CompositesWorld
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NEWS CompositesWorld.com 23 3D Preforming prepregged fiber constructs and then placing the pre-impregnated preform (the prepreg) into the mold and overmolding it. us, the problem of poor impregnation of continuous fiber in the injection or compression mold is avoided by impregnating the continuous fiber outside of the mold and then placing the prepreg in the mold. "By encapsulating unidirectional fiber and textile composite inserts in injection and compression molded parts, QEE-TECH provides a step-change in the design space for high-volume composite materials and facilitates the integration of multiple functions in a single part," she explains. "is allows the designer the freedom to optimize both cost and performance by placing expensive, high-performance continuous fiber material only where it is required while still maintaining the shape freedom afforded by lower cost, lower performance 'flowable' materials." "We have demonstrated 20-30% weight reduction (in excep- tional cases up to 50%) and 10-20% cost reduction in a range of applications," she adds. CW first covered EELCEE back in 2013 after the company won a JEC Innovation Award at the 2013 JEC Asia event in Singapore for a thermoplastic bumper system manufactured via 3D QEE-TECH by molder Hanwha for Hyundai-KIA Motor Group, both based in Seoul, South Korea, (see Learn More, p. 25). More recently, at SPE's 2016 Automotive Composites Confer- ence & Exhibition in Novi, MI, US, Chang-Manson discussed the use of the company's technology in the high-volume manufacture of composite automotive parts. Automated process e QEE-TECH 3D preform cell is designed to manufacture parts with complex shapes, multiple functions and tailored structural properties in a single-step operation. e fully automated process begins by pulling multiple continuous carbon or glass fiber rovings or tows from a creel through a series of dies that wet out the fiber with the appropriate resin (PA, PP, ABS, PEEK, etc.). "Glass fiber has shown to be a preferred alternative when strength is the main requirement, while carbon fiber may be preferred if high stiffness is a priority," says Chang-Manson. e material passes through a preheating oven during the wet-out process. Next, the homogeneous molten tow is deposited on a jig fixed to a rotating, sliding or tilting table robot. A consolida- tion roller applies pressure to the tow during deposition. In all, the cell employs three robots — a head robot system that deposits the material, the table robot system, and a support robot system. By rapidly placing the composite material into the desired 3D shape, an open, tailored 3D skeleton (prepreg) is created. Placed material is cooled via an air-jet system. e finished, solid composite preform is then automatically cut and moved to the over- molding operation. Fully automated, the QEE-TECH cell can be synchronized to inte- grate overmolding operations, providing high layup rates at temper- atures up to 400°C. e 3D preforming process is completed within a cycle time on the order of 60 seconds. Assembling a continuous fiber "skeleton" The QEE-TECH Cell (see photo on p. 24) quickly lays out the door module's main structural strength components (above left), creating the pieces with which an open, tailored 3D skeleton can be assembled in the mold. Reportedly, the preforming process does not impact the cycle time of the overmolding process when placed in an integrated line. Source | EELCEE