Special screw for blow-moulding machine capable of using powder resin

Abstract

The invention relates to a screw specially used in a blow molding machine, which can use powder resin; the screw is made of the material of 38CrMoAl high-quality alloy steel and consists of a feeding section with helixes of unequal distance and depth and the length of 5 to 7 pitches, a compression section with helixes of equal distance and unequal depth and the length of 8 to 10 pitches and a metering section with helixes of equal distance and depth and the length of 10 to 12 pitches; wherein, the outer diameter of an integral screw edge of the screw is in unequal diameter gradual enlargementtype; the size of the outer diameter of a screw edge of the extreme end of the metering section is larger by 1 to 2mm than that of the outer diameter of the most front end of the feeding section . The purpose of producing high-quality PVC blow molding films by directly using a powder resin mixing material as the raw material can be realized by increasing compression ratio, prolonging plasticizingtime, adjusting the rotational speed of the screw, changing technical parameters of the screw such as the length-diameter ratio of the screw and changing performance indexes. A single-screw extrudingmachine of the screw, which can directly adopt the powder resin mixing material as the raw material, is widely used for producing PVC blow molding fruit-vegetable fresh-keeping films.

Description

technical field [0001] The invention belongs to equipment parts of plastic blow molding machines, in particular to a special screw for blow molding machines which can use powder resin. Background technique [0002] When processing polyvinyl chloride (PVC) products, due to the limitation of the characteristics of raw material PVC resin, PVC resin and various processing and modification aids added such as: plasticizer, heat stabilizer, lubricant, filler, The dyes and the like are mixed evenly by heating and mixing to form a mixed powder that can be used for molding. The powder mixture produced at this time is used separately according to the difference of subsequent processing equipment. When twin-screw extrusion equipment is used, due to the high compression ratio and strong plasticizing ability of the equipment, the powder mixture can be directly added to the screw of the twin-screw extruder to directly complete the extrusion molding process; and for single-screw extrusion ...

AI Technical Summary

Problems solved by technology

Single-screw extrusion molding equipment Single-screw extrusion molding equipment, the operation process is complicated, the production process is long, the consumption of raw materials, energy and labor is large, and the production cost is high.

However, the production equipment investment required by the single-screw extrusion molding process is much lower than that of the twin-screw extrusion molding process equipment, which is one of the reasons why the two extrusion molding processes of PVC have coexisted for a long time

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