Abstract: A method and apparatus for continuously and cost-effectively producing expanded thermoformable materials encompassing the steps of: providing raw thermoformable material into an extruder or mold; heating the material in the extruder or mold; extruding or co-extruding molding planar sheet material of suitable engineering performance parameters to a gauge and width; cutting or shearing the extruded or molded material while it is still hot to suitable lengths for expansion in a coreformer; conveying the hot thermoformable sheet material in between forming platens; heating the thermoformable material to a temperature at which the material adhesively bonds to the platens; expanding the cross-section of the thermoformable material; and then cooling the expanded thermoformable material by changing the temperature of the forming platens such that the thermoformable material can maintain its structural integrity and be released from the platens.

Abstract: A method for continuously producing high-strength welded composite panels from thermoformable material facings and expanded thermoformable material cores comprising the steps of: simultaneously feeding facing sheets and core into a welder that has automated feed rollers; heating the lower side of the top face and the upper side of the lower face simultaneously with both faces of the inner core of expanded thermoformable material; continuing to heat them to 100-400° C. until the surfaces reach the initial melt and/or hot tack temperature of the materials; pressing the heated faces together against the heated surface of the core material to consolidate the composite structure; and allowing the materials to cool while under pressure and continuing to move forward in the engaged roller mechanism until the entire panel has been welded and is dimensionally stable.