Classification And Performance Introduction Of PU Shoe Material

　　 Classification and performance introduction of PU shoe material

First, PU fabric

1) classification basis of PU fabrics

PU fabric can be classified according to its manufacturing process, base material, base texture, surface texture, product usage, color, width, thickness, physical properties and post processing technology.

1, production process

According to the different manufacturing processes, PU fabrics have two main categories: dry and wet.

Wet PU usually consists of three layers, namely the subbase, the foaming layer and the surface layer, while the dry PU is usually made up of the base course and the surface layer two layers.

2. Base material

There are usually seven types of materials used for PU base.

Cotton

Polyester fiber

Nylon

Chlorine fiber

Vinylon

Polypropylene fiber

Artificial fibre (viscose)

Among the seven materials mentioned above, cotton, polyester and nylon are the mainstream of the market. Among the three main materials: polyester material is rigid, tensile resistant and relatively low flexibility; nylon material has good flexibility and high strength, and its cost is the highest among the three materials; the physical properties and cost of cotton fiber materials are in the middle.

3. Bottom based weaving

According to the weaving method of base fiber, the bottom base can be divided into 5 major categories: plain weave, knitted fabric, needle punched nonwovens, washed nonwovens and Lycra cloth.

Plain weave is made of warp threads and weft threads. It is extensible without elasticity.

Knitted fabric is similar to woollen sweater, and is made of single thread knitted fabric with unidirectional elasticity.

Needle punched nonwoven fabric is a material that is made of needles fixed by steel needles and contracted by hot steam or hot water.

The principle of washing non woven fabric is the same as needle punched nonwoven fabric, which is obtained by puncture with high pressure small water beam instead of steel needle.

Lekab was first developed by the DuPont Co of the United States, and the fabrics made of such characteristics all over the world are known as "Lycra fabric" or "imitation Lycra fabric". The characteristics of these materials are elastic in all directions.

Among the 5 base groups, plain woven fabric, knitted fabric and needle punching nonwoven fabric are the mainstream of PU materials at present.

4. Surface texture

There are various patterns on the surface of PU fabric. The basic means of obtaining these patterns are:

Release paper

The release paper is roughly equivalent to the "flexible mold" with pattern.

At present, there are no more than ten manufacturers in the world, among which the most famous and most widely used ones are Japan's Asahi and Lintec.

Embossing

During the production process, the embossing technique of embossing plates can also emit various lines on the fabric. At this point, the pattern of the pattern depends on the design of the embossing board, and its quantity is varied.

Printing

That is to print all kinds of patterns on the PU fabric.

Grinding, etc.

The surface of the PU fabric is ground, so that the surface of the fabric is small and short. The typical product is (imitation) Niu BA (imitation) sheep.

In addition to the above four basic means, the formation of the surface pattern of PU fabric can also make any two, three or even four kinds of techniques to be combined to form the ever-changing surface effect.

7, width

At present, the width of PU fabric is mainly 54 inches and 52 inches two.

8, thickness

Commonly used PU fabric thickness has 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.3mm, 1.4mm and so on.

9. physical property

The physical properties of PU fabrics include peel strength, hydrolysis resistance, yellowing resistance, tear resistance, folding resistance, tensile load and so on.

According to the characteristics of physical properties, some product categories have been derived.

1. High peel PU fabric: peel strength is greater than 90N/3cm;

Medium peel PU fabric: peel strength is greater than 60N/3cm;

Ordinary peel PU fabric: peel strength is greater than 30N/3cm;

Resistance to hydrolysis: after 10%NaOH/24h alkali etching, the peel strength is above 75 N/3cm.

10, post processing

Post processing refers to the need for deep processing of some products after the completion of PU fabric manufacture. These materials are still PU materials in a broad sense. These deep processing techniques include:

(1) put EVA/ cloth / sponge on the back.

2. Two layers of PU fit;

3. PU and other materials are multi-layer;

PU surface coating (metal effect);

Strips of PU material are woven into large PU products.

11. Special effects

PU fabrics sometimes make some special effects, which depend largely on the resin properties of the PU sizing formula. Typical special effects of PU fabrics are chameleon leather, stretch coloured leather, photochromic leather, rubbing leather and so on.

In the market, the name of PU fabric is quite confusing and very incomplete. Typical PU products are: sheep stripe PU, Napa PU, pearlescent PU, mirror PU, PU Bago, reflective PU, crazy horse skin, mirror leather, space leather, elastic leather, single coated leather, litchi stripe PU, Hami melon pattern PU and so on. The above commodity names basically indicate the main characteristics of the PU fabrics, but they are not involved in color, thickness and physical properties. Buyers can not identify the overall product status from the name. Moreover, for many commodity names, only professionals who are more familiar with the industry can understand what kind of PU fabric the name basically refers to.

Among the names, sheep pattern PU, lychee grain PU, Hami melon PU are classified from the texture of PU surface; Napa PU refers to the soft texture of the handle; Pearl PU and reflective PU are special effects on the surface; mirror PU means that the surface of the PU surface is extremely bright and smooth, like the mirror surface effect; PU bovine Bago refers to the grinding effect of the PU surface; the crazy horse skin is the surface effect obtained by the use of the offset paper and the printing; the space leather is the fabric of the base of needle punched nonwovens; the elastic leather is the fabric of the knitted fabric base; the single leather is a kind of fabric with the base of the plain cloth and the surface only leaving the type paper. Goods listed above