Round screw-arris plastic extruder screw

Abstract

The invention provides a round screw-arris plastic extruder screw. The screw consists of a conveying section, a transition section, a first compression section and a second compression section, wherein the length of the conveying section is 25 to 35 percent of the effective length of the screw; the length of the transition section is 5 to 8 percent of the effective length of the screw; the lengthof the first compression section is 40 to 50 percent of the effective length of the screw; and the length of the second compression section is 15 to 20 percent of the effective length of the screw. Both the conveying section and the transition section are equidistant and isobathic double-end screw arrises; two main screw arrises and two secondary screw arrises are arranged in both the first and second compression sections, the lead of the secondary screw arrises is greater than that of the main screw arrises, and two solid-phase channels and two liquid-phase channels are formed; the liquid-phase channels in the first compression section are isobathic, while the solid-phase channels therein are gradually changed in depth, namely the depth thereof is from deep to shallow and is zero at the tail end; both the liquid-phase channels and solid-phase channels in the second compression section are isobathic; and the cross section of the secondary screw arrises is arc. The screw plastics have a higher plasticizing speed and high quality and can be extruded out with low cost, low energy consumption, low temperature and high speed.

Description

technical field [0001] The invention belongs to the technical field of plastic machinery, and in particular relates to a screw of a plastic extruder with round helical edges. Background technique [0002] Ordinary plastic extruder BM screw is generally composed of three sections: conveying section, compression section and metering section. The conveying section and the metering section are all single-ended screw flights; an auxiliary screw flight is added in the compression section to form a solid phase channel and a liquid phase channel. The cross-sectional shape of the main screw flight is rectangular, and the cross-sectional shape of the auxiliary flight type. With this type of screw, when the molten plastic in the solid phase channel is pressed into the liquid phase channel, the resistance is large, so that the solid and the melt cannot be separated in time. Due to the existence of the molten material in the solid phase channel, the shear force between the materials is ...

AI Technical Summary

Problems solved by technology

With the screw of this structure, when the molten plastic in the solid phase channel is pressed into the liquid phase channel, the resistance is large, so that the solid and the melt cannot be separated in time. Due to the existence of the molten material in the solid phase channel, the shear force between the materials is small, and the plastic Slow speed and low production efficiency

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