Dynamic behavior of polyolefin thermoplastic hot melt adhesive under impact loading conditions

In this work, the static and the dynamic response of adhesive joints, bonded with a polyolefin hot-melt adhesive (HMA), were investigated by means of Single Lap Joint (SLJ) tests. The adhesive studied in this work is used in automotive application for bonding plastic internal and external plastic components, such as plastic bumpers that can be subjected to impacts during its life. The substrates used in this activity are made of a polypropylene copolymer with 10% in weight of talc. The main aim of this study is to test standard specimens, SLJ, under dynamic impacts with the use of a modified Charpy pendulum in order to compare the differences between static and dynamic behaviour. The analysis showed that the joint separation in the quasi-static tests is mostly cohesive, whereas it becomes completely adhesive in dynamic tests.