A screw extruder for extruding a kneaded material includes a screw and a casing housing the screw and having a material supply port on an upstream side in an extrusion direction of the kneaded material and a tip-side opening on a downstream side in the extrusion direction. A pressure sensor for measuring a pressure inside the casing is provided between a downstream end of the supply port and the tip-side opening of the casing. A rotational speed of the screw is controlled depending on the pressure measured by the pressure sensor.

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.

A process and associated system for creating color effects in extrudable material, such as plastic and metal for example, are presented. Flows of first and second viscous materials of respective colors are provided and then combined in a predetermined pattern to form a stream of combined viscous material. In a first aspect, the flow rate of the first viscous material is caused to vary over time in order to vary an amount of the first viscous material in the stream. In a second aspect, which may be used alone or in combination with the first aspect, the first and second viscous materials have distinct viscosities to reduce an amount of color blending between the first color and the second color in the stream of combined viscous material. A static mixer may then be used to apply a predetermined dividing, overturning and combining motion to the stream of combined viscous material to partially mix the first viscous material and the second viscous material, such that upon exiting the static mixer, the first material of the first color and the second material of the second color form a color pattern in the stream of combined viscous material. Sheets of extrudable material may be created using such process and used in the manufacturing of many different products including for example kayaks and stand-up paddle boards.

A screw extruder for extruding a kneaded material, includes: a screw; and a casing housing the screw and having a material supply port on an upstream side. The screw has a shaft portion and a helical flight portion provided on an outer peripheral surface of the shaft portion. Regarding a clearance between a top portion of the flight portion and an inner wall surface of the casing, the clearance at a downstream side end of the flight portion is larger than the clearance at a downstream side end of the supply port. No area where the clearance decreases from the upstream side toward the downstream side is present between the downstream side end of the supply port and the downstream side end of the flight portion.

A squeezing roller granulator that has a squeezing roller pair composed of a toothed pressure roller and a toothed squeezing roller. The teeth of the pressure roller and the squeezing roller have tooth flanks that are situated between a tooth root region and a tooth tip region. The tooth root region has an outer diameter that is smaller than the outer diameter of the tooth tip region, and the tooth tip region of at least one of the rollers of the squeezing roller pair has three squeezing zones including a middle squeezing zone, which define different distances between the tooth tip regions with a minimum distance in the region of the middle squeezing zone, and the contour of the tooth flanks and the tooth root region of the rollers of the squeezing roller pair defines a maximum cross-section of granulate cushions to be formed.

A thermoplastic starch (TPS)/polylactic acid (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blend modified biodegradable resin is prepared by using a chain extender, and is prepared from the following raw materials: 20-30 parts by weight of TPS; 20-30 parts by weight of PLA; 40-60 parts by weight of PBAT; and 0.5-0.9 parts by weight of a chain extender KL-E. The preparation method is a two-step method: blending the TPS with the PBAT in a twin screw for granulating; mixing TPS/PBAT mixed granules with PLA granules, and dissolving the chain extender KL-E into an ethyl acetate solution. The chain extender KL-E can be uniformly distributed in PLA and TPS/PBAT mixed granules by using a spraying method, and the remaining short-chain molecules and terminal carboxyl molecules in the mixed granules can be changed into long-chain molecules.

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 relates to a low-gloss heat-resistant ABS resin composition and its preparation method. The low-gloss heat-resistant ABS resin composition includes following components by weight: 100 parts of acrylonitrile-butadiene-styrene (ABS) resin, 5-30 parts of heat-resistant agent, 1-5 parts of matte masterbatch D, 0.2-1.0 parts of light stabilizer, and 0.5-2.0 parts of other additives. The preparation method includes steps of: stirring and fully mixing the above-mentioned raw materials in a high-speed mixer, and then feeding the raw materials into a twin-screw extruder through a metering device; melting and compounding the materials under the conveying, shearing and mixing of the screws, and then extruding, pulling, cooling and granulating, and finally obtaining the low-gloss heat-resistant ABS resin composition. The resin composition provided by the present invention not only has excellent mechanical properties, but also has an ultra-low gloss; therefore, it is very suitable for use in the field of automotive interior parts.

A nozzle, a tundish arrangement used for the production of granulated material, and a method and apparatus for the production of a granulated material with an improved size distribution are provided. The grain size and grain size distribution is controlled by a nozzle having a specific design. The nozzle comprises an upper inlet opening, sidewalls forming a channel, a bottom and at least one outlet opening or at least one row of outlet openings at the lower end of the channel. The outlet opening(s) in the channel have a size of at least 5 mm in the smallest dimension. A cross sectional area of the channel at the inlet A.sub.C is at least 3 times bigger than the total area of the outlet openings A.sub.T.

An object of the present invention is to provide a method for producing water absorbent resin powder in which permeability potential (SFC) is improved while a water absorbing rate (FSR) is being kept. The method is a method for producing water absorbent polyacrylic acid (salt) resin powder including the steps of: (i) polymerizing an acrylic acid (salt) monomer aqueous solution; (ii) during or after the step of (i), performing gel grinding of a hydrogel crosslinked polymer obtained by the polymerization, wherein the hydrogel crosslinked polymer has resin solid content of 10 wt % to 80 wt %, and the gel grinding is carried out with gel grinding energy (GGE) of 18 [J/g] to 60 [J/g]; (iii) drying a particulate hydrogel crosslinked polymer obtained by the gel grinding, wherein the drying is performed at 150 C. to 250 C.; and (iv) carrying out a surface treatment to the particulate hydrogel crosslinked polymer thus dried.