The intrinsic difference between synthetic leather and synthetic leather

In daily testing, it is common to encounter synthetic leather materials and fabrics, but currently there is no relevant identification method standard or accurate definition in China, resulting in a lack of accurate basis when issuing reports, and can only be judged based on experience or habits, leading to confusion in labeling. Therefore, it is necessary to establish reasonable classification principles for synthetic leather and synthetic leather before the relevant identification method standards are issued.

Definition and classification in relevant domestic standards and literature

1.1 Definition and classification in relevant domestic standards

At present, there are about a dozen standards related to synthetic leather in China, and their definitions and classification methods are mainly based on several aspects such as base materials, coating materials, and production processes. The detailed content is shown in Table 1. Among these standards, only GB2192-2008 [1] has clear definitions for synthetic leather and synthetic leather [1-12].

Synthetic leather: refers to a material that is artificially synthesized to form a polyurethane resin film layer or a leather like structure on a base cloth made of woven, non-woven (non-woven), leather, or other materials, with an appearance similar to natural leather; Artificial leather: refers to a material that is artificially synthesized to form a film layer of polyvinyl chloride or other resin or a structure similar to leather on a base cloth (including no base cloth) made of woven fabric, non-woven fabric (non-woven fabric) or other materials, and has an appearance similar to natural leather.

From the definition alone, it can be basically considered that the coating material for synthetic leather is polyurethane resin, and the coating material for synthetic leather is polyvinyl chloride and other resins. However, the appearance of "polyvinyl chloride synthetic leather" in the standard "3.3 Characteristics Production Process and Equipment" contradicts this conclusion. Meanwhile, in other relevant standards, the base materials, coating materials, and production methods of synthetic leather and synthetic leather intersect with each other without clear classification principles. However, in the relevant light industry standards, synthetic leather is coated with polyurethane resin, while synthetic leather is coated with resins such as polyvinyl chloride or polyurethane resin.

The main differences between synthetic leather and synthetic leather in relevant domestic standards

1.2 Definition and division in relevant domestic literature

In China, people are used to calling artificial leather produced with polyvinyl chloride (PVC) resin PVC artificial leather (artificial leather for short); The artificial leather produced by using polyurethane (PU) resin and traditional fabrics is called PU artificial leather (abbreviated as PU leather); Artificial leather produced using PU resin and non-woven fabric is called PU synthetic leather (abbreviated as synthetic leather). This is a classification introduction of synthetic leather and synthetic leather in some literature [13-16]. Classification is mainly based on coating materials and base materials: synthetic leather is made with polyurethane resin as the coating material and non-woven fabric as the base fabric, while synthetic leather is made with polyvinyl chloride or polyurethane resin as the coating material and traditional fabric as the base fabric. However, this classification method differs significantly from the definitions or classifications in relevant standards.

Another representative classification method in literature is the Synthetic Leather Professional Committee of the China Plastics Processing Industry Association, which divides synthetic leather into PVC synthetic leather and PU synthetic leather based on different raw materials. See Table 2 [17] for details. Its classification method is similar to that of GB21902-2008 for synthetic leather and synthetic leather