| 摘要 |
PURPOSE: To prevent the thermal degradation of plastics by obtaining blow molding parison being uniform In its overall circumference and having no weld therein. CONSTITUTION: The molding machine is constituted of a cylinder 24 provided with a cylindrical inner wall, a cylindrical screw plunger 25 being rotatable and freely movable forward and rearward in the axial direction within the cylinder 24 provided with a screw and counterfoil prevention mechanism 48 in its outer periphery, a rod 26 being inserted in the central portion thereof and extending in the axial direction, a ring die 27 attached on the extrusion side of the cylinder 24, and a core die 28 forming a die hole in conjunction with the ring die at the inside of the ring die 27 secured to the rod 26. The screw plunger 25 is rotated by a rotating mechanism 31, and moves forward and rearward by a cylinder 40. The plunger acts to melt unmolten plastics supplied from the side face of a stationary plate 21 into the hole 23 and then push molten plastic forward to be accumulated, and further extrude it through the die hole 52. |
