Polyester spinning method of reducing screw melt extrusion machine

Abstract

The invention provides a polyester spinning method of a reducing screw melt extrusion machine, and in particular relates to a polyester spinning method of an integrated reducing screw melt extrusion machine. According to the polyester spinning method of the integrated reducing screw melt extrusion machine, the extrusion machine is divided into a feed pre-crystallization drying zone, a pre-melt exhaust zone, a melt zone and a compression metering zone from front to back; barrels in the feed pre-crystallization drying zone, the melt zone and the compression metering zone are cylindrical, and a barrel in the pre-melt exhaust zone is conical; the diameter of the barrel in the melt zone is the same as that of the barrel in the compression metering zone but is less than that of the barrel in the feed pre-crystallization drying zone; and a feed pre-crystallization drying temperature is controlled to be 110 to 170 DEG C, and a pre-melt air exhaust temperature is controlled to be lower than a raw material melt temperature of 3 to 10 DEG C. By the method, raw materials can be uniformly dried and pre-crystallized in the extrusion process and fully dehydrated without bulky drying equipment; and the method is suitable for melt spinning of polyester.

Description

technical field [0001] The invention relates to a polyester spinning method of a variable-diameter screw melting extruder. Background technique [0002] In the polyester (PET, PBT, PDT) spinning process, the presence of moisture will seriously affect the mechanical properties of the material, so the raw materials need to be dried before the screw extruder. If conventional drying equipment is used, it will take up a lot of space, resulting in a waste of energy, space, manpower and other resources. [0003] In order to remove the moisture in the raw material, relevant researchers have designed a conical screw extruder. The conical screw extruder can effectively avoid the installation of drying devices, and can also achieve other excellent effects. In patent 200820083445, it is mentioned that two conical screws rotate in the same direction in the barrel to make the plasticization of raw materials in the barrel more uniform, and the shear rate is higher, which greatly improves...

AI Technical Summary

Problems solved by technology

[0004] However, the conical screw extruder in the previous patent involves either a screw that is conical from feeding to extrusion, or a parallel structure at the rear of the screw (patent number: 201020548822.0), and these extruders Mainly used in rubber or plastic fields, not for spinning

The tapered structure from the feed to the extrusion will cause the melt to advance unstable, which will seriously affect the quality of the raw silk; and the use of a parallel structure at the rear end of the screw can make the melt extrusion uniform, but from the diagram It can be seen that two-thirds of the entire screw section is still a conical feeding and melting section, and only one-third is a parallel extrusion section. This structure is beneficial to plastic extrusion molding.

However, for the spinning pellets or powder, the pre-crystallization and vacuum exhaust drying of the feed must be very uniform, because the pre-crystallization of the spinning raw material and the unstable fluctuation of the moisture content will inevitably affect the melt in the subsequent compression and metering section. Stability, which affects the uniformity of the spinneret drawing and the quality of fiber formation

It is difficult for the existing technology to ensure that the drying and pre-crystallization of the raw materials are carried out uniformly during the extrusion process and at the same time ensure that the moisture in the raw materials can be fully removed. After many tests, this patented technology can effectively solve the shortcomings of the existing technology and can meet Polyester spinning requirements

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