Coating processing method

Coating processing method

There are many different methods for coating processing. Except for different coating methods, the processing process is the same. The process is: base cloth → coating → drying and sintering → cooling and rolling → rolling. There are several common coating methods in China:

(1) Powder coating method: The powdered hot melt adhesive is placed in a funnel, and the powder is embedded in the gap of the clothing roller by a doctor blade, and the vibration brush causes the powder to be scattered on the base cloth. After radiant heating, the hot melt adhesive melts and penetrates into the fibers of the base fabric and is fixed on the cloth surface. . In this way, the hot melt adhesive is unevenly distributed and is suitable for low-grade interlinings and temporarily bonded interlinings.

(2) Powder coating method: the powder hot melt adhesive is placed in the funnel, and the powder is embedded in the pit of the engraving roller through the scraper until the pit is filled, and the engraving roller itself is heated to make the powder portion Melt and bond into a mass. The base fabric is heated by a heating roll and passed through an engraving roll to bond the powder mass to the base fabric due to heat transfer. Thus, the size of the powder is the same, and the arrangement is arranged according to the pattern of the engraving roll, the powder point is even and tidy, and the bonding effect is good. It is suitable for the production of high-grade interlinings, especially permanent interlinings for woven fabrics.

(3) Slurry point method: firstly add hot melt glue to water and auxiliary agent to prepare slurry, then use pump to input into the round net, and apply the slurry to the base cloth through the scraper in the round net and the hole on the round net. The drying room first dries the slurry to remove moisture, and then melts and sinters. The slurry point method is more suitable for other medium and high-grade non-woven adhesive linings and woven adhesive linings with special requirements.

(4) Two-point method: The two-point method is developed on the basis of the above three coating methods. The basic principle is to consider the difference between the fabric of the base fabric and the fiber of the fabric, so the adhesive properties are also different. Therefore, two hot melt adhesives with different properties are selected to be overlapped, and the lower layer is bonded to the base fabric, and the upper layer and the fabric are bonded. Bonding to obtain a more ideal bonding effect, the bonding state is shown in Figure 1-5.

There are three methods for double-dot coating, namely double-powder method, double-paste method, and slurry-powder method. The shape is shown in Figure 1-6.

Slurry point dusting method is a combination of slurry point method and dusting method. It is also the most commonly used two-point method to produce hot-melt adhesive lining process. It is based on the slurry point method to add dusting and powder recovery device. [4]. The basic principle is to superimpose two different properties of hot melt adhesive on the base fabric according to the adhesive properties of the base fabric and the fabric. The lower layer is bonded to the base fabric, and the upper layer is bonded to the fabric to obtain a better adhesion. Combined effect. In the production, the pulp point is first coated with a round net, and the pulp point is not dried. Then, a layer of hot melt adhesive powder is sprinkled by dusting method, a part of the powder is stuck on the pulp point, and another part is not adhered to the powder. After being sucked away by the powder absorption device, it is recycled, and then dried and sintered to form a double-layer coating. The working principle is shown in Figure 1-7 [5]. In the slurry dusting method, the key is to select the mutual adhesion of the two pastes. Generally, the thermal fluidity of the upper hot melt adhesive should be greater than the thermal fluidity of the lower hot melt adhesive. It is suitable for the production of light, thin and soft medium and high-grade adhesive interlinings based on woven fabrics and medium and high-grade nonwoven fabrics. The adhesive interlining cloth produced by the pulp point coating process not only has good hand feeling and high coating amount, but also can mix and coat the hot melt adhesive materials of different properties, thereby improving the comprehensive performance of the adhesive interlining.

The double-point method is suitable for the lining cloth with high production quality requirements and difficult to bond the fabric. It has made significant progress in the development of double-point special domestic base fabric and double-point special domestic hot melt adhesive, ultra-fine base fabric and elastic base. The development of cloth has filled the blank of China's original base fabric, and the newly developed special base pulp suitable for China's double-point lining has played a pioneering role in the improvement and improvement of the domestic double-point lining. In addition, the requirements of hot-melt adhesives for double-point linings are also very strict. In recent years, domestic hot melt adhesive manufacturers have developed a large number of special rubber types, and have successfully developed a low-melting, soft-feel PA series suitable for double-point lining. Special glue, special PES glue, and developed special hot melt adhesives such as PES-A and PES-U.

The double-point adhesive lining produced by the pulp point powdering method has its own characteristics: no reverse osmosis phenomenon, uniform coating, that is, the peeling strength fluctuation amplitude after bonding is small, the bonding strength is uniform; steam pressing can be used; The second pressing, the peel strength is reduced less; the hand feels soft and rich in "soft and quite" characteristics; the thinner base fabric can be used, the amount of hot melt adhesive can also be reduced, the cost can be reduced, and the pollution can be reduced. The development of double-point coating technology has improved the overall technology of Chinese lining.