Talking About The Production Process And Products Of Microfiber Nonwoven Fabric

December 28, 2022

Microfiber non woven fabrics are new technologies and products that have been developed in recent years. Microfibers are a kind of chemical fiber with very fine fineness of monofilament. There are no standard definitions for fine denier in the world, but fibers with a single filament fineness of less than 0.3 dtex are usually called ultrafine fibers. Microfiber nonwoven fabrics have the following excellent properties:

(1) The texture is light and thin, the hand feels soft and comfortable, and the drape is good;
(2) The diameter of the single fiber is reduced, the specific surface area is increased, the adsorption property is enhanced, and the detergency is improved;
(3) There are many fiber roots per unit area, the fabric density is increased, the warmth is good, and it is waterproof and breathable.

Microfiber products are popular in the international market for their unique performance. The world's major companies are competing to develop and continuously introduce new varieties.
The ultrafine fibers currently used in the production of nonwoven fabrics mainly include split - type composite fibers, sea - island composite fibers, and direct fibers. The processing methods mainly include:
(1) using a split - type or island - in - the - sea composite fiber to form a mesh, and then forming a microfiber by splitting and dissolving;
(2) flashing spinning directly into the net;
(3) Melt - spraying method into a net.
Composite microfiber non woven fabric roll processing technology
1.1 Fiber raw material composite Microfiber nonwoven fabric can be made of the following two kinds of composite microfibers.
(1) Composite split - type superfine fiber composite split - type ultrafine fibers are two kinds of polymers which are completely different in chemical structure and mutually incompatible with each other, and the two polymers are alternately arranged in cross section by a composite spinning method, made of composite fiber. Since the adhesion between the component composite interfaces is weak, it can be peeled off by a chemical or mechanical method, whereby the fine fiber bundle can be obtained by the above method.
The number of microfibers and the fineness of the monofilament depend on the number of the two components in the composite fiber, and the cross section of the fiber is a different shape, such as a rice type, a orange type, etc., and the single fiber fineness processed by this method can reach 0.1 to 0.2 dtex.
The types and ratios of the two components of the composite fiber can be adjusted, and it is generally required that the two polymers have similar and suitable melt viscosities at the spinning temperature. The combination of components is PET / PA, PP / PA, PET / PP, PET / PE, PE / PA, and the like.
(2) Island - type microfiber island - type microfibers are made by dissolving a soluble polymer and another insoluble polymer into two - component fibers, and a polymer is distributed in the form of microfibers ( island component ). In another polymer matrix ( sea component ), the soluble component ( sea component ) is dissolved in a solvent to obtain an ultrafine fiber, and the processing fineness can be up to 0.05 to an island type freely changeable sea.

1.2 Production technology of composite microfiber nonwoven filter cloth material. The production process of composite microfiber nonwoven filter cloth is as follows:
Split - type or island - in - the - sea composite fiber → combing → forming a net → acupuncture or spunlace → post-processing ( cracking or dissolving ) → After the fiber of the microfiber nonwoven fabric is opened, the weight is set according to different varieties ( g / m2 ) continuously feed the card, comb the fibers into a net, make a sheet - like non - oriented web, and then enter the needle machine ( or spunlace machine ) for multiple acupuncture ( or spunlace ) Thereby, a nonwoven base fabric having a certain degree of elongation and a certain width is obtained. In the hand, the base fabric made by the spunlace method is softer, but the strength is not as high as that of the needle punching method. From the weight range of the base fabric, the acupuncture method is generally suitable for the production of high - weight products of more than 100 g / m2; the spunlace method has certain difficulties in the production of thick products, the weight is generally in the range of 30 ~ 300 g / m2 Internal adjustment.
The resulting base fabric needs to be post - processed by splitting or dissolving one of the two components of the composite fiber to form an ultrafine fiber nonwoven fabric. For the needle punched nonwoven, a chemical treatment method is generally used. For example, for the PET / PA split - type composite fiber, the alkali reduction method can be used to swell and split the two components. For the PET / PS island - type composite fiber, the PS component can be dissolved with a trichloroethylene solvent to leave the PA ultrafine fiber. Since the split - type composite fiber can utilize the mechanical force of the high - pressure jet of the spunlace to peel off the two components, the web - forming technique and the stripping technique are organically combined in one process, and the web is not damaged like a needle punch, so the method has been show a certain degree of competitiveness.
1.3 Application of composite microfiber nonwovens: The most successful example of the application of composite microfiber nonwovens is the production of imitation leather products such as artificial suede, synthetic leather and the like. The protein fiber contained in the leather is very fine, and the diameter of the fiber is equivalent to one tenth to a few percent of the ordinary fiber.
The successful development of suede products is based on the careful analysis of the structure of natural suede and the successful use of composite microfibers. It has been found through research that the natural suede is composed of a colloidal fiber bottom plate and a layer of dense fiber fluff on the surface of the bottom plate.