Synthetic leather is a term relative to "leather" (genuine leather). It is also called artificial leather and synthetic leather. There is no standard term for synthetic leather in China. It is generally divided into PVC artificial leather and PU synthetic leather according to the type of surface resin.

Classification of artificial leather

Due to the different synthetic resins used in artificial leather, different types of substrates, different production processes, whether there is foaming and different uses, artificial leather can be divided into many types. Here, artificial leather is classified according to the synthetic resin used, substrate, whether there is foaming, production process and use.

Resin classification

1. Polyvinyl chloride artificial leather

It is a mixture of polyvinyl chloride resin, plasticizer and other compounding agents, coated or laminated on fabric, and made into a plastic product through a certain processing process. In addition, there is also double-sided polyvinyl chloride artificial leather with plastic layers on both sides of the substrate.

2. Polyamide artificial leather

It is a plastic product with a continuous cellular structure made by coating nylon 6 or nylon 66 solution on fabric using a wet film-forming method.

3. Polyolefin artificial leather

Polyethylene artificial leather is a foamed artificial leather made of low-density polyethylene resin as the main raw material, mixed with modified resin, cross-linking agent, lubricant, foaming agent and other components.

4. Polyurethane artificial leather

Polyurethane artificial leather is divided into dry polyurethane artificial leather and wet polyurethane artificial leather. The so-called dry polyurethane artificial leather refers to a multi-layer structure composed of a multi-layer film obtained by evaporating the solvent from the solution of solvent-based polyurethane resin and a base fabric. The wet polyurethane artificial leather is a multi-layer structure with good air permeability and moisture permeability and a continuous porous layer obtained by using a film-forming method in water on a solvent-based polyurethane resin.

In addition to the above four main types of artificial leather, there are also polyurethane-polyvinyl chloride composite artificial leather, rubber-plastic nylon canvas leather, etc.

Base material classification

！！ Plain cloth, bleached cloth, dyed plain cloth-based artificial leather -

！！Canvas-based artificial leather

Cotton cloth-based artificial leather

Knitted cloth-based artificial leather

！！Raised cloth-based artificial leather

！！Nylon spun polyurethane artificial leather

Synthetic fiber-based-wet single-coated polyurethane artificial leather

Fiber-based-paper-based polyvinyl chloride artificial leather

！！Non-woven fabric-based artificial leather

Currently, the base materials used in China are various types of cotton cloth, such as plain cloth, bleached cloth, dyed plain cloth, canvas, knitted cloth (including synthetic fiber), raised cloth, recycled cloth, non-woven fabric, etc.; some use cotton/chemical fiber blended cloth, such as nylon knitted cloth, etc.; a small amount of chemical fiber cloth, such as nylon silk, polyester silk, etc.; and synthetic fiber non-woven fabrics are rare. With China's reform and opening up, technological progress and the rapid development of the petrochemical industry, chemical fiber cloth and synthetic fiber non-woven fabrics will develop rapidly.

Classification by foaming or not

This classification method is currently limited to PVC artificial leather, which can be divided into non-foamed PVC artificial leather and foamed PVC artificial leather.

Classification of production methods

1. Direct scraping method artificial leather

The rubber material is directly scraped on the pre-treated base fabric with a scraper, and then put into the plasticizing box for gelation and plasticization, and then embossed, cooled and other processes to obtain the finished product. This method can produce ordinary artificial leather, film artificial leather and foam artificial leather with various cloth bases.

2. Transfer scraping method artificial leather

The transfer scraping method is also called the simple scraping method. The carrier used is release paper or stainless steel belt, so it is divided into release paper method and steel belt method. It is to apply the paste on the carrier with a reverse roller or a scraper, and after gelation, the base fabric is compounded on the gelled material layer without tension, and then plasticized, cooled, and peeled from the carrier, and then processed to obtain the finished product. This method is suitable for the production of ordinary artificial leather, foam artificial leather and dry polyurethane artificial leather based on knitted fabric, plain fabric, raised fabric, or non-woven fabric.

3. Calendering and laminating artificial leather

According to the formula requirements, the resin, plasticizer and other compounding agents are measured and put into the kneading machine for uniform mixing, and then plasticized by a mixer or extruder, and then sent to a three-roll or four-roll calender to calender into a film of the required thickness and width, and laminated with the pre-heated base fabric, and then embossed and cooled to obtain the finished product. This method is suitable for the manufacture of polyvinyl chloride artificial leather, floor leather and polyvinyl chloride artificial leather with various cloth bases.

4. Artificial leather by extrusion lamination

Mix the resin, plasticizer and other compounding agents evenly in a kneader, and then extrude them into a film of a certain thickness and width through an extruder after plasticization. Then, laminate them with the preheated base cloth on a three-roller setting machine, and then preheat, laminat, emboss, and cool them to obtain the finished product. This method is suitable for the production of thicker products, such as floor leather, conveyor belts, etc.

5. Artificial leather by round screen coating

Artificial leather is produced by coating the latex polyvinyl chloride paste resin configured in the formula through a round screen on the cloth base with a scraper. This method is suitable for the production of polyvinyl chloride artificial leather and floor leather.

6. Wet artificial leather

This method is in contrast to the dry method. Its definition can be found in polyamide artificial leather. This method is suitable for the production of wet polyurethane artificial leather, polyamide artificial leather, etc.

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