German vehicle components supplier Gutsche Engineering is using thermoplastic elastomers (TPEs) produced by Kraiburg TPE to manufacture an innovative roof rail cover with integrated seals.
The cover combines acrylonitrile styrene acrylate (ASA) with Kraiburg’s Thermolast A compound and is produced using multi-component injection moulding technology.
The innovative product simplifies the assembly process of the cover, while reducing costs, Kraiburg TPE said in a release 17 July.
“We were looking for a TPE for the seal that could be moulded directly onto the ASA hard component of the cover and ensure permanent and reliable adhesion to this copolymer,” explained Martin Gutsche, managing director of Gutsche Engineering.
Another decisive factor, according to Gutsche, was the TPE’s viscosity, which made it possible to implement the thin sealing lip geometry without imprints on the hard components by using the lowest mould cavity pressures possible.
On the back of previous successful projects, Gutsche Engineering brought Kraiburg TPE into the development of the application at an early stage in order to identify the TPE that would be most suitable for the application.
“In order to determine the adhesion of the various material combinations depending on different processing parameters, we at Kraiburg TPE offer the service of performing specific tests to check peeling resistance in accordance with the specifications of the VDI 2019 standard,” explained Matthias Michl, expert for window encapsulations, covers and frames at Kraiburg TPE.
In addition to established adhesion to polar thermoplastics, the selected compound features high flowability, ensuring complete mould filling even with complex component geometries, according to Kraiburg TPE.
The main requirements for the roof rail covers also included high weather resistance, as the covers are mounted at the highest point on the vehicles.
The compound was selected as it met the OEM's requirements, which including successfully withstanding two year-cycles of weathering in accordance with PV 3929 and PV 3930 standards and achieving > level 4 on the grey scale.
The product featuring Thermolast A has been in mass production as part of a roof rail system for a premium SUV since the first quarter of 2019, according to Kraiburg TPE.
According to Michl, exterior covers applications are becoming an increasingly important part of Kraiburg TPE’s business and the company is expanding its portfolio to meet the growing demand in the market.