Adhesion Test Methods

Multi-component moulding, typically pairing hard and soft materials has greatly advanced, but the assessment of how well the materials bond to one another has not. No international standard exists for determining bond strength between hard and soft components, so raw material manufacturers have developed their own individual test methods.

PTS has an extensive range of thermoplastic elastomers tailored to bond to specific thermoplastics and has produced a booklet describing its own testing methods. This is the result of extensive research and testing in the R&D laboratories at PTS Compounding in Germany. The work showed that test procedures that simply measure the tear resistance of the soft compound instead of the bond strength are inadequate.

The tests favoured by PTS are peel tests, which give significantly more accurate results than tension and shear tension tests. The roller peel test according to DIN EN 1464 has been slightly modified for this to allow for a thicker wall section of the hard component to minimise the effect of bending under high loads at extreme bonding strength.

Analysis of test results has enabled PTS to chart the relative bonding strength of pairs of materials, and also to determine optimum moulding parameters for a given combination. This expertise enables PTS to offer unprecedented knowledge when it comes to material choice for your application.