A process for injection molded microcellular foaming various flexible foam compositions from biodegradable and industrially compostable bio-derived thermoplastic resins for use in, for example, footwear components, seating components, protective gear components, and watersport accessories wherein a process of manufacturing includes the steps of: producing a suitable thermoplastic biopolymer or biopolymer blend; injection molding the thermoplastic biopolymer or biopolymer blend into a suitable mold shape with inert nitrogen gas; controlling the polymer melt, pressure, temperature, and time such that a desirable flexible foam is formed; and utilizing gas counterpressure in the injection molding process to ensure the optimal foam structure with the least amount of cosmetic defects and little to no plastic skin on the outside of the foamed structure.

This document discloses a process for manufacturing recyclable injection molded microcellular foams for use in, footwear components, seating components, protective gear components, and watersport accessories. The process includes the steps of providing a thermoplastic polymer which comprises at least one monomer derived from depolymerized post-consumer plastic, inserting a fluid into a barrel of a molding apparatus. The fluid is introduced under temperature and pressure conditions to produce a super critical fluid. The process further includes mixing the thermoplastic polymer and super critical fluid so as to create a single phase solution, and injecting the single phase solution into a mold of an injection molding machine under gas counter pressure. The process further includes foaming the single phase solution by controlling the head and temperature conditions within the mold.

Described herein is a liquid injector for a barrel extruder as well as methods and processes of manufacturing irradiation crosslinked polypropylene foam. In some embodiments, this includes a liquid injection barrel element that is incorporated in an extruder barrel that includes at least one injection port, a temperature sensor well, and cooling channels.

The invention provides a valve disposed in a fluid supply path to control opening or closing of the supply path, configured to comprise, as components of the supply path, an inflow channel, a second channel, a first channel, and an outflow channel that are in communication with each other in sequence, in such a manner that fluid from a supply source entering the inflow channel passes through the second channel and the first channel in sequence and then flows out through the outflow channel. The valve further comprises a first valve piece and a second valve piece disposed movably in the first channel and the second channel respectively. Blocking or unblocking of the communication between the first channel and the outflow channel is controlled by movement of the first valve piece in the first channel, while blocking or unblocking of the communication between the inflow channel and the first channel via the second channel is controlled by movement of the second valve in the second channel. In this way, the valve enables opening or closing of the supply path through dual control by the first valve piece and the second valve piece.

A molding method includes providing a molding device, wherein the molding device includes a first mold and a second mold corresponding to the first mold; moving the first mold towards the second mold to form a first mold cavity; supplying a gas to the first mold cavity; injecting a material into the first mold cavity; and moving the first mold away from the second mold to form a second mold cavity and discharge at least a portion of the gas out of the molding device, wherein a first volume of the first mold cavity is substantially less than a second volume of the second mold cavity.

A method for producing low density polyester foam utilizing low I.V. polyester feedstock includes providing a low intrinsic viscosity raw material. The low intrinsic viscosity raw material includes between 25% to 100% of a post consumer polyester and has an intrinsic viscosity of less than 0.8 dl/g. The intrinsic viscosity of the low intrinsic viscosity raw material is increased via a de-condensation reaction configured to support foaming. The intrinsic viscosity of the low intrinsic viscosity raw material is increased to 1.1 dl/g or greater. A starting formulation is created including the low intrinsic viscosity raw material with the increased intrinsic viscosity. The starting formulation is foamed to create the polyester foam. Wherein, the polyester foam produced has a specific gravity of less than 0.65 g/cc.

Molded polymer foam articles are described as having a novel a foam structure. The polymer foam articles include a continuous polymer matrix defining a plurality of pneumatoceles therein which is present throughout the entirety of the article, including in the surface region extending 500 microns beneath the surface of the article. The surface region is further characterized as having compressed pneumatoceles. The novel foam structure is achieved even when molding polymer foam articles comprising a thickness of more than 2 cm, a volume of more than 1000 cm.sup.3; or both a volume of more than 1000 cm.sup.3 and a thickness of more than 2 cm. Methods of making the molded polymer foam articles are also described.

The present disclosure relates to a screw of an injection molding machine in which a heating cylinder is formed with a first compression section, a starvation section, and a second compression section, and in which an inert gas is to be introduced into the starvation section. At a portion of the screw corresponding to the first compression section, a barrier flight as a double flight including a combination of a main flight and a sub-flight having a lead angle larger than that of the main flight is formed, and a dam flight having a predetermined-width ring shape is formed, downstream of, i.e., in front of the barrier flight. A seal structure to prevent backflow of the resin may be provided between the dam flight and the starvation section.

The invention relates to a process for producing a foam molded part, wherein a foamable material S comprising a thermoplastic polymer matrix M and at least one foaming agent F is foamed by foam injection molding. The polymer matrix M is preferably based on at least one thermoplastic styrene copolymer, such as ABS and ASA, and wherein the at least one foaming agent F is selected from chemical foaming agents, releasing carbon dioxide, and physical foaming agents, being carbon dioxide or nitrogen.

Molded polymer foam articles are described as having a novel a foam structure. The polymer foam articles include a continuous polymer matrix defining a plurality of pneumatoceles therein which is present throughout the entirety of the article, including in the surface region extending 500 microns beneath the surface of the article. The surface region is further characterized as having compressed pneumatoceles. The novel foam structure is achieved even when molding polymer foam articles comprising a thickness of more than 2 cm, a volume of more than 1000 cm.sup.3; or both a volume of more than 1000 cm.sup.3 and a thickness of more than 2 cm. Methods of making the molded polymer foam articles are also described.