Rapid Prototype Composite Tooling Using CFOAM® Carbon Foam Introduction Asthe world movesfaster and partsare developed via computer aided design, the old methodsof buildi ng mas ters(plugs) and pulling parts has become too s low and costly. Designer swant to go from a CAD file to a composit e part as fast aspossible. At Touchstone Research Laboratory, there has been a breakthrough in the development of inexpensiv e, off-the-shelf coatings providing dimensionally stable, low coefficient of thermal expansion (CTE) , large (and small) rapid prototypesof carbon fiber reinforced plastics. Rapid Prototype Composite Tooling Using CFOAM Carbon Foam Touchston e is currently developing seve ral process esto apply tooling surfacesto CFOAM carbon foam that are suited for prototype tools designed to make lessthan ten parts. It is an inexpensive proces sthat can be manufactured quickly. The “rapid prototype” sur facing concept begins with the application of a filler material to the top layer of the foam. The filler material has high use temperatures , suitable compressive strengths, and iseasily machined or sanded. The purpos e of the filler material is to fill the CFOAM pore structure in order to create the base for a tool surface that will maintain vacuum integrity during vacuum bagging on the surface. High-temper ature epoxy paint isthen applied to the fil led foam surfa ce in a carefully controlled manner in order to manage the final tolerance that takesinto account the paint thicknes s. This sys tem can be seen in the photomicrogr aphsbelow. Steps in Making a Rapid Prototype Tool Using CFOAM Carbon Foam 1. BLOCK AND MACHINE: First, panelsof CFOAM are bonded together and machined to within 0.004" of the desired final geometry of the tool. 2. FILL AND CURE: The filler coat isthen applied to the surfac e of the machined foam with a squeegee and adds no measurable thick nesswhen applied and prepared proper ly. The picture below showsa tool that hasbeen filled. An oven cure in excessof 350° F istypically performed. A second coating of filler materialscould be applied and oven cured if required. Another optional proces sfor applying a different filler material isto apply it very liberally over the entire surface of the machined tool, cure it at room temperature within an hour while the tool ison the mill, and then re-machining the tool to the finish dimens ions. This eliminateshand workand the filler providesa very hard surface. 3. PRIMER COATIN G: After the filler material has been completely smoothed, consistent with the CFOAM carbon foam surface by hand or via machining, a primer coating isapplied by either spraying or rolling. The primer used istypically part of a two part epoxy paint that has use temperature of 400° F (204° C). The primer coating fillsany remaining poros ity in the filled CFOAM surface. After the primer coat isapplied, the sur face isready for the second coat of the two part epoxy paint. Below are two examplesof completed rapid prototype toolswith both coatsof the two part epoxy paint sys tem. The tool on the l eft showsthe mask ing paper on the edges. The paint system addsapproximately 0.004” to the surface of the tool. To date, the rapid prototype tooling surf acesused at Touchstone have been used to success fully cure composite partswhen the tool was vacuum bagged to a flat table, or the entire tool wasenvelope bagged. Touchston e has a development plan to expand the robust nessof the rapid prototype sur facesfor autoclave process esand to achieve a vacuum integral surface. What We Offer We currently offer rapid prototyp e tools built to order. In addition, Touchst one can manufacture a rapid prototype tool and pull a part . If the part isacceptable, Touchst one can machine away the prototype surface andreplace it with a durable rate tool surface. We also supply CFOAM carbon foam eith er in panels or machined to shape for our customersto bu ild thei r own tools. Although our customer s are alwaystrying something new, we will provide the best advice we can offer and we do offer on-site consulting and assistance in dev eloping new composite to oling specifically for you r special needs. For more information about our Rapid Compos ite Tooling, please call or email usfor a prompt respo nse. Telephone: 304.547.5800 email:[email protected] Voice: (304) 547-5800 Fax: (304) 547-5802 Email: [email protected] CFOAM® isa regi stered trademarko f Touchstone Research Laboratory, Ltd. CFOAM® productsmay be covered under the following patentswith more patents pending: 6,656,238 - 6,656,239 - 6,689,470 - 6,749,652 - 6,814,765 - 6,833,011 - 6,833,012 - 6,849,098 - 6,860,910 - 6,861,151 - 6,869,455 - 6,899,970 - 7,192,537 - 7,247,368 © 2004-2008 Copyright Touchstone Research Laboratory Ltd. Term and Conditions Privacy Policy Sitemap 04.02.2011 Rapid Prototype Composite Tooling http://www.cfoam.com/rapid prototype_composite_tooling.htm 1/1