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The manufacturing process of automotive air bags (taking car seat ventilation bags as an example) mainly revolves around material selection, structural design, automated production processes, and key technologies, as detailed below:
I. Material Selection and Adaptability The core materials for automotive seat ventilation bags must balance breathability, durability, and environmental friendliness. Common combinations include:
TPU (Thermoplastic Polyurethane): Due to its high elasticity, abrasion resistance, and oil resistance, it has become the main material for ventilation bags, especially suitable for seat structures that require frequent deformation.
Non-woven fabric: As a base material, it provides support and enhances breathability. When combined with TPU, it forms a "TPU + non-woven fabric" structure, balancing strength and comfort.
PE (Polyethylene): Some products use a "PE + non-woven fabric" combination, which is lower in cost, but its breathability is slightly inferior to TPU.
Material Adaptability: Different car models have different requirements for the size, shape, and elasticity of the ventilation bags. For example, Mercedes-Benz E-Class seats require high-elasticity TPU ventilation bags to match their ergonomic design, while economy models may use a PE + non-woven fabric combination to reduce costs.
II. Structural Design: Ventilation Frame and Airtightness
The internal structure of the ventilation bag directly affects its ventilation effect and durability. Core design elements include:
Ventilation Frame: A plastic frame is embedded within the TPU or PE layer to form regular ventilation channels, ensuring even air distribution. The frame design must avoid sharp edges to prevent material puncture.
Airtightness Structure: The edges of the ventilation bag are welded using high-frequency welding technology to create a seamless seal, preventing air leakage. Some high-end products add reinforcing ribs at the weld points to improve tear resistance.
Case Study: A certain brand of ventilation bag uses a honeycomb ventilation frame, combined with a TPU + non-woven fabric structure, achieving a ventilation volume of 50 liters per minute and remaining leak-free after 100,000 consecutive uses.
III. Automated Production Process
Modern automotive ventilation bag production is highly automated. Taking the Puxiong automotive seat ventilation bag automated production line as an example, the process is as follows:
Roll Loading: TPU or PE rolls are automatically loaded onto the production line by robotic arms, reducing manual intervention.
Automatic Cutting: A laser cutting machine precisely cuts the material according to preset dimensions, with an error controlled within ±0.1mm.
High-Frequency Welding:
Fully Automatic Mode: Material is conveyed to the high-frequency welding machine via a slide table. High-frequency electromagnetic waves cause frictional heat between material molecules, instantly fusing the ventilation frame and outer layer material.
Semi-Automatic Mode: Employs a dual-station slide table high-frequency welding machine with manual positioning assistance, suitable for small-batch production.
Automatic Material Discharge and Waste Recycling: Finished products are output via conveyor belt, and waste is collected by a dust collection system, achieving zero waste.
Efficiency Comparison: A fully automatic production line can produce 200 ventilation bags per hour, while the semi-automatic mode can only complete 80. However, the semi-automatic mode is more flexible during mold changes and suitable for multi-variety production.
IV. Key Technologies: Integrated High-Frequency Welding and Fusion Cutting
High-frequency welding is the core technology in ventilation bag production. Its advantages include:
Precise Fusion Cutting: High-frequency electromagnetic waves only heat material molecules, without damaging the surface, resulting in weld strength consistent with the raw material.
Integrated Fusion Cutting: Some equipment can complete edge fusing simultaneously with welding, eliminating the need for subsequent trimming processes. For example, Shanghai Puxiong's high-frequency heat sealing machine, equipped with a synchronous melting function, can achieve simultaneous "welding-cutting," reducing single-piece production time to 3 seconds.
Environmental friendliness: High-frequency welding eliminates the need for glue, avoiding volatile organic compound (VOC) emissions and meeting automotive interior environmental standards.
V. Quality Inspection and Standards
After production, the ventilation bags must pass the following tests:
Air tightness test: Inflate the ventilation bag to 0.5 Bar and immerse it in water to observe for leaks.
Durability test: Simulate 100,000 seat deformations to check for cracks or deformations in the ventilation bag.
Environmental testing: Test the content of heavy metals, phthalates, and other harmful substances in the materials to ensure compliance with international standards such as REACH and RoHS.