Nonwovens without textile

Column:Industry News Time:2021-03-12 Source: 科技日报 Browsing volume: 1934
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In the public perception, traditional cloth is made of textile. But the name of non-woven fabric is puzzling. Does it really need to be woven?

Non woven fabric is also known as non-woven fabric, that is, fabric that does not need to be woven or woven. It is not the traditional sense of the yarn one by one intertwined, braided, but the fibers directly bonded together through physical methods to form fabric. In terms of production technology, non-woven fabric is a kind of non-woven fabric which directly uses polymer chips, short fibers or filaments to form the fibers into a net by air flow or machinery, and then reinforced by spunlace, needling or hot rolling, and finally finished.

The production process of non-woven fabrics can be divided into the following steps:

1. Combing the fiber; 2. Forming the web; 3. Fixing the web; 4. Heat treatment; 5. Finishing.

According to the causes of non-woven fabrics, they can be classified as follows:

(1) Spunlaced non-woven fabric: high pressure micro water jet to one or more layers of fiber network, so that the fibers entangled with each other, so as to strengthen the fiber network.

(2) Thermosetting non-woven fabric: it refers to adding fibrous or powdery hot-melt bonding reinforcement materials to the fiber web, so that the fiber web is heated, melted and cooled, and then reinforced into cloth.

(3) Pulp airlaid nonwovens: also known as dust-free paper, dry process paper-making nonwovens. It uses the air flow net forming technology to turn the wood pulp fiber into single fiber, and uses the air flow to make the fiber agglutinate on the net forming curtain, and then reinforces it into cloth.

(4) Wet process non-woven fabric: the fiber raw materials placed in the water medium are opened into single fiber, and the different fiber raw materials are mixed to make fiber suspension slurry, which is transported to the web forming mechanism, and then the web is formed and reinforced in the wet state.

(5) Spunbonded non-woven fabric: after the polymer is extruded and stretched to form continuous filament, it is laid into a network, and the fiber network is bonded or mechanically strengthened to become a non-woven fabric.

(6) Melt blown non-woven fabric: the manufacturing steps are polymer input - melt extrusion - fiber formation - fiber cooling - Netting - reinforcement.

(7) Needle punched non-woven fabric: it is a kind of dry non-woven fabric. It uses the puncture effect of needle to reinforce the fluffy fiber net into cloth.

(8) Seam woven non-woven fabric: it is a kind of dry non-woven fabric, which is made of warp knitted coil structure to reinforce fiber web, yarn layer, non-woven materials (such as plastic sheet, etc.) or their combination.

Non woven fabrics need a wide range of fiber materials, such as cotton, hemp, wool, asbestos, glass fiber, viscose fiber (rayon) and synthetic fiber (including nylon, polyester, acrylate, PVC, vinylon, etc.). But now the production of non-woven fabric is no longer based on cotton fiber, rayon and other fibers have replaced its position.

Non woven fabric is also a new type of environmental protection materials, with moisture-proof, breathable, elastic, light weight, non combustion, easy to decompose, non-toxic and non irritating, rich color, low price, recyclable and other characteristics, so the application field is very wide.

Among the industrial materials, non-woven fabrics have the characteristics of high filtration efficiency, insulation, heat insulation, acid resistance, alkali resistance, tear resistance and so on. They are mostly used to make filter media, sound insulation, electrical insulation, packaging, roofing and grinding materials. In the daily necessities industry, it can be used as clothing lining material, curtain, wall decoration material, diaper, travel bag, etc. In the medical and health products, it can be used in the production of operating clothes, patient number clothes, masks, sanitary belts, etc.