The material and heat sealing process of the car lumbar support airbag

I. Material Selection
TPU (Thermoplastic Polyurethane)
Properties: TPU is a polymer material with excellent elasticity, abrasion resistance, high impact resistance, and biocompatibility, ensuring no skin irritation or allergic reactions.
Application: As the preferred material for automotive lumbar support airbags, TPU is suitable for high-frequency heat sealing processes due to its excellent thermoplasticity and processability.

PVC (Polyvinyl Chloride)
Properties: PVC offers good wear resistance, corrosion resistance, and lower cost.
Application: Commonly used in budget-friendly automotive lumbar support airbags, though its elasticity and comfort are slightly inferior to TPU.

Other Materials
Polyamide 66 (PA66): High strength, low initial modulus, excellent elongation, and high enthalpy, suitable for airbags requiring high strength.
Polyester (PET): Offers high strength, shape retention, chemical resistance, and heat resistance, but with higher costs.

II. Heat Sealing Process
High-Frequency Heat Sealing
Principle: High-frequency electromagnetic waves generate heat through molecular vibration and friction, melting the material, which then solidifies under pressure to create a strong bond.
Equipment: High-frequency heat sealing machines (e.g., four-station rotary table-type machines) with automated efficiency and precise control.
Advantages:

• Automation: Four-station rotary design doubles production efficiency.
• Precision Control: PLC programming and touchscreen interfaces enable precise settings for time, temperature, and pressure.
• Reliability: Durable construction with cold-cutting and edge-trimming functions ensures smooth, airtight seams.

Parameter Control

• Temperature: Adjusted based on material type (e.g., 150–200°C for TPU).
• Time: Optimized for material thickness and temperature to ensure complete melting and solidification.
• Pressure: Ensures tight bonding and structural stability for airtightness.

Process Flow

1. Material Preparation: Cut materials into required shapes/sizes per design.
2. Heat Sealing: Assemble airbag components using the heat sealing machine.
3. Quality Inspection: Check appearance and conduct airtightness tests to meet standards.

III. Precautions

• Material Compatibility: Verify materials are suitable for high-frequency heat sealing to avoid bonding failures.
• Equipment Maintenance: Regularly service machines for stable performance.
• Safety: Operators must wear protective gear to minimize exposure to high-frequency electromagnetic waves.