Patent ID: 6290885
Filing Date: 2001-09-18
Classification: B29C,E04D,Y10T

Abstract:
A method for making a molded roofing unit from a fiber-reinforced plastic composition, said method comprising:drying a fiber-reinforced plastic composition to a water content ranging from 0 to 2 percent by weight, said composition comprising a polyolefin blended with fibers that have been at least partially delignified, wherein said polyolefin is selected from the group consisting of polyethylene and polypropylene;melting said composition in an injection molding machine until liquefied to a temperature ranging from 325 to 393.degree. F.injecting said melted composition into a mold configured to form a molded roofing unit, wherein said composition is injected into said mold through a gated structure to orient the fibers within the molded unit in a longitudinal position relative to the length of the roofing product;cooling said melted composition until said molded roofing unit is formed; andremoving said molded unit from said mold.