Styrenic sheet composite material delivers on structural and aesthetic demands with a single material

Ineos Styrolution is showcasing StyLight, a new generation of thermoplastic composite sheets based on a modified styrene-acrylonitrile (SAN) matrix and woven glass reinforcement, at the 23rd China International Composites Industrial Technical Expo in Shanghai, China (September 6-8, 2017) and at the 12th Composites Europe Trade Fair and Forum for Composites, Technology and Applications in Stuttgart, Germany (September 19-21, 2017).

The new composite reportedly combines structural stiffness with surface aesthetics, opening up opportunities in the automotive industry to address both structural and aesthetic demands with a single material. The thermoplastic composite sheets can then be thermoformed, back-injection-molded and decorated in just one processing step. At the same time, the lower shrinkage during the solidification phase of the styrenic copolymer matrix reduces the surface roughness or “waviness” significantly, resulting in a superior surface quality.

Further, the new material offers a thickness reduction potential of 50 to 70% compared to injection-molded parts resulting in a weight reduction of 40 to 50% by square meter. Because of its characteristics, StyLight is specifically targeting semi-structural applications in automotive interior including seating modules, lower consoles, instrument clusters and tailgate modules.

Traditional car applications often consist of a frame or structural part that is complemented by visible parts providing a certain aesthetical value to the user. StyLight is said to offer an excellent mechanical performance profile including stiffness, strength and impact strength. It is reportedly on a par with today’s most advanced polyamide (PA) 6 or polypropylene (PP) based thermoplastic composites available in the market.

Ineos Styrolution has partnered with Austrian engineering firm KTM Technology to develop and propose innovative design concepts for several applications.

Automotive door module: Typically, a door comprises of three functions, an externally visible surface, typically a sheet of painted metal, a non-visible semi-structural part, typically supporting all electronics and mechatronics of the door module and insulating the cockpit from water, and an interior visible surface. Here Styrolution has developed a concept to integrate the non-visible semi-structural function with the visible interior.

Automotive central console: This application is also very demanding with a directly visible surface, supporting electronic equipment and providing local structural stiffness. Moreover, the space available inside a console is very tight. It should allow sufficient room for the wiring harness and storage space. Here again a thin wall providing structural stiffness and offering a high surface quality is offering potential for the integration of multiple functions.

Automotive lift gate: There are many lift gate designs available depending on vehicle shape and design. Different composite solutions from long glass fiber reinforced PP to sheet molding compound (SMC) have been used for quite some time. Traditionally, the interior visible surface covers the structural frame. Attempts were made to overmold a thermoplastic composite retainer with injected molded GF PP but this adds cost and weight. Here StyLight offers a potential integration solution.

Body panel for trucks or tractors: A massive weight reduction is possible with the replacement of the thick SMC panel, which is currently being used in this field. Dimensional stability, class A surface quality, wind resistance, and resistance to powerful vibrations are among the long list of specifications for this very demanding application. Some of these panels also integrate functions like front lights or a bonnet. Here, StyLight again reportedly delivers a good value proposition to reduce weight.

A StyLight demonstrator will be presented both in Shanghai and in Stuttgart. The demonstrator combining different surface aesthetics such as gloss surface, grained surface, molded surface and design foil and a semi-structural reinforcement provides a first impression of the material’s potential. A team of Ineos Styrolution experts will be available at the booth in Stuttgart to discuss the innovative implications of the recent design study for StyLight.