There is provided a polymer fabrication method for forming 3-dimensional shapes from a sheet polymer blank (10) by machining at least one re-entrant, elongate groove forming a reduced thickness portion (25) permitting the blank to be folded and having opposed edges (12) at the surface, folding the blank about the groove to form at least a portion of the 3-dimensional shape, the re-entrant of the groove forming an elongate chamber (21) adjacent the reduced thickness portion and opening through an elongate gap (20) between the opposed edges, hot air welding the opposed edges across the gap with filler rod (22), and heating the reduced thickness portion to a selected thermo-reforming temperature via the chamber.

A composite core material and methods for making same are disclosed herein. The composite core material comprises mineral filler discontinuous portions disposed in a continuous encapsulating resin. Further, the method for forming a composite core material comprises the steps of forming a mixture comprising mineral filler, an encapsulating prepolymer, and a polymerization catalyst; disposing the mixture onto a moving belt; and polymerizing said encapsulating prepolymer to form a composite core material comprising mineral filler discontinuous portions disposed in a continuous encapsulating resin.

A composite core material and methods for making same are disclosed herein. The composite core material comprises mineral filler discontinuous portions disposed in a continuous encapsulating resin. Further, the method for forming a composite core material comprises the steps of forming a mixture comprising mineral filler, an encapsulating prepolymer, and a polymerization catalyst; disposing the mixture onto a moving belt; and polymerizing said encapsulating prepolymer to form a composite core material comprising mineral filler discontinuous portions disposed in a continuous encapsulating resin.

A rubber product that includes a cylindrical molded body having a plurality of reinforcing layers coaxially layered between inner and outer layers. In producing/vulcanizing the molded body, a rubber product including a cylindrical portion, each of multiple reinforcing layers composed of cord fabrics including a large number of fiber cords aligned and subjected to a predetermined adhesion treatment and coating rubber layers covering both surfaces of the cord fabric, and a bias structure in which the fiber cords of the reinforcing layers extend in an intersecting direction is formed. Each of the cord fabrics has: a tensile strength of 4320 N/cm in a cord extension direction and a weight of 950 g/m.sup.2, each of the cord fabrics has a bending hardness of 30 g/cm after the predetermined adhesion treatment, and each of the coating rubber layers has a layer thickness of 0.2 mm and 1 mm.

Expandable substrates, which are referred to as blanks, are created by compressing thermobonded nonwovens after heating the binder material above its melting temperature, and then cooling the compressed nonwovens so that the binder material hardens and holds the fibers of the nonwoven together in a compressed configuration with stored kinetic energy. A mold for the component to be manufactured can be partially filled with a number of boards (or blanks) in a stacked, vertically, adjacent or even random orientation. Upon application of heat to the boards or blanks or parts in the mold, the binder material is melted so as to allow the nonwoven material to expand in one or more directions, and thereby fill all or part of the mold. Upon cooling, the binder material again hardens, and the molded component is retrieved from the mold.