Description
Industrial Textile
Non-woven cloth has been in industrial production since the 1940s. Because of its high output, low cost and wide range of use, it has developed rapidly. Non-woven cloth is divided into two types: thin type and thick type. The weight of the thin type is usually 20g / m, 100g / m (used as decorative cloth for garment lining, handkerchief, women's sanitary articles, etc.); the thick type is used for floc, carpet, filter material, geotextile (roadbed cloth), etc. Can also be used to make heat insulation, breathable, heat-resistant, wear-resistant, sound-proof, shock-proof, anti-toxic, anti-radiation and other special purposes of the material. The production technology of nonwoven cloth originated from papermaking and felt making. Early nonwoven fabrics were made of waste cotton or textile mill scraps treated and pressed as low-grade floc mats or warm-keeping materials. Since the 1950s, chemical fiber has greatly developed, non-textile cloth production technology has also been improved, needle, tufting, sewing and other technologies have been adopted, natural fiber and chemical fiber without textile cloth production increased greatly, the use has become increasingly widespread. The manufacturing methods of non-woven cloth can be divided into two categories: dry method and wet method.
The technological process of folding Editing this Section.
Folding dry method.
First, the fiber raw materials are opened, mixed and combed on the cotton or woolen spinning equipment to make a fiber net, and then the non-woven cloth is made by means of adhesive cloth, mechanical cloth or spinning cloth, etc.
Folded fiber mesh.
There are parallel into the network, staggered into a network, air into a network and so on. The fiber network outputted by one or two carding machines is overlapped several times to form a fiber network arranged longitudinally. The non-woven fabric made of this fiber net has high longitudinal strength and low transverse strength. Interlacing is to fold the fiber net out of the carding machine into a certain number of layers by laying a screen curtain, and the fibers are basically arranged horizontally. The air-flow network is composed of the single fiber which has been combed and condensed in the output net belt to form the fiber net. Due to the irregular arrangement of the fibers, the breaking strength of the non-woven cloth in the vertical and horizontal directions is about the same. In addition, the combed fibers can be stacked into quantitative fiber flocs, drawn into a network by several pairs of sawtooth rollers, and the fibers are arranged randomly in the flocs.
Fold and bond into cloth.
There are dipping method thermoplastic fiber sticking method powder method and printing point method and so on. Impregnation method is to impregnate the fiber network (layer) adhesive, after rolling or vacuum absorption to remove the excess adhesive, and then drying. The non-woven cloth made by impregnation has a higher breaking strength but a harder handle. To make cloth fluffy and soft, foam impregnation and spray inhalation can also be used to reduce the amount of adhesives. The bonding method of thermoplastic fiber is that the thermoplastic fiber with low melting point is used as adhesive, and the fiber is uniformly mixed into the fiber used. The fiber mesh is made by hot air dryer, and the temperature in the machine is slightly higher than the melting point of the thermoplastic fiber with low melting point. When the low melting point thermoplastic fiber is melted and then cooled, other unmelted fibers will be glued. The non-woven cloth made is fluffy and soft, and has good air permeability. The powder method is to tear the powder adhesive evenly in the fiber net, then melt the powder after heating and stick to the fiber after cooling. The non-woven cloth made by this method is fluffy and soft. Printing point method is the use of similar printing method will paste adhesive printed to the fiber net, drying into a non-woven cloth, feel is also very soft.
Folding machine cloth.
The non-woven cloth is made from fiber net or yarn by mechanical method. The main methods are needle-punched method, stitch-knitting method and felt-making method.
How to fold and edit this paragraph.
Folding needling method.
A steel needle of triangular section (figure 1 [triangular needle]) with a notch distributed on the spindle. When a steel needle is punctured up and down on a fiber net, the gap on the needle shuttle takes part of the surface fiber to penetrate the inner part of the fiber net, thus making the fiber net intertwined with each other. After needling, the fiber layer becomes thinner and consolidated, and every square meter of fiber net generally has to go through about 3 ~ 50, 000 times before it can be fixed. In order to gradually compress the fiber layer, acupuncture can be divided into two times, that is, pre-acupuncture (Fig. 2 [two-zone needling process diagram]). The non-woven cloth made by needling method is compact and has good elasticity.
Fold seam method.
The knitting machine is used to sew the yarn on the fiber layer or the base cloth, or to sew it into a loop and then take up the pile to form a pile fabric.
The method of making felt is to make use of the shrinkage property of the felt after the fiber is pressed and heated, so that the fiber net is entwined together to form a felt-like non-woven cloth.
Spinning into cloth.
The synthetic fiber melt spinning equipment is adopted. The spinning fiber is gathered into a net through a guide roller and a press roller, and a sheet non-woven cloth is formed by using adhesive or hot melt bonding.
It can be divided into two kinds: short fiber method and filament method:
1 short fiber method: the fiber from the spinneret hole is blown and sprayed by the high pressure hot air around it, one side is stretched, one side is dispersed in the space, and after being absorbed and congealed by the metal mesh, it is sent to the hot press roller and compacted, so that the fibers are closely bonded to each other to form a cloth.
(2) filament method: the fibers from the spinneret are charged by a high-voltage electrostatic generator, and are sprayed by compressed air into the transport belt with opposite charge through the wire collector, so that the fibers are loosely agglomerated into a net and pressed into a cloth by a hot pressing roller.
Folding wet method.
Similar to papermaking, the forming of fiber net is carried out in wet state, which is the highest yield method in the production of non-woven cloth. The cost is relatively low, and the products are mostly used as sanitary products, which belong to the "disposable" products. The process and equipment are basically similar to the papermaking industry. The specific method is: 1 using the traditional papermaking equipment and process. (2) the water-soluble fiber is mixed with other fibers to form a mesh, which is formed by rolling and pressing in wet state, and then dried to form a non-woven cloth. (3) the fiber net is formed in wet state, and then heated and pressurized to make non-woven cloth. 4 using solvent treatment, so that a local dissolution of a fiber and sticky, bonding other fibers, volatile solvent will become a non-textile cloth. 5 use adhesive (often emulsion) to disperse the fiber to bond, and then baked to make non-textile cloth.
Complaint
