In an injection foam molding method, a relationship between a flow front moving speed (cm/s) of a foamed resin material in an injection step of injecting the foamed resin material into a cavity and amount of gas generated per 1 g of a resin material (ml/g) is defined as follows: the amount of gas generated per 1 g of the resin material is 0.36 ml/g or more; and the flow front moving speed (cm/s) is 75×the amount of gas generated per 1 g of the resin material (ml/g)−35 or more and 12 cm/s or more.

A process of microcellular foam molding an article includes using a modifier to modify properties of amorphous PLA, pouring the modified amorphous PLA into a high pressure vessel, dissolving an SCF in the high pressure vessel to impregnate the modified amorphous PLA in the high pressure vessel which is configured to allow the SCF to effuse through, forming foamed pellets, conveying the foamed pellets to a mold in a second vessel filled with water or oil, heating the second vessel, and cooling the second vessel until a foamed article is finished in the mold.

A die for extrusion molding includes an extrusion port configured to extrude a plastic composition, and a plastic flow channel configured to cause the supplied plastic composition to flow to the extrusion port. The plastic flow channel includes a supply flow channel, and an extrusion flow channel. The supply flow channel is configured to be supplied with the plastic composition. The extrusion flow channel has an upstream end coupled to the supply flow channel, and downstream end having the extrusion port. In the extrusion flow channel, a flow channel cross-sectional area perpendicular to the flow direction of the plastic composition in the extrusion flow channel gradually changes to the extrusion port, and an inner wall surface of a flow channel has a protruding surface protruding toward an inside of the flow channel in a cross section including an extrusion central axis and parallel to the extrusion central axis.

The disclosure is directed to a solid part, and a device and process of making the solid part. The process includes introducing a glass fiber filled polymeric material to a hopper of an injection molding machine, where the glass fibers have a pre-molding length, melting the glass fiber filled polymeric material to form a melt in a plasticizing unit, pressurizing the plasticizing unit of the injection molding machine with a blowing agent, dissolving the blowing agent into the melt, injecting the melt into a mold cavity up to 100% of volume, and forming the solid part.

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.

Provided is a method of shaping a composite blade made of a composite material by curing prepreg in which reinforcing fibers are impregnated with resin. A foaming agent disposed in an internal space of the composite blade contains a plurality of foaming bodies and foaming agent resin. The foaming bodies foam by being heated. The foaming agent resin cures by being heated. The foaming bodies include low-temperature side foaming bodies and high-temperature side foaming bodies. The low-temperature side foaming bodies foam in a low temperature range during a curing step. The high-temperature side foaming bodies foam in a high temperature range corresponding to temperatures higher than the low temperature range during the curing step.

A mixing method provided by the invention comprises steps of melting a solid-state polymer raw material into a flowable molten raw material fluid to flow into a mixing space at a first volume flow rate, when the raw material fluid entering the mixing space, introducing a foaming agent in a fluid form into the mixing space simultaneously or at a different time, mixing the foaming agent with the molten raw material fluid into a mixture in the mixing space, circulating the mixture in the mixing space at a second volume flow rate, and causing the second volume flow rate greater than the first volume flow rate.

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.

The invention relates to a process for manufacturing a copolymer foam containing polyamide blocks and polyether blocks, comprising the following steps: mixing the copolymer melt with a blowing agent, said copolymer having a coefficient of thermal diffusivity a and a crystallization temperature T.sub.c; providing a mold of thickness h at a temperature T.sub.m; injecting the mixture of the copolymer and of the blowing agent at a temperature T.sub.p, into the closed mold; foaming the mixture by opening the mold;
in which the maintenance time between the injection of the mixture of the copolymer and of the blowing agent into the closed mold and the opening of the mold is within the range extending from (t.sub.opt−25%) to (t.sub.opt+25%),
t.sub.opt being expressed in seconds and obtained by equation (I):

[00001]$\begin{array}{cc}{t}_{\mathrm{opt}}=-\frac{1}{{\pi }^2}\frac{h^2}{a}\ln \left(\frac{\pi }{4}\frac{T_m-T_c}{T_m-T_p}\right),& \left(I\right)\end{array}$

in which a is expressed in m.sup.2/s, h is expressed in m and T.sub.m, T.sub.c and T.sub.p are expressed in ° C.

A process for producing foamed thermoplastic polyurethane particles comprises the steps of a) melting a thermoplastic polyurethane in a first extruder (E1), b) injecting a gaseous blowing agent in a second extruder (E2), c) impregnating the gaseous blowing agent homogeneously into the thermoplastic polyurethane melt in a third extruder (E3), d) extruding the impregnated thermoplastic polyurethane melt through a die plate and granulating the melt in an underwater granulation device under temperature and pressure conditions to form foamed thermoplastic polyurethane particles.