CompositesWorld
Issue link: https://cw.epubxp.com/i/742140
SPE's Automotive Composite Conference spotlights diverse approaches to RTM while Teijin and a European research trio spot new opportunities involving SMC. AUTOMOTIVE NOVEMBER 2016 12 CompositesWorld TRENDS The Society of Plastics Engineers' (SPE) Automotive Composites Conference and Exhibition (ACCE; Sept. 6-9, Novi, MI, US) has grown to become the world's largest composites-only event devoted to automotive manu- facturing. With almost 1,000 attendees, more than 90 presentations and 75 exhibitors, it has become an accurate reflection of the state of autocomposites design, material and process development. Although there is obvious and great interest in auto- composites, how they might be inserted into the automo- tive supply chain remains to be seen, and many of the presentations emphasized technologies designed to help composites clear the design and cycle-time hurdles they face. Because of this, there was substantial emphasis on processes, particularly compression molding, injection molding, preforming, and on materials, with emphasis on thermoplastics. That said, thermoset advocates weren't sitting on their hands, and proved that the automotive end- market is critical to their success. Some highlights: One of the most intriguing presentations came, surpris- ingly, at the end of the last day. Philipp Rosenberg, from Fraunhofer ICT (Pfinztal, Germany) discussed work he's done using in-mold sensors to modulate pressure require- ments for high-pressure resin transfer molding (HP-RTM). Dubbed pressure-controlled RTM (PC-RTM), the process uses cavity pressure to drive process control, with other variables, such as mold gap and compression time, modi- fied to promote good resin flow at low pressures — 20 bar, compared to 120 bar. Advantages are faster cycles, lighter and less expensive molds and possible use of core materi- als without core crush. Another RTM variable was presented by J. Javier Acosta, R&D; composite project manager at Fagor Arrasate (Gipuzkoa, Spain). Fagor's compression RTM (CRTM) process uses mold-gapping during injection to promote resin flow and reduce cycle time compared to RTM and HP-RTM. Acosta showed a carbon fiber/epoxy demonstra- tor car roof part that could be made in volumes of up to 90,000 units per year from one CRTM machine. That same volume reportedly would require two HP-RTM systems and seven RTM systems. The utility of chopped carbon fiber was demonstrated by Hiroyuki Hamada, from the Kyoto Institute of Technology (Kyoto, Japan), who described his work with what he calls K-class carbon fiber — non-standard carbon fiber reclaimed as waste from the carbon fiber manufacturing process. This continuous, unsized carbon fiber was used in the direct fiber feeding injection molding process (DFFIM), in which fiber is fed into the injection barrel, where it is sheared by the feedscrew prior to mold injection. Testing with polypro- pylene, polycarbonate and polyamide showed promising physical properties. A modified check ring helped increase mean fiber length to 2.63 mm. Hironori Nishida, from Doshisha University (Kyoto, Japan), introduced advanced automatic tape placement (AATP), which uses a Tajima Group (Kasugai, Japan) embroidery machine to quickly build carbon fiber preforms. It was used to fabricate a composite transverse steering structure that not only reduced weight from the sheet-metal version (2.4 kg) to a carbon fiber version (0.9 kg), but also reduced waste by 50% and processing time by 75%. The future also appeared to be bright for composite leaf springs. Sigrid ter Heide, global market develop- ment manager transportation at Hexion (Rotterdam, The Netherlands), highlighted that company's work with ZF Friedrichshafen AG (Friedrichshafen, Germany) to develop a material and process for the RTM manufacture of a glass fiber/epoxy leaf spring for an automotive axle. It withstands prolonged fluid contact and has good corrosion resistance, and consumes less energy during manufacturing than steel competitors — 13,010 MJ for steel vs. 3,180 MJ for composites. SPE ACCE 2016 proves big and busy Cincinnati Inc. (Cincinnati, OH, US) used the Big Area Additive Manufacturing machine co-developed with Oak Ridge National Laboratory (Oak Ridge, TN, US), to "print" a Shelby Cobra body (a blue one) a couple of years ago. It proved so popular that Cincinnati printed another, and brought it to SPE ACCE to demon- strate additive manufacturing's potential. Source | CW / Photo | Jeff Sloan