Polytetrafluoroethylene hollow fiber stretching device

Abstract

The invention discloses a polytetrafluoroethylene hollow fiber stretching device. Cylindrical surfaces of two guide rollers, a plurality of stretching rollers and a cooling roller of the device are provided with uniform grooves of which the number is the same as that of the uniform grooves of degreasing rollers; and a baking oven consists of a stretching baking oven, a degreasing baking oven and a baking oven exhaust hood. An unwinding roller, the cooling roller and a winding roller are positioned outside the baking oven; a plurality of the degreasing rollers which are staggered up and down are arranged in the degreasing baking oven; a plurality of the guide rollers and a plurality of the stretching rollers two of which form a group are arranged in the stretching baking oven; the polytetrafluoroethylene hollow fibers which are wound on the unwinding roller and have the same number as the groove number of the degreasing rollers pass through the degreasing rollers in the degreasing baking oven, and the degreased hollow fibers enter the stretching baking oven, pass through the guide roller, the stretching rollers arranged in pairs and the other guide roller, and then the degreased hollow fibers is wound on the winding roller through the cooling roller. The device has the following advantages that: degreasing and stretching are performed in the baking oven to save energy resources; the degreasing and stretching of a plurality of the hollow fibers are performed, and the efficiency is high to ensure the processing quality; and stepwise stretching is adopted to effectively realize pore control of a hollow fiber membrane.

Description

technical field [0001] The invention relates to a stretching device, in particular to a polytetrafluoroethylene hollow fiber stretching device. Background technique [0002] As a common membrane module, hollow fiber membrane has the characteristics of self-supporting, easy to clean, high packing density, and small footprint. widely used in. Common hollow fiber membrane materials include cellulose acetate, polyvinyl chloride, polypropylene, polyethylene, polyacrylonitrile, polysulfone, polyethersulfone, polyvinylidene fluoride, etc. Different membrane materials have different preparation methods, such as wet or dry-wet spinning, using solvent-non-solvent or thermal phase inversion mechanism to obtain hollow fiber membranes. Most of the current hollow fiber membranes use this method. Or use melt spinning, use stretching method to form holes, such as the preparation of polypropylene, polyethylene, or even polyvinylidene fluoride hollow fiber membranes. [0003] Different app...

AI Technical Summary

Problems solved by technology

However, due to the free-moving mandrel method, for hollow fibers with a small inner diameter, the mandrel diameter is very small, and it is difficult to effectively control the mandrel during the stretching process. At the same time, the mandrel processing is very difficult, and the stretching operation is very inconvenient.

U.S. Patent No. 4,496,507 provides a stretching device using slotted hot rollers. In this device, heating rollers are used for temperature control, and one hollow fiber is stretched at a time. During the stretching process, the hollow fiber is prone to breakage and hollow fiber collapse. And other issues

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