A modifier for structural and exterior components has been developed by the GRAFE company of Blankenhain. It offers cycle time optimization while at the same time improving the surface and mechanics of plastic components – especially for thick-walled and large components or those where the polymer melt has to travel long distances. Carrier components “under the hood” have already been realized.
“In the engine compartment, or generally under the hood, fiber-reinforced plastics have now taken over a not inconsiderable share of the automobile. These materials are exposed to extreme temperature loads as well as aggressive oils, fuels and environmental conditions,” explains product manager Danny Ludwig. “By reducing weight, compared to metal, a considerable cost reduction, often in the order of 30 to 40 percent, can be achieved”.
“Of course,” says the expert, “these savings potentials vary from application to application. Within polyamide materials, there is a wide variety of property profiles and fillers, such as glass fibers and minerals. Glass fiber contents of between 15 and 60 percent are common. However, this often creates major design challenges for processors, toolmakers and injection moulders.
According to Ludwig, these include the long distances that the polymer melt has to travel, processing conditions or loads, material damage or stress, and long cycle times, which in turn have an impact on commercial aspects. In addition, components with large volumes and long flow paths could damage the material or create other negative side effects, such as poor component surfaces resulting from upright or non-integrated glass fiber components.
“Thanks to our additive expertise, we have developed a masterbatch that meets the above challenges and can improve many aspects,” explains Clemens Rösler, Head of Automotive Sales. “Especially with glass fiber-filled polyamides (PA), for example, filling the cavities is easier because the modifier makes the polymer melt flow more freely and the mold can be filled faster and more easily.
In addition, the glass fibres and the polymer can be processed more gently and the mechanics are retained. “The surface quality can be significantly improved and the additive results in a considerable cycle time improvement of up to 30 percent,” says Rösler. “It also facilitates, component removal from the respective injection mold.” A further advantage is that the material offers excellent properties to support good crystallization in the injection molding process.