A new tool to precisely simulate the thermal processes in Lanxess’s weight-saving Tepex continuous-fiber-reinforced thermoplastic composite was announced by the company at the recent Plastics in Automotive Engineering conference at Mannheim, Germany.
It comprises a fresh modeling simulation solution that can be applied during and after draping in the injection mold. Tepex is used in the construction of seat shells as well as for front ends, brake pedals, chassis components, and infotainment modules.
Said Lanxess CAE specialist Pablo Willms: “This enables us to examine more precisely whether critical component geometries can still be shaped, or whether fibers would rip or wrinkles form.”
Also, the sheet geometry for the target component can be determined more accurately beforehand, he explained. “This means that fewer trials are required. The processor benefits from savings in terms of both time and cost.”
Lanxess has developed various simulation tools for the design and production of composites.
The new modeling approach has so far been designed for Tepex dynalite 102-RG600, used for automotive structural components. It contains 47% by volume of continuous glass fibers in the form of bidirectional layers. Lanxess says the next step in the tool’s application will involve expanding its usability for Tepex with unidirectional or multi-axial layers of continuous fibers.
Lanxess singles out its application of Tepex for automotive seat shells as being particularly significant.
Overmolded Tepex inserts can be used as substitutes for metal reinforcements such as sheets and bars, enabling weight savings of “well over” 30%, claims the company. Lanxess has tailored compound materials such as Durethan BKV 55 TPX for such applications.
“The polyamide 6 reinforced with 55% short glass fibers is tailored to Tepex. It is extremely free-flowing, tough, and stiff, and is therefore particularly suitable for thin-walled composite lightweight components with large flow path/wall thickness ratios,” Willms said.
Tepex’s advantage over use of metals for comparable applications is its ability to be shaped in the injection mold, overmolded and, as the company puts it, simultaneously “functionalized in a single automated process step so that no further finishing is required.”
In comparison, with thermoset composites, Tepex has been developed to provide high levels of stiffness and strength at lower densities and also provide high strength, favorable impact behavior, excellent formability, and recyclability.
At the Mannheim event, Lanxess revealed what the company describes as a “material innovation” for the DLFT (direct long-fiber thermoplastic) compression molding process. Durethan B 24 CM H2.0 is a polyamide 6, claimed to have significantly better flow properties than conventional polyamide 6-based long-fiber molding compounds. It also produces no flue gases on extrusion, and heat resistance means the material can withstand the temperatures involved in cataphoretic painting (CP), thus offering a CP-capable alternative to polypropylenes in the DLFT process.
The hybrid molding process sees Tepex inserts simultaneously molded and back-injected in an injection mold for a seat shell.
Tim Arping, a senior executive with Lanxess’s High Performance Materials Business Unit, said, “In the event of a crash, the component absorbs considerably more energy than comparable designs using sheet steel or plastics reinforced with long glass fibers. This provides a greater degree of safety.” The safety component is about 800 g (28.2 oz) lighter than previous versions.
Arping also detailed a new lightweight material: Durethan BKV 60 XF. Also a polyamide 6, it is reinforced with 60% glass fibers. Its mechanical property profile is of a similar standard to that of the series production Durethan BKV 60 H2.0 EF; its melt flow is more than 30% better, said Arping.
“This enables the construction of strong structural components that exhibit intricate rib structures with wall thicknesses of less than 1 mm,” he added.