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.

A screw-driven extrusion system includes a novel screw-drive extruder. The extruder includes a motor-driven screw. The screw moves solid pellets from a feed hopper into a section that is actively heated. The solid pellets fully liquefy as they pass through the heated section. A control system controls screw, heating, and optionally cooling, operations to selectively control flow of liquefied material from the extruder's tip. The dynamically-controlled can continuously adjust its feed speed and temperature to keep up with continuously changing demands of a larger control system involved in monitoring and running a corresponding 3-D printer in an additive manufacturing process. In contrast to wirefeed extrusion systems that rely on the rigidity of the material in wire-formed feedstock, this screw-driven extrusion system is well-suited to use of less-rigid thermoplastic elastomers for the manufacture of objects for use in soft robotics, medical and mold-making applications.

A screw-driven extrusion system includes a novel screw-drive extruder. The extruder includes a motor-driven screw. The screw moves solid pellets from a feed hopper into a section that is actively heated. The solid pellets fully liquefy as they pass through the heated section. A control system controls screw, heating, and optionally cooling, operations to selectively control flow of liquefied material from the extruder's tip. The dynamically-controlled can continuously adjust its feed speed and temperature to keep up with continuously changing demands of a larger control system involved in monitoring and running a corresponding 3-D printer in an additive manufacturing process. In contrast to wirefeed extrusion systems that rely on the rigidity of the material in wire-formed feedstock, this screw-driven extrusion system is well-suited to use of less-rigid thermoplastic elastomers for the manufacture of objects for use in soft robotics, medical and mold-making applications.

Method and device for the extrusion of thermomechanically deformable materials, as well as a compact screw extruder. The configuration of the material infeed in a screw extruder, has a significantly smaller length-diameter ratio than known solutions from the fields of injection moulding and additive manufacturing and a crushing tool, located in the funnel-shaped infeed region of the vertically arranged screw extruder which prevents the rotational movement of the material in the funnel, and also thereby forces movement in the conveying direction of the screw extruder in combination with the gradient of the screw flanks. In addition, a portion of the coarse material is crushed, whereby the bulk material density is increased in the region of the screw and less air must be pressed out of the material in the region of the plasticization and homogenization zone.

There is provided a method which includes: plasticizing and melting a thermoplastic resin to provide a molten resin in a plasticization zone of a plasticizing cylinder; allowing the molten resin to be in a starved state in a starvation zone of the plasticizing cylinder; introducing a pressurized fluid containing a physical foaming agent having a fixed pressure into the starvation zone to retain the starvation zone at the fixed pressure; bringing the molten resin in the starved state in contact with the pressurized fluid containing the physical foaming agent having the fixed pressure in the starvation zone in a state in which the starvation zone is retained at the fixed pressure; and molding the molten resin having been brought in contact with the pressurized fluid containing the physical foaming agent into the foam-molded product.

There is provided a method which includes: plasticizing and melting a thermoplastic resin to provide a molten resin in a plasticization zone of a plasticizing cylinder; allowing the molten resin to be in a starved state in a starvation zone of the plasticizing cylinder; introducing a pressurized fluid containing a physical foaming agent having a fixed pressure into the starvation zone to retain the starvation zone at the fixed pressure; bringing the molten resin in the starved state in contact with the pressurized fluid containing the physical foaming agent having the fixed pressure in the starvation zone in a state in which the starvation zone is retained at the fixed pressure; and molding the molten resin having been brought in contact with the pressurized fluid containing the physical foaming agent into the foam-molded product.

A method of recycling a mixed plastic waste comprising plastics having different melting temperatures includes conveying the mixed plastic waste through an extruder such that at least some of the higher melting point plastic is passes through the extruder without melting and is present in the extrudate as solid material.

A screw for a plasticating apparatus has one or more helical flights. A portion of the screw has a plurality of advancing grooves arranged in a noncontinuous helix cut in the screw. The advancing grooves are dimensioned to receive material therein as the material is conveyed through the barrel. The screw has a plurality of noncontinuous cross-cut grooves traversing one or more of the advancing grooves. The cross-cut grooves have a second helix angle greater than the first helix angle and less than ninety degrees; and/or one or more of the cross-cut grooves have a third helix angle of about ninety degrees.

A screw for a plasticating apparatus has one or more helical flights. A portion of the screw has a plurality of advancing grooves arranged in a noncontinuous helix cut in the screw. The advancing grooves are dimensioned to receive material therein as the material is conveyed through the barrel. The screw has a plurality of noncontinuous cross-cut grooves traversing one or more of the advancing grooves. The cross-cut grooves have a second helix angle greater than the first helix angle and less than ninety degrees; and/or one or more of the cross-cut grooves have a third helix angle of about ninety degrees.

Lower discharge temperatures and improved flow rates are obtained for the processing of meltable, solid crosslinkable compositions comprising a polymer, e.g., polyethylene, and a peroxide, in a single barrel extruder by equipping the extruder with an energy transfer (ET) screw that comprises: (1) an ET section with a distance averaged ET section depth of 8.0% to 10% of the extruder barrel internal diameter, and (2) a metering section with a metering section depth of 6.0% to 8% of the extruder barrel internal diameter.