Provided is a water absorbent resin that is useful to sanitary materials such as a disposable diaper, a sanitary napkin, and a blood absorbent for medical use each having a higher liquid permeability and a higher water absorbing speed. Further provided is a water absorbent resin powder that is useful to sanitary materials such as a disposable diaper, a sanitary napkin, and a blood absorbent for medical use each having increased in absorbency of a liquid and in heat retaining property. A gel grinding device to be used to produce a water absorbent resin, includes: a screw; a feed opening; an extrusion opening; a porous plate; and a barrel, the barrel including a return preventing member provided on an inner surface thereof, and the return preventing member satisfying at least one of specific parameters.

A method for producing a rubber member according to the present invention includes the steps of: supplying a rubber composition to a cylinder provided in an extruder; extruding the rubber composition to a downstream side of the cylinder while kneading the rubber composition in an internal space of the cylinder that includes a plurality of protruding members protruding from an inner wall surface of the cylinder; compressing the rubber composition at least once in the step of extruding the rubber composition to the downstream side; discharging a gas generated from the compressed rubber composition to outside of the cylinder; discharging, through a discharge outlet of the cylinder, the rubber composition after the gas has been generated; and molding the rubber composition that has been discharged through the discharge outlet into a predetermined rubber member shape.

A single-screw extruder for changing a morphology of superabsorbent polymer gel. The single-screw extruder has an input aperture, a channel, a screw and an output aperture. The screw in the invention has a first pitch value of a pitch of the screw flights along the conveying zone of the channel and, following in conveying direction, has a second pitch value of the pitch of the screw flights along the conveying zone of the channel, where the second pitch value is smaller than the first pitch value.

A single-screw extruder for changing a morphology of a superabsorbent polymer, specifically a polymer gel. The single-screw extruder has an input aperture, a channel, a screw and an output aperture. The screw has a pitch value of a pitch of the screw flights along the conveying zone of the channel, where the channel has a mixing-element arrangement with at least one mixing element which protrudes into the channel of the single-screw extruder and which is configured for the mixing of the SAP polymer gel.

Provided is a water absorbent resin that is useful to sanitary materials such as a disposable diaper, a sanitary napkin, and a blood absorbent for medical use each having a higher liquid permeability and a higher water absorbing speed. Further provided is a water absorbent resin powder that is useful to sanitary materials such as a disposable diaper, a sanitary napkin, and a blood absorbent for medical use each having increased in absorbency of a liquid and in heat retaining property. A gel grinding device to be used to produce a water absorbent resin, includes: a screw; a feed opening; an extrusion opening; a porous plate; and a barrel, the barrel including a return preventing member provided on an inner surface thereof, and the return preventing member satisfying at least one of specific parameters.

Provided is a water absorbent resin that is useful to sanitary materials such as a disposable diaper, a sanitary napkin, and a blood absorbent for medical use each having a higher liquid permeability and a higher water absorbing speed. Further provided is a water absorbent resin powder that is useful to sanitary materials such as a disposable diaper, a sanitary napkin, and a blood absorbent for medical use each having increased in absorbency of a liquid and in heat retaining property. A gel grinding device to be used to produce a water absorbent resin, includes: a screw; a feed opening; an extrusion opening; a porous plate; and a barrel, the barrel including a return preventing member provided on an inner surface thereof, and the return preventing member satisfying at least one of specific parameters.

The disclosure relates to various measures for increasing the cooling effect on a planetary roller extruder section/module. Those measures include a choke being arranged at an outlet of the planetary roller extruder section or module, a distance between centerlines of adjacent planetary spindles being at least equal to an outer diameter of the planetary spindles, providing a pressurized melt supply, having a cooling section composed of several sections/modules, providing at least one section/module in which a flow, during melt supply is converse to the conveying direction of the extruder, and providing cooling tubes arranged within the central spindle.

Disclosed is a hydrogel shredding device. The hydrogel shredding device includes: a first barrel body in which a first transfer space for transferring a hydrogel is formed, and extending in a first direction; a first transfer unit installed in the first barrel body and transferring the hydrogel in the first transfer space; a second barrel body installed on a lateral side of the first barrel body, and in which a second transfer space connected to the first transfer space extends in a second direction traversing the first direction; a second transfer unit installed in the second barrel body and transferring the hydrogel in the second transfer space; a cutter member installed in the second barrel body and pulverizing the hydrogel transferred by the second transfer unit; and a porous plate for discharging the hydrogel particles pulverized by the cutter member to an outside of the second barrel body.

An Extruder for shaping a viscous material such as a blend of rubber is disclosed herein. The extruder includes a screw rotationally driven about an axis (XX) in a barrel and bearing one or more helical flights extending radially outwards from a central shaft of the screw, the extruder comprising a material homogenization zone (H) through which a screw portion comprising interrupted flight elements forming empty annular spaces extends axially, and a barrel portion delimiting the said homogenization zone bearing flight elements extending radially inwards into the said empty annular spaces. According to the disclosure, the barrel portion delimiting the homogenization zone is itself rotationally driven about the axis XX to form a rotary barrel.

A method and apparatus for thermolysing organic material. The method comprises steps of: A) feeding the material in a single-screw extruder (100), the extruder comprising a cylindrical rotor member (1) having diameter (D) and length (L) and comprising a feeding zone (14), the rotor member (1) arranged in a barrel (2), the cylindrical surface of the rotor member (1) carrying cavity/cavities and/or projection(s) (5) arranged in helically extending rows, the helically extending row(s) of the rotor member (1) having a pitch (P) and depth (d) in the feeding zone (14) of the rotor member, wherein the relation of the depth (d) to the diameter (D) of the rotor member, i.e. d:D, is not more than 1:20, and the relation of the pitch (P) of the rotor member to the diameter (D) of the rotor member, i.e. P:D, is not more than 1:4, B) heating the material in the single-screw extruder (100) to a flowable state, and C) thermolysing the material.