Methods for extrusion of polyolefins (112 ) that control specific energy input to the extruder (102 ) for gel reduction. Disclosed herein is an example method for forming plastic products (120, 208 ) with reduced gels, comprising: melting a polyolefin resin (112 ) in extruder (102 ) to form a melt; adjusting specific energy input in the extruder (102 ) to reduce gels in the melt; and forming the melt into a polyolefin product (120, 208 ). Disclosed herein is also an example method for forming plastic products (120, 20 ) with reduced gels, comprising: melting a polyolefin resin in extruder (102 ) to form a melt; selecting a throttle valve (104 ) position for gel reduction; setting the throttle valve (104 ) at the selected throttle valve (104 ) position to restrict flow of the melt out of the extruder (102 ); and forming the melt into a polyolefin product (120, 208 ).

Methods for extrusion of polyolefins (110) that utilize melt temperature to control molecular weight and also reduce gels. Disclosed herein is an example method for controlling polymer chain scission in an extrusion system (100), comprising: melting a polyolefin resin (110) in extruder (102) at a first melt temperature to form a first melt (112); passing the first melt (112) through a screen pack (106); forming the first melt 112) into a first polyolefin product (116, 118); melting additional polyolefin resin (110) of the same grade in the extruder (102) at a second melt temperature to form a second melt (112), wherein the second melt temperature differs from the first melt temperature by 5° C. or more to control chain scission in the extruder (102); passing the second melt (112) through the screen pack (106); and forming the second melt (112) into a second polyolefin product (116, 118).

An optical resin formed body manufacturing method includes: (i) depressurizing an inside of a container holding a molten optical resin; (ii) pressurizing the inside of the container holding the molten optical resin; and (iii) shaping the optical resin taken out of the container into a given shape. The steps (i) and (ii) are sequentially performed once each or are alternately performed two or more times each. In the step (i), a duration t1 [min] of the depressurization of the inside of the container is set such that the duration t1 and a viscosity .Math.1 [Pa•s] of the molten optical resin satisfy a relation .Math.1/t1 < 200. In the step (ii), a duration t2 [min] of the pressurization of the inside of the container is set such that the duration t2 and a viscosity .Math.2 [Pa•s] of the molten optical resin satisfy a relation .Math.2/t2 < 200.

One or more embodiments of the present invention provide an apparatus for applying a mixture of a first compound and a second compound, the apparatus comprising a first extruder for processing a first compound and a second extruder for processing a second compound, wherein the outlet from the first extruder is in fluid communication with a first channel of a housing, and the outlet from the second extruder is in fluid communication with a second channel of the housing, wherein a gear pump is positioned in each channel, wherein a nozzle is in fluid communication with an outlet of the first channel and an outlet of the second channel, and a coextruded continuous strip is produced. The ratio of the first compound to the second compound may be adjusted instantaneously.

An object of the present invention is to provide a polyphenylene ether melt extrusion formed body which can be obtained by melt forming without mixing other resin components and has excellent properties such as mechanical strength, and a method for producing the same. The present invention relates to a polyphenylene ether melt extrusion formed body comprising a polyphenylene ether component which has a rearrangement structure having a continuous structure bonded at an ortho-position in a repeating unit continuously bonded at a para-position.

The present rotary extruder includes: a rotor having a cylindrical surface centered on a rotor axis extending in a horizontal direction; and a casing having an inner peripheral surface that defines a bore, wherein: the casing defines an input port into which a resin material including a thermoplastic resin is fed, and a discharge port from which a plasticized molten resin is discharged; the cylindrical surface of the rotor and the inner peripheral surface of the casing are arranged eccentric with each other, thereby forming a gap whose cross section is crescent-shaped, extending in a rotation direction of the rotor from the input port to the discharge port between the inner peripheral surface and the cylindrical surface; and the input port is arranged at a top portion of the casing and the discharge port is arranged at a lower portion of the casing.

The present rotary extruder includes: a rotor having a cylindrical surface centered on a rotor axis extending in a horizontal direction; and a casing having an inner peripheral surface that defines a bore, wherein: the casing defines an input port into which a resin material including a thermoplastic resin is fed, and a discharge port from which a plasticized molten resin is discharged; the cylindrical surface of the rotor and the inner peripheral surface of the casing are arranged eccentric with each other, thereby forming a gap whose cross section is crescent-shaped, extending in a rotation direction of the rotor from the input port to the discharge port between the inner peripheral surface and the cylindrical surface; and the input port is arranged at a top portion of the casing and the discharge port is arranged at a lower portion of the casing.

A core-sheath conjugate fiber for artificial hair including a core part and a sheath part is provide. The core part includes a polyester-based resin composition that contains a polyester-based resin and the sheath part is comprised of a polyamide-based resin composition that contains a polyamide-based resin. The core-sheath conjugate fiber for artificial hair has a single fiber fineness of 20 dtex or more and 80 dtex or less and a coefficient of variation of the single fiber diameter of 10% or more and 40% or less. With this configuration, a core-sheath conjugate fiber for artificial hair that has a touch close to that of human hair and a good gloss, a hair ornament product including the same, and a method for producing the same are provided.

A core-sheath conjugate fiber for artificial hair including a core part and a sheath part is provided. The core part contains a polyester-based resin composition containing a polyester-based resin, and the sheath part contains a polyamide-based resin composition containing a polyamide-based resin. The core-sheath conjugate fiber for artificial hair has a core-to-sheath area ratio of core:sheath=2:8 to 8:2 and includes a hollow part, and the area of the hollow part constitutes 7% or more and 40% or less of the area of a fiber cross section. A core-sheath conjugate fiber for artificial hair that has a touch close to that of human hair and good voluminousness and curl setting property, and a hair ornament product including the same, and a method for producing the same are provided.

One or more embodiments of the present invention provide a method for applying a dual compound coextruded continuous strip of a first compound and a second compound, the method comprising a first extruder for processing a first compound and a second extruder for processing a second compound, wherein the outlet from the first extruder is in fluid communication with a first channel of a housing, and the outlet from the second extruder is in fluid communication with a second channel of the housing, wherein a gear pump is positioned in each channel, wherein a nozzle is in fluid communication with an outlet of the first channel and an outlet of the second channel, and a coextruded continuous strip is produced. The ratio of the first compound to the second compound may be adjusted instantaneously.