How is artificial leather produced?

How is artificial leather produced?

Artificial leather, also known as synthetic leather or faux leather, is a material that closely resembles natural leather in appearance and feel, but is entirely made through synthetic or artificial processes. It is typically produced by applying or impregnating a polymer resin (mainly PVC or PU) onto a textile fabric base. The material then undergoes processes such as foaming, embossing, dyeing, and surface treatment to complete its production.

Compared to traditional natural leather, artificial leather offers significant advantages in cost, environmental impact, and production processes, which is why it is widely used in a variety of areas, such as bag manufacturing, furniture production, and automotive interiors production.

Today, let's explore the production process of artificial leather and the technology behind it.

I Raw Material Preparation: Substrate and Polymers

1．Substrate

The substrate of artificial leather refers to the bottom layer support material, which determines the texture, flexibility, and durability of the synthetic leather. Common substrates for artificial leather include the following types:

• Woven Fabric: Also known as shuttle-woven fabric, it is stiff and strong. This type of leather has a stable structure, making it suitable for making faux leather handbags, synthetic leather briefcases, and other bags that require shape retention.
• Knitted Fabric: Soft and highly stretchable, often used for shoe uppers and clothing, it can also be used to make leather casual backpacks or leather fashion tote bags.
• Nonwoven Fabric/Needle-Punched Felt: Fluffy and easily permeable, when combined with wet-process PU, it can form continuous micro-holes, offering good breathability.
• Microfiber Nonwoven Fabric: Made from 2–5 µm island-type ultrafine fibers that are needle-punched into a high-density felt, then further fiber-processed to form a “three-dimensional mesh” structure similar to the collagen fibers of natural leather, serving as the substrate for high-end microfiber leather.

2．Polymer Formulation

The polymer formulation for artificial leather is typically a combination of synthetic polymers and various additives to achieve the desired properties such as flexibility, abrasion resistance, waterproofing, etc. Below are common polymer formulations for artificial leather and their components:

(1) Polyvinyl Chloride (PVC) Artificial Leather Formulation

PVC artificial leather is one of the most common types. Its polymer formulation typically includes the following components:

• Polyvinyl Chloride Resin (PVC Resin): This is the primary component of PVC artificial leather, providing structure and strength.
• Plasticizer: Plasticizers are used to improve the softness and flexibility of PVC. Common plasticizers include phthalates (such as DOP, DINP) and non-phthalate plasticizers (such as DOA).
• Stabilizer: To prevent thermal degradation of PVC resin during processing, stabilizers are added, such as lead salts, calcium-zinc stabilizers, etc.
• Filler: Fillers are typically used to reduce costs and increase the rigidity of the material. Common fillers include calcium carbonate, talc powder, etc.
• Pigment: Pigments are used to color artificial leather, and they are selected based on the required color. Common types include inorganic and organic pigments.
• Toughening Agent: Sometimes, toughening agents (such as rubber or resin-based agents) are added to enhance the impact resistance and durability of artificial leather.

(2) Polyurethane (PU) Artificial Leather Formulation

PU artificial leather is closer in texture to natural leather compared to PVC and is often used for high-end leather products. Its formulation typically includes:

• Polyurethane Resin (PU Resin): The core component of PU artificial leather, usually produced by the reaction of isocyanates with polyether or polyester polyols.
• Solvent: Solvents are used to dissolve the PU resin and other additives, facilitating the coating process. Common solvents include alcohols, ether solvents, etc.
• Plasticizer: Used to enhance the flexibility of PU, typically compatible plasticizers are selected, such as phthalate-based plasticizers or non-phthalate plasticizers.
• Catalyst: Catalysts are used to accelerate the reaction process. Common catalysts include tin-based compounds (such as tin salts) or other organic catalysts.
• Crosslinking Agent: Crosslinking agents help form chemical bonds between polyurethane molecules, improving mechanical properties and heat resistance.
• Filler: Fillers are sometimes added to improve the performance of artificial leather, for example, to enhance abrasion resistance or reduce costs.

(3) Thermoplastic Polyurethane (TPU) Artificial Leather Formulation

Thermoplastic polyurethane (TPU) artificial leather performs well in flexibility and abrasion resistance, and is commonly used in products such as footwear and sports equipment. Common components include:

• Thermoplastic Polyurethane (TPU) Resin: TPU is the primary substrate, offering good flexibility and transparency.
• Plasticizer: Plasticizers are sometimes added to further improve softness and increase comfort.
• Stabilizer: Stabilizers are used to improve the thermal stability of polyurethane, preventing degradation during processing.
• Colorant: Different pigments or dyes are added as needed to achieve the desired color.
• Filler: Fillers such as calcium carbonate or talc powder may be added to improve the rigidity of the material or reduce costs.

(4) Other Common Polymer Formulations

In addition to PVC, PU, and TPU, there are other types of polymers that can be used in the production of artificial leather, such as:

• Acrylic Polymer: Used for certain special-purpose artificial leathers, offering high gloss and good transparency.
• Polypropylene (PP) Polymer: Sometimes used to make high-performance artificial leather with special chemical resistance and UV protection.
• Polyethylene (PE): Although less common, it is sometimes used in low-cost applications or products requiring high waterproof performance.

II. Coating Process: Formation of the Plastic Layer

One of the core processes in artificial leather production is the coating process. Taking PVC as an example, the production process typically includes the following steps:

1.Raw Material Mixing: PVC resin, plasticizers, stabilizers, pigments, and other raw materials are mixed in proportion to create a coating compound.

2.Coating: The mixed coating compound is evenly applied to the substrate (such as textile fabric). During the coating process, mechanical equipment is typically used, such as rollers or scrapers, to spread the coating onto the fabric surface, forming a uniform layer.

3.Heating and Curing: The coated substrate is heated to evaporate the solvent in the coating, ultimately forming a solid plastic layer. This process ensures that the coating firmly bonds to the substrate and imparts the appearance and feel of leather.

4.Embossing and Polishing: To mimic the texture and feel of natural leather, different patterns are often embossed onto the surface of artificial leather using embossing machines. Additionally, the surface may be treated with a gloss or waterproof agent to enhance its appearance and durability.

III. Post-Treatment: Adjusting Physical Properties

During the production process, artificial leather also undergoes several post-treatment processes to enhance its quality and functionality. Common post-treatment steps include:

1.Hot Pressing and Cooling: To improve the strength and flexibility of artificial leather, it is typically subjected to a hot pressing process. This helps form a more durable material structure.

2.Coating Treatment: Some artificial leather products receive additional coatings, such as waterproof coatings or UV-resistant coatings, to enhance their durability and comfort.

3.Dyeing and Spraying: If specific color effects are required, the surface of artificial leather may undergo dyeing or spraying treatments to make the color more vivid and uniform.

IV. Testing and Quality Control: Ensuring Compliance with Standards

Quality control is crucial during the production process. To ensure that artificial leather meets the required standards, rigorous testing is typically conducted:

1.Abrasion Resistance Test: This test measures the abrasion resistance of artificial leather, especially for products like bags and footwear that experience prolonged friction.

2.Tensile Strength Test: This test evaluates whether the artificial leather will tear or break under stretching.

3.Moisture and Humidity Test: Ensures that the artificial leather does not deform or deteriorate in damp or humid environments.

4.Environmental Testing: Checks whether the materials used in the production process comply with environmental standards and if they contain any harmful substances.

V. Applications and Market

As people become more concerned about environmental protection and animal welfare, an increasing number of brands and consumers are choosing artificial leather products. Artificial leather not only resembles natural leather in appearance but also offers advantages in cost, maintenance, and durability. It is widely used in the following fields:

• Bags and Apparel: Fashion brands are increasingly opting to use artificial leather to manufacture bags, shoes, belts, and other products.
• Automotive Interiors: Many car seats, steering wheels, and interior decorations are made from artificial leather, offering comfort while reducing costs.
• Furniture: Many modern furniture items, such as sofas and chairs, also use artificial leather as an alternative material.

In summary, with the continuous improvement of production processes and the increasing demand for environmental protection, the application prospects of artificial leather are very promising. From raw material selection to coating processes, post-treatment, and quality testing, every step relies on precise craftsmanship and technology. In the future, with the emergence of more innovative techniques, artificial leather will showcase its unique appeal in more fields and become an indispensable part of daily life.

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