Common sense of non woven fabrics

1、 Introduction to non woven fabrics

Non woven fabric (English Name: non woven) is a kind of fabric that does not need spinning and weaving. It is a kind of fabric formed by directional or random arrangement of short textile fibers or filaments, and then reinforced by mechanical, thermal bonding or chemical methods. To put it simply: it is not interwoven and knitted by one yarn, but the fibers are directly bonded together by physical methods. Therefore, when you get the adhesive scale in your clothes, you will find that you can't pull out the thread ends one by one. It is a new generation of environmental protection materials, with moisture-proof, breathable, flexible, light weight, non combustion, easy decomposition, non-toxic and non irritating, rich color, low price, recyclable and so on. For example, polypropylene (PP) granules are usually used as raw materials, which are produced by continuous one-step process of high-temperature melting, wire spraying, thread laying and hot pressing coiling. It is called cloth because of its appearance and some properties.

2、 Application of non woven fabrics

Its main uses can be roughly divided into: (1) medical and health cloth: operating clothes, protective clothing, disinfection bags, masks, diapers Women's sanitary napkin, disposable sanitary cloth, etc.; (2) household decoration cloth: wall cloth, tablecloth, bed sheet, bedspread, wallpaper, etc.; (3) follow up cloth: lining, adhesive lining, wadding, set cotton, various synthetic leather backing cloth, etc.; (4) industrial cloth: filter material, insulation material, cement packaging bag, geotextile, wrapping cloth, etc.; (5) agricultural cloth: crop protection cloth (6) other: Space cotton, thermal insulation materials, linoleum felt, cigarette filter, bag tea bag, all kinds of packaging bags, gift bags, shopping bags, etc.

3、 Characteristics of non woven fabrics

The new fiber products with soft, breathable and plane structure have the advantages of air permeability, filtration, heat preservation, water absorption, waterproof, expansion, good handle, softness, no fabric directionality, high productivity, fast production speed, low price and mass production, etc. Its disadvantages are: (1) the strength and durability are poor compared with textile fabrics; (2) they cannot be cleaned like other fabrics; (3) the fibers are arranged in a certain direction, so they are easy to crack from the right angle, and so on.

The characteristics of non-woven fabric: 1. Light weight: polypropylene resin as the main raw material, the proportion of only 0.9, only three fifths of cotton, fluffy, good handle. 2. Soft: it is composed of fine fibers (2-3D) and hot-melt bonding. The finished product has moderate softness and comfortable feeling. 3. Draught and air permeability: Polypropylene chip does not absorb water and has zero moisture content. The finished product has good water repellency and is composed of 100% fiber. It is porous and has good air permeability. It is easy to keep the cloth dry and easy to wash. 4. Non toxic and non irritant: the product is produced with FDA food grade raw materials, without other chemical components, stable performance, non-toxic, no odor, and no skin irritation. 5. Antibacterial and chemical resistance: polypropylene is a kind of chemical blunt substance, which is not moth eaten, and can isolate bacteria and insects in the liquid; antibacterial, alkali corrosion and finished products will not affect the strength due to erosion. 6. Antibacterial: the product has the property of drawing water, not moldy, and can isolate the corrosion of bacteria and insects in the liquid. 7. Good physical properties: it is made of polypropylene spinning directly laid into a net and thermally bonded. The strength of the product is better than that of ordinary staple fiber products. The strength is non directional and the longitudinal and horizontal strength is similar.

4、 Non woven fabric has environmental protection function

At present, the raw material of most non-woven fabrics is polypropylene, while the raw material of plastic bags is polyethylene. Although the names of the two substances are similar, their chemical structures are quite different. The chemical molecular structure of polyethylene is very stable and difficult to degrade, so it takes 300 years for the plastic bag to decompose; the chemical structure of polypropylene is not firm, the molecular chain can be easily broken, so it can be effectively degraded, and in the non-toxic form into the next environmental cycle, a non-woven shopping bag can be completely decomposed in 90 days. Moreover, the non-woven shopping bags can be reused for more than 10 times, and the pollution degree of the environment after waste is only 10% of that of the plastic bags.

5、 Classification of non woven fabrics by production mode

(1) Spunlaced non-woven fabric Spunlaced technology is to spray high-pressure micro water into one or more layers of fiber network, so that the fibers are entangled with each other, so that the fiber mesh can be strengthened and has certain strength.

(2) Thermal bonded non-woven fabric thermal bonded non-woven fabric refers to adding fiber-shaped or powdery hot-melt bonding reinforcement material into the fiber mesh, and then heating, melting and cooling to form a cloth.

(3) Pulp air laid non-woven fabric is also called dust-free paper and dry papermaking non-woven fabric. It uses air flow netting technology to loosen the wood pulp fiberboard into a single fiber state, and then uses the air flow method to make the fiber agglutinate on the netting curtain, and then the fiber mesh is reinforced into cloth.

(4) Wet process non-woven fabric wet non-woven fabric is to open the fiber raw materials placed in the water medium into single fiber, and mix different fiber raw materials to make fiber suspension slurry. The suspension slurry is transported to the meshing mechanism, and the fiber is netted in wet state and then reinforced into cloth.

(5) Spunbonded non-woven fabric spunbonded non-woven fabric is a kind of non-woven fabric after polymer has been extruded and stretched to form continuous filament. The filament is laid into a net, and then the fiber mesh is self-adhesive, thermal bonded, chemical bonded or mechanically reinforced to make the web into non-woven fabric.

(6) Melt blown non-woven fabric melt blown non-woven fabric process: polymerization