Airbag Cover Composite Structure for Seamless Tearable Sewing
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Solution Overview
Problem
Current composite structures for airbag covers lack flexibility and softness, making them difficult to process and sew, while also requiring material weakening for safe airbag deployment without visible seams.
Innovation Solution
A composite structure comprising a foam layer with a density of 40 to 100 kg/m3, a cover layer with specific thermoplastic sublayers, and a lacquering layer, which allows for tearable coatings without material weakening, enhancing haptics, handling, and sewing properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If foam laminates with high density foam layer are used for airbag covers, then tearing properties and structural strength are improved, but flexibility and softness deteriorate, making them difficult to process and sew
Solution Approach 1:
The patent applies parameter changes by precisely controlling the foam layer density within 40-100 kg/m3 and gel content within 20-80%, along with specifying Shore A hardness of 20-45. These parameter optimizations enable the foam layer to provide sufficient structural strength and tearing properties while maintaining flexibility and softness for easy processing and sewing operations.
Solution Approach 2:
The patent employs composite materials by combining the foam layer with a cover layer having specific gel content (0-20%) and thermoplastic properties. This composite structure integrates the cushioning and strength benefits of foam with the structural integrity and processability of thermoplastic materials, resolving the contradiction between strength and ease of operation.
2Reliability
If material weakening is provided in the cover for airbag deployment, then airbag deployment safety is improved, but visual appearance and design quality deteriorate due to visible seams
Solution Approach 1:
The patent extracts the material weakening function from the visible cover surface and relocates it to the foam layer through controlled density variations and gel content distribution. This allows the cover to maintain a seamless, aesthetically pleasing appearance while the underlying foam structure provides the necessary material weakening for safe airbag deployment.
Solution Approach 2:
The patent utilizes porous foam materials with controlled density (40-100 kg/m3) and gel content (20-80%) to create internal material weakening. The porous structure allows for controlled deformation and energy absorption during airbag deployment, providing safety functionality without requiring visible seams or weakenings in the outer cover.
3Ease of manufacture
If the thickness of the composite structure is reduced, then manufacturing costs are lowered, but haptics and handling during processing deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing the thickness and density distribution within the composite structure. By controlling foam layer density (40-100 kg/m3), gel content (20-80%), and Shore A hardness (20-45), the patent achieves cost-effective thin-section construction that maintains adequate haptics and handling properties during processing.
Data Source
AI summary
The present invention provides a composite structure, a method for its manufacture, a sewing product containing the composite structure, and a method for manufacturing the sewing product. The composite structure has a Shore A hardness according to DIN 53505 of 20 to 45 and comprises a foam layer, a cover layer and a lacquering layer in this order, wherein the foam layer has a density of 40 to 100 kg/m3 and a gel content of 20 to 80% and contains a polyolefin and the cover layer has a gel content of 0 to 20%, is thermoplastic and comprises at least two compact sublayers each comprising at least one thermoplastic selected from polyolefin and polyvinyl chloride.