automotive sector.
  • Waterborne adhesives: waterborne adhesives are developed using water as the carrier substance instead of a solvent. This provides the product with reduced weight as well as eliminating the VOC emissions as well as minimizing the risk for fire during processing. Waterborne adhesives are common for example in the mattress industry, where they replace solvent based systems.
  • Biobased adhesives: to call a glue biobased, most of the materials in it must be natural such as starch, vegetable oil, resins, lignins and proteins. These materials guarantee reduced carbon footprint of the products.

The demand for so called green adhesives is ever-growing and encourages new ways of sustainability in adhesives development. Below you can find five types of sustainable adhesives that are likely to experience a boost in demand in the coming years. For any enquiries for sustainable adhesives, we encourage you to contact us, share your project´s needs and let us help you find the manufacturer to produce the system.

1. Renewable adhesives

Renewable adhesives refer to those made of materials such as beeswax and plants, and have no petroleum derivatives in their formulations. Not only do these sustainable adhesives reduce carbon footprint but also contribute to overall sustainability of a great number of applications including paper lamination, carton sealing and bottle labeling.

2. Recyclable adhesives

When an adhesive is recyclable, once the finished product has come to the end of its service life, the adhesive can be melted and recollected without producing any adhesive waste or residue. Recyclable adhesives are generally common in the automotive industry as well as in bonding glass, aluminum and steel.

3. Biodegradable sustainable glue

Biodegradable technology brings the sustainability of adhesives to the next level. The biodegradable adhesives are designed to be broken down by bacteria and other microorganisms. The degrading process produces water, carbon dioxide and other natural gases defined by the environment. These adhesives are mainly present in paper and packaging, envelopes, hygiene products and medical devices.

4. Compostable green adhesives

Compostable adhesives belong to the group of biodegradable sustainable glue. The main difference is that the compostable systems break down under specific (compost) conditions. These sustainable adhesives break down in industrial or domestic compost environments and the broken-down product is suitable for enriching soil. Compostability is currently present in packaging adhesives such as hot melts and PSA adhesives.

5. Repulpable adhesives

In paper and packaging, repulpable adhesives are likely to grow in popularity as they dissolve completely during paper repulping process. Used for instance in carbon boxes, envelopes and other paper products, repulpable adhesives are by far the most sustainable glue options. They completely dissolve without leaving any residue behind.

Choose for the right green adhesive systems

Sustainability of adhesives is of great importance regardless of the project or product. In case you need any assistance regarding sustainable adhesives, do not hesitate to contact us. Our experts are here to help, and happy to provide you with the best possible sustainable glue system for your needs.

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industrila sealants being applied

Durable seals with industrial sealants

A sealant is a chemical product which creates a mechanical seal. The main purpose of both DIY and industrial sealants is to fill gaps, cracks, joints and other openings that otherwise might cause seepage of liquids, gas or other unwanted matter. When two or more parts are joined together, gaps are inevitable. Also damage and deterioration may lead to cracks that require filling in order to guarantee durability. This is where industrial sealant solutions come into picture creating strong and watertight seals.

Note that sealants are no alternative to adhesives even though some sealants, such as epoxies and specially formulated polymers, have adhesive properties. Also special sealant adhesives exist.

Why industrial seal systems

Industrial sealants and adhesives are generally considered stronger than the systems intended for consumer use. Even though this may be true, it is good to keep in mind that the industrial seal solutions also involve working with more aggressive chemicals and may require broader knowledge of working with chemicals in order to guarantee optimal results. Therefore, a DIYer may sometimes achieve better results with less strong, consumer products. However, when looking for sealing systems for industry, marine and industrial sealants are a must.

Sometimes industrial sealants and adhesives can be used together to create the best solutions. An adhesive bond can be sealed afterwards to protect the bond and guarantee longevity.

Choosing industrial sealants based on curing process

Generally industrial sealants are present throughout industries from automotive and infrastructure to electronics and aerospace. There are many different types of industrial seals. One of the ways to divide them into categories is looking at the sealant curing processes.

Curing is the process which hardens the sealant to its final shape and strength.Some industrial sealants cure in a few minutes whereas others may require weeks to be completely hardened.

The main types of curing are as listed below:

  • Evaporation: the  industrial seal solutions that cure in room temperature through evaporation are either water or solvent based. The sealant reaches its final cure when the moisture has left the system.
  • Thermal curing: thermal curing sealants do not reach their final strength and toughness before they can harden under high heat specified for each product. Thermal cure sealants exist as thermosets which do not soften in high temperatures, and thermoplastics which can be reshaped when heated again.
  • UV/Radiation: some sealants cure under exposure to UV light or electron beam instead of heat. The UV and EB curing sealants have shorter curing time than thermally cured sealants and the curing demands less energy consumption. 
  • Anaerobic curing: the anaerobic curing sealants cure in the absence of oxygen. They are common in joining metal parts exposing them to metal ions. 
  • Moisture curing:  the moisture curing sealants are applied to the joint and left untouched to allow them to cure at room temperature using the moisture in the air or material to cure. The curing time varies from 30 minutes to 4 hours depending on the product, the thickness of the seal and the ambient humidity.

The 5 main types of industrial sealants

Currently, there are more than 40 different types of industrial sealants available. However, the list of the most used sealants is much shorter: here we will introduce the 5 most common industrial sealants looking into their properties and uses throughout industries. You can receive more information on these or any other type of industrial sealants by contacting us.

1. Polymer based sealant solutions

Description: polymer based sealants are a group of products including polyester, polyamide, polysulfide, vinyl and polyurethane sealants. They are most commonly cured in ambient temperature but allow for other curing methods such as thermal and anaerobic curing.

Properties: polymer sealants form permanently flexible seals, which makes them ideal for joints that experience movement.

Industrial uses: polymer sealants are the most common in locations requiring expansion joints such as airport runways. Brickwork and bridge joints also use polymer seals, and polymer glazing can be used for capping glazing purposes.

2. Phenolic industrial seal solutions

Description: phenolic sealants are usually realized as a combination of phenol and formaldehyde. These sealants not only seal joints but also provide effective bonding. Phenolic sealant is also the only type of sealant that exists as powder, liquid and films.

Properties: phenolic sealants are especially famous for their resistance to high temperatures and temperature fluctuation. They also have adhesive properties.

Industrial uses: phenolic sealants are suitable for applications involving sealing and bonding plywood, constructing buildings and in appliance industry.

3. Epoxy sealants for industry

Description: when extreme strength and toughness is sought for, epoxy sealant is the solution. Epoxy sealants are usually supplies as two component systems consisting of a resin and a hardener, just like epoxy adhesives. They are mixed together prior to application at a rate set specifically for each product. Epoxy sealants cure in room temperature, but sometimes need additional heat to harden completely.

Properties: epoxies are the most famous for their extreme strength and toughness. They also make up one of the few sealants that have exceptional adhesive properties.

Industrial uses: due to their strength epoxies are common across industries including automotive, marine and aviation. They also provide exceptional electrical insulation making them perfect for electronics.

4.  Acrylic industrial sealants

Description: acrylic sealants exist from acrylic acid via catalytic reaction. These sealants are curable through various methods. When thermally cured, the curing time is the lowest.

Properties: acrylic sealants have good bonding properties and they eliminate all kinds of infiltration by foreign particles. Additionally, they are paintable, odorless and flexible. Acrylic sealant is also an option for outdoor applications since it is resistant to the elements. Note that acrylics are prone to chemical damage and should not be applied where chemical exposure is likely.

Industrial uses: the most common applications of acrylic sealant includes sealing doors and window frames. They are also common in many domestic applications.

5. Silicone based sealants

Description: silicone based sealants are the most common industrial sealants as they are versatile, strong and affordable. They have a life expectancy of 10-20 years. Silicone based sealants exist in two types: neutral cure and acetoxy.

Properties: silicone based sealing solutions are strong and watertight. Thanks to modification, they can also have special properties such as heat and chemical resistance.

Industrial uses: the range of industrial uses of silicone sealing systems is broad. They are suitable for example for glazing as a structural sealant and sealing electric sockets.

Material compatibility of sealants in industrial applications

When choosing an industrial sealant, one of the most important things to consider is the product´s compatibility with the planned substrate. To enlighten the possibilities we have created a list of the most common substrates and the sealant types compatible with them.

  • Concrete: one of the most common construction materials, concrete, can be sealed with polymer sealants.
  • Metal: silicone and polymer sealants usually provide the best results for metal joints. Silicone works especially well on aluminum, iron and steel.
  • Porous materials: sealants with high viscosity or gelly structure work the best on porous surfaces. Silicone, polymers and epoxy are common on porous materials.
  • Textiles: phenolic and silicone based sealants work the best on textile.
  • Plastics: silicone and polymer sealants perform the best on plastic surfaces depending on the composition of the plastic.
  • Ceramics: epoxy silicone and acrylic sealants bring the best results on non-metallic ceramic surfaces.

More information about industrial sealing solutions

Do you need assistance in choosing the right industrial durable sealant, or have you chosen one and would like to find the best product? Contact us and let our experts help you find the best industrial sealants for your applications.

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biobased adhesives and sealants from sustainable resources

Biobased adhesives and sealants respond to the needs of the market

Due to growing world population and increasing living standards, the need for adhesives is greater than ever. At the same time environmental concerns and decreasing fossil resources discourage the use of fossil based materials. This has led to the development of biobased adhesives and sealants which work towards reduced carbon footprint while efficiently bonding different substrates.

Instead of relying on traditional fossil-based raw materials, bio adhesives and sealants consist of renewable, biobased materials such as starch, vegetable oils, proteins, lignin and natural resins. Not only are biobased adhesives and sealants environmentally friendly, but they also have beneficial mechanical and chemical properties that contribute to their efficiency.

Materials that make up bio based adhesives and sealants

The raw materials used in biobased adhesives and sealants are derived from biomass which is mostly produced by the agricultural and silvicultural processes. Consequently, these materials are climate-neutral and the finished bio based adhesives and sealants do not affect the environment. See the biobased materials that can replace petroleum based polymers, tackifiers and waxes in the table below.

Biobased material typeIngredients in biobased adhesives and sealants
PolymersSoy protein
Starch esters
Tackifiers Pine rosin
Dimerized fatty acids
Possible ingredients of biobased adhesives and sealants

Different types of biobased adhesives and sealants

The term bio-based adhesives and sealants generally refers to systems that consist of biobased materials up to a certain point. The first biobased adhesive and sealant systems were general purpose, waterborne solutions that benefitted industries like packaging, furniture and textile. However, as the technology has advanced, there are now specific adhesive and sealant systems for specific industries. Currently, the packaging industry benefits the most from bio based adhesives and sealants.

The bio based adhesive and sealant systems are no longer limited to waterborne dispersions and emulsions, but they also exist as hot melt systems and pressure sensitive adhesive solutions.

From biobased to biodegradability and compostability

When biobased adhesives and sealants contain enough natural raw materials, they can be classified as biodegradable or compostable. These two terms are often used as synonyms, nonetheless, they are not exactly the same: the main difference is that biodegradable products break down naturally whereas compostable systems require a certain setting in order to break down.

Compostable or biodegradable bio based adhesive and sealant systems exist for example as heat seals and general packaging adhesives.

European Norms EN 16785 and EN 13432 assess bio-based adhesives and sealants

When biobased adhesives and sealants first were introduced, there were neither internationally acknowledged standards nor testing for biobased materials. In order to make it easier to define biobased materials and products that use them, several standards exist nowadays. The most important ones are the European Standards EN 16785-1 and EN 13432.

eco friendly sticker biobased adhesives
Eco-friendliness of biobased adhesives & sealants is assessed by European Norms.
  • EN 16785-1 verifies biobased content of products in two ways: by radiocarbon analysis and elemental analysis according to CEN/TS 16440 for Carbon- 14 component. The standard EN 16785-1 defines biobased as “derived from biomass”. The biobased adhesives and sealants are thus those partially or entirely made of materials derived from biomass. The standard covers a broad range of products since it is applicable to solid, liquid and gaseous compositions which contain carbon.
  • EN 13432 evaluates biodegradability of adhesives and sealants by four tests: biodegradation, disintegration, ecotoxicity and heavy metals. An adhesive or sealants is biodegradable if 90% of the total mass of the adhesive is turns to CO2 within 180 days, the germination rate and plant biomass in the compost are more than 90% of those in the corresponding blank compost, the products resulting from composting process are suitable for enriching soil or do not harm floral growth in the area, and the heavy metals in the product do not exceed the limits set in the standard.

Certified bio based adhesives and sealants benefit manufacturers and buyers

Obtaining a biobased certificate helps manufacturers demonstrate the biobased content of their products on the labels. This increases the trustworthiness of the products and company in general.

As for the buyer, it is good to look for products that have biobased certification according to EN 16785 or another similar standard to be sure of the contents of the product.

Interested in bio-based adhesives and sealants?

Biobased adhesives and sealants are gaining more and more share on various markets ranging from wood and construction to paper and packaging. In case you would like to receive more information on biobased products, or like to enquire about a suitable biobased solutions for your process, do not hesitate to contact us.

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polyurethane adhesives being applied to car glazing

Polyurethane adhesives and sealants among the most used systems

Polyurethane (PUR) systems are among the most used adhesives, sealants and adhesive sealants due to their unique properties and the possibility to give them other characteristics through modification. The PUR systems are best known for the elasticity of seams and bonds they create. However, polyurethanes also exist as tougher rigid formulations which are more common as adhesives only.

One of the greatest reasons for the popularity of polyurethane adhesives and sealants is the fact that they adhere to almost any surface regardless its porosity. Polyurethane sealants and glues are also applicable in challenging environments and tricky locations.

Advantages of PUR adhesive and sealant systems

Polyurethane adhesives and sealants exist as single and multicomponent systems which can be elastic or rigid depending on the formulation. Note that the rigid systems are excellent PUR adhesive systems, whereas elastic systems are common polyurethane sealants and glues as well as PU adhesive sealant systems.

The benefits

  • Curing in challenging environments: polyurethane adhesives and sealants are either heat or moisture curing. Ambient humidity can be very high as the system only cures faster in the presence of moisture. Generally the systems also cure even if the ambient temperature fluctuates or shifts towards extremes. This varies per product.
  • Suitable for numerous materials: polyurethane bonds and seals porous and nonporous materials including metals, wood, concrete, most plastics, rubber, epoxy, leather, paper, glass and many more. PUR adhesives and sealants are also suitable for bonding dissimilar materials. Note that most polyurethanes do not adhere well to polypropylene, polyethylene, silicone or surfaces coated with fluoropolymers like Teflon.
  • Waterproof: polyurethane sealants and glues are generally waterproof, however, the water resistance varies per formulation. Most systems resist water enough to cause no problems in exterior construction applications. Nonetheless, polyurethane adhesives and sealants are not recommended for full immersion underwater.
  • Wide operating temperature range: as PUR adhesives are extremely weatherproof, they are also suitable for a wide range of operating temperatures. Polyurethane glue is a considerable option when the temperature is between -40°C and 100°C.
  • Environmentally friendly: polyurethane offers sometimes a more eco-friendly alternative: for example timber lamination is possible with PUR adhesives instead of formaldehyde containing systems. PUR adhesives and sealants are generally solvent-free and have zero to very low VOC. Also food safe polyurethane sealants and adhesives exist.
  • Stress absorption and vibration damping: especially the elastic polyurethane adhesives and sealants absorb stresses and damp vibration and noise. Therefore, they are common in vehicles, for example in transport vehicle glazing and cabins of agricultural machinery. Here also PU adhesive sealant systems are common.
  • Paintability: to increase aesthetic appeal or protect seams and bonds from factors like UV radiation, PUR adhesives and sealants are paintable. Acrylic paints are the most suitable for the job.

Considerations regarding PUR adhesive and sealant systems

Even though polyurethanes have many benefits that often make them the preferred choice, they are not flawless. Some factors that must be considered when working with polyuretahne sealants and adhesives are as follows.

  • Strength: polyurethane forms strong joints yet they are not comparable to those formed by epoxy adhesives and sealants. Especially when bonding metal to metal, epoxy is likely to deliver stronger results.
  • Contains isocyanates: isocyanate groups are a crucial part of polyurethane formulation. However, they are toxic and require additional safety measures during processing. Nevertheless, once the polyurethane reaches its final strength, isocyanate is not a hazard.
  • Short pot life/ skin formation time: working with polyurethane adhesives and sealants requires speed as the curing process starts quickly. When working with 2K polyurethane adhesives or sealants, the pot life must be kept in mind as the reaction starts as soon as the components are mixed. On the other hand, the skin formation of 1K products can also start fast.
  • Long curing times: even though PUR adhesives and sealants exist as fast curing systems, there are also solutions that require up to 48 hours to reach final cure. However, these adhesives can also be beneficial, and they are suitable for example for the book binding industry. The advantages (moisture, cold and heat resistance, fast setting, low melting point etc.) are greater than the long time it takes to reach for final cure.

Types of polyurethane adhesives

The two most common adhesive types are epoxy and polyurethane. The latter is more flexible when it comes to modifying the bonding systems. Polyurethane adhesive exists as one and two component systems which can be either elastic or rigid depending on the composition. The single component polyurethanes are generally easier to work with as they do not require mixing prior to application. On the other hand, 2K polyurethane adhesive systems tend to be stronger and have more desired physical properties.

Single component moisture curing polyurethane adhesive

polyurethane adhesives applied in construction
Single component moisture curing polyurethane adhesives are common as general purpose glues in interiors and exteriors.

Moisture curing polyurethane adhesives are predominantly single component systems which require moisture in order to set. Prior to application, these adhesives are sticky, and they cure into a bond which remains elastic. Therefore, these polyurethane adhesive glue systems are often used for applications such as glazing and construction.

When working with moisture curing polyurethane adhesives, it is important to consider the skin formation time of the adhesive. As soon as the PUR adhesive comes into contact with the moisture in the air, a skin starts forming. The skin formation time is the time one has to work the glue.

Single component heat curing PUR adhesive

The other type of one component polyurethane glue cures when heat from external source is applied. This type of adhesive forms rigid bonds and is generally stronger than its moisture curing alternative. However, it is not as strong the 2K rigid PUR adhesive, which is why the 1K systems are often applicable in simple assembly applications.

Rigid heat curing polyurethane glues can be processed faster than moisture curing adhesives as the speed of curing process can be controlled with heat. With rigid adhesives, thick layers should be avoided as the curing starts from the outside. The thicker the layer, the greater the chance of incomplete cure in the inside.

2K polyurethane adhesive systems

Two component polyurethane adhesives can be either rigid or elastic depending on the chemical composition. The elastic 2K polyurethane glues are thermoplastics meaning that heating allows for reworking them. The rigid adhesives, for their part, are thermosets, which means that once cured, reworking is not possible.

Multicomponent polyurethane adhesive systems allow for easier modification than the single component alternatives. Therefore, they can have more physical properties and are suitable for use throughout industries in applications varying from printed wiring boards to vehicle glazing and interior trim. Contact us for more information on the possibilities with 2K polyurethane adhesive.

Tip: if you are looking for an adhesive with the characteristics of polyurethane but require faster curing, lighter weight and stronger bonds, you might want to take a look at alternative adhesive systems which have chemistry very close to the one in PUR adhesives.

About polyurethane sealants

Also, when it comes to sealants, polyurethane is the most common choice next to silicone. The two types of sealants are both flexible allowing for up to 50% movement and they keep water and air out. However, they also have differences: polyurethane sealant is organic and silicone is inorganic.

Due to their organic nature, polyurethane sealants tend to be less durable than silicone. They often have a life span of 5 to 10 years whereas silicone can reach the double. However, this can also be seen in the price: polyurethane sealant is usually about a half the price of silicone. If you are looking for a product that has the beneficial properties of both silicone and polyurethane sealants, take a look at silane modified polymer products.

Note that if you wish to replace a silicone seam with polyurethane sealant, or vice versa, make sure to remove all of the sealant before applying another one. If the sealant is not properly removed, the new sealant is likely to adhere poorly.

Looking for polyurethane sealants or adhesives?

As polyurethane glues and sealants can be modified rather easily, they are sometimes found in surprising applications. Therefore, in case you are looking for a suitable sealant or adhesive for your project or product, considering polyurethane might be worth your while. For more information on the possible applications, hit the button below and contact us. Our experts are determined to find the best bonding and sealing solutions for each application.

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a wooden house being built using low carbon adhesives for construction

Carbon neutral buildings with low carbon adhesives for construction

In recent years, carbon neutral and low carbon buildings have caught more and more attention. The common trend is shifting towards environmentally friendly solutions, lower carbon dioxide emissions and generally greener buildings. Carbon dioxide emissions are part of every phase of a building’s lifespan: manufacturing raw materials, construction, use and demolition. Next to the use phase manufacturing accounts for the largest environmental impact. This is where low carbon adhesives for construction come into the picture. To reduce a building’s carbon footprint, low carbon adhesives are applicable on construction timber, windows, door areas and many other applications.

The carbon footprint of construction adhesives

The construction adhesives exist in four groups: water-based dispersions, hot melt thermoplastics, solvent based glues and reaction adhesives. The amount of adhesives used in constructions is rather small compared to most other building materials. However, the carbon footprint of the adhesives contributes to the overall footprint of the building.

Of these four, reaction adhesives have the most negative environmental impact, whereas water-based dispersions have the smallest carbon footprint. Thermoplastic hot melts are often considered a green option, and solvent based glues are thought to have negative impact on the environment. However, surprisingly they share the same size of carbon footprint. Naturally, the actual environmental impact of adhesives is dependent on the product´s formulation and composition. This means that not every solvent based glue has low impact, and that reactive adhesives can also have lower impact.

Eco-friendly buildings with other low carbon materials

Sometimes achieving the smallest carbon footprint requires the use of less environmentally friendly adhesives combined with bio-based building materials. These materials include wood and innovative materials derived from it. In these cases the carbon content of the adhesive is not important as long as the bonds hold without replacing or maintenance for as long as possible.

Different applications of low carbon construction adhesives

an open window with low carbon adhesives for construction
Low carbon adhesives for construction are common as sealing and bonding solutions for windows.

Low carbon adhesives for construction are usually water based dispersions, or at least solvent free. They know numerous compositions and formulations, each having a design for a specific application.

Some of the uses of low carbon adhesives for construction include bonding and sealing windows, making stairs as well as laying wall and floor tiles. However, glues also play a role of paramount importance in providing strong and carbon neutral structures, especially in wooden buildings. Timber constructions have been proven to be as strong as concrete and steel but lighter in weight, lower in cost and carbon neutral. Adhesives are suitable for laminating timber enabling beams that are sufficiently strong to be for use in bearing structures.

More information on low carbon glues

As carbon neutral buildings become more and more desired, low carbon adhesives for construction are growing in popularity. In case you wish to gain more information on low carbon possibilities, or are looking for a supplier for your project, click the button below and share your project with us. Our experts are happy to help you find the right adhesive system for your project or product.

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testing intumescent sealant in an oven with flames

Intumescent sealant for passive fire protection

Flames and smoke can spread through the smallest of gaps causing extreme damage to buildings and even human lives. Applying an intumescent sealant to linear joints, around pipes and between cables to close all the gaps and add fire resistance.

An intumescent seal slows down the burning process and does not contribute to spread of flames. Therefore, it can minimize the damage by protecting structures, giving fire fighters more time to arrive and take the fire under control as well as fireproofing escape routes allowing for efficient evacuation.

How does intumescent sealant work?

Intumescent seals are known as means of passive fire protection, but what is an intumescent sealant in practice? Also known as expansion sealant, intumescent sealant expands when it becomes exposed to extreme heat and can swell up to 40 times its original volume. The sealant increases in volume but decreases in density forming a char layer. The expanded sealant does not actually catch fire, but the char burns eventually, still much more slowly than most building materials.

Depending on the product formulation, application and backing material, an intumescent sealant can be resistant to fire for up to 240 minutes. Buildings require different levels of fire resistance depending on their size and whether they have a residential purpose.

The difference between intumescent mastic and sealant

When looking for a fire retardant sealant, one inevitably encounters the term intumescent mastic. But what is an intumescent mastic and should you opt for one instead of a sealant? In principle, a sealant is any substance used to seal a surface or to fill and seal gaps and voids. A mastic, for its part, can be a cementitious adhesive, sealant or filler which is waterproof and remains flexible. Thus, the choice between intumescent mastic and sealant should be made based on the needs of the application.

Both, intumescent mastic and sealant, can result in the same level of fire resistance. Fire resistance is not determined solely by the sealant or mastic, but also the backing and the materials that require an intumescent seal.

Common applications that require an intumescent seal

In a building, many applications can be made fireproof, however, intumescent sealants and mastic are suitable for a limited range of applications. The most common of these include compartment walls, linear gap joints, movement joints and penetration seals. Below are some examples of such applications.

intumescent sealant around cables
Intumescent sealant seals and fireproofs gaps around and between cables.
  • Fire doors: sealing fire doors with an intumescent product helps keep the evacuation routes open for longer as well as preventing the fire from spreading past the doors.
  • Windows: it is also important to apply intumescent sealant to windows in order to ensure the fire does not spread outside. Nor should oxygen be able to seep through the windows feeding the fire.
  • Around plastic pipes: sometimes a fire collar is installed around pipes that go through walls. However, fire collars are not needed if a fire protection sealant is applied.
  • Cables: as flames and smoke can pass through the smallest of gaps, it is important to seal around cables running through the construction. Some intumescent sealant systems are also suitable for cable trays and between cables.

International standards to consider when fireproofing structures and buildings

Fire safety is one of the main concerns when it comes to constructing buildings and other structures. Therefore, many international and national standards are used to assure fire safety of products, such as intumescent sealant, and eventually entire constructions. The standards are often based on a time/temperature curves and consider integrity and insulation as well as give fire rating to the materials based on their contribution to spreading flames and producing smoke.

International standards for Intumescent sealants

The European standard EN 13501-2 classifies materials from A to F based on their contribution to the flames spread, A indicating that the material does not contribute to the fire. The standard additionally rates smoke production by materials from s1 to s3 and d0-d2. In Europe and North America this is one of the most relevant standards assessing intumescent sealants.

Other relavant, international standards are presented in the table below.

Fire rating standardScopeNotes
EN 1366-3 and 4Test standard for penetration sealsMost relevant standards for fire resistance testing of intumescent sealant systems.
EN 13501-2Classification standard for linear joint seals and service penetration sealsLeading to EI classes. Relevant for EN 1366 and EAD
BS 476-20Test standard for linear joint seals and service penetration sealsBritish standard; replaced by EN 1366/EN 13501 but still in use in some regions
EAD 350454-
Fire stopping and fire sealing products – penetration sealsSuperseded ETAG 026. Leading to CE marking and DoP.
Fire resistance tested according to EN 1366
EAD 350141-
Fire stopping and fire sealing products – linear joints and gap seals
ULCertification scheme for product safety based in the USDifferent test methods and requirements for different regions
AS 1530.4Test and classification for linear joint seals and service penetrationsAustralian standard, technically the same as EN 1366
CertifireCertification scheme for fire protection productsRelevant for intumescent sealants in the Middle East
International standards relevant to intumescent sealant systems
super glue and other adhesives for home repairs

Repair instead of throwing away – super glue and other adhesives for DIYers

Glues are used almost everywhere from heavy industrial processes to everyday consumer goods and small home repairs. Adhesive like super glue is also a great thing to have at home, in the car or somewhere else within hand’s reach. There are several types of adhesives that are perfect for home repairs and DIY projects. They can save you money as you can repair broken items without needing to buy new ones.

Super glue is by far the most well-known adhesive used in repairs, yet it is not the only option. There are numerous adhesives that can be used for a wide variety of applications. Here we will take a look at the most common glues used in households including super glue, epoxy, wood adhesive and silicone based glues.

Super glue – the best adhesive for small repairs

Substrates: Metal, rubber, wood, ceramic, plastic and porcelain

Super glue is an adhesive that ended up on the list of most useful inventions in the 20th century. And that is no wonder, as the cyanoacrylate based glue bonds almost anything as long as the surfaces are small and flat. Super glues not only are superior repair adhesives to use at home, but industrial super glue also performs well even in heavy duty applications.

Super glue properties and curing

Generally, there are two types of super glue: gel and glue. Both of these have superior bonding power. The difference is that gel is less likely to drip and leak. Super glue is often called instant glue as it cures in a matter of seconds. You should, however, not be fooled by the very short curing as the full cure may take up to 24 hours. Therefore, after gluing the parts together, you should let the adhesive cure longer and keep the parts together with clamps or zip ties to preserve the true super glue properties.

Where to use instant glue

Most super glues are suitable for a wide range of substrates and they are ideal for glueing broken dishes, shoes, tears in car upholstery, disconnected car mirrors, handles, hoses and many more applications. You can even super glue metal to wood, an application where other general repair adhesives often fail. Just make sure the manufacturer confirms the use of their instant glue product on the specific material.

The best super glue products

As instant glue is a preferred product for many applications, multiple brands offer these products. Although everyone has their own preferences, two brands can be said to be more popular than the rest: Gorilla and Loctite.

loctite ultra gel control super glue package

Loctite Ultra Gel Control Super Glue

gorilla super glue gel pack

Gorilla Super Glue Gel

Where NOT to use super glue

Even though super glue is very strong, it is not the best choice for filling gaps and cracks. This is due to the fact that super glue forms thin, transparent layers which are not hard enough to remain in form. For gap and crack filling, you could use super epoxy glue instead.

Strong bonds on large surfaces with epoxy glue

Substrates: Metal, plastic, wood, fiberglass and composite materials

Epoxy is one of the strongest adhesives for industrial and consumer use. It is usually a two component system which is sold a set of resin and hardener packed separately. Prior to application, the two components must be mixed with each other on a surface like newspaper or cardboard. When the components are mixed, the chemical reaction that results in curing strats. Therefore, the epoxy glue must be applied soon after mixing. Note that also single comonent, easy to apply epoxies exist: these are sometimes called super epoxy glue, as the properties resemble those of super glue.

Epoxy curing time

Epoxy cures when two components are mixed with each other and a crosslinking process is started. Some epoxy products cure faster than others however, the rule of thumb is the longer the curing time the stronger the bond. Like super glue, epoxy should be let cure for 24 hours to reach its full strength. Use clamps or zip ties to create pressure and keep the parts in place until the adhesive is fully cured.

Where to use epoxy glues

Epoxy glues work the best where super glues don´t: large surfaces and crack and gap filling are common applications. Epoxy cures into a plastic like, transparent or opaque bond which is hard to beat it toughness. Therefore, epoxy beats super glue in strength also when bonding metal or wood. Common epoxy applications include shoe repairs, fixing handles (for example screwdrivers) and minor car repairs including disconnected mirrors and patch cracked lights.

Best epoxy products for home repairs

Some of the most popular epoxy glues for home repairs include Gorilla two part epoxy and Bob Smith quick-cure epoxy..

Gorilla 2 Part Epoxy, 5 Minute Set, .85 ounce Syringe, Clear

Gorilla 2 Part Epoxy, 5 Minute Set, .85 ounce Syringe, Clear

Bob Smith Industries BSI-201 Quik-Cure Epoxy (4.5 oz. Combined)

Bob Smith Industries BSI-201 Quik-Cure Epoxy (4.5 oz. Combined)

Wood adhesive for crafts and repairs

Substrates: wood

Wood is a porous material and requires a special adhesive which soaks into the pores. The wood glues are used for wood to wood bonding and it is common for crafts and home repairs. Wood glue is usually white and becomes transparent as it hardens. The glue should be applied by spreading an even amount on both surfaces that are about to be banded. After that the parts are connected and should be clamped together to ensure they stay in place till the glues is fully cured.

Curing wood glue

Like for super glue and epoxy, the longer the product is let cure, the stronger the bond. Many products are available and they all have specific curing times. Stick with the manufacturer’s advice to achieve the best result.

Get the best wood glue products

Titebond III ultimate wood glue and Gorilla wood glue are among the most popular wood glue products as they are easy to apply and form strong transparent bonds in wood to wood applications.

Titebond 1416 III Ultimate Wood Glue, 1-Gallon (2-(Pack))

Titebond 1416 III Ultimate Wood Glue, 1-Gallon (2-(Pack))

Gorilla 6231501 Gallon Glue, Natural Wood Color

Gorilla 6231501 Gallon Glue, Natural Wood Color

Silicone glue for watertight bonds

Substrates: Glass, plastic, metal and wood

Better known as sealant, silicone creates watertight bonds which resist chemicals and weather. Therefore, the best use of silicone glue is sealing there where adhesive properties are needed, too. Silicone glues cure to form a transparent or colored bond which remains flexible under any circumstances.

Uses of silicone glue

As mentioned, silicone glue is often used in applications that require both: sealing and bonding. Common uses of silicone glue in home repair projects include bathrooms and glass to glass connections such as in building and repairing aquariums. Silicone is also suitable for outdoor applications thanks to its superior water and weather resistance. Other uses are door frames, vinyl tops, roofs, shoes, toys and many more.

Best brands to work with

Permatex clear RTV silicone adhesive sealant and loctite clear silicone waterproof sealant are two products that work extremely well when silicone is the desired material.

Permatex 80050 Clear RTV Silicone Adhesive Sealant, 3 oz

Permatex 80050 Clear RTV Silicone Adhesive Sealant, 3 oz

Loctite Clear Silicone Waterproof Sealant 2.7-Ounce Tube (908570)

Loctite Clear Silicone Waterproof Sealant 2.7-Ounce Tube (908570)

different types of sealants used in a bathroom with blue towels

Different types of sealants for home improvements

Sealants are chemical materials which fill gaps and cracks as well as seal joints and seams. Most sealant types are waterproof and air tight. They may also have light adhesive properties, be chemical resistant and prevent growth of microorganisms like mold and mildew. But what is sealant used for? Sealants are commonly used by construction contractors, but they are also suitable for DIYers for small repairs and home improvement. Sealants can be used for example in bathrooms and kitchens as well as sealing and filling interior and exterior gaps and cracks. The different types of sealants for home include the following:

  • Acrylic
  • Butyl
  • Polysulfide
  • Polyurethane
  • Silicone
  • Water based latex

What are the different types of sealants for home?

The purpose of sealants is to prevent passage of liquids, gasses and fumes: often sealants are used to make joints air and watertight. There is no single type of sealant that is always the best choice: the sealant should rather be chosen based on the requirements of the substrate(s) and environment as well as the wished end result. There are several different types of sealants for home repairs and improvement as you will discover here below.

Red Devil 0646 Masonry and Concrete Acrylic Sealant Repair, Gray, 10.1 Oz Cartridge
Red Devil 0646 Masonry and Concrete Acrylic Sealant Repair, Gray, 10.1 Oz Cartridge

Acrylic sealants

When UV stable solutions are sought, acrylic sealants provide a considerable option. Due to their UV stability they are suitable especially for exterior applications. They are also not prone to shrinkage, which makes them a reliable solution. However, acrylic sealants for home repairs and improvement may be tricky to apply compared to other systems. They should not be used when significant movement is involved as they lack flexibility. The life expectancy of acrylic sealants varies from 5 to 10 years.

Acrylic sealants also exist as anaerobic systems. this means that they cure in the absence of oxygen. This type of acrylic sealants are used for securing screws and bolts (threadlocking).

Butyl sealants

Butyl sealants are sometimes preferred due to their rather low costs and ability to adhere to a wide range of substrates. Butyl sealants have stringy consistency which may make the application difficult. These sealants should not be used for demanding construction applications but other types of sealant solutions should be considered instead. they also lack the ability to accomodate shearing movement. Butyl sealants usually last from 5 to 10 years after which they must be replaced.

Polysulfide sealants

Boat Life Lifeseal Sealant Cartridge, Clear
Boat Life Lifeseal Sealant Cartridge, Clear

Polysulfide sealants are becoming more and more popular as they are flexible solutions which retain the joint elasticity even in low temperatures. They involve minimum shrinkage and are resistant to UV radiation, which enables exterior applications. These sealants are suitable even for underwater applications.

Polysulfide sealants are generally more expensive than comparable sealants for home. However, they have a life expectancy of 15 to 20 years which compensates on the initial price. Another factor to keep in mind is the rather high VOC content of polysulfide sealants. The use of these types of sealant systems requires additional safety measures for protection. These are commonly given by the manufacturer and added to the packaging of the product.

Polyurethane sealant solutions

A common go-to solution is polyurethane sealant. Not only are polyurethane sealants flexible but they also have strong adhesion and are abrasion and shear resistant. Polyurethane sealants for home adhere well to a wide range of substrates and they are easy to apply, as they require minimum surface preparation. Polyurtehane sealant belongs to the sealant types that exist as regular and low VOC solutions. As a rule of thumb: the higher the volatile organic compound, the more safety measures the sealant application requires.

Gorilla Clear 100 Percent Silicone Sealant Caulk, Waterproof and Mold & Mildew Resistant, 10 ounce Cartridge, Clear, (Pack of 1)
Gorilla Clear 100 Percent Silicone Sealant Caulk, Waterproof and Mold & Mildew Resistant, 10 ounce Cartridge, Clear, (Pack of 1)

Silicone sealants for home

The most common, but also the most expensive sealant for home repairs and improvement is silicone sealant. Silicone sealants are extremely flexible and durable: they have a life expectancy of 10 to 20 years depending on the product. Given the silicone sealant life expectancy, this type of sealant is among the most durable. These sealants can be modified for specific purposes: there are anti mold silicones, heat resistant sealants and food safe solutions. Silicone is a common material as bathroom sealant.

The downsides of silicone sealants include possible staining on some substrates, tendency to collect dirt and the need for primers in some cases. Despite the drawbacks, silicone sealants are the most common sealing systems, also in industrial applications.

Water based latex sealants

Water based latex sealants have gained their popularity by being easy and safe to apply as well as adhering to many different surfaces. Another advantage of water based latex sealants is that they are paintable, which contributes to the visual appeal of the end result. These sealants are especially suitable for very small gaps and voids where movement is minimal. Latex should not be used for waterproofing as it is prone to shrinkage and may pull away from the substrate creating gaps.

Properties to consider when choosing sealants for home

Flexibility and longevity are the two most important properties of sealants, however, there is more to it: some applications require hardness whereas others need strong adhesion. Below you can find some of the most important characteristics of different types of sealants for home.

  • Adhesion: some sealants adhere to the substrate(s) better than others. Always check the manufacturer’s advice on suitable substrates and provided adhesion data.
  • Cost: bear in mind that cheaper rarely means better. Invest in quality products as they are more flexible, easier to work with and last longer.
  • Durability: before choosing the sealants for home repairs or improvement consider the required durability of the seams. This usually affects the type of sealant you will need. For example polysulfide and silicone sealant life expectancy are among the highest.
  • Ease of application: try to choose for a sealant that is easy enough to apply. Incorrect or poor application may lead to failure of the seal.
  • Flexibility: the different types of sealants for home come in different rates of flexibility. Make sure the sealant you choose is flexible enough to accomodate the movement involved in your application. For instance polyuretahne sealant is an extremely flexible sealant solutions.
  • Hardness: sometimes the sealants are required of hardness. It is important to note that as the hardness increases, the flexibility decreases.
  • Resistance: consider the environment where the sealant will be applied. Do you require UV stability, chemical or mold resistance, or is heat resistance of high importance?
  • Staining: especially when working with silicone sealants some materials such as stone may be stained by the sealan. Make sure you choose a product designed for the substrate.
  • VOC content: the VOC content (volatile organic compound) refers to the toxicity of the product. The sealants for DIYers generally have lower VOC content than industrial systems. However, for example polysulfide sealants have a higher VOC content and therefore, safety measure must be taken during application.
2k epoxy adhesives in a tube

Epoxy adhesive – the most used industrial adhesive

Epoxy adhesives are by far the most common industrial adhesives and probably the most versatile structural adhesives. The popularity of epoxy adhesive is not the least due to the extreme toughness of the cured product nor their incredible ability to adhere to a wide range of materials. Epoxy resin adhesive systems are also easy to modify to make them meet the unique property needs of every individual project.

Epoxy adhesives are realized using different epoxy adhesive resin types which define the fundamental properties of the adhesive. The most suitable and strongest epoxy for specific application is usually determined by looking at the resin: a heat proof epoxy resin is the best when high temperature resistance is required where as a flexible epoxy resin is the go to solution when movement may be involved. Here yoy can find the general benefits of epoxy resin adhesives as well as the most common epoxy resin types and some epoxy adhesive applications.

What is so special about epoxy adhesives?

The presence of epoxy groups in the chemical formulations of the adhesives grants them several advantages. Epoxy resin adhesive can be modified and given desired properties rather easily, but all epoxy adhesives share some characteristics including:

  • Chemical resistance: generally, all epoxy resins resist chemical exposure better than most alternatives. With modification epoxy adhesives can even withstand total immersion in harsh chemicals.
  • Heat resistance: due to the chemical composition of epoxy, the adhesives are heat resistant by nature. Also a property that can be enhanced by modifying the formulation. Usually, epoxy adhesives are heat resistant up to 200°C (390°F). However, also heat proof epoxy resin types exist which withstand even higher temperatures.
  • Durability and final strength: once cured, the epoxy bonds are among the strongest in industrial applications: they even hold the truck lift world record using adhesive, having lifted a 17, 500 kilogram truck. They also retain stability over a long period of time. Industrial epoxy adhesive systems that use various resins are among the strongest epoxy systems.
  • Electrical properties: one of the desired properties of epoxy resin adhesive is its excellent electrical insulation which makes it suitable for applications like printed circuit boards.
  • Watertightness: probably the most well known property of epoxy adhesives. Not only do they create strong bonds, but also effectively seal and make joints and gaps watertight.

1 compoonent and 2K epoxy resin adhesive

Epoxy adhesives exist in one and two component glue systems, which both form extremely strong bonds, but differ from each other by curing process and final properties as well as applications. 2K epoxy resin adhesive is generally tougher than single component systems.

2K epoxy glue

Mixing two component epoxy adhesives on green surface
The 2K epoxy resin adhesives require mixing of the two components prior to application. Curing of epoxy adhesives is triggered as the components react with each other.

The two component epoxy resin adhesives are greater in versatility, as they are used in all market segments. They are slightly more complex to process, as the two components, resin and catalyst, must be mixed with each other, and the worklife is limited from a few minutes to a couple of hours depending on the industrial epoxy adhesive formulations. These 2K epoxy resin adhesives cure in ambient temperature, but the process can be sped up by applying heat or an external source of energy such as UV light depending on the formulation. Generally, the epoxy adhesives cure to the toughest bonds when the curing period has been the longest.

The major advantage of 2K epoxy glue solutions is that they adhere to almost any surface including wood, metals, plastics, ceramics and various types of rubber. They also are resistant to physical and chemical influences including heat resistance to 95° to 200°C (200°F to 390°F).

Single component epoxy glues

One component epoxy resin adhesives are easy to process as they do not require mixing unlike 2K epoxy glue. They usually have a paste-like consistency which makes them ideal for application by trowel or extrusion by beads. These adhesives cure in elevated temperature between 120° and 175°C (250° and 350°F) depending on the formulation. The single component heat cure adhesive systems fill and seal gaps efficiently, particularly between metal surfaces.

One part epoxy adhesives also appear in a form of heat curing film adhesive. The film adhesives are the best applied on large areas for bonding or laminating purposes. These films are found for example in the aerospace industry in assembly compounds. The one part epoxy resins adhesives are also common as construction epoxy adhesive which can be applied for instance when laying tiles.

5 common types of epoxy resin adhesive

Epoxy glue is not simply just one and two component adhesives, but many formulations exist depending on the resin, catalyst, modifiers and additives. The most important ingredient that gives the system most of its properties is the epoxy adhesive resin. It is also possible to use a combination of resins in order to guarantee the best possible solution. Here we will take a closer look at the five most common epoxy resins used in adhesives. In case you require any additional information on these or other types of epoxies, contact us and let us find the solution that benefits your application the most.

1. DGEBA epoxy resin

Diglycidyl ether of bisphenol A (BPA), better known as DGEBA epoxy, is the oldest epoxy resin, and by far the most important in epoxy adhesive formulations, not the least due to its relatively low cost of raw materials. Additionally, this resin is compatible with a wide range of catalysts allowing for a broad selection of properties to be created. The industrial epoxy adhesive systems using DGEBA epoxy, cure either in room temperature or with additional heat.

DGEBA epoxy resin exists as low molecular weight liquids, high molecular weight semi solids and solids as well as brominated resins. The latter are used primarily for application requiring ignition resistance. Therefore, brominated resins are common for example in circuit boards and other applications where flame retardance is needed.

2. Epoxy novolac adhesives

Epoxy novolac adhesives are best known as the most chemical resistant and high temperature resistant epoxies. They also have better adhesion than the BPA epoxies. In order to develop these properties to their best, the epoxy novolac must be cured in a high temperature. When cured in room temperature, the properties that can be achieved are similar to the ones of DGEBA epoxy adhesives. The length cycle of the curing process significantly affects the thermal stability of the cured bond.

Epoxy novolac resins are generally complex to process due to their high viscosity. Low viscosity alternatives have recently been developed in order to ease the processing. However, these products tend to have lower epoxy resin content. Whatever the case, epopxy novolac is almost predominantly a 2K epoxy glue.

3. Flexible epoxy resin glues

Epoxy glues and adhesives are generally not known for their flexibility. However, long chain aliphatic epoxy resins make it possible to add flexibility to the properties of epoxy adhesives. Nevertheless, the addition of this flexible epoxy resin compromises on toughness of the glue. Therefore, flexible epoxy resins are generally not used alone but rather mixed as modifiers with other epoxies to create a tougher and stronger yet flexible solution. When the resin content comprises of aliphatic epoxy for 10-30%, a required level of flexibility can be achieved without remarkably influencing other properties. These are the best flexible epoxy adhesive systems.

Flexible epoxy resin adhesives are used for instance for laminating safety glass, dampening vibration and sound as well as encapsulating electrical components and other delicate components that require thermal cycling.

4. Waterborne epoxy adhesives

By nature, epoxies are hydrophobic, thus not dispersible in water. Water dispersibility can, nonetheless, be conveyed to epoxies in two ways: chemical modification or emulsification. The latter is primarily used for resins in waterborne epoxy adhesives and done by separating the water from the resin with a surfactant. The choice of the surfactant and processing parameters determine the mechanical and chemical stability of the adhesive.

5. Epoxy acrylate resins

When formulating adhesives, two types of epoxy acrylate resins are used: vinyl ester and a special resin for radiation curing. These resins act more like polyester resins despite of being epoxies. They are easy to process, cure fast at room temperature and can use peroxides as the curing agent. In adhesives, these epoxy resins create lower viscosity, more flexibility and better wetting characteristics than conventional DEGBA epoxies. However, they do shrink more than any other epoxy adhesive while curing.

The epoxy acrylate resins can also be cured by radiation from an external source of energy such ultraviolet (UV) or electron beam (EB). These epoxy resin adhesives are generally low in viscosity and high in vapor pressure.

Examples of epoxy adhesive applications

As epoxy glue is a versatile product that exists as many formulations, the uses of the different types are nearly endless. Here below you can find some examples of tepoxy adhesive applications.

  • Chemical and biochemical industry: due to its outstanding chemical resistance, epoxy adhesives are common in applications that involve harsh chemicals. Especially epoxy novolac based formulations are used in tanks and other means to store chemicals.
  • Automotive industry: the strength of epoxy is also needed in the automotive industry where adhesives are replacing conventional fasteners and welded bonds, as they are remarkably lighter in weight. Also flexible epoxy resin glue is common for damping sound and vibration.
  • Aerospace: the aerospace industry uses epoxy adhesives as one component films and 2K epoxy glue systems for various applications. For example helicopter rotor baldes are bonded with epoxy glues due to the adhesives´ extreme strength and mechanical stability.
  • Marine: as epoxies form watertight bonds and are resistant to salt water, they are ideal for marine environments.
  • Construction: epoxy adhesive is also used in construction for example for repairing floors and tiles. The adhesives are resistant against the elements and therefore, suitable also for outdoor applications. Next to being an industrial adhesive, construction epoxy adhesive is also popular among DIYers.

Tip: for what ever you are using epoxy adhesive, research shows that proper storage of the glue can remarkably improve efficiency.

Find the epoxy adhesive that is a perfect match to your project

As we have now discovered, epoxy glue is not simply one type of adhesive, but covers a wide variety of formulations which all have their advantages. In case you are looking for the best possible industrial epoxy adhesive for your project, contact us and let our experts connect you with the most suitable epoxy resin adhesive.

Contact us

adhesive chemistry raw materials, blue and green polymer resins

The basics of adhesive chemistry

Adhesive can be defined as any substance that can hold materials together in a functional way by separation resistant surface attachment. Adhesives can roughly be divided into natural adhesives and synthetic adhesives based on the raw materials they consist of. In synthetic adhesive chemistry, the most important ingredient is a polymer which for a great part defines the physical and mechanical properties of the adhesive. Polymers make up the most crucial adhesive raw materials, and exist as different types.

Adhesive chemistry affects adhesion

The chemistry behind adhesives essentially define the physical and mechanical properties of the systems including adhesion. In order to create long lasting bonds the adhesive chemistry must be matched with adherend and the surface. Therefore, the chemical composition has a creat impact on the adhesion. Four types of adhesion are recognized: absorption and surface reaction, mechanical interlocking, interdiffusion and electrostatic attraction. Most of these are relevant to adhesive adhesion and can be enabled by the chemical composition of the adhesive systems.

Types of adhesives and what they are made of

Adhesives can be divided into two groups defined by the nature of raw materials used to produce them. These groups are natural and synthetic adhesives.

Natural adhesives

Natural adhesives long dominated the adhesives market. Research implies that forms of natural adhesives were used as early as in the stone age. The current chemistry of today ́s natural adhesives uses raw materials based on animal or vegetable oils. Even though the use of natural adhesives experienced a decrease in the mid 20th century, especially wood and paper industries have been using them continuously. Some raw materials of natural adhesives have regained their position in the adhesives market, as they come from renewable sources. These adhesive raw materials can contribute to the development of biodegradable and biobased adhesives, which are likely to increase in popularity in the near future.

New adhesives are also continuously developed taking inspiration from natural adhesive materials. For instance, sticky snail trails and geckos have recently inspired a new super strong polymer.

Thermoplastic and thermoset synthetic adhesives

Synthetic adhesives were introduced as the stronger and easy to modify alternative for natural adhesives. The term synthetic refers to the raw materials having been developed in a laboratory setting. The synthetic adhesive chemistry is for a big part built on different polymers. The adhesive raw materials, the polymers exist as thermoplastic and thermoset variations.

  • Thermoplastic polymers: these polymers provide good adhesion and strong bonds at normal temperatures. Thermoplastics come in a solid form and are liquidized using heat. After curing, they can be brought back to liquid phase by applying high heat.
  • Thermoset polymers: thermosetting adhesive chemistry allows for irreversibly curing systems. These systems are known for their excellent chemical and heat resistance.

The most important adhesive raw materials in synthetic adhesives

In synthetic adhesives, the polymer is the key raw material. Not only does it impact the adhesive ́s reaction to heat, but defines other mechanical and physical properties such as chemical resistance, water resistance, load bearing capacity, abrasion resistance and flexibility.


The adhesive ingredients used in thermoplastic systems include nitrocellulose, polyvinyl acetate, vinyl acetate-ethylene copolymer, polypropylene, polyethylene, polyesters, acrylics, polyamides and cyanoacrylates. These polymers are also used in hot melt adhesives that provide a greener, solvent free option.

Thermosetting systems

Thermosetting adhesive chemistry uses raw materials such as epoxy, polyurethane, urea formaldehyde, unsaturated polyesters and phenol formaldehyde. Of the thermosetting systems adhesives that use epoxy resin are often considered the strongest. When a more flexible systems is sought, polyurethane makes up a considerable choice.

Elastomeric adhesives

Next to thermoplastic and thermoset adhesives, there are also elastomeric systems which can act as either of the previously mentioned polymer types depending on the adhesive ́s need for cross linking. Elastomeric adhesives are fast assembly, superior flexibility, easy to modify and versatile in uses. The adhesive raw materials for elastomeric systems include natural rubber, butyl rubber, butadiene rubber, silicone, neoprene, nitrile rubber and styrene butyl rubber.

Market developments affecting adhesive chemistry and raw materials

The main concern for the adhesive chemistry and raw materials market are the ever stricter local and international regulations regarding the chemicals industry. The regulations are set to limit the VOC (volatile organic compound) values of chemical products. Therefore, the use as well as export and import of high VOC adhesives has been restricted in some areas. Also the use of some polymers is likely to be subject to restrictions. The development of standards and regulations leads to innovative adhesive raw materials derived from more natural resources contributing to more sustainable systems.