Patent ID: 8211350
Filing Date: 2012-07-03
Classification: B29C,B29L

Abstract:
1. A method of molding a composite building product comprising: providing first and second surface mold tools, each of the first and second surface mold tools having a front side and at least one article molding region formed into the front side, wherein the second surface mold tool is formed of a base and at least one lifter having a front side, the second surface mold tool and the at least one lifter cooperatively forming the at least one article molding region on the second surface mold tool, wherein each article molding region has a body bounded by a perimeter that defines an outer edge for a molded composite building product wherein the at least one lifter defines at least a portion of the perimeter, and wherein the body of each article molding region of the first surface mold tool is adapted for molding a top surface for the composite building product and the body of each article molding region of the second surface mold tool and at least one lifter are adapted for molding a bottom surface for the composite building product when the surface mold tool and the second surface mold tool and the at least one lifter are brought together in mating relation with the front sides thereof contacting one another such that the respective article molding regions thereof cooperatively form at least one closed molding cavity within which at least one composite building product having an uninterrupted top surface is formed; providing a distribution channel in at least the second surface mold tool, the distribution channel having a main portion outside of the article molding regions of the first and second surface mold tools, and a downstream terminus in communication with the body of the at least one article molding region of the second surface mold tool, and wherein the at least one lifter has a portion of the distribution channel formed therein, and wherein at least one of the first and second surface mold tools includes a port outside of each article molding region and in communication with the distribution channel to deliver the flowing composition of a polymer and a filler to the distribution channel; positioning the first and second surface mold tools in mating relation with one another to form the at least one closed molding cavity; flowing a blended composition of a polymer and a filler through the distribution channel and into the at least one closed molding cavity; applying pressure to the blended composition via flowably connected excess blended composition in said port for a period of time sufficient to cure the blended composition within each closed molding cavity into the composite building product; and separating the first and second surface mold tools to reveal one or more molded composite building products; wherein the distribution channel is adapted to form a gating piece on the bottom surface of each composite building product with the outer edge of each composite building product being free from attachment with the gating piece; and for each closed molding cavity where a composite building product has been molded, displacing each respective lifter away from the base and the front side of the second surface mold tool to expose the gating piece and allow free removal of the composite building product.