Abstract: A plastic building product for placement on the wall of a building to provide a louver or window wherein siding abuts the product the product comprises a plastic body having a peripheral wall circumscribing the louver or window, an integral flange extending laterally from the wall for fastening the body to the wall of a building, and a movable flange memebr telescoped over the peripheral wall of the body. The flange member includes a laterally extending flange adapted to overlie portions of abutting siding or the like. The flange member and the peripheral wall include interengaging portions for selectively positioning the flange member at predetermined distances which respect to the flange on the body to accommodate siding of varying thickness.

Abstract: A heat bonded composite plastic article comprises a sheet of solid thermoplastic material such as polypropylene an envelope or jacket of urethane foam, the jacket of foam being heat staked directly to the thermoplastic material in a plurality of adjacent but discontinuous locations characterized by permanent compression of the foam and welding of the solid thermoplastic material into the foam, the areas in the opposite faces of the article being in substantially exact registration with one another. The apparatus for producing the article comprises a press like combination of heated platens mounted on pivot arms which are operated by air cylinders, each of the platens having stakes which perform the compression and welding functions described above. In addition, one of the platens preferably carries a knife edge to trim the urethane foam around the periphery of the solid plastic body. An assembly method using a semi-automated apparatus is disclosed.