According to industry experts, research and development in adhesives is moving at a fast pace. Goals include increasing the life of the products, recycling and sustainability.
Philip Bruce, Secretary General of the Fédération Européenne des Industries de Colles et Adhésifs (FEICA), says many innovations are focusing on the “circular” use of resources.
It is about ‘closing the loop,’ improving energy efficiency and extending the life of the product the adhesives are used in. There is a big emphasis on end-of-life, on enabling the repair or recycling of the product or its components.
One recent innovation is a new adhesive from Carlsberg which replaces plastic rings in bonding aluminium cans together. The Danish producer says “snap packs” will reduce the use of plastic in its packaging by 75%. For Mr. Bruce,
There are also no longer the environmental impacts of the plastic rings, including the danger to birds and fish.
Aluminium has traditionally been used in plastic pouches to give good barrier performance but it is very difficult to separate it from the plastic to allow the packaging to be recycled. Dow has developed a polyurethane adhesive that ties the two layers of plastic together. This offers good barrier performance but allows the whole pouch to be recycled.
Another area of interest is a new peelable liquid adhesive, which has a strong bond but can be removed easily so electronic products can be detached.
You can pull this away to allow for repair of a product part-way through life: the display on a phone, for example, can now be removed and replaced.
Jim Palmer, an independent technical consultant to the adhesives and sealants industry and Technical Officer for British Adhesives and Sealants Association (BASA), agrees “disbondability” is a key focus.
But, he says, its requirements need to be considered on a case-by-case basis, taking into account factors such as the value of the disbonded materials and the ease of reuse or recycling.
Adhesives and sealants are used in such a diverse range of applications from the minute, such as electronic devices, to the macro, like buildings, ships, trains, planes and automobiles. Clearly high– value components containing rare elements are worth recovery, but low value building materials are most likely better recycled on site, for example by crushing and using for backfilling aggregate in the construction of new buildings.
Mr. Palmer says there is also a focus on the development of adhesives based on natural proteins and other bio-derived materials.
These are essentially to replace the current oil-derived materials. There is also considerable interest in the development of systems that can resist the extremes of environmental conditions by mimicking systems that occur in nature, for example in marine environments.
Arjan Klapwijk co-owns Sustainable Adhesive Products Ltd (SAP), which developed BioTAK, a compostable adhesive made from bio-based material that is suitable as a pressure-sensitive adhesive (PSA).
Although at the start there was not that much interest in sustainable products, nowadays we are experiencing a growing demand. BioTAK is a water-based adhesive, which has numerous applications, like tape, laminates and label materials. It is also suitable for food applications.
Ultraviolet (UV) and electron beam (EB) technologies continue to be important in adhesives and sealants for healthcare (dental and medical implants) and precision engineering (electric motor armature bonding for domestic appliances).
Allnex, a specialty chemicals pioneer, works to support its adhesives customers in these areas and emerging trends.
Scott Auger, its Global Marketing Manager for Packaging Coatings and Inks, says:
Laminating adhesives are the largest current use of UV resins for adhesives but it is one of the smallest UV resin segments overall. PSAs are the fastest growing sub segment as formulators try to get rid of PVC in this application. Mass customization is also changing packaging as print service providers have shorter runs thus look to reduce make-ready times.
David Beke, Global Marketing Manager New Business Development, adds:
With some mature 3D printing applications having gained broad adoption and having illustrated the benefits, manufacturers have started investing in the technology. This triggers the need for materials that are more durable and with requirements that are new for the UV technology.
Mr. Auger says Allnex is also working with suppliers to remove solvents from laminating adhesives used in labels and conduct the printing and lamination in one step.
Mr. Bruce says research into adhesives for electric vehicles is also taking place.
There are products being patented for installing electric batteries into a car – this is not always easy as there are concerns about fire and temperature control.
He believes there are many exciting developments taking place in this sphere at the moment:
After all, it is hard to imagine a world without adhesives. Adhesives are invisible yet they are ubiquitous.