To make viscosity characteristics of a resin uniform and to reduce an irregular thickness of a molding by coupling a cylinder between an extruder and a mold, providing a protrusion on an inner surface of the cylinder, and rotatably or swingably providing the cylinder.
An extruder, a cylinder and a mold for extrusion molding are sequentially coupled. The cylinder is formed of a cylinder body 11 and a protrusion 12 provided on an inner surface of the cylinder so as to be rotatable or swingable. A molten resin extruded from the extruder is mixed by rotating or swinging the cylinder. The body 11 is formed in a double structure of an inner cylinder 111 and an outer cylinder 112 and the cylinder 111 having the protrusion 12 is rotated or swung. In the form for rotating the cylinder, an outside of the cylinder 111 is machined in a gear state, impregnated with carbon for securing its hardness. An opening is provided partly at the cylinder 112 so that the gear outside the cylinder 111 is engaged with a gear 13 disposed at the body 11 side to drive the gear 13 by a motor to rotate the inner cylinder.
YOKOYAMA JUNICHI
SHINKO TADASHI
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