ABSTRACT
Throughout the ages, from cork and mud to rock wool and fiberglass, mankind has sought to insulate buildings against extremes in temperature, and the ultimate in insulation has arrived in the form of polymeric foams. Simply stated, "A polymeric foam is a gas-filled plastic". Polyurethane/polyisocyanurate foam sales are double that of polystyrene sales. Polystyrene foam sales are three times that of polyvinyl chloride foam. In consumer products, many of the polyurethane (PU) foams are used in bedding, upholstery, and packaging, and the polystyrene (PS) foams are found in floatation devices and Styrofoam food storage containers. Most of the PU and PS foams building materials are used in rigid insulation panels and spray foam sealants. In construction, polyvinyl chloride (PVC) foam is used in nonstructural thermal insulation, rigid water/frost insulation, exterior/interior rigid wall panels, and flexible coated fabric flooring. Polyethylene (PE) foam is processed by melting low-density polyethylene (LDPE) with additives and blowing a gas foaming agent into the molten polymer.
