| 摘要 |
PURPOSE:To make the title screw possess at low cost plasticizing properties and uniform kneading properties which are identical with those of a screw whose lead angle is diofferent from the title screw, by so constituting the title screw that an auxiliary flight consists of a part running parallel with a main flight and a weir which is obtained by bending at about right angle from both ends of the parellel part to the main flight and the tips of them are connected with the main flight, a height of the parallel part to the main flight is made lower than that of the main flight and further a height of the weir is made lower than that of the parallel part to the main flight. CONSTITUTION:An auxiliary flight 23 is provided in the middle of main flights 22 and lead angles of both the main and auxiliary flights 22, 23 are identical with each other. The tip of an inflow side of the auxiliary flight 23 is bent rightward at about a right angle and connected with the main flight 22 as a weir, and the tip of an outflow side of the same is bent leftward at about a right angle and connected with the main flight 22 as a weir 25. A height of the auxiliary flight 23 is constant 23 and gaps delta1-delta4 of the main and auxilia ry flights 22, 23 and weirs 24, 25 with a heating cylinder 26 are made into delta1<delta2.delta2<delta3.delta2<delta4=delta4. |
