The present invention relates to a method of producing a powder coating material containing a fluororesin and a non-fluororesin. The method of producing a powder coating material includes kneading a raw material containing the fluororesin and the non-fluororesin with a kneading extruder equipped with a screw having a kneading zone, wherein a ratio of a length L.sub.K of the kneading zone to an effective length L.sub.S of the screw (L.sub.K/L.sub.S100) is 21.0 to 50.0%.

A shearing part for a plasticising screw has at least one inlet channel and at least one outlet channel, which run helically around or parallel to the longitudinal axis (X) of the shearing part. The inlet channel is open upstream and closed downstream. The outlet channel is open downstream and closed upstream. The inlet outlet channels are arranged lying directly adjacent to one another and contiguous to one another, and are connected directly with one another fluidically, so that inflowing melt can flow over directly from the inlet channel into the outlet channel, wherein a flow direction transversely to longitudinal axis (X) of the shearing part is produced. The inlet channel has a depth (T) at which shearing action on the melt is substantially avoided. The outlet channel is configured as shearing surface, so that shearing action is present onto melt flowing through the outlet channel.

The present invention relates to a worm shaft for a mixing and kneading machine particularly for continual processing having a shaft bar, on the circumferential surface of which blade elements are arranged to be spaced apart from one another extending outwards from the circumferential surface of the shaft bar, wherein the blade elements are arranged on the circumferential surface of the shaft bar, at least in one section extending in the axial direction of the worm shaft, in two rows extending in the axial direction of the worm shaft.

Systems for molding products that include sheer sensitive materials are disclosed. The systems may include a barrel. A hopper may be in communication with the barrel. A screw may be disposed within the barrel. The screw may be designed to rotate and reciprocate within the barrel. The screw may include a metering section. A plurality of dome members may be coupled to the screw and disposed along the metering section.

Provided is a screw that is for use in an injection molding machine and that makes it possible to benefit from the kneading effect of a multi-start screw while minimizing the received friction resistance. The screw for an injection molding machine is provided with a first stage 20 on the upstream side and a second stage 30 on the downstream side. The screw for an injection molding machine is characterized in that: the first stage 20 is provided with a compression section 22 comprising a main scraper 25 and an auxiliary scraper 26 having a smaller outer diameter than the main scraper 25; and the second stage 30 is provided with a multi-start screw section 31, said multi-start screw section being provided on the upstream side and comprising a plurality of scrapers, and a fin kneading section 32 provided downstream from the multi-start screw section.

Apparatus and methods for extruding plastic materials are disclosed. An exemplary apparatus comprises: a feeding portion; a melting portion in communication with the feeding portion and configured to transmit heat into material received from the feeding portion; and an output die in communication with the melting portion to permit extrusion of the material. The melting portion comprises: a melting barrel having an inner surface defining a melting chamber in communication with the feeding portion; and a melting insert inside the melting chamber. The melting insert comprises an outer surface in contact with the inner surface of the melting barrel where the outer surface comprises one or more open-ended channels formed therein. In some embodiments, the feeding portion and the melting portion may be thermally insulated from each other and a propeller of the feeding portion may be disposed entirely outside of the melting portion.

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).

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.

An EVOH resin composition excellent in inorganic compound dispersibility and a method of producing an EVOH resin composition excellent in productivity and inorganic compound dispersibility are provided. The EVOH resin composition contains an EVOH resin (A) and an inorganic compound (B), and has a crystallinity of not lower than 36%. The EVOH resin composition is produced by: feeding an EVOH resin (A), an inorganic compound (B) and water (C) into a kneading apparatus including a screw-type side feeder (3); melt-kneading the resulting EVOH resin mixture while driving the screw-type side feeder (3); and expelling water vapor from the screw-type side feeder (3) to reduce the water content of the EVOH resin mixture to lower than 5 weight % while suppressing leakage of the EVOH resin kneaded body from the screw-type side feeder (3).