A system for curing a composite part, includes a mandrel configured to receive and support the uncured composite part; a plurality of expandable pellets disposed on the uncured composite part; and a mold configured to hold the mandrel, the uncured composite part, and the plurality of expandable pellets, wherein the plurality of expandable pellets are configured to expand and apply a positive pressure to the uncured composite part according to a change in condition or triggering event, and wherein each of the plurality of expandable pellets includes a blowing agent, a polymer matrix configured to hold the blowing agent, and a flexible skin configured to encapsulate the polymer matrix and the blowing agent, wherein the flexible skin is at least partially permeable with respect to the blowing agent or a gas released by the blowing agent.

An improved process for fabricating expanded thermoplastic polymers (eTP) starting from non-expanded TP is disclosed whereby said process has improved thermal control, uses preferably environmentally friendly foaming gasses, avoids anisotropy and sticking of the eTP during the processing and minimises the duration of the charging step.

Composite particles are provided including a chemical blowing agent particle encapsulated within a shell including an uncrosslinked thermoplastic material. The uncrosslinked thermoplastic material exhibits at least a certain minimum complex viscosity at a decomposition temperature of the chemical blowing agent particle. Also described are compositions and foam compositions containing the composite particles. Further, articles are provided including the foam compositions, such as a sheet, tape, or hearing protection article. Methods of making and using the foam compositions are additionally described herein.

Methods of making a foamed article include: (a) milling a block or sheet of thermoplastic polymer to form a precursor; (b) crosslinking the thermoplastic polymer; (c) heating the precursor to a first temperature to soften the thermoplastic polymer; (d) infusing the thermoplastic polymer with at least one inert gas at a first pressure that is sufficient to cause the at least one inert gas to permeate into the softened thermoplastic polymer; and (e) while the thermoplastic polymer is softened, reducing the pressure to a second pressure below the first pressure to at least partially foam the precursor into a foamed article, wherein the foamed article is substantially the same shape as the precursor.

The present invention relates to thermoplastic olefin elastomer expanded beads, having an average aspect ratio of 1.10 or less and an average circularity of 0.985 or more. The thermoplastic olefin elastomer expanded beads preferably have a crystal structure such that a melting peak inherent in the thermoplastic olefin elastomer (inherent peak) and one or more melting peaks on a higher temperature side than the inherent peak (high temperature peaks) appear on a DSC curve obtained when heating the expanded beads from 23° C. to 200° C. at a heating rate of 10° C./min.

A system for curing a composite part, includes a mandrel configured to receive and support the uncured composite part; a plurality of expandable pellets disposed on the uncured composite part; and a mold configured to hold the mandrel, the uncured composite part, and the plurality of expandable pellets, wherein the plurality of expandable pellets are configured to expand and apply a positive pressure to the uncured composite part according to a change in condition or triggering event, and wherein each of the plurality of expandable pellets includes a blowing agent, a polymer matrix configured to hold the blowing agent, and a flexible skin configured to encapsulate the polymer matrix and the blowing agent, wherein the flexible skin is at least partially permeable with respect to the blowing agent or a gas released by the blowing agent.

The present invention provides a polymer composition for manufacturing a foam, the polymer composition comprising a vinyl aromatic based copolymer and a processing aid, wherein the amount of the processing aid in the total weight of the polymer composition is equal to or more than 5 wt % and equal to or less than 75 wt %; and the polymer composition does not comprise ethylene-vinyl acetate copolymer, ethylene-butyl acrylate copolymer, ethylene-α-olefin copolymer, homopolymer and copolymer of polyethylene, homopolymer and copolymer of polypropylene, homopolymer and copolymer of polybutene and olefin-based ionic polymer. The present invention also provides the foam and the method for forming the same.

A thermoplastic polyurethane (TPU) foam product with high flatness, and a preparation method and a use thereof are provided. The TPU foam product is prepared by processing aliphatic thermoplastic polyurethane (ATPU) beads with a melting range of 20° C. to 50° C. and a melting point of 90° C. to 160° C. by a physical gas foaming process to obtain foamed ATPU beads and heating the foamed ATPU beads with a heat source to make the foamed ATPU beads fused. The TPU foam product with high flatness has a density of 0.08 g/cm.sup.3 to 0.8 g/cm.sup.3 and a flatness value of less than 2 mm, and the flatness value is determined by a fixed-length ruler. The TPU foam product not only has high flatness such that diversified designs are allowed for a surface of the product, but also has high resilience.

Ultra-stable aqueous foam comprises hydrophobic silica particles residing within bubbles in an aqueous solution of a hydrophilic polymer, a protein, or aqueous dispersible colloidal particles. The combination of the hydrophobic and hydrophilic components stabilizes the foam interfaces to result in long term stability of the foam. The foams can be crosslinked to stable monolithic foams and used for structural foams, coatings, and thermal insulating for construction.

Disclosed, among other things, are ways to manufacture reduced density thermoplastics using rapid solid-state foaming and machines useful for the saturation of plastic. In one embodiment, a foaming process may involve saturating a semi-crystalline polymer such as Polylactic Acid (PLA) with high levels of gas, and then heating, which may produce a reduced density plastic having high levels of crystallinity. In another embodiment, a foaming process may produce layered structures in reduced density plastics with or without integral skins. In another embodiment, a foaming process may produce deep draw structures in reduced density plastics with or without integral skins. In yet another embodiment, a foaming process may utilize additives, blends, or fillers, for example. In yet another embodiment, a foaming process may involve saturating a semi-crystalline polymer such as Polylactic Acid (PLA) with high levels of gas, and then heating, which may produce a reduced density plastic having high levels of crystallinity.