Cast PUR & Fabric Make a Living-Hinge Prototype.To provide customers with prototypes that incorporate a living hinge A living hinge is a hinge or flexure bearing with no moving parts. It is generally a thin section of the material that bends to allow movement. The lack of any friction and very little wear in such a hinge makes it essential in the design of microelectromechanical systems, and the , J.P. Pattern Inc. of Butler, Wis., developed a method of over-molding linen fabric with liquid polyurethane. The first step is to make a preform pre·form tr.v. pre·formed, pre·form·ing, pre·forms 1. To shape or form beforehand. 2. To determine the shape or form of beforehand. n. 1. : A piece of linen is placed in a two piece acrylic mold that has been machined with a cavity that will yield a hinge with a thick center section that tapers out to thin sidewalls. Then a resilient 85 Shore A liquid FUR system is poured over the fabric and the mold is closed, squeezing the resin into the cloth. J.P. Pattern uses Ren RP 6402-1 R/H R/H Rads Per Hour resin system from Vantico, Inc.'s Adhesives & Tooling Div. (formerly Ciba Specialty Chemicals “Ciba” redirects here. For the pre-1971 company, see Novartis. Ciba Specialty Chemicals is a chemical company based in and near Basel, Switzerland. It was formed as the non-pharmaceuticals elements of Novartis were spun out in 1997, following the merger in the ) in East Lansing, Mich. After the linen/PUB preform is removed from the acrylic mold, it is placed in a silicone-rubber mold, where a different PUB system is poured in to encapsulate en·cap·su·late v. 1. To form a capsule or sheath around. 2. To become encapsulated. en·cap the preform and produce the hinged prototype. For this step, J.P. Pattern uses Vantico's Ben EP 6405 R/H, which has a thermoplastic-like appearance but requires 24 hr before demolding. If shorter cycles are required, Vantico's fast-setting RP 6452 R/H demolds in 15-30 min. |
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