At the recent DKT trade exhibition, API introduced its new VDI 2019 standard for measuring the adhesive strength of TPE on rigid substrates. Indeed, the Vicenza-based company is part of a committee, formed with the purpose of harmonising the various methods used in the past for measuring this parameter, and bringing them together in a single standard.

The VDI 2019 standard makes it possible, through a systematic peeling test procedure, to define and measure the strength with which TPE adheres to a rigid substrate, and it sets out in detail the documentation required. The standard could shortly be extended to cover adhesion to rigid non-plastic substrates too.

The demand for combinations of TPE with rigid materials has been rising constantly in recent years and now, especially in the industrial and automotive sectors, more and more components feature soft surfaces chemically adhering to rigid substrates. To this end, the simultaneous injection of soft and rigid materials can offer not only specific process benefits in complex applications, but also greater freedom in designing otherwise unobtainable geometries.