Debonding on Demand of Adhesively Bonded Joints: A Critical Review

Adhesive bonding is a viable technique for joining a wide range of materials (e.g. metals, polymers, ceramics, etc., and combinations of any of these materials). However, one disadvantage of adhesive bonding is the permanent character of the joint. In many situations, it is desirable that the joint can be separated so that the materials can be reused on a qualitatively high level. Nowadays, due to the significant pressure on reducing costs and increasing demand for material recyclability, the development of new techniques and processes for easy recycle and repair of bonded structures is becoming of great interest for the industry. This review presents the recent developments in the use of debonding techniques and summarizes the different strategies and approaches used for adhesive debonding. The use of reversible (reworkable) adhesive systems and electrically debondable adhesives is presented. Next, the use of fillers in the adhesive which can be triggered by an external stimulus (e.g. heat: thermal and induction, electrical or magnetic flux) to induce mechanical separation of the substrates is discussed. It is concluded that there is no universally accepted debonding method due to the wide variety of adhesive bonded joint systems and applications. The selection of the appropriate debonding technique will depend on the particular application needs and constraints.