A method for producing a foam-molded product uses a producing apparatus including a plasticizing cylinder. The plasticizing cylinder has a plasticization zone, a starvation zone, and an introducing port which is formed in the plasticizing cylinder and via which a physical foaming agent is introduced into the starvation zone. The method includes: plasticizing and melting a thermoplastic resin into a molten resin in the plasticization zone; introducing a pressurized fluid containing the physical foaming agent having a fixed pressure into the starvation zone; allowing the molten resin to be in the starved state in the starvation zone; bringing the molten resin in the starved state into contact with the pressurized fluid having the fixed pressure in the starvation zone; and molding the molten resin into the foam-molded product. At least one pressure boosting part is provided in the starvation zone.

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.

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.

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.

An apparatus for producing a foam-molded product, including a plasticizing cylinder which has a plasticization zone for plasticizing and melting a thermoplastic resin into a molten resin and a starvation zone for allowing the molten resin to be in a starved state and which is formed with an introducing port for introducing a physical foaming agent into the starvation zone; and a physical foaming agent supply mechanism which supplies the physical foaming agent to the plasticizing cylinder via the introducing port, wherein the introducing port is open at all times, and the physical foaming agent having a fixed pressure is continuously introduced into the starvation zone from the physical foaming agent supply mechanism via the introducing port during the producing of the foam-molded product.

Molded polymer foam articles are described as having a novel 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. The surface region is further characterized as having compressed pneumatoceles. The novel foam structure is achieved even when molding polymer foam articles comprising a shape and volume wherein a sphere having a diameter between 2 cm and 1000 cm would fit within the article in at least one location without protruding from a surface of the article, and the article further has a total volume of more than 1000 cm.sup.3. Methods of making a stabilized molten polymer foam, and of making a molded polymer foam article using the stabilized molten polymer foam are also described.

Molded polymer foam articles are described as having a novel 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. The surface region is further characterized as having compressed pneumatoceles. The novel foam structure is achieved even when molding polymer foam articles comprising a shape and volume wherein a sphere having a diameter between 2 cm and 1000 cm would fit within the article in at least one location without protruding from a surface of the article, and the article further has a total volume of more than 1000 cm.sup.3. Methods of making a stabilized molten polymer foam, and of making a molded polymer foam article using the stabilized molten polymer foam are also described.

A producing method for producing a foam-molded product by using a plasticizing cylinder having, from an upstream side in the following order: a plasticization zone, a flow rate adjusting zone and a starvation zone, the producing method includes: plasticizing and melting a thermoplastic resin into a molten resin in the plasticization zone; adjusting a flow rate of the molten resin in the flow rate adjusting zone; allowing the molten resin to be in a starved state in the starvation zone; introducing a pressurized fluid containing the physical foaming agent having a fixed pressure into the starvation zone so as to retain the starvation zone at the fixed pressure; bringing the molten resin in the starved state in contact with the pressurized fluid in the starvation zone in a state in which the starvation zone is retained at the fixed pressure; and molding the molten resin into the foam-molded product.

The method for manufacturing a foamed product uses a manufacturing apparatus having a plasticizing cylinder in which an introduction port for introducing a physical blowing agent into a starvation zone is formed, and an introduction speed adjustment container connected to the introduction port, wherein the manufacturing method comprises: turning a thermoplastic resin into a molten resin; introducing the physical blowing agent at a predetermined pressure into the starvation zone through the introduction speed adjustment container and maintaining the starvation zone at a predetermined pressure; setting the molten resin to a starved state; bringing the molten resin in the starved state and the pressurized fluid into contact with each other; and molding the molten resin into a foamed product. The maximum value of the inner diameter of the introduction speed adjustment container is larger than the inner diameter of the introduction port.

The interior of a heating cylinder (2) is divided into a first stage (5) and a second stage (7) due to the shape of a screw (3). A first compression zone in which a resin is compressed is formed in the first stage (5). A starvation zone (7a) in which an inert gas is injected and a second compression zone in which the resin is compressed are formed in the second stage (7). A barrier flight (13) that is obtained by combining a main flight (14) and a sub-flight (15) having a greater lead angle than the main flight is provided to a section of the screw (3), said section corresponding to the first compression zone. A multiple flight is provided to another section of the screw (3), said section corresponding to the second stage (7).