Patent ID: 6716384
Filing Date: 2004-04-06
Classification: B29C,C08J,Y10S,Y10T

Abstract:
A process for rotationally molding a hollow polyurethane article within a mold cavity of a rotational mold comprising:a) obtaining a resin comprising at least one compound with at least two isocyanate-reactive groups; b) mixing the resin with a filler, which is of a type and an amount sufficient to alter the flow characteristic of a mixture comprising the resin, the filler and a hardener such that, upon rotation of a rotational mold, the mixture will uniformly coat the interior of the mold cavity without pools, puddles or uncoated sections of any wall of the mold cavity; c) heating the combined resin and filler sufficient to improve its ability to flow; d) adding the hardener, which comprises at least one di- or polyisocyanate, to the resin and filler to form the mixture; e) placing the mixture in the mold cavity of the rotational mold, which is at about ambient temperature; f) rotating the rotational mold about at least one axis of the rotational mold, until the mixture is sufficiently gelled to allow the molded hollow polyurethane article to be removed from the rotational mold; and g) removing the molded hollow polyurethane article from the rotational mold.