A method for reducing fluctuations over time in discharge of a plastics composition when extruding plastics products, including melting plastics material in an extruder and supplying the plastics material to an extrusion die by way of one or more extruder screws arranged in the extruder, and conveying a plastics composition along an extrusion axis by rotating the one or more extruder screws as pressure builds up, wherein discharge of the plastics material at a transition region from the extruder to the extrusion die or in the extrusion die is kept constant by changing a rotational speed of the one or more extruder screws, and wherein changing the rotational speed is carried out within one revolution of the one or more extruder screws.

Improvements in the extrusion of thermohardenable materials are achieved by cooling the material in the initial zone of the extruder and reducing residence time by use of a prescribed length to diameter ratio and screw speed, particularly useful for intermittent application during robotically controlled mass production.

The invention relates to a process for devulcanizing a vulcanized rubber mixture, comprising the following steps: A) providing or producing a vulcanized rubber mixture, B) comminuting the vulcanized rubber mixture into a granulate of vulcanized rubber particles, C) extruding the vulcanized rubber particles produced in step B) in a twin-screw extruder to form a devulcanized rubber mixture, wherein, during the extruding in step C) at least one regeneration reagent is added to the extruded rubber particles, wherein the regeneration reagent comprises at least one silane, at least one plasticizer, at least one aging stabilizer or mixtures thereof. The invention also comprises an apparatus for performing the method and the uses of the apparatus, and a rubber mixture and also a pneumatic vehicle tyre or a technical rubber article comprising a component composed of the rubber mixture.

The present invention relates to a processing technology for manufacturing seepage irrigation pipe with alternating effluent sections and non-effluent sections, and in particular, to the field of underground seepage irrigation in agriculture and forestry. The processing technology combines the production unit for water-effluent pipes with the production unit for non-effluent pipes, and produces the seepage irrigation pipeline by adjusting the raw material ratios, controlling the spindle speed, spindle acceleration time, and spindle deceleration time of the two pipeline production units, to generate a seepage irrigation pipe with alternating effluent sections and non-effluent sections. The lengths of the effluent sections and non-effluent sections can be adjusted, the pipe wall thickness can also be adjusted by adjusting the inner and outer diameter of the internal mold of the pipe forming unit, a seepage irrigation pipe with alternating effluent sections and non-effluent sections is environment-friendly, efficient, water-saving, and useful for underground irrigation.

Disclosed is a flame-retardant HIPS material and a preparation method thereof, comprising the following components: 90 parts to 67 parts of a HIPS resin; 8 parts to 15 parts of a brominated flame retardant; and 3 parts to 7 parts of an auxiliary flame retardant; wherein the auxiliary flame retardant is a 1,3,5-triazine compound. In the present invention, a synergistic compounding of the brominated flame retardant and the auxiliary flame retardant effectively reduces an amount of the brominated flame retardant, and a stable UL 94 (1.5 mm) V-0 flame-retardant class can be achieved. Compared with the existing brominated flame-retardant HIPS, the present invention has a low halogen content, low gas, and high cost performance ratio, which avoids excessive acid gas from forming air lines on the surface of parts, has a good appearance.

The present invention discloses a method for preparing high-melt-strength polylactide resin by two-step reaction, which comprises the following steps: mixing polylactide resin and GMA to obtain a premix; mixing multifunctional reactive monomer, a peroxide initiator and organic solvent to obtain a monomer mixture; and adding the premix and the monomer mixture into a screw extruder in sections, after melting, blending, extruding, cooling, pelletizing and drying to obtain a high melt strength polylactide resin. The method of the present invention has a simple production process, can be adapted to large-scale industrial production, the graft modification reaction is rapid and controllable, and the obtained product is safe without residue and high in purity. The high-melt-strength polylactide resin has a low melt flow index, high complex viscosity and storage modulus, and is a green polymer material with wide application prospects.

Provided is a three-dimensional modeling material used for a fused deposition modeling three-dimensional printer. The three-dimensional modeling material has a multilayer structure and contains, in respective different layers, a thermoplastic resin (A) having a shear storage elastic modulus (G′) of 1.00×10.sup.7 Pa or less as measured at 100° C. and 1 Hz and a thermoplastic resin (B) having a shear storage elastic modulus (G′) of more than 1.00×10.sup.7 Pa as measured at 100° C. and 1 Hz.

The present disclosure relates to a thermoplastic resin composition and a molded article including the same. The thermoplastic resin composition includes 10 to 70% by weight of a graft copolymer (A) including an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A-1) containing acrylate rubber having an average particle diameter of 50 to 150 nm and an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A-2) containing acrylate rubber having an average particle diameter of 300 to 600 nm; and 30 to 90% by weight of a non-grafted copolymer (B) including a high molecular weight aromatic vinyl compound-vinyl cyanide compound copolymer (B-1) having a weight average molecular weight of 160,000 to 200,000 g/mol and a low molecular weight aromatic vinyl compound-vinyl cyanide compound copolymer (B-2) having a weight average molecular weight of 80,000 g/mol or more and less than 160,000 g/mol.

Provided is a three-dimensional modeling material used for a fused deposition modeling three-dimensional printer. The three-dimensional modeling material has a multilayer structure and contains, in respective different layers, a thermoplastic resin (A) having a shear storage elastic modulus (G′) of 1.00×10.sup.7 Pa or less as measured at 100° C. and 1 Hz and a thermoplastic resin (B) having a shear storage elastic modulus (G′) of more than 1.00×10.sup.7 Pa as measured at 100° C. and 1 Hz.

Calibration method for machines for the production of segmented extruded products comprising the steps of: activating an extrusion process according to a plurality of operating parameters suitable for producing a segmented extruded product having at least one segmentation portion (6); injecting a marker at the segmentation portion (6) during its extrusion; detecting a plurality of characterizing parameters of the marker and/or of the segmentation portion (6), by selecting at least one of spatial distribution of the segmentation portion (6) and axial and/or radial position of the segmentation portion (6); selecting at least one operating parameter according to at least one of the detected characterizing parameters, so as to modify spatial distributions and/or axial and/or radial positions of the segmentation portion (6).