Groaning” automotive interior leather has been the cause of many complaints from customers over the years and as a result OEMs demand test certificates from their suppliers to verify the quality of the materials. However, there was no uniform standard for measuring this, until now. The VDA in Germany has now issued standard VDA 230-206, that expressly recommends an objective investigation of the stick-slip behaviour of materials, with a specific section relating to leather.

In this standard an objective measurement procedure is described to evaluate the stick-slip behaviour of materials. The stick-slip effect is the root cause for squeaks and groans. The stick-slip test SSP-01 from Zins Ziegler-Instruments GmbH has been found to fulfil all of the testing conditions mentioned in the VDA standard—from the conditioning of the specimen to the test report. As a result Zins Ziegler states that this impartial test will avoid disagreements between suppliers and OEMs and guarantees that no materials are selected that might cause annoying noises.