How are marquee fabrics heat-welded together?

I. Principles of Heat-Sealing and Splicing

High-Frequency Heat-Sealing: Utilizes high-frequency electromagnetic waves to induce molecular polarization and friction-generated heat within materials like PVC tarpaulin, achieving molecular-level fusion under pressure.

II. Heat-Sealing and Splicing Process

1. Material Preparation

Cutting and Layout: Precisely cut the tarpaulin according to the tent design dimensions, ensuring proper alignment at the seams.
Surface Cleaning: Remove oil, grease, and impurities to enhance sealing quality.

2. Heat-Sealing Operation

High-Frequency Heat-Sealing: Place the tarpaulin on the high-frequency welding machine's worktable and adjust the electrode gap and pressure. Activate the high-frequency generator to fuse the materials under a pressure of 0.3–0.5 MPa at a welding temperature of 180–220°C.

3. Hot-Air Welding: Use a hot-air gun to preheat the splicing area until the coating softens. Apply rapid pressure to fuse the two layers of tarpaulin; a welded seam forms upon cooling.

4. Quality Inspection

Strength Testing: Test the tensile strength of the seam using a tensile testing machine (requirement: ≥35 MPa).
Sealing Integrity Test: Inflate and pressurize to check for seam leakage.
Visual Inspection: Verify that the seam is smooth and free from burn marks or wrinkles.

III. Advantages of Heat-Sealing and Splicing

1. High Strength: Seam tensile strength approaches that of the base material, capable of withstanding loads such as strong winds and snow accumulation.

2. Excellent Sealing: Seams are free of pinholes and offer superior waterproofing, making them suitable for long-term outdoor use.

3. High Efficiency: High-frequency welding speeds can reach 15 meters per minute, making it ideal for large-scale production.

4. Weather Resistance: Seam aging resistance matches that of the base material, ensuring a long service life.