Keeping it Together
The following is from an article for our sister publication Packaging and Converting Intelligence due to be published later this month
Adhesive techniques have experienced substantial developments in recent years. Sonia Sharma finds out more about what it takes to hold the industry together.
The importance of adhesives can sometimes be overlooked; however they play an important part in the lives of each and every one of us. From packaging and building construction to hygiene products and water filtration, adhesive and sealant solutions hold the world’s most useful and important products together. Durable boxes, safe food packaging, drinkable water supplies and even thin, absorbent baby diapers would not be possible without adhesives.
Adhesives and sealants are vital to the integrity and safety of the package, and it is a market that holds high value. We spoke to FEICA – the multinational association representing the European adhesive and sealant industry – about innovations within the sector and how companies ensure that things stick when they should.
A variety of sectors
FEICA represents close to 800 adhesives and sealants producers in Europe, through its National Association Members in 16 countries, 20 Direct Company Members and 11 Affiliate Company Members. The adhesive and sealant industry represents about 2% of the total European chemical industry’s turnover, contributes more than €14 billion to the EU economy, employs more than 41,000 people and invests about €370 million on R&D.
In 2016 the European adhesives and sealants demand was 19% for Germany; 10% for the UK and France; 9% for both Russia and Italy, 7% for Spain, Turkey and Portugal, 6% for Poland and 23% for the rest of Europe. By market segment converting/packaging accounts for 34%; construction at 27%; assembly including footwear and leather at 12%; woodworking at 10%; and consumer/DIY and transportation at 9% and 8% respectively.
Philip Bruce, Secretary General of FEICA said: “We call ourselves the voice of the European industry. We are located in Brussels, and our aim in life is that we are interfacing and advocating on behalf of our industry with the commission to make sure that we are inputting into any regulatory issues, European challenges and European opportunities in areas such as the circular economy.”
Different market segments each require a specific adhesive or sealant for their product. Techniques are constantly evolving to incorporate other factors, such as what needs to be done when the product reaches the end of life. “Innovation is one of our key paths” Bruce states. “Certainly for the circular economy in some sectors – for instance for an electronic display for a computer – the parts are often held together by adhesives or by double-sided tape, as well as by soldering, so when it comes to the end of the life what do you do with it? How can you get any components out of that system? If the adhesive is too strong then it means that to separate the components out will basically break the components and that of course is not very good for recycling.”
Ensuring that the correct adhesive or sealant system is used for the product is vital for the recycling stream and the life cycle of the materials. Bruce said: “The commission call these things eco-design so you are designing for recycle, or economic design which includes energy use, as well as recycle, re-use and ease of repair. If you can’t separate the components to repair your computer, then what happens is you will have to throw the whole thing away. In most cases, it will be more sensible if you could recycle or repair your machine to get another three years out of it, rather than throw it away and buy a new one.”
He continues: “One of the areas that our members are involved in – for example electronics – is in ways of developing adhesives that are, firstly strong and can sustain the life of the computer when the consumer is using it, and secondly, if there is more heat applied or another application, say infrared or micro-waves, that can heat up or dismantle the parts much more regularly. The developments are happening, in some cases, to make it easier for separation if it is at the end of life or for repair. So rather than just having extremely strong adhesives that will never separate unless you smash it, it is one that with temperature you are able to dismantle – we call it de-bond. There is a great interest in this for the automotive sector. If you have a car with fibre parts in the body structure – such as aluminium, steel and carbon fibre – and they are all glued together, at the end of its life there should be a system where you can de-bond the parts so that they separate relatively easily and you can recycle them.”
Hybrid adhesive development
The 2017 AIMCAL Awards Competition saw Unifoil Corporation earning the Marketing Award in the Packaging: Non-food Category as the converter for a holiday beverage carrier for Budweiser beer from Anheuser-Busch InBev. Selectively applied strips of metallizing on the front, top and rear panels eliminated any gluing concerns on the packaging line and reduced package cost and weight. The judges said: “The selective metallizing adds value to the package. If the side flaps had been metallized, you’d probably see some scuffing caused by the flap-folding and gluing process and contact with conveyor rails.” The selective metallizing provided a highly bondable surface for gluing, demonstrating how the paper and packaging adhesives is developing.
Bruce said: “I think for structural adhesives you would be looking at a 5% growth per annum and for paper and packaging adhesives, it will depend on the state of the economy, but it will probably be estimated at 2.5% to 3% growth. We see adhesives still continuing to grow faster than GDP. Solvent based adhesives and sealants have generally been reducing whilst one area of growth is water based adhesives. However if you actually look at where the fastest growing sector for adhesives percentage wise is, it is often in structural adhesives. It is replacing screwing. Adhesives can stick multi materials together so if you go back to components on a car, laptop or computer, adhesives can stick silicone, glass and plastic together. Previously you would have needed more screws and soldering which is frankly slower for separating or de-bonding in the recycling stream.”
He continues: “There is also growth in construction but it tends to be driven by how much construction is happening. The sealants are very good, they are well known, and the adhesives that are used tend to be the lower end. I think polyurethanes are probably the most general material that can be used in the chemical sector; the non-water based polyurethanes are really big. We are starting to see from some of our members that they are working with co-hybrid adhesives. Cyanoacrylate adhesive tends to cure very fast but they are quite brittle so they can be a little rigid meaning it could break over a lot of usage. For instance, if it was holding a truck together, with the movement of the truck, eventually the cyanoacrylate will break. Whereas a polyurethane system tends to be much tougher and can move quite a lot as it is very flexible, so if you can develop a hybrid with a cyanoacrylate plus a polyurethane together you can get the fast cure of the cyanoacrylate and the toughness of the polyurethane.”
Challenges and restrictions
The adhesive and sealant industry is one that has prominence in Europe, being valued at €14 billion last year. “Europe frankly leads the world. We have more big European headquartered companies in adhesives and sealants than most of the other sectors, more than American or Japanese so this is an important sector for the European market for continued growth” Bruce states.
“In Europe the biggest market for producers, as well as for consumption of adhesives is Germany. Most of the major adhesive producers in Europe are either headquartered in Germany or have a significant factory there. It is a very important market for my members as the Germans are extremely technically sophisticated with a lot of the leading developments of adhesives coming from Germany” he explains. “Europe has become much more effective. For example, if there is some legislation that is driving a need for a new adhesive in Germany, it very quickly goes to Brussels, and then they will recommend that all of the other members should be doing the same thing. It doesn’t stay within a country for long and if you’re manufacturing adhesives in France, you will have to conform to German standards and vice versa. Therefore, from a manufacturing company perspective, they are all really keen to have European legislation and regulation in place so that their products, which could be manufactured in Germany, France, Spain etc, will be able to be sold across Europe.”
Within Europe, legislation and regulations are undergoing rapid changes and one of the biggest challenges that the market currently faces is diisocyanate polyurethane. Bruce said: “The European commission is currently consulting on legislation that is likely to be implemented within the next 6-12 months that qualifies restriction conditions on diisocyanates. The restriction condition on the use of diisocyanate is that if there is an adhesive or sealant which has a percentage above .1% of pre-diisocyanate in the adhesive, then the restriction condition says either in reaction it does not emit a .1% and it’s an exemption, or we have to train you as to how to use that particular product. This restriction condition means that if we do not do the training and it emits more than .1% diisocyanate in the product when it is in use then that product will be banned from being sold in the European market. The German regulatory authority was concerned about the levels of diisocyanate, other countries then agreed with them and it is now going through the European Union regulatory committee for someone there to discuss it. What we have done as FEICA is that we have established an EU restriction condition working group. We have 16 different members providing our representatives to this working group and we are going through the end products that are manufactured using diisocyanate to check whether we need to train everyone about those sealants or whether we will be able to get an exemption under the regulations because it could be less than .1%. We are working through the list of products now and in sealants we are developing an exemption dossier to be able to show to the commission or to the European regulators that these sealants stay within the regulation houses established by the law or the future law to be implemented. We are working to make sure that our members are producing products that can continue to be sold within the guidelines set by the regulations.”