New compounds from KRAIBURG TPE for automotive exterior applications

KRAIBURG TPE has extended its portfolio of thermoplastic elastomers (TPEs) by additional efficient compounds. The four new THERMOLAST® K types are primarily suited for sophisticated hard-soft composite components with high requirements in relation to surface quality and permanent weather resistance.

Visible exterior vehicle components are permanently exposed to the immediate influence of weather conditions. High insolation with the corresponding temperatures and a potentially harmful share of UV radiation is a particular challenge for plastics. Consumers are expecting perfect surfaces that still look good after many years. Some manufacturers, therefore, intend to increase the standards for UV stability to two year-cycles of accelerated aging based on the DIN EN ISO 4892-2 standard.

In multicomponent composites made of TPEs in combination with various thermoplastics such as ASA, ABS, PMMA, and PC, adhesive strength must also be permanently maintained and ensured.

“We are known for our flexible, market-driven and customer-oriented development of custom-engineered thermoplastic elastomers. Our new materials address the increased requirements for exterior vehicle components,” says Gerhard Berger, Director Product Development EMEA at KRAIBURG TPE. “The fast development of these innovative materials underlines the customer focus of our sales and development teams and how closely the teams are working together.”

The new THERMOLAST® K compounds are a further development of established materials of KRAIBURG TPE’s previous “exterior” portfolio. The hardness grades of the TC5MUZ, TC6MUZ, TC7MUZ and TC8MUZ types range from 55 to 85 Shore A. The compounds’ increased weather resistance was proven by tests involving simulation of two year-cycles of sun exposure in accordance with the PV 3930 (Florida conditions) and PV 3929 (Kalahari conditions) Volkswagen standards.

An aspect worth mentioning is that the weathering caused only minor changes that were rated greater than level 4 on the gray scale – without oiling out and cracking. All four products have shown excellent peeling resistance in hard-soft combinations with ASA, ABS, PMMA, and PC during tests in accordance with the VDI 2019 standard. The products even maintain their outstanding adhesion after hot-air aging. What is unique in the TPE market is the new products’ performance that combines weather resistance and adhesion to ASA and PMMA.  

The new compounds are also characterized by a wide processing window. The material is processed at temperatures up to 250 °C depending on each specific application and shows high resistance to shear rates. Therefore, it is possible to precisely produce an image of even the most complex tool contours. The high-quality surfaces, which do not need any finishing, are characterized by high color stability.

The combination of these characteristics makes the new TPE compounds from KRAIBURG TPE such unique materials on the market. They were particularly developed for use in the construction of vehicles, and their quality makes them ideal for applications such as polycarbonate window encapsulations and pillar covers. Other target applications include frames, door sill panels, side mirror mountings, and brake light frames.  

KRAIBURG TPE continues to invest in the development of new thermoplastic elastomers, with its focus being on optimizing the modifications in relation to friction, scratch resistance and wear resistance, as well as the color settings according to OEM specifications.