Special two-section BM type screw rod for wire and cable extruder

Abstract

The invention provides a special two-section BM type screw rod for a wire and cable extruder. The homogenization effect is ideal, the probability of material self-heating is low, the consumed motor power is low, and the material conveying capacity is high. The special two-section BM type screw rod comprises a feeding section, a melting section and a homogenizing section, wherein a main thread is formed in the screw rod in the whole course; a first auxiliary thread and a second auxiliary thread which are connected end to end are formed in the melting section in the whole course; the groove depth h1 of the main thread is larger than the groove depth h2 of the first auxiliary thread and the groove depth h3 of the second auxiliary thread; the spiral angle Phi 1 of the main thread is smaller than the spiral angle Phi 2 of the first auxiliary thread; the spiral angle Phi 2 of the first auxiliary thread is smaller than the spiral angle Phi 3 of the second auxiliary thread; a double thread is arranged on the front section of the feeding section; the upper surfaces of the first auxiliary thread and the second auxiliary thread are arc-shaped; and the length-diameter ratio of the screw rod is 30:1, and the compression ratio i of the screw rod is equal to 1.3-1.8.

Description

technical field [0001] The invention relates to a wire and cable extruder, in particular to an extruder screw. Background technique [0002] Most wire and cable extrusion molding equipment is single-screw extrusion. The screw is the main part of the extruder, which is related to the application range and production efficiency of the extruder. The structural characteristics and basic parameters of the screw have a great impact on the plasticization and molding effect of the plastic. Generally speaking, plastics with high viscosity and poor fluidity generate heat quickly due to friction, and are more sensitive to temperature shear, so a screw with a large length-to-diameter ratio and low compression ratio should be selected; in the prior art, wire and cable The homogenization effect of the screw of the extruder is not ideal, and the self-heating phenomenon is obvious due to the huge shearing of the shear-sensitive material, resulting in overheating of the material during the e...

AI Technical Summary

Problems solved by technology

[0002] Most wire and cable extrusion molding equipment is single-screw extrusion. The screw is the main part of the extruder, which is related to the application range and production efficiency of the extruder. The structural characteristics and basic parameters of the screw have a great influence on the plasticization and molding effect of the plastic. Generally speaking, plastics with high viscosity and poor fluidity generate heat quickly by friction, and are more sensitive to temperature shear, so it is advisable to choose a screw with a large length-to-diameter ratio and a low compression ratio; in the prior art, wire and cable The homogenization effect of the screw of the extruder is not ideal, and the self-heating phenomenon is obvious due to the huge shearing of the shear-sensitive material, which causes the material to overheat during the extrusion process; in addition, the power consumption of the motor during the shearing process of the existing screw is large, Material conveying capacity is not ideal

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