What are the points to note when welding PVC and PVDF coated fabrics

1. Temperature Control

• PVC: Avoid excessive temperatures during high-frequency welding to prevent material decomposition.
• PVDF: Precise temperature control is critical (e.g., hot plate welding at 210-230°C). Overheating may cause decomposition, releasing toxic hydrogen fluoride (HF).

2. Pressure and Time

• Apply uniform pressure during welding to avoid localized overpressure or insufficient bonding.
• Adjust melting time based on material thickness to ensure complete fusion.

3. Cleanliness

• Thoroughly clean surfaces before welding to remove oil, dust, and moisture.
• PVDF is hygroscopic: Preheat in an oven at 80-100°C for 2-4 hours to remove absorbed moisture prior to welding.

4. Cooling and Post-treatment

• Allow welded joints to cool naturally below 50°C before releasing pressure to prevent stress-induced cracking.
• Perform stress-relief annealing if necessary (e.g., 100-120°C for 1-2 hours).

5. Safety Precautions

• Wear heat-resistant gloves and safety goggles to prevent burns.
• During high-temperature PVDF welding:
  • Ventilate the workspace or use gas masks to avoid exposure to hydrogen fluoride (HF).