Screen printing 1000 questions (365-382)

365. What kind of plant fiber?
A: Plant fibers (cellulosic fibers) are divided into natural plant fibers and artificial regenerated fibers. Natural plant fibers mainly refer to cotton fibers and hemp fibers; artificial regenerated fibers refer to rayon, rayon, and artificial wool.

366. What kind of animal fibers?
Answer: Animal fibers (protein fibers) used in fabrics include wool (goat wool and cashmere), camel hair, rabbit hair, yak plush, mohair, and silk (mulberry silk and tussah silk).

367. What kinds of artificial protein fibers?
A: The artificial protein fibers used in fabrics are mainly peanut protein fiber, corn protein fiber and soybean protein fiber.

368. What are the types of artificial cellulose fibers?
A: The man-made fibers used in fabrics are mainly ketamine, acetate and viscose fibers (rayon and rayon).

369. What are the synthetic fibers?
A: The synthetic fibers used in fabrics are spandex (polyurethane fiber), vinyl chloride (polyvinyl chloride fiber), polypropylene (polypropylene fiber), acrylic (polyacrylonitrile fiber), vinylon (polyvinyl alcohol fiber) , Nylon (polyamide fiber) and Polyester (polyester fiber) 7 kinds.

370. What are the main components of cellulose fiber?
A: The main component of cellulosic fiber is cellulose. Cellulose is a long-chain polymer compound formed by the dehydration of glucose. Its molecular formula is C6H12O5.

371. How do fibers and dyes combine?
A: From the molecular structure of the fiber: [-C6H7O(OH)3-O-C6H7O(OH)3-O-](n-2)/2·C6H7O(OH)3-OH can be seen for each glucose unit There are three hydroxyl groups (-OH) in the structure, n is the degree of cellulose polymerization. The degree of polymerization of cotton and linen fibers is generally more than a few thousand, so we can say that there are many hydroxyl groups (-OH) on the fiber composed of cellulose or fibers, and hydroxyl groups can easily form hydrogen bonds with direct dyes and thus generate reactive dyes. Chemical bond. In addition, the aromatics in the dye molecules also generate non-polar van der Waals interactions with the cellulose molecules and generate adsorption.

372. Why are animal fiber fabrics easily stretchable?
A: Animal fibers (protein fibers) are polypeptide fibers, the molecular structure shown in Figure:
Dehydrated by a combination of amino acids. Most of the chain polymers in this type of fiber are aligned along the fiber axis, and the intermolecular binding is not limited to the hydrogen bonding of the amide group. The wool has a cystine molecular chain -SS-; this side chain is Important factors that affect the physical and chemical properties of wool, such as the use of hot water, steam, or alkaline treatment at room temperature, can destroy the chemical structure of the side chains, causing the wool to stretch easily.

373. What are the properties of polyester fiber?
A: Polyester fiber (polyester fiber, PET) has good hydrophobicity and can not be wetted by water at all. Generally, it is interwoven with natural silk and blended with cotton or wool. After blending, it can not only exert the heat setting property of PET, but also Poor PET absorbency can be overcome.

374. What are the main properties of nylon?
A: Nylon (polyamide fiber) has high tensile strength and high resilience compared to various natural fibers and viscose fibers, so it is not easy to wrinkle and hard to cause mechanical fatigue. However, the Young's modulus of nylon is smaller than that of cotton, silk, and rayon, and is generally 500 to 600 kg/mm2. The fiber is soft and the fabric is difficult to maintain in a stiff state.

375. What are the main properties of acrylic?
A: Acrylic fibers (acrylonitrile fibers, PAN) are mostly short fibers, which are easy to be dyed by basic dyes. If dyed with cationic dyes, bright and beautiful colors can be obtained.

376. What are the properties of vinyllon?
A: Chloride is composed of polyvinyl chloride fiber and polyvinylidene chloride fiber. Its composition ratio is 90% for vinyl chloride and 10% for vinyl acetate. Its polymer combines PVC hard and hard to dissolve, vinyl acetate is soft and Easy to dissolve properties; vinyl chloride and vinylidene chloride copolymers have lower melting point, higher density, lower strength, and better flame resistance and heat resistance than polyvinyl chloride fibers.

377. What are the main properties of vinylon?
A: Vinylon (polyvinyl alcohol fiber, PVA) is a fiber component with different characteristics in synthetic fibers. It is more hydrophilic than other synthetic fibers, close to natural fibers, and less hygroscopic than cotton, silk and wool. Vinylon's strength and fastness are similar to nylon and polyester.

378. What are the main properties of polypropylene?
A: Polypropylene (polypropylene) is divided into isotactic polypropylene and atactic polypropylene. Isotactic polypropylene is high in crystallinity, hard to dissolve, high in density, high in softening point (508-160°C), and softer than atactic polypropylene. The point (75°C) is much higher and the mechanical properties and elastic recovery rate are good. Isotactic polypropylene can produce fibers comparable in strength to polyester, nylon, and vinylon.

379. How to define the fiber denier? There are several ways to express?
A: The degree of fiber thickness is called fineness (fineness). There are three representations of denier, namely metric count (Nm), inch cotton count (Neb) and denier.
The metric Nm represents the length of one gram of yarn (or fiber) in meters. The larger the count, the finer the yarn. The English-made cotton spinning count (Neb) is measured in English. The relationship with the metric conversion is: Neb = 0.59 Nm. The fineness of rayon is expressed in denier and is defined as the weight of a 900m long filament expressed in grams. The larger the denier, the thicker the filament.

380. What are the main components of dye-based fabric printing inks?
A: The main components of dye-based fabric printing inks are dyes, pastes and related auxiliaries.

381. What is the coloring mechanism of dye-based fabric printing inks?
A: The coloring of dye-based fabric printing ink is based on the fact that the dyestuff adheres the dyestuff to the fabric, and then the dyestuff infiltrates into the fiber for coloration. After the printing is fixed, the slurry is washed out.

382. How are dyes classified by source?
A: The dyes can be divided into natural dyes and synthetic dyes according to their sources. Natural dyes mainly include plant dyes, such as indigo, alizarin, etc.; animal dyes such as cochineal, galloplasma, etc.; mineral dyes such as green alfalfa, chrome yellow, etc.; synthetic dyes can be divided into acid dyes due to their different characteristics. Basic dyes, reactive dyes, ice dyes, direct dyes, disperse dyes, sulfur dyes, and vat dyes.

Source: "Printing Technology"