Abstract: In a die assembly, plural pairs of extrusion ports are set up on concentric circles different in diameter. The die assembly is also provided with a core material feeding layer which spreads in such a planar state as to be connected to all core material extruding passageways and a sheath material feeding layer which spreads in such a planar state as to be connected to all sheath material extruding passageways and the core material and the sheath material are fed through the passageways. This constitution makes it possible to set up extrusion ports in arbitrary positions corresponding to the core material feeding layer and the sheath material feeding layer which each spread in a planar state, which enables simultaneous production of more multilayer extrusions while inhibiting the enlargement of the assembly.

Abstract: In a die assembly, plural pairs of extrusion ports are set up on concentric circles different in diameter. The die assembly is also provided with a core material feeding layer which spreads in such a planar state as to be connected to all core material extruding passageways and a sheath material feeding layer which spreads in such a planar state as to be connected to all sheath material extruding passageways and the core material and the sheath material are fed through the passageways. This constitution makes it possible to set up extrusion ports in arbitrary positions corresponding to the core material feeding layer and the sheath material feeding layer which each spread in a planar state, which enables simultaneous production of more multilayer extrusions while inhibiting the enlargement of the assembly.

Abstract: Extrusion equipment provided with a die assembly for extruding a multilayer extrusion having a core-sheath structure composed of a core material and a sheath material covering the core material, which assembly has the first die assembly body provided with a core material feeding port on the sidewall and the second die assembly body provided with a sheath material feeding port on the sidewall, the bodies being vertically connected in a detachable way. The first and second die assembly bodies are constituted in such a way as to be connected even when one of the bodies is horizontally turned by an angle of twice the angle ? to the other. To absorb the vertical shift after the rotation, the first extruder and the second extruder are equipped with elevator devices. Thus, an extruder for a core material can be exchanged for an extruder for a sheath material without changing the directions of the extruders connected to a die assembly.

Abstract: A process for manufacturing multilayer pellets having a core-sheath structure with a molding material forming a sheath which covers the outer circumference of another molding material forming a core, which includes (a) supplying the core material and the sheath material to a die extruder having multiple extrusion-forming parts arranged along a circumference, (b) extruding multiple multilayer strands from the extrusion-forming parts by covering around the outer circumference of the core material concentrically with the sheath material, and (c) cutting the extruded multilayer strands to manufacture multilayer pellets.

Abstract: A process for manufacturing multilayer pellets having a core-sheath structure with a molding material forming a sheath which covers the outer circumference of another molding material forming a core, which includes (a) supplying the core material and the sheath material to a die extruder having multiple extrusion-forming parts arranged along a circumference, (b) extruding multiple multilayer strands from the extrusion-forming parts by covering around the outer circumference of the core material concentrically with the sheath material, and (c) cutting the extruded multilayer strands to manufacture multilayer pellets.

Abstract: A process for manufacturing multilayer pellets having a core-sheath structure with a molding material forming a sheath which covers the outer circumference of another molding material forming a core, which includes (a) supplying the core material and the sheath material to a die extruder having multiple extrusion-forming parts arranged along a circumference, (b) extruding multiple multilayer strands from the extrusion-forming parts by covering around the outer circumference of the core material concentrically with the sheath material, and (c) cutting the extruded multilayer strands to manufacture multilayer pellets.

Abstract: Pigment dispersion is manufactured by continuously flushing pigment press-cake. First and second troughs supply hydrophobic liquid organic media and the pigment wet-cake respectively at a constant rate to a twin screw co-rotating extruder having a L/D (length/diameter) value of 25 or more. The twin screw co-rotating extruder includes a feeding part where the hydrophobic liquid organic media and the pigment wet-cake are fed from the first and second troughs, a flushing part for flushing the pigment particles from water phase to form an organic medium phase, and a dehydrating part for removing water from the flushed mixture. The hydrophobic liquid organic media and the pigment wet-cake are fed to the twin screw co-rotating extruder, and the pigment press-cake is flushed and dehydrated continuously in the extruder to obtain the pigment dispersion.