A method and a device for introducing and/or adding non-dry-powder additive materials and/or coating materials with a liquid, solid, semi-solid, or paste-like consistency or in suspended or emulsified form, for example, peroxides, fats, waxes, IV improvers, polymers, or similar materials, to an existing lumpy or particulate material which is moved and mixed, and optionally warmed and reduced to small pieces in a receptacle and/or compressor, said material being in particular polymer particles and/or flakes, wood fibers, paper cuttings, or similar materials. According to the invention, the additive material is introduced below the level of the material and/or material particles already in the receptacle.

A twin-screw extruder is configured to produce rolls of plastic stretch film on a continuous basis, starting from the extrusion of granules of one or more polymers an using cast extrusion.

A single-screw extruder for changing a morphology of superabsorbent polymer gel. The single-screw extruder has an input aperture, a channel, a screw and an output aperture. The screw in the invention has a first pitch value of a pitch of the screw flights along the conveying zone of the channel and, following in conveying direction, has a second pitch value of the pitch of the screw flights along the conveying zone of the channel, where the second pitch value is smaller than the first pitch value.

A single-screw extruder for changing a morphology of superabsorbent polymer gel. The single-screw extruder has an input aperture, a channel, a screw and an output aperture. The screw in the invention has a first pitch value of a pitch of the screw flights along the conveying zone of the channel and, following in conveying direction, has a second pitch value of the pitch of the screw flights along the conveying zone of the channel, where the second pitch value is smaller than the first pitch value.

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.

An extruder is disclosed including: a barrel; and a screw provided with a helical groove; wherein the screw comprises a dewatering portion comprising a first portion, and a second portion at a location downstream from the first portion; wherein, at the dewatering portion, clearance between the groove and the barrel decreases as one proceeds downstream; and wherein clearance reduction ratio at the first portion is greater than clearance reduction ratio at the second portion.

An extruder is disclosed including: a barrel; and a screw provided with a helical groove; wherein the screw comprises a dewatering portion comprising a first portion, and a second portion at a location downstream from the first portion; wherein, at the dewatering portion, clearance between the groove and the barrel decreases as one proceeds downstream; and wherein clearance reduction ratio at the first portion is greater than clearance reduction ratio at the second portion.

A screw element (100) for an extrusion machine is provided. The screw element (100) includes a first section (200) and a second section. The first section (200 has a first core (212) with a plurality of facets (214) connected to each other along splines (216). The facets (214) and splines (216) extend longitudinally along the screw element (100). The facets (214) and splines (216) can be helically-shaped. The first core (212) increases in diameter in a continuous manner along the direction of flow of material. The first and second sections (200, 300) include one or more helically-shaped flights (218,219) wrapped around the longitudinal axis of the screw element (100).

A system for extrusion of material, for example chopped waste plastic, comprises a treatment device (101) for extruding the material and a feeder device (102) comprising a screw conveyor (103) for supplying the material to the treatment device. A screw element (104) of the screw conveyor has: a) a conical profile so that a diameter of the screw element decreases in a moving direction of the material and/or b) a thread-pitch decreasing in the moving direction of the material and/or c) an axial thickness of a screw thread crest increasing in the moving direction. The conical profile of the screw element and/or the thread-pitch decreasing in the moving direction and/or the axial thickness of the screw thread crest increasing in the moving direction improve the ability of the screw conveyor to compact the material and thereby to supply a sufficiently uniform material flow to the treatment device.

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.