Step by step, fiber-reinforced components are being integrated into production vehicles today to build up knowledge about composites systematically. Thermoplastics perform well here thanks to their short cycle times, weldability, and potential functional integrations, in which a component can take on multiple additional functions. Not only are thermoplastics getting better all the time as matrix materials, new production methods and even design principles are also opening up. "The transformation happening in the automotive industry as well as in aircraft construction and other industries could not be more thrilling," states Martin Würtele, Manager of Technology Development at KraussMaffei. "The transition from steel and aluminum sheets to fiber-reinforced thermoplastics is far more than a change in materials. The designers have to search for opportunities to achieve functional improvements using high-performance composites and designs appropriate to the materials." For example, a load-carrying thermoplastic carbon-fiber-reinforced part—manufactured from a composite sheet—can have ribbing molded onto it in the injection molding process, along with other integration and function elements. KraussMaffei is offering an overview of fiber-reinforced high-performance composites at the ITHEC 2012 on October 29-30, 2012 in Bremen.
Even today, upon hearing the term "composites" many people still think of the classic carbon-fiber-reinforced components with carbon fibers in an epoxy resin matrix. For KraussMaffei, however, this field is far broader. "Among reactive materials we also see polyurethane and cast polyamides as alternative matrix materials; among thermoplastic materials, polyamide and polypropylene have proven themselves," explains Erich Fries, Manager of the Composites/Surfaces Business Unit. In this area, KraussMaffei has combined its expertise over all lightweight construction technologies across the entire process chain and material systems. "In this dynamic environment of development there is still no clear trend to be identified, but it is certain that the developments still have not been completed." Depending on the requirement for mechanical strength or the component cost, all more or less common fiber types come into question as reinforcement material.
The HP-RTM (high pressure RTM) method has already proven itself in many areas of application for manufacturing composites with carbon fibers for pre-batch production and is now finding its way into large series. "With our expertise and high-quality machine technology, we are setting new standards in the automotive market," says Fries. "Our systems are now in use by numerous major producers in the automotive and commercial vehicle industries, and we are brought into new developments very early on, since we can contribute to solutions at every step of the process chain." The HP-RTM (high pressure RTM) method keeps gaining importance for series production in high-technology industries. Development of the method, however, is still long from being completed. The very complex requirements springing from required numbers of pieces, automated processes, affordable material costs, and the greatest possible weight savings for a component lead to many variants. As of recently, the different methods for resin transfer molding (RTM) known as compression RTM and wet molding are available, each exhibiting its own specific advantages. With wet molding, for example, carbon fibers can also be recycled as piece goods, the scrap from the preform manufacturing. Reliable partnerships form the basis for efficient implementation of these developments. As part of its cooperation with Dieffenbacher GmbH, KraussMaffei supplies complete systems that cover the entire production process, from processing the carbon fibers to the post-mold-processed part that is ready to install.