Screw for extruder and method of manufacturing the extruder, and rubber member for tire and method of manufacturing the rubber member
AssigneeBridgestone Corporation
InventorGou Shimada
Life of this patent
Estimating the term…
Abstract
A screw 12 for an extruder 10 rotatably supported on the cylinder of the extruder and carrying roll-heated rubber material supplied from a hopper port 13s provided at the rear part of the cylinder 11, wherein the height of the portion of the flight portion 12z of the screw 12 located below the hopper port 13s is set lower than the height of the flight portion 12a on the downstream side of the screw 12, whereby the pulsation of extruded matter can be reduced while maintaining a high discharge rate.
Claims5
A screw for use in an extruder comprising a cylinder for carrying a rubber material supplied from a hopper port at an upstream end of the cylinder by the screw, molding it into a predetermined sectional form and extruding it from a nozzle attached to a downstream end of the cylinder,
- wherein a height of a flight portion of that part of the screw located below the hopper port is lower than a height of a flight portion located on a downstream side, said height at said part varies continuously in a peripheral direction over a predetermined rotational angle of the screw and the predetermined rotational angle is an angle beginning 90° before a position where the height of the flight is lowest and ending 90° after the position where the height of the flight is lowest, and
- wherein the diameter of the screw located below the hopper port is between 2% and 6% smaller than the diameter of the screw at the downstream side owing to the reduced height of the flight at the part located below the hopper.
Dependencies are inferred from the claim text.