Multilayer Foam Sheet Structure for Thin, Flexible Impact Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing foam sheets used in electronic devices face challenges with flexibility, impact resistance, and strength differences between machine and transverse directions, leading to potential breakage and impaired waterproofness during handling and use.
Innovation Solution
A multilayer foam sheet design with specific resin and foam layers, each having defined thickness, compressive strength, and density ratios, ensuring uniform tensile strength across directions and enhanced flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the foam sheet becomes thinner to satisfy space constraints in thin electronic devices, then the device can be made thinner, but the mechanical strength such as tensile strength decreases
Solution Approach 1:
The patent applies composite materials by combining a foam layer with a resin layer to create a multilayer structure. The foam layer provides cushioning and compression resistance, while the resin layer provides tensile strength and structural integrity. This composite structure allows the foam sheet to maintain thin thickness while recovering the mechanical strength that would otherwise be lost in thinner configurations.
Solution Approach 2:
The patent segments the foam sheet into distinct functional layers: a foam layer for compression and cushioning, and a resin layer for tensile strength and structural support. This segmentation allows each layer to independently provide its specific function, enabling the thin overall structure to maintain both cushioning and strength properties.
2Adaptability or versatility
If the foam sheet is made more flexible to improve step followability and adhesiveness, then the flexibility and adhesiveness are improved, but the tensile strength and impact resistance decrease
Solution Approach 1:
The patent uses composite materials where the foam layer provides flexibility and step followability, while the resin layer provides tensile strength and impact resistance. The combination allows the material to simultaneously achieve both flexibility and strength, resolving the contradiction between these properties.
Solution Approach 2:
The patent applies local quality by assigning different functional properties to different layers: the foam layer is optimized for flexibility and cushioning, while the resin layer is optimized for strength. This local differentiation of material properties allows the overall structure to exhibit both flexible and strong characteristics.
3Strength
If the foam sheet has high tensile strength to prevent damage during rework, then the tensile strength is improved, but the flexibility and step followability decrease
Solution Approach 1:
The patent employs composite materials where the resin layer provides high tensile strength to prevent damage during rework, while the foam layer maintains flexibility and step followability. This composite structure enables the foam sheet to simultaneously achieve high tensile strength and flexibility, resolving the contradiction between these opposing requirements.
4Length of moving object
If the foam sheet is made thinner to reduce overall device thickness, then the device can be made thinner, but the waterproofness may be impaired
Solution Approach 1:
The patent applies composite materials where the resin layer provides a waterproof barrier that prevents water penetration, while the foam layer provides cushioning. This composite structure enables thin overall thickness while maintaining effective waterproofness through the resin layer's barrier property.
Data Source
AI summary
A multilayer foam sheet having a resin layer and a foam layer on each of both sides of the resin layer, wherein the thickness of the resin layer is 10 μm or more, and the 25% compressive strength is 1000 kPa or less. A foam sheet having high impact resistance and flexibility can be provided.