Cable mold capable of realizing highly compact and uniform extrusion molding

Abstract

The invention discloses a cable mold capable of realizing highly compact and uniform extrusion molding. The cable mold comprises a mold sleeve, a mold core and an extrusion molding runner, wherein a work part of the mold core comprises an extrusion corrugation section, an extrusion compaction section and a mold core front cone section, a mold sleeve guide cone hole and a nesting hole which are communicated with each other are formed in the mold sleeve, the work part of the mold core is located in the mold sleeve guide cone hole at intervals, and the axis of the mold core and the center line ofthe mold sleeve guide cone hole are located in the same straight line; a setting nest is nested in the nesting hole of the mold sleeve, a cone hole surface for nesting the guide cone hole on the setting nest and the cone hole surface of the mold sleeve guide cone hole are located in the same cone surface. The extrusion corrugation section adopts a conical structure, and the conical surface of theextrusion corrugation section is a sine curve rotation surface. The extrusion compaction section is a semi-parabola rotation surface extending from the extrusion corrugation section to the mold corefront cone section. An extrusion molding layer of the cable extrusion molding mold has the characteristics of being fully plasticized, uniform, compact, consistent in thickness and good in appearancequality.

Description

technical field [0001] The invention relates to a wire and cable production and manufacturing equipment, in particular to an extrusion mold of an extruder in the wire and cable sheath layer extrusion equipment. Background technique [0002] The wire and cable industry is the second largest industry after the automobile industry. With the continuous expansion of the electric power industry, data communication, urban rail transit industry, automobile industry and shipbuilding industry, the demand for wire and cable will also increase rapidly. The development potential of the wire and cable industry is huge. Wires and cables usually include a metal core wire and an insulating layer covering the metal core wire or a sheath layer outside the insulated wire. The plastic sheath layer of the wire and cable is extruded by continuous extrusion. Most of the extrusion equipment is Screw extruder. [0003] The extrusion mold is the key tooling in the extruder of the wire and cable prod...

AI Technical Summary

Problems solved by technology

With the improvement of the production speed and efficiency of wire and cable extrusion equipment, the current extrusion molds show more and more defects and deficiencies during high-speed extrusion: Radial extrusion and shearing are not formed in the annular flow channel of the mold, so that the heat exchange effect between the flowing plastics of each layer in the annular flow channel is insufficient, and it is difficult to achieve the heat balance between the surface and the inside, and the formed viscous flow plastic will be mixed With unplasticized matter, "particles" or air bubbles appear in the viscous plastic, which eventually makes the structure of the coated plastic uneven and poor in compactness

Furthermore, since the flow velocity of the melted and plasticized plastic passing through the plastic flow channel of the mold changes little, there is stickiness between the surface of the softened plastic and the surface of the flow channel, which makes the flow velocity of the softened plastic fluctuate, and finally makes the sheath layer The appearance quality deteriorates, resulting in uneven outer diameter, uneven surface, and even burrs, pitch shape, slub shape or local roughness, etc.

Secondly, because the molten plastic in the existing mold flow channel cannot be subjected to radial extrusion from the mold, the bonding degree between the core and the coating rubber layer is not high, and the bonding between the rubber layer and the core is not tight.

The defects of uneven structure, uneven thickness and insufficient bonding fastness of these plasticized plastics will seriously affect the electrical and mechanical properties of wires and cables. For power cables, the unevenness of the sheath layer will directly affect the performance of power cables. The insulation state and the safe operation of the cable, the uneven insulation layer of the digital cable will limit the improvement of the transmission frequency and transmission speed, and these defects will seriously affect the tensile and compressive mechanical properties of the wire and cable

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