Some knowledge about modified fiber of jigger dyeing machine

Common fiber modification methods

1. Physics

Physical modification usually uses various physical methods and means to improve fiber properties by changing the aggregation structure, morphological structure, surface composition, etc. of the fiber without changing the main structure of the fiber-forming polymer macromolecule. The formation of ceramic fibers and metal fibers and the transformation of the crystal phase structure are usually related to the control of melt spinning and sintering methods, and these are the results of physical modification and processing methods.

2. Biological law

This is a new modification method that has only appeared in recent years. It uses biotechnology, such as genetic engineering and biosynthesis technology, which not only increases the number of ways to modify fiber products and improves the performance of existing fibers, but also creates Some brand new "biofibres". This is the synthesis of chemistry and biology. Development status of new functional textile materials in my country.

3. Chemical method

Chemical modification of polymers is a type of modification method that changes the types of atoms or original groups of macromolecules and their combination methods through chemical reactions of polymers. After chemical modification, the chemical structure of existing macromolecules is changed, thereby improving the performance of the fiber or giving it new properties. The effect of chemical modification is durable, but changes in the chemical structure will also cause certain changes in the structure to a certain extent, thereby triggering a series of changes in the properties of the fiber.

At present, China's functional fiber materials have reached the international advanced level, which are characterized by the multifunctionality and high performance of conventional fibers, with flame retardant, bacteriostatic, antistatic and other functions, such as: silicon-nitrogen flame retardant viscose short fiber , polyacrylonitrile pre-oxidized fiber, flame-retardant polyester, flame-retardant nylon, conductive polyester-nylon composite fiber, conductive meta-aramid fiber, copper carbon nano-polyamide 6 ecological antibacterial fiber, polylactic acid ecological antibacterial fiber, ultra-fine denier Porous regenerated polyester ecological antibacterial fiber, special-shaped polyamide 6 ecological antibacterial fiber, etc. are mainly used in special military uniforms and firefighting suits, aircraft and high-speed rail interior materials, high-end textiles, medical sanitary materials and other fields.

At the same time, "Made in China 2025" proposes important contents such as the development of new materials, high-value biomedical materials, energy conservation and environmental protection, resource recycling, fashionable clothing and apparel, mid-to-high-end home textiles, and industrial textiles, and the development of aerospace, marine equipment, and wind power equipment. , key materials for new energy vehicles, etc.

Common types of modified fibers

1. Surface micro-grooves and high specific gravity fibers

High specific gravity fibers can be obtained by blending inorganic particles and organic matter to improve the drape of the fabric. When the fiber mixed with inorganic particles is reduced by alkali, the polymer around the inorganic particles is hydrolyzed, and many flame-like micropores appear on the surface of the fiber. This surface gives the fabric a cooling feel.

2. High shrinkage fiber

① Low shrinkage acrylic fiber

Fibers with a shrinkage rate of 20-50% (70%) during heat treatment (the boiling water shrinkage rate of general fibers is not >5%, and that of filaments is not >9%).

② High shrinkage acrylic fiber

During heat treatment, the shrinkage rate in boiling water reaches 15-45%; for high shrinkage polyester, the shrinkage rate in boiling water reaches 30-50%.

3. Self-stretching yarn

Refers to the property of self-elongation when heat treated. Its self-elongation can reach 8-15%. The self-stretching yarn is combined with high and low shrinkage yarns to form high differential shrinkage composite yarn, and the shrinkage difference between the components can reach 30-45%.

After finishing, the low-shrinkage yarn floats on the surface of the fabric, forming dense ultra-short wave yarn loops and a peach skin feel. High shrinkage yarns are concentrated inside the fabric as a skeleton.

Easy dyeing means that it can be dyed with different dyes, and has bright colors, complete chromatograms, uniform tones, good color fastness, and mild dyeing conditions. Polyester is the most difficult fiber to dye among commonly used synthetic fibers. Easily dyeable synthetic fibers mainly refer to dyed modified fibers of polyester. In addition to polyester that can be dyed with cationic dyes, common varieties of easy-to-dye synthetic fibers include cationic dyeable polyester at normal temperature and pressure (ECDP), polyester that can be dyed with acid dyes, polyester that can be dyed with acid or alkaline dyes, and acrylic fibers that can be dyed with acid dyes. Dyeable nylon fiber, cationic dyeable nylon fiber, etc.

5. Water-absorbent fiber

Hygroscopic fibers are fibers that have the ability to absorb moisture and transport it to adjacent fibers. Compared with natural fibers, most synthetic fibers have poor hygroscopicity, especially polyester and polypropylene. To improve the hygroscopicity and comfort of synthetic fibers, chemical and physical modification methods can be used to improve the wetting and expansion of the fibers. ability, or make porous fibers to form a micro-hole system inside to increase the fiber's water absorption capacity. Water-absorbent fibers are mainly used in functional underwear, sportswear, training clothes, sports socks and other products.

6. Mixed fiber yarn

Mixed filaments refer to multifilaments composed of single filaments with different geometric shapes or physical properties. The purpose is to improve the natural feel of synthetic fibers. Common mixed fiber types include different shrinkage, special shape, different denier and multi-different mixed fiber.

① Special-shaped mixed fiber yarn

Mixed filaments composed of monofilaments with different cross-sectional shapes have gaps and capillary structures between the fibers, which can reduce the friction coefficient between fibers. The fabric has good fluffiness, hygroscopicity and resilience.

② Different shrinkage mixed fiber yarn

Differential shrinkage mixed fiber is a composite yarn composed of high shrinkage fiber and ordinary fiber. During the fabric finishing and post-processing process, the high shrinkage fiber shrinks due to heat and becomes the core fiber. The fiber with low shrinkage rate floats due to the difference in fiber length. It comes out of the surface and produces curl, and at the same time, gaps are formed between the fibers, giving the fabric a fluffy feel.

③ Different denier mixed silk

Microfiber fabrics have good softness and drape, but often have no body bones. In order to pursue a soft but not rotten style, a different-denier fiber mixing method of mixing coarse-denier fibers and micro-fibers can be used.

④ Multi-heterogeneous mixed fiber yarn

It refers to a mixed fiber that combines fibers with various characteristics such as linear density, cross-sectional shape, thermal shrinkage, elongation, uneven single filament thickness, etc. in different forms, with the purpose of making it closer to natural fiber. style.