DSM is extending its portfolio of UV-stabilized grades of its glass fiber reinforced Akulon polyamide (PA) 6 for exterior automotive parts that require very good surface quality even when unpainted. The company is unveiling these new grades at the JSAE Automotive Engineering Exposition, taking place on May 21-23 in Yokohama, Japan (booth 164).

By eliminating the need to paint such exterior parts, DSM says it is making a major contribution to unit cost savings without compromising on quality. The new grades are reportedly particularly suitable for complex-shaped parts, such as exterior mirror bases and also for parts made using gas-assist injection molding technology, such as door handles.

Painting provides a high quality surface, and also serves to protect the substrate from weathering. However, the painting stage in the production of automotive components is very costly, and has a negative effect on the environment, especially when solvent-borne paints are used. As a result, car makers aim to eliminate paint wherever possible. This trend is supported by DSM, which has made important progress in developing high-strength materials with improved resistance to UV radiation and with high levels of aesthetics.

DSM is initially introducing two new Akulon PA6 grades. The first, originally developed for exterior mirror bases, is highly glass-filled (50% fiber), and yet it still yields parts with excellent surface quality and UV resistance. Trials in a number of different designs have shown that even in complex designs a very good surface quality is achievable. The second grade, intended for door handles, contains 30% glass fiber reinforcement and is particularly suitable for parts produced using gas-assist injection molding technology. 

DSM developed these new grades on the request of a leading system supplier in India who was looking for a new material for the base of unpainted external mirrors it produces for a Japanese car company. The demands of the application were daunting: high strength and high stiffness (to minimize vibrations), and very good surface finish without the need for being painted that would last over time. 

DSM says it has extensive know-how on the determination of the outdoor durability of glass fiber reinforced PA 6. It also has its own plastics compounding operation in Pune, India. Together, these two capabilities enabled the company to carry out development of the new grades locally, working closely with the customer.

DSM can supply these new grades on a global basis. The company believes they offer an excellent solution, not only for the two main target applications, but also for other smaller exterior components that can be used unpainted.