A method of preparing a polymer hollow particle, a low-specific gravity and monodispersed polymer hollow particle of various shapes prepared using the method, and a composite including the polymer hollow particle are provided. The method includes: a first step of providing, onto a substrate including a engraved pattern, at least one expandable particle comprising a foaming agent-containing expandable core and a thermoplastic polymer shell; a second step of removing an excess of the at least one expandable particle from a resulting product of the first step; a third step of expanding the at least one expandable particle in the engraved pattern of the substrate by thermally treating a resulting product of the second step; and a fourth step of separating, from the substrate, expanded hollow polymer particles which are a resulting product of the third step.

The present invention relates to a foamable composition used to prepare foamed thermoplastic polyurethane and a microwave molded body thereof. The foamable composition includes unfoamed thermoplastic polyurethane particles, a thickener or a bridging agent, and a foaming agent, wherein the unfoamed thermoplastic polyurethane particles have a viscosity of 1,000 poise to 9,000 poise measured at 170 C. according to JISK 7311 test method.

The invention relates to the co-use of a) a certain type of silica and b) a certain type of graphite, wherein the silica and the graphite are used in a weight ratio in a range of from 1:1 to 1:10, for decreasing the thermal conductivity of vinyl aromatic polymer foam.

Provided are resin foam particles that enable shaping of a sound absorbing member having excellent sound absorption performance through a resin foam shaped product. Also provided is a laminate that includes a resin foam shaped product as a base material and with which high sound absorption performance can be obtained even when the laminate is a thin material. The resin foam particles contain a resin and have a recessed external part. A ratio .sub.0/.sub.1 of density of the resin .sub.0 and true density .sub.1 of the resin foam particles is 2 to 20, and a ratio .sub.1/.sub.2 of true density .sub.1 of the resin foam particles and bulk density .sub.2 of the resin foam particles is 1.5 to 4.0.

Provided are composite particles in which reinforcing fibers adhere to the surface of thermoplastic resin expanded beads via a thermosetting resin being in an uncured state, a cured product of the composite particles, an in-mold molded article of the composite particles, a laminate of the composite particles and a reinforcing fiber sheet material, a composite of the composite particles, and a method for producing composite particles.

The invention refers to a method for producing expanded polymer pellets, which comprises the following steps: melting a polymer comprising a polyamide; adding at least one blowing agent; expanding the melt through at least one die for producing an expanded polymer; and pelletizing the expanded polymer. The invention further concerns polymer pellets produced with the method as well as their use, e.g. for the production of cushioning elements for sports apparel, such as for producing soles or parts of soles of sports shoes. A further aspect of the invention concerns a method for the manufacture of molded components, comprising loading pellets of an expanded polymer material into a mold, and connecting the pellets by providing heat energy, wherein the expanded polymer material of the pellets or beads comprises a chain extender. The molded components may be used in broad ranges of application.

A method for impregnating a polymeric granulate with a physical blowing agent is disclosed. The polymeric granulate can be a typical material such as a polycarbonate that is used in foam injection moulding processes. The physical blowing agent can be carbon dioxide which impregnates that polymeric granulate at a temperature range of 40 to 120 C. and a pressure range of 15 to 55 bar. Preferably, the polymeric granulate is heated in a range of 50 to 90 with a range of 60 to 80 preferred. A pressure range of 0 25 to 45 bar is preferred with a range of 30 to 40 bar more preferred.

Circuit and to a process for managing transients and process and product anomalies in a plant for production of granulated expandable polymers EPS or extruded polymers XPS, said circuit being placed e.g. in a granulation plant along which are positioned: a mixing device suitable for mixing additives and expanding agent within a stream of molten polymer; a granulator or an extrusion device positioned downstream of said mixing device; a deviation valve suitable for molten polymers placed along the line connecting said mixing device to said granulator or to said extrusion device upstream of said granulator or extruder, said deviation valve being provided with at least one inlet (A), a Stand-by position (A.fwdarw.C) and a Run position (A.fwdarw.B), said circuit further comprising a heating device downstream of said valve, a separation device downstream of said heating device suitable for physically separating the blowing agent from the polymer and any additives present therein, and a cooling device positioned between said separation device and said mixing device.

The invention relates to the co-use of a) a certain type of silica and b) a certain type of graphite, wherein the silica and the graphite are used in a weight ratio in a range of from 1:1 to 1:10, for decreasing the thermal conductivity of vinyl aromatic polymer foam.

Low-density thermoplastic expandable microspheres are disclosed. Various low-density structures, in particular, sandwich panels, based on foam prepared from the low-density microspheres, are also disclosed. Process of preparing low-density polymeric microspheres, per se, and the corresponding low-density structures, based on the microsphere foam, are also disclosed.