The present invention relates to a worm shaft for a mixing and kneading machine in particular for continuous preparation processes, comprising a shaft rod, on the circumferential surface of which blade elements are arranged which are spaced apart from one another and which extend outward from the circumferential surface of the shaft rod, wherein the blade elements are arranged on the shaft rod, at least in one section extending in the axial direction of the worm shaft, in three rows extending in the axial direction of the worm shaft, wherein at least one of the blade elements of one of the rows is different from one of the blade elements of one of the other rows, and/or the rows of blade elements, viewed in cross-section of the shaft rod, are distributed irregularly over the circumference defined by the outer circumferential surface of the shaft rod.

With a mixing and kneading machine (100), wherein a worm shaft (12) moves in a housing (10) in a rotating manner and moves back and forth in a translatory movement, receptacles for kneading elements (12) are distributed non-uniformly. It is thereby possible to equip the receptacles with varying numbers of kneading elements. Quick adaptation is also thereby possible. In one embodiment, the number of kneading elements even varies over the extension direction of the mixing and kneading machine (100).

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.

An extruder screw for the plasticizing of at least one plastic material or a plastic material mixture, with a melting zone, a wave zone and a mixing zone arranged between the melting zone and the wave zone, wherein a conveying web extending in a helix-like manner along a screw longitudinal axis is formed in the melting zone and in the wave zone, wherein a conveying web of the melting zone terminates at an end of the melting zone facing the mixing zone, and a conveying web of the wave zone begins at an end facing the mixing zone. The application also relates to an extrusion device with this extruder screw, and a method for plasticizing at least one plastic material or a plastic material mixture.

A preparation method of a fruit and vegetable preservation film is used for preparing a three-layer co-extrusion film having a thickness ranging from 0.02 mm to 2.0 mm. A preservation master-batch composed of 5-20% of an inorganic nano-powder and 80-95% of a resin material is uniformly distributed in one layer of the co-extrusion film.

A method for manufacturing wet rubber masterbatch obtained from raw materials in the form of at least filler, dispersion solvent, and rubber latex solution, includes an operation in which the rubber latex solution is mixed and coagulated with a slurry solution containing the filler and the dispersion solvent to manufacture a filler-containing rubber coagulum; and a heating operation in which a single-screw extruder is used to carry out dewatering, drying, and plasticization of the filler-containing rubber coagulum in a single operation. The method satisfies conditions: 0.02C/(AB)0.15, where A indicates, for a portion of the screw which is located at the dewatering portion, the pitch volume (mm.sup.3), B indicates rotational speed (rpm) of the screw, and C indicates feed volume per minute (mm.sup.3/min) of the filler-containing rubber coagulum which is fed into the single-screw extruder.

To provide a rubber extruder capable of efficiently removing volatile components in unvulcanized rubber without decreasing productivity of the unvulcanized rubber. The rubber extruder 1 is for extruding the unvulcanized rubber (G) while kneading. It includes a barrel 2 having an input port 5 for introducing the unvulcanized rubber (G) and a discharge port 6 for discharging the unvulcanized rubber (G), a screw 3, which is arranged in the barrel 2, for extruding the unvulcanized rubber (G), and a vent 4 for sucking out air in the barrel 2. The screw 3 has a dam portion 7 which locally controls an extrusion amount of the unvulcanized rubber (G), a first screw portion 8 defined between the input port 5 and the dam portion 7, and a second screw portion 9 defined between the dam portion 7 and the discharge port 6. An effective screw length (L1) of the first screw portion 8 is 50% or more of a total effective screw length (L) of the screw 3.

A method in which a stream of dry cementitious powder from a dry powder feeder passes through a dry cementitious powder inlet conduit to feed a first feed section of a fiber-slurry mixer. An aqueous medium stream passes through at least one aqueous medium stream conduit to feed a first mixing section the fiber-slurry mixer. A stream of reinforcing fibers passes from a fiber feeder through a reinforcing fibers stream conduit to feed a second mixing section of the fiber-slurry mixer. The stream of dry cementitious powder, aqueous medium stream, and stream of reinforcing fibers combine in the fiber-slurry mixer to make a stream of fiber-cement mixture which discharges through a discharge conduit at a downstream end of the mixer.

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 for producing a foam-molded product by using a plasticizing cylinder, includes: plasticizing and melting the thermoplastic resin to provide the molten resin in a plasticization zone of the plasticizing cylinder; introducing a pressurized fluid containing the physical foaming agent at a fixed pressure into a starvation zone of the plasticizing cylinder to retain the starvation zone at the fixed pressure; allowing the molten resin to be in the starved state in the starvation zone; bringing the molten resin in contact with the pressurized fluid containing the physical foaming agent at 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.