Adhesives and sealants deliver benefits to businesses, consumers, and the environment, contributing to the principles of the circular economy in line with the European Union Ecodesign Directive. This legislative file has been in force since 2008 and is undergoing regular revisions. The proposal for a new EU Ecodesign Regulation is relevant to adhesives and sealants because it involves regulatory standards for mobile phones, tablets, and laptops, where adhesives and sealants play an important role. Adhesives and sealants have truly unique properties in the electronics sector. Their adaptation for usability, repairability, and recyclability of electronics is therefore certainly possible.

Unique Properties 

Because of their unique properties in the electronics sector, adhesives and sealants make a difference in terms of process efficiency, design optimization, durability, repairability, and recycling. The EU ecodesign, resource-efficiency requirements for smartphones, other mobile phones, cordless phones, and slate tablets over their service life include design for reliability (e.g. scratch resistance), design for repair (e.g. removable fasteners), and requirements for recycling (e.g. compatibility and traceability).

Thanks to adhesives and sealants, electronics are particularly reliable. Further clarification, though, is needed regarding the repair and recycling of electronic waste. Better communication across the value chain is necessary, and consumer awareness must be created.

Possible Adaptation 

Insofar as adhesives and sealants are able to be adapted, they can promote the usability, repairability, and recyclability of electronic devices. In this context, the question is why there should be debonding on demand.

The European Commission intends a circular economy for plastics to avoid waste and to promote recycling. Hence the EU-wide Waste of Electrical and Electronic Equipment (WEEE) Directive was established, which sets a goal for the recycling of electrical waste. In addition, the Plastics Strategy is intended to lessen environmental litter to further a circular economy for plastics. Against this backdrop, the role of adhesives is critical, because adhesives used in electronic products allow debonding of parts so that repairability and recycling, and so a circular economy, are feasible.

How, then, do adhesives make debonding possible? The key notion is that of a trigger (stimulus), which can switch off adhesion of the adhesive to the substrate. In general, two kinds of separations of the adhesive from the substrate can take place because of a trigger. In one case, separation can occur by mechanical force supported by temperature. (The adhesive has not been modified). In the other, separation can occur because of, for instance, light, temperature, electricity, or magnetic fields. (The adhesive has been modified by additives or by an alteration of the polymer).

Perspectives on Smartphone Battery Debonding 

The intent of a circular economy is to preserve the value of products, materials, and resources for as long as possible, namely, to return them to the product cycle and to minimize the production of waste. So, a circular economy is the maintaining of functionality over time. In a consideration of the hierarchy of options that exist regarding waste management versus the circular economy, waste disposal’s controlled dump is the lowest option, and waste diversion’s reduction and reuse are the highest ones.

The reversible bonding that is possible regarding the battery of a smartphone affords a case study in the potential of a circular economy. Different scenarios may be examined, ranging from no debonding of the battery plus recycling of the phone (least desirable), to debonding of the battery plus good maintenance of the phone (most desirable).

The various scenarios can be considered from three perspectives: functional, environmental, and economic. The best solution will come through introducing circular business models, but benefits will need to be fairly distributed between businesses and customers in order to create a win-win for the environment and society. The proposal for a new EU Ecodesign Regulation is therefore very relevant to the adhesives and sealants industry.

FEICA, the Association of the European Adhesive & Sealant Industry held a webinar titled, "Adhesives and sealants' unique properties in electronics under the EU Ecodesign Regulation." The presentation and recording are available via www.feica.eu.