Mainstream Processing Technologies for PVC Fabrics: Calendering, Coating, and Lamination Technologies

Calendering Process

Calendering is a fundamental process in PVC fabric production.  It involves mixing PVC resin with additives under high temperature and pressure, extending the mixture into a thin film, and then laminating it with a base fabric to form a composite material.

1. Process Flow

Formula Design: PVC resin, plasticizers (such as DOP), and stabilizers (such as calcium-zinc salts) are mixed in specific proportions to ensure material flexibility and weather resistance.

Calendering and Forming: The mixture is heated to 160-180℃ in a calendering machine and extruded through rollers to form a thin film of uniform thickness (0.05-1mm). After cooling, it is peeled off and prepared for further processing.

Lamination with Base Fabric: The film and pre-treated base fabric (such as polyester non-woven fabric) are laminated under pressure at high temperature (150-180℃). After cooling, PVC leather is formed.

2. Technical Advantages

High-precision control: Four-roll calendering machines can achieve a thickness error of ≤0.02mm, suitable for high-end luggage and automotive interiors.

Environmental friendliness: Modern equipment uses low VOCs emission technology, conforming to green production trends.

Application scenarios: Shoe leather (wear-resistant and anti-slip), industrial packaging leather (pressure-resistant and shock-absorbing).

Coating Process

The coating process uses a coating machine to evenly apply PVC paste onto the surface of a substrate, forming a protective or decorative layer, especially suitable for PVC coated fabrics.

1. Core Steps

Substrate Pre-treatment: The base fabric (such as polyester mesh fabric) needs to be desized, dried, and flattened to ensure a surface flatness deviation of ≤0.05mm.

Coating Formula: PVC resin, plasticizers, and fillers (calcium carbonate) are mixed in specific proportions, controlling the viscosity to 2000-5000 mPa·s. Coating and Plasticizing: The doctor blade gap is adjusted to 0.1-0.3mm. After coating, the material is foamed and shaped in an oven at 180-200℃ to form a closed-cell structure (cell diameter 50-200μm).

2. Technical Highlights

Functional Enhancement: Abrasion-resistant agents (such as PTFE micropowder) can be added to improve surface scratch resistance, or antibacterial agents can be introduced to meet the needs of medical supplies.

Economical: Raw material utilization rate is over 95%, suitable for large-scale production.

Application Scenarios: Advertising light box fabric, rainproof tarpaulin, water sports equipment.

Lamination Process

The lamination process combines PVC film with base fabric or other functional layers through hot pressing, giving the material composite properties.

1. Key Technologies

Base Fabric Selection: Commonly used polyester non-woven fabric (breaking strength ≥10N/cm) or lace fabric, requiring pre-treatment to improve adhesion.

Hot Pressing Parameters: Temperature 160-190℃, pressure 2-4MPa, time 3-5 minutes, ensuring no bubbles between layers.

Post-treatment: Embossing (depth 0.1-0.3mm) to enhance wear resistance, or coating with an abrasion-resistant coating (such as polyurethane) to improve scratch resistance.

Conclusion

Calendering, coating, and lamination processes are driving PVC fabrics towards high performance and environmental friendliness. In the future, with the integration of intelligent manufacturing and new material technologies, PVC coated fabrics will unleash greater potential in new energy, medical, and other fields.