Abstract: The invention is a method of producing a melt compression molded work piece (18) includes the steps of introducing an in-mold coating (19) onto a first mold half (12) of a mold tool (10), and introducing a work piece material (17) onto a second mold half (14) of the mold tool. The work piece material has a temperature at or above a temperature at which at least a portion of the work piece material is in a molten state. The mold is then opened and the work piece (18) is removed after the work piece material has at least partially cooled.

Abstract: An improved polyurethane RIM process using a polycarboxy-functional alkyl siloxane as an internal release agent characterized by:(1) Tool break-in or preconditioning with siloxane treatment of the surfaces;(2) Supplying the siloxane to the mix head as a third stream when necessary to prevent undesired side reactions;(3) Using a minimal amount of siloxane that is inadequate for mold release in the absence of the tool preconditioning;(4) Adjustment of catalyst package to counter the inhibiting effects of the siloxane.The use of a bare minimal amount of siloxane prevents excess siloxane from appearing in the surface of the article and causing subsequent paint wet-out and like difficulties. The third stream isolating of the siloxane prevents its carboxy-functional groups from reacting with the prepolymer or with other ingredients that may be carried in the polyol blend.