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"Ventilation bag" typically refers to the airflow guiding layer in the ventilated seat cushion or backrest, a core component of automotive seat ventilation systems. It is made of multiple layers of functional materials (such as 3D mesh fabric, porous breathable membrane, non-woven fabric, etc.) through a heat-sealing process to guide and evenly distribute airflow.
Below is a systematic analysis of the technical points, processes, and applications of this specialized heat-sealing machine.
I. Core Concepts and Products
Ventilation Bag: Unlike an airbag, it is part of the seat ventilation module. Its function is to deliver airflow from a small fan evenly, quietly, and without obstruction to the entire surface of the seat that contacts the occupant, achieving cooling or heating ventilation.
Structure: Typically a multi-layered composite structure, for example:
Top Layer: Breathable 3D spacer mesh fabric (provides support and airflow space).
Middle Layer: TPU/PE film or non-woven fabric with a specific perforation pattern (guides airflow direction).
Bottom Layer: Sealing or adhesive layer (bonded to the fan vents and heating pad).
Purpose of Heat Sealing: To precisely weld these layers of material together, forming pre-defined airflow channels, sealing boundaries, and fixing points, while ensuring that the weld is either airtight (sealing the air passage) or airtight (connecting the air passage) to achieve complex airflow distribution designs.
II. Types and Technologies of Specialized Heat Sealing Machines
Based on the materials, design complexity, and production scale of the ventilation bag, the following heat sealing processes and corresponding equipment are mainly used:
High-Frequency Heat Sealing Machine (High-Frequency Heat Sealing Machine)
Applicable Materials: This is the first choice when the ventilation bag contains polar thermoplastic materials, such as TPU film or certain PVC-coated fabrics.
Working Principle: Utilizes a high-frequency electromagnetic field to generate heat and fuse the internal molecules of the material through friction.
Equipment Features:
Precision Mold: The mold design is complex, not only including sealing outer frame weld lines, but more importantly, the internal weld lines have numerous breaks, dotted lines, or special patterns to form a labyrinthine airflow channel.
High Stability: Requires consistent weld strength to ensure reliable sealing of each air passage.
Advantages: High welding strength, good sealing performance, and fast speed, suitable for mass production.