High-Performance Composites

MAR 2013

High-Performance Composites is read by qualified composites industry professionals in the fields of continuous carbon fiber and other high-performance composites as well as the associated end-markets of aerospace, military, and automotive.

Issue link: https://hpc.epubxp.com/i/110847

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Page 38 of 67

WORK IN PROGRESS percent disparity was noted, and Kuppers reports that the temperature variation across the part was virtually nil. Favorable comparisons Vistex also conducted a comparative study in which the benchmark part was cured via three methods: with TPC, in an autoclave and in the out-of-autoclave curing process developed by Quickstep Technologies (Bankstown Airport, New South Wales, Australia, and Dayton, Ohio). Autoclave cure was done by Kaman Composites – Vermont Inc. (Bennington, Vt.), and the Quickstep cure was done by Quickstep Composites LLC in Dayton (see "Learn More," below). The comparative costs for the three methods were tallied, and the parts were cut into coupons and destructively tested to compare their mechanical properties. The results show that the rapid temperature-ramping capabilities of TPC and Quickstep reduce cure time to the minimum required by the prepreg manufacturer. TPC cure was accomplished in 4.25 hours, compared to roughly 8.5 hours in the autoclave. Kuppers asserts, "The high temperature ramp rates achievable with TPC can reduce cycle times for any resin system." Dimensional tolerances on the TPC part were comparable to the autoclaved part, with minimal to no surface defects. Further, TPC used far fewer consumables because it requires no vacuum bagging, in contrast to the other methods, so layup is fast and straightforward. Most telling, the energy consumption for TPC was nearly two orders of magnitude less than for the autoclave and Quickstep process, attributable to the fact that TPC heats only half the mold (and the heat source is in direct contact with the part). Finally, the capital equipment cost for TPC is a fraction of that for the other two methods. Although TPC offers major benefits in speed, cost and part quality, Vistex is quick to point out that more work will be necessary to scale the process for larger parts. Also, tooling costs will increase for rate production because multiple tool sets and inserts would be needed, and inserts, which reportedly perform well into the low hundreds of cycles, would need replacement in lengthy runs. Kuppers and his colleague, Vistex COO Dr. Casey Hoffman, report that Vistex is currently investigating new part materials, including thermoplastics and bio-composites, testing thicker laminates and more complex part geom- Bring us your challenge. We can help. If the world's 10 largest aerospace companies rely on our sophisticated automation systems to accelerate composite processing, maximize material utilization and ensure quality, shouldn't you? We offer a complete suite of solutions to accelerate composite processing including a laser-guided ply layup system, automated nesting software, computer-controlled cutting, laser-guided kitting, and laser ply inspection system. Learn More Contact us today to discuss your challenge. @ www.compositesworld.com Read this article online at http://short. compositesworld.com/aFL1ccaN. Read more about the Quickstep curing process in "An out-of-autoclave progress report," HPC September 2011 (p. 9) or visit http://short. compositesworld.com/2w4xwLDf. etries, and considering process automation. Currently, Vistex molds prototypes for several customers in marine energy turbine, motorcycle and other markets. In the future the toolmaking technology and, alternatively, ready-to-use tools could be leased to customers. Concludes Hoffman, "We plan to offer manufacturers a fast, very cost-effective, out-of-autoclave solution that is capable of producing an autoclave-quality part." That goal is well within reach. NESTING I CUTTING I KITTING I PLY LAYUP I PLY INSPECTION + march 2013 | 37

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