What is polypropylene?
The polypropylene fiber of the scientific name is melted and flammable in the near flame. It burns slowly and emits black smoke from the fire. The upper end of the flame is yellow, the lower end is blue, and the oil smell is emitted. After burning, the ash is hard round, light yellow and brown particles, and the handcuffs are brittle. . 100% Polyester Shu Velveteen,Knitting Fabric Velveteen,Velveteen Textile Raw,Velveteen Textile Fabric SUZHOU JINYULAI TEXTILE CO.,LTD , https://www.jyltextile.com
It is a fiber obtained by polymerization and melt spinning of propylene as a raw material. Polypropylene officially began industrial production in 1957, and is a rising star in synthetic fiber. Because polypropylene has the advantages of simple production process, low cost, high strength and light relative density, polypropylene has developed rapidly. At present, polypropylene is the fourth largest variety of synthetic fibers and the lightest fiber among common chemical fibers.
Polypropylene varieties include filaments (including undeformed filaments and expanded filaments), staple fibers, silk, membrane fibers, hollow fibers, shaped fibers, various composite fibers, and non-woven fabrics. The main purposes are to make carpets (including Carpet backing and suede), decorative fabrics, furniture fabrics, various ropes, strips, fishing nets, oil absorbing felts, building reinforcements, packaging materials and industrial fabrics, such as filter cloth, bag cloth. Wait. In addition, it is also widely used in clothing. It can be blended with various fibers to make different types of blended fabrics. After knitting, it can be made into shirts, outerwear, sportswear, socks and so on. The floc made of polypropylene hollow fiber is light in weight, warm and has good elasticity.
Polypropylene does not contain a chemical group capable of binding to a dye on a macromolecular structure, so dyeing is difficult. The pigment preparation and the polypropylene polymer are uniformly mixed in a screw extruder by a melt coloring method, and melt-spun to obtain a colored fiber having high color fastness. Another method is copolymerization or graft copolymerization with acrylic acid, acrylonitrile, vinyl pyridine, etc., to introduce a polar group capable of binding with a dye on a polymer macromolecule, and directly dyeing by a conventional method. Various additives are often added during the production of polypropylene to improve dyeability, light resistance and flame resistance.
Polypropylene for civilian use: can be purely spun or blended with wool, cotton or viscose to make a variety of clothing. Can be used to weave a variety of knitwear such as hosiery, gloves, sweaters, knit pants, dish cloth, mosquito net cloth, wadding, warm filler, wet diapers, etc.
Industrial use of polypropylene: carpets, fishing nets, canvas, hoses, concrete reinforcements, industrial fabrics, nonwoven fabrics, etc. Such as carpets, industrial filter cloth, ropes, fishing nets, building reinforcements, oil absorbing blankets and decorative fabrics. In addition, polypropylene film fibers can be used as packaging materials.
The main physical and chemical properties of polypropylene
1. The longitudinal direction of the polypropylene is flat and smooth, and the cross section is circular.
2. The biggest advantage of density polypropylene is its light weight. Its density is only 0.91g/cm3, which is the lightest of the common chemical fibers. Therefore, the same weight of polypropylene can obtain higher coverage than other fibers.
3. The strong stretch polypropylene has high strength, large elongation, high initial modulus and excellent elasticity. Therefore, polypropylene has good wear resistance. In addition, the wet strength of polypropylene is basically equal to dry strength, so it is an ideal material for making fishing nets and cables.
4. Hygroscopicity and dyeing properties are light and warm; almost non-hygroscopic, but strong in heart-absorbing ability, obvious in moisture absorption and perspiration; polypropylene has little hygroscopicity and almost no moisture absorption, and the general moisture regain rate under atmospheric conditions is close to zero. However, it has a wicking action that transfers water vapor through the capillary in the Fabric, but does not itself absorb any absorption. The dyeability of polypropylene is poor, and the chromatogram is not complete, but the method of coloring the original liquid can be used to make up for the deficiency.
5. Acid-resistant and alkali-resistant polypropylene has good chemical resistance. In addition to concentrated nitric acid and concentrated caustic soda, polypropylene has good resistance to acid and alkali, so it is suitable for use as filter materials and packaging materials.
6. The light resistance and other polypropylene fibers have poor light resistance, poor thermal stability, easy aging, and are not resistant to ironing. However, it is possible to improve the anti-aging property by adding an anti-aging agent at the time of spinning. In addition, polypropylene has good electrical insulation, but it is easy to generate static electricity during processing.
7. The strength of the high-strength polypropylene yarn is second only to nylon, but the price is only 1/3 of the nylon; the fabric is stable in size, wear-resistant and elastic, and has good chemical stability. However, it has poor thermal stability, is not resistant to the sun, and is prone to aging and brittleness. For this reason, an anti-aging agent is often added to the polypropylene.