Views:312 Author:Site Editor Publish Time: 2019-07-11 Origin:Site
Differential fibers generally refer to chemical fibers that are chemically modified or physically deformed. Modified in the polymerization and spinning process: copolymerization, super-light, ultra-high shrinkage, meta-staining, anti-static, anti-pilling, anti-mildew, anti-bacterial, anti-fouling. Deodorant type, moisture absorption and sweatproof waterproof type, fluorescent color change type, etc. In the spinning, stretching and deformation processes, there are blending, compounding, hollow, profiled, shrinking, dissimilar, heterochromatic, fine denier, superfine denier, extra coarse denier, coarse detail, three-dimensional crimp, entanglement filament such as mixed fiber, mixed, mixed color, coated (pine, double, single), flocked yarn, yarn or filament strip are all categories of differentiation.
The polyamide 6 filament had a softening point of 180 °C, a melting point of 215 to 220 °C, and a polyamide 66 filament having a softening point of 235 °C and a melting point of 245 °C. The glass transition temperature of the polyamide 6 is 48 ° C and the polyamide 66 is 50 ° C as measured by Dsc.
The polyamide yarn has a large crystallinity, an orientation degree, and an intermolecular force, and has high strength. Generally, the polyamide filaments for textile have a breaking strength of 4.4 to 5.7 cN/dtex, and the wet strength is 85% to 90% of the dry state. The elongation at break varies with the variety, the strong filament is lower, about 20% to 30%, and the ordinary filament is 25% to 40%. The initial modulus of the polyamide yarn is 17.6 to 44.1 cN/dtex, which is lower than most other fibers and is easily deformed during use. Polyamide yarn is the most abrasion resistant filaments of all textile yarns, and its abrasion resistance is 10 times that of cotton, 20 times of wool, and 50 times of viscose fiber. Polyamide yarns have lower hygroscopicity than natural fibers and rayon fibers, but in synthetic fibers (except for vinylon), their hygroscopicity is high.
Polyamide 6 filament are slightly more hygroscopic than polyamide 66 filament due to the presence of monomers and low molecular weight. In the standard state, the moisture regain of the polyamide 6 filament is 3.5% to 5.0%, and the polyamide 66 filament is 3.4% to 3.8%. The polyamide yarn has a density of 1.14 g/cm3, and among all the fibers, it is only higher than polypropylene and polyethylene filaments. Although the dyeability of polyamide yarns is inferior to natural fibers and rayon fibers, it is easier to dye in synthetic fibers, and it is generally dyed with acid dyes, disperse dyes and other dyes.
The use of polyamide yarns is for civil and industrial use. Civil use, including clothing and household, can be generally divided into woven, knitted, warp knitted fabrics and the like. Polyamide yarn can be used to make socks, underwear, shirts, sweatshirts, carpets, etc. And can be blended with fibers such as cotton, wool, viscose, etc. So that the blended fabric has good abrasion resistance, and can be made into bedding and outdoor accessories, furniture cloth, etc. In industrial applications, polyamide yarns are mainly used in the production of tire cords, transmission belts, conveyor belts, fishing nets, cables, awning base fabrics, sewing threads, filter cloths, non-woven fabrics, etc. Involving transportation, fisheries, military and other fields.
The isotactic polypropylene has a glass transition temperature of about -30 to 25 ° C and a melting point of 164 to 176 ° C, which is higher than polyethylene and lower than polyamide. At normal temperature, the strength of the polypropylene filament is 3.1 to 4.5 cN/dtex, and the elongation at break varies depending on the variety; the strength of the industrial yarn is 6.6 to 7.9 cN/dtex, and the elongation at break is 15% to 20%. The initial modulus of polypropylene filaments is 35.3 to 105.8 cN/dtex, which is superior to polyamide yarns and inferior to polyester fibers.
The instantaneous resilience of the polypropylene yarn is between the polyamide yarn and the polyester fiber, and when the elongation is 5%, the rebound rate is 88% to 98%. The polypropylene filament has the lowest hygroscopicity and density of conventional synthetic fibers, and has a moisture regain of 0.03% and a density of 0.90 to 0.92 g/cm3. The polypropylene molecule does not contain a polar group or a reactive functional group, and the fiber structure lacks a position suitable for accommodating the dye molecule. Therefore, it is very difficult to dye the polypropylene filament, and the colored fiber is generally obtained by a pre-spinning method.
Polypropylene filament has high strength, high toughness, good chemical resistance and low price, so it has a wide range of applications in the industrial and decorative fields. Polypropylene filament can be used for knitting, and the fabric can be made into underwear, ski jackets, socks and children's wear. Polypropylene filament blended with wool can be used to make cold-resistant outdoor clothing, motorcycle sportswear, mountaineering wear, sailing suits and flight suits. The fine linear density polypropylene filament has excellent wicking effect, excellent ventilation and moisture permeability, and can keep the skin dry and not sultry when worn close to the body. The garment made with it is 2/5 lighter than the pure cotton garment, and the warmth is better than the warmth. Wool, therefore, can be used for knitted underwear, sportswear, swimwear, suede fabrics, imitation peach fabrics and imitation silk fabrics.
Carpet is an important application field of polypropylene filament today. High abrasion resistance, stain resistance and easy washing are important features of polypropylene carpet. Among the various non-woven fabrics, the spunbonding method is the fastest developed, and the spunbonded non-woven fabric is mostly polypropylene. The textiles used in civil engineering are collectively referred to as geotextiles. Polypropylene woven geotextiles made of polypropylene filament with high strength, acid and alkali resistance, antimicrobial resistance, dry and wet strength, etc., for civil works (such as dams, reservoirs, highways, railways , etc.) built on soft soil foundations acts as a reinforcement and distributes the load evenly, so that the roadbed settles evenly and reduces ground cracks.
Polypropylene filament can also be used in decorative fabrics, felts, canvas, bags, cigarette filters, artificial turf and medical and hygiene products.