A wear-resistant screw of a twin-screw extruder and its processing technology

Abstract

With increase of amount of filler in extruded materials, abrasion to a screw rod of a double-screw extruder is increasingly serious, and as a kneading block is a main component for shearing and extruding materials, it is very urgent to solve the problem about abrasion. The invention provides an abrasion-resistance screw rod of a double-screw extruder. The kneading block of the screw rod comprisesa steel base, silicon nitride ceramic bars and an alloy coating, concave pits are evenly distributed in the outer surface, parallel to the axis direction of the screw rod, of the steel base; the halfportions of the silicon nitride ceramic bars in the length direction are located in the concave pits, the other half portions of the silicon nitride ceramic bars in the length direction are exposed outside the surface of the steel bar, the alloy coating completely covers the surface of the steel base, and the top ends of the silicon nitride ceramic bars are exposed outside the alloy coating. According to the abrasion-resistance screw rod, the problem about abrasion to the screw rod of the double-screw extruder can be effectively solved.

Description

technical field [0001] The invention relates to twin-screw extruder equipment, and more specifically relates to a wear-resistant screw of a twin-screw extruder and a processing technology thereof. Background technique [0002] The screw is an important part in the twin-screw extruder, and wear is one of the main reasons for its failure. During the material extrusion process, the material will friction and wear with the surface of the screw, which will cause the gap between the screw and the barrel to increase, increase the leakage flow of the extruded material when it advances, and affect the normal operation of the twin-screw extruder. Severe wear on the surface of the screw element makes the screw unusable. [0003] Currently commonly used screw alloy materials include 45 steel, 40Cr steel, 38CrMoAlA, etc., and nitriding treatment is used to improve its wear resistance, but in order to improve the extrusion performance of the material, it is often necessary to add a lot o...

AI Technical Summary

Problems solved by technology

During the material extrusion process, the material will friction and wear with the surface of the screw, which will cause the gap between the screw and the barrel to increase, increase the leakage flow of the extruded material when it advances, and affect the normal operation of the twin-screw extruder. Severe wear on the surface of the screw element makes the screw unusable

[0003] Currently commonly used screw alloy materials include 45 steel, 40Cr steel, 38CrMoAlA, etc., and nitriding treatment is used to improve its wear resistance, but in order to improve the extrusion performance of the material, it is often necessary to add a lot of fillers, such as calcium carbonate, glass fiber And talcum powder, due to its high hardness will lead to rapid wear of the screw, and some screws will fail in about 6 months, and the cost of replacing the screw is very high, using cemented carbide coating containing Cr, W, Co, B and other elements Spraying and surfacing repair treatment can make the screw reuse for extrusion process

However, field experience shows that the service life of the repaired screw needs to be further improved. Once new wear occurs in other parts, the screw will need to be replaced again, which will affect the normal production

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