The present disclosure is directed to a physically crosslinked, closed cell continuous multilayer foam structure comprising at least one foam polypropylene/polyethylene layer with a KEE cap layer. The multilayer foam structure can be obtained by coextruding a multilayer structure comprising at least one foam layer composition layer with at least one cap layer composition layer, irradiating the coextruded structure with ionizing radiation, and continuously foaming the irradiated structure.

The present invention discloses a multilayer composite rubber-plastic foam insulation material and a preparation method thereof. The composite rubber-plastic foam insulation material includes a two-layer structure; the two-layer structure includes an insulation layer and a first functional layer; the insulation layer and the first functional layer are both made of a rubber-plastic foam material; the first functional layer and the insulation layer are integrally molded by blending extrusion and vulcanization foaming, and the first functional layer and the insulation layer form an integral structure. The multilayer composite rubber-plastic foam insulation material provided by the present invention adopts a vulcanization foaming integral molding process, and not only ensures the thermal insulation property of the insulation layer, but also gives the functional layer corresponding functions by selecting different functional polymers, thereby satisfying a variety of personalized needs in engineering applications.

Described herein are physically crosslinked, closed cell continuous multilayer foam structures that includes a foam layer comprising polypropylene, polyethylene, or a combination of polypropylene and polyethylene and a polyamide cap layer. The multilayer foam structure can be obtained by coextruding a multilayer structure comprising at least one foam composition layer and at least one cap composition layer, irradiating the coextruded structure with ionizing radiation, and continuously foaming the irradiated structure.

A polyolefin-based resin foamed sheet includes a polyolefin-based resin, wherein a thickness of the foamed sheet is 0.05-0.5 mm, a 25% compression hardness defined in JIS K6767(1999) is 20-100 kPa, a ratio of cell sizes in longitudinal and thickness directions is 9-30, a ratio of cell sizes in width and thickness directions is 9-30, and an average cell film thickness in the thickness direction of the foamed sheet is 2-7 μm.

A method of microcellular foam molding an article is provided with filling a mold with a polyolefin compound; forming crosslinks in the mold to obtain a crosslinked mold; dissolving a supercritical fluid into the crosslinked mold under a predetermined pressure and at a predetermined temperature for a predetermined period of time to obtain a second mold configured to allow the supercritical fluid to effuse through; and heating the second mold at a second predetermine temperature for a predetermined foaming time until a foamed article is finished in the second mold. A second embodiment involves using elastomers as foaming materials is also provided.

A polymeric sheet, at least partially cross-linked and/or foamed, having a substantially open cell foam structure is described. A continuous method of manufacturing of an at least partially cross-linked, open cell foamed polymeric sheet is also described.

The present invention discloses a multilayer composite rubber-plastic foam insulation material and a preparation method thereof. The composite rubber-plastic foam insulation material includes a two-layer structure; the two-layer structure includes an insulation layer and a first functional layer; the insulation layer and the first functional layer are both made of a rubber-plastic foam material; the first functional layer and the insulation layer are integrally molded by blending extrusion and vulcanization foaming, and the first functional layer and the insulation layer form an integral structure. The multilayer composite rubber-plastic foam insulation material provided by the present invention adopts a vulcanization foaming integral molding process, and not only ensures the thermal insulation property of the insulation layer, but also gives the functional layer corresponding functions by selecting different functional polymers, thereby satisfying a variety of personalized needs in engineering applications.

Described herein are physically crosslinked, closed cell continuous multilayer foam structures that includes a foam layer comprising polypropylene, polyethylene, or a combination of polypropylene and polyethylene and a polyamide cap layer. The multilayer foam structure can be obtained by coextruding a multilayer structure comprising at least one foam composition layer and at least one cap composition layer, irradiating the coextruded structure with ionizing radiation, and continuously foaming the irradiated structure.

There is provided a polyolefin resin foam sheet formed by foaming a polyolefin resin, wherein the expansion ratio of the foam sheet is 1.5 to 20 cm.sup.3/g, the average cell sizes in the MD direction and the TD direction of the foam sheet are 130 μm or less, and the following formulas (1) and (2) are satisfied:
T.sub.M/D≥6  (1); and
T.sub.T/D≥5  (2), where T.sub.M denotes the tensile strength at 90° C. in the MD direction, T.sub.T denotes the tensile strength at 90° C. in the TD direction, and D denotes the density (g/cm.sup.3) of the foam sheet.

A method is disclosed for manufacturing a structured polymeric material. In the method, a body is provided comprising a substantially homogenous precursor polymeric material. An interference pattern of electromagnetic radiation is set up within the body to form a partially cross-linked polymeric material, the interference pattern comprising maxima and minima of intensity of the electromagnetic radiation, the interference pattern thereby causing spatially differential cross linking of the precursor polymeric material to form crosslinked regions having relatively high cross linking density and non-crosslinked regions having relatively low cross linking density, the crosslinked regions and non-crosslinked regions corresponding to the maxima and minima of intensity of the electromagnetic radiation, respectively. The partially cross-linked polymeric material is then contacted with a solvent to cause expansion and crazing of at least some of the non-crosslinked regions to form a structured polymeric material containing pores.