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Injection Molding Urethane Rubber

IP.com Disclosure Number: IPCOM000087472D
Original Publication Date: 1977-Feb-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Friery, EJ: AUTHOR [+2]

Abstract

In the molding of polyurethane parts, a sticking condition has been found to exist in many cases, i.e., the molded part tends to stick to the mold walls after molding. This presents a special problem in "two shot" molding operations when a second operation molds urethane onto a previously molded first part and mold releases are not feasible to use. Tearing away of the second part from the first part is frequently encountered.

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Injection Molding Urethane Rubber

In the molding of polyurethane parts, a sticking condition has been found to exist in many cases, i.e., the molded part tends to stick to the mold walls after molding. This presents a special problem in "two shot" molding operations when a second operation molds urethane onto a previously molded first part and mold releases are not feasible to use. Tearing away of the second part from the first part is frequently encountered.

A better mold releasing surface is formed by applying a polytetra- fluorethylene coating to the mold wall. This is not a mold release compound which is consumed in the process but rather a permanent coating on the surface. The coating is preferably 0.001 to 0.003 inches thick and is cured at about 500 degrees F.

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