What materials are suitable for high-frequency machine heat sealing

Thermoplastic Materials for High-Frequency Welding

I. Common Thermoplastics

1. PVC (Polyvinyl Chloride)

   • Preferred for HF welding
   • Applications: Inflatables (swimming rings, air mattresses), rainwear, tents
   • Key properties: Dielectric loss factor 0.08-0.12 (1MHz), weld strength ≥15 N/15mm

2. PET (Polyethylene Terephthalate)

   • Requires polar group modification (e.g., glycol-modified PET)
   • Applications: Packaging laminates, flexible films
   • Weld parameters: 180-220°C @ 40.68MHz

3. PU (Polyurethane)

   • Used for leather/textile composites
   • Typical uses: Automotive interiors (dashboards, door panels), footwear
   • Peel strength: ≥20 N/25mm (ISO 11339)

4. TPU (Thermoplastic Polyurethane)

   • Maintains 90-95% elasticity post-welding
   • Medical applications: Orthopedic braces, compression sleeves
   • Shore hardness: 70A-85A

II. Polar Group-Containing Composites

• Material Combinations
  PVC/nylon fabrics (interlayer adhesion ≥8 N/cm)
  PET/aluminum foil laminates (used in barrier packaging)
• HF Compatibility: Requires dielectric constant ≥3.0 (ASTM D150)

III. Specialized Materials

1. EVA (Ethylene-Vinyl Acetate)

   • Requires 12-18% VA content for HF compatibility
   • Applications: Yoga mat welding, shoe midsoles

2. Modified Rubbers

   • Polar additives: 5-10% carbon black/silica
   • Processable types: Chlorosulfonated PE (CSM), polar silicone rubbers

Advantages of HF Welding Technology

This technology enables energy savings of 30-40% compared to ultrasonic welding, while achieving consistent weld quality (Cpk≥1.67) for mission-critical applications across automotive, medical, and consumer goods industries.