An underwater granulation system has a water box, a perforated plate with multiple through-openings for feeding a polymer melt into the water box, and a cutting plate support which is arranged in the water box so as to be driven in rotation about an axis of rotation (X) in a cutting direction. The cutting plate support has multiple cutting plates which face the perforated plate and are adapted to form granules by shearing particles from the polymer melt entering through the perforated plate. The water box is connected to a water supply for heat evacuation and for evacuating the separated particles from the water box. The water box also has a hollow cylindrical portion relative to the axis of rotation (X), in which multiple water inlets distributed over the circumference and multiple water outlets distributed over the circumference are arranged.

Polymer foams based on polyetherimides (PEI) or blends of polyetherimides and polyether ether ketone (PEEK) meet the legal requirements demanded by the aviation industry for aircraft interiors and for aircraft exteriors too.

A method for drying polyolefin-containing particles includes a drying step of supplying polyolefin-containing particles to a drying container, supplying a drying gas to the drying container, and drying the polyolefin-containing particles in the drying container. In the drying step, a numerical value determined by the following formula (a) is 441 or more and 600 or less.

38.0×[η]CXIS [dL/g]−0.500×CXIS content [% by mass]+1.20×particle temperature during drying [K]+3.29×drying time [hr]  Formula (a):

A powder for solid freeform fabrication includes a first resin particle and a second resin particle, wherein MFR2 is greater than MFR1 and a ratio of MFR2 to MFR1 is from 2 to 5, where MFR1 represents a melt mass-flow rate (MFR) of the first resin particle and MFR2 represents a melt mass-flow rate of the second resin particle.

A powder for solid freeform fabrication includes a first resin particle and a second resin particle, wherein MFR2 is greater than MFR1 and a ratio of MFR2 to MFR1 is from 2 to 5, where MFR1 represents a melt mass-flow rate (MFR) of the first resin particle and MFR2 represents a melt mass-flow rate of the second resin particle.

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.

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.

The present invention aims to provide a method for improving the fluidity of a crystal nucleating agent for polyolefin resins without impairing other properties, and a polyolefin resin composition containing the crystal nucleating agent with improved fluidity and having excellent properties including transparency, and a molded article thereof. Adjustment to specific characteristics can improve the fluidity of a crystal nucleating agent for polyolefin resins, and the use of such a crystal nucleating agent having specific characteristics remarkably improves the workability during molding processing and provides a polyolefin resin composition excellent in properties such as transparency, and a molded article thereof.

A cellulose-fiber-dispersing polyolefin resin composite material, containing a polyolefin resin containing a polypropylene resin, and a cellulose fiber dispersed in the polyolefin resin, in which a proportion of the cellulose fiber is 1 mass part or more and 70 mass parts or less in a total content of 100 mass parts of the polyolefin resin and the cellulose fiber, and the water absorption ratio satisfies the following Formula: (Water absorption ratio [%])<(Cellulose effective mass ratio [%]).sup.2×0.01; a pellet and a formed body using this composite material; and a production method for this composite material.

A cellulose-fiber-dispersing polyolefin resin composite material, containing a polyolefin resin containing a polypropylene resin, and a cellulose fiber dispersed in the polyolefin resin, in which a proportion of the cellulose fiber is 1 mass part or more and 70 mass parts or less in a total content of 100 mass parts of the polyolefin resin and the cellulose fiber, and the water absorption ratio satisfies the following Formula: (Water absorption ratio [%])<(Cellulose effective mass ratio [%]).sup.2×0.01; a pellet and a formed body using this composite material; and a production method for this composite material.