PLA and PTT double-component semi-embedded composite fiber and preparation method thereof

Abstract

The invention discloses PLA and PTT double-component semi-embedded composite fiber and a preparation method thereof. The preparation method includes: respectively drying a first component and a secondcomponent, wherein the first component is formed by PLA slice of 0.8-1.8dL / g in intrinsic viscosity and 60-70% in mass percentage, and the second component is PTT slice of 0.6-1.3dL / g and of 30-40% in mass percentage; subjecting a dried material of each of the first component and the second component to melt extrusion through a screw, conveying through a melt pipeline and metering through a metering pump; guiding spinning melt of the first and second components into a spinning component of a spinning box, allowing the spinning melt to respectively flow towards a spinneret plate, converge on the same and be ejected by the same to form melt streamlet with the second component semi-embedded in the first component, and subjecting the melt streamlet sequentially to lateral-air-blowing cooling,oiling, stretching, networking and winding to obtain the composite fiber. The composite fiber is high in wear resistance, elasticity and production efficiency and has good cohesive force.

Description

technical field [0001] The invention belongs to the technical field of composite fiber and its preparation, in particular to a PLA and PTT two-component semi-embedded composite fiber, and also relates to a preparation method thereof. Background technique [0002] The PLA mentioned above is the English abbreviation of the Chinese name "polylactic acid", and PTT is the English abbreviation of the Chinese name "polytrimethylene terephthalate". Fibers made from PLA chips are PLA fibers (polylactic acid fibers), and fibers made from PTT chips are PTT fibers (polytrimethylene terephthalate fibers). [0003] PLA fiber is a new type of bio-based fiber formed from corn, potato, sugar beet or grain starch through fermentation, purification and a series of reactions. It is environmentally friendly and degradable (carbon dioxide and water are generated after degradation), and the production process It has the advantages of low energy consumption, good antibacterial properties of the ma...

AI Technical Summary

Problems solved by technology

Since polyester and nylon are conventional chemical fiber raw materials, the elasticity of the obtained composite fiber is not enough to replace the role of spandex in the fabric. This kind of two-component composite fiber (short fiber) can only be used as filling material and general textile yarn.

[0006] In addition, there are deficiencies in the above-mentioned preparation method recommended by CN108130606A: first, the melting point of polyester is very high, while the melting point of polylactic acid is very low, and the difference between the melting points of the two is more than 90 degrees. The melting point of lactic acid raw materials is only between 170-180°C, and the melting point of polyester is as high as 265°C. In the specific production process, if the temperature set at each point of the spinning machine exceeds 270°C, the strength of the produced fiber will lose more than 20%. Therefore, the "polylactic acid box temperature is 280-300°C" given in this patent will accelerate the degradation of polylactic acid due to excessive spinning temperature, and eventually reduce the strength of the composite fiber

Second, in paragraph 0012 of its description, it is mentioned that "the total draw ratio is 4.0-5.0 times" and in paragraph 0013, it is mentioned that "the fiber fineness of the polylactic acid side-by-side composite fiber is 8.80-22.20dtex" (single Filament density), according to the aforementioned fiber fineness and draw ratio, which indicates that the fiber is conventionally spun (conventional spinning is also called low-speed spinning, because the melt pressure in the spinning assembly is very high, the melt from the spinneret When extruding from the capillary, the melt will expand rapidly, forming a puffed region of the spun fiber, which makes the molecular arrangement in the fiber disorderly, so a large draw ratio is required to increase the orientation of the macromolecules in the fiber. Conventional spinning generally To produce fiber varieties with large deniers, the fibers spun have low requirements on evenness and dyeing), and obtain polylactic acid fiber products by this method, so the evenness of this type of fibers is poor

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