High strength polyester industrial filament and preparation method thereof

Abstract

The invention relates to a high strength polyester industrial filament and a preparation method thereof. Modified polyester is subjected to solid phase polycondensation tackifying, melting, metering,extrusion, cooling, oiling, stretching, heat setting and winding to obtain the high strength polyester industrial filament; during cooling, the vertical height is kept unchanged and the cross sectionarea of a slow cooling chamber is increased; at the same time, the slow cooling chamber maintains the plate surface temperature of a spinneret plate by the way of heat preservation; a molecular chainof the modified polyester consists of a terephthalic acid chain segment, an ethylene glycol chain segment and a diol chain segment with a branched chain, and diol with the branched chain has the following structural formula defined in the specification, wherein R1 and R2 are independently selected from straight-chain alkylene with the carbon atom number of 1-3 , R3 is selected from alkyl with thecarbon atom number of 1-5, and R4 is selected from alkyl with the carbon atom number of 2-5. The fracture strength of the prepared high strength polyester industrial filament is more than or equal to8.1 cN / dtex. The method is simple and reasonable, and the prepared industrial filament has the advantages of high breaking strength and good mechanical properties.

Description

technical field [0001] The invention belongs to the field of fiber preparation, and relates to a high-strength polyester industrial yarn and a preparation method thereof. Background technique [0002] Since the appearance of polyethylene terephthalate (PET) fiber, it has developed rapidly because of its excellent performance, and its output has become the crown of synthetic fiber in the world. Polyester fiber has a series of excellent properties such as high breaking strength, high elastic modulus, moderate resilience, excellent heat setting performance, good heat resistance and light resistance, acid resistance, alkali resistance and corrosion resistance, and the fabric prepared from it has wrinkle resistance. And good stiffness, so polyester fiber is widely used in clothing and home textiles and other fields. [0003] However, during the polycondensation reaction of synthesizing ethylene terephthalate, especially when producing linear high polymers, linear and cyclic olig...

AI Technical Summary

Problems solved by technology

There are two main modes of heating in the slow cooling zone, both of which are active heating. figure 1 As shown, the heating medium is used to heat the box. Once the spinning temperature is determined, it is generally no longer adjusted. It is relatively passive and difficult to adapt to different application conditions; the other such as figure 2 As shown, electric heating is used for heating, and the setting temperature can be higher than the temperature of the heat medium in the box, or lower, which is more flexible and can be set according to the actual situation, but high temperature will aggravate the oligomer on the spinneret. If the temperature is lowered, for example, the power is cut off without heating, since the heater is usually made of a heavy aluminum material with good heat transfer effect, it will absorb a large amount of heat from the box, causing the heat medium around the outer edge of the component chamber to rapidly Condensation, insufficient heat supplement, resulting in a drop in the temperature of the spinning assembly, a significant drop in melt flow performance, and a large amount of hair loss in the product, especially for the production of fibers with special-shaped cross-sections. There is a large amount of accumulation at the orifice, which is easy to scratch the yarn, and the elbow yarn appears. The existence of this kind of defect will cause single-filament breakage during the high-speed operation of the yarn, which is manifested in the form of hair reduction on the surface of the yarn cake. The existence of fluff brings great trouble to post-processing and unwinding, and affects the strength and elongation of the tow. This is something to be avoided in production. In addition to the defects of the heating method, the slow cooling zone in the prior art There is a fatal defect, that is, the slow cooling zone is a cylindrical chamber, and the oligomers cannot escape quickly and smoothly, and the oligomers gather in the high-temperature field, which must coke a large amount on the spinneret, causing the spinneret Blockage shortens the cleaning cycle, otherwise the coke will adhere to the spinneret hole, resulting in bent wires, the appearance quality of the product will deteriorate rapidly, the broken end will increase significantly, the production efficiency will decrease, and the labor intensity of the workers will be high, especially in the production of super-bright special-shaped The performance on cross-section fibers is particularly obvious, which seriously affects the normal production operation and causes a huge waste of production cost

[0005] With the increasing production of polyester fiber, people's requirements for fiber quality are also increasing day by day. Fibers are often required to have excellent mechanical properties. breaking strength, but due to the high content of oligomers in the fibers prepared by the prior art, the mechanical properties of the fibers are reduced, causing the fibers to be uneven, and it is easy to make the fibers produce fuzz

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