Expanded Laminate Impact Resistance via Direct Bonding
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Solution Overview
Problem
Conventional expanded materials used in snow and surf boards, such as EPS, are prone to dents and unable to return to their original shape due to impact compression, lacking effective impact resistance and cushioning.
Innovation Solution
An expanded laminate comprising a plastic sheet directly bonded to upper and lower surfaces of first and second expanded layers, with the plastic sheet made of polyethylene or similar materials, and the expanded layers made of EPE or EPP, effectively distributing and cushioning impacts without using adhesives or additional bonding layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional expanded materials (EPS) are used, then the product is light and inexpensive, but the material cannot return to its original shape after impact compression
Solution Approach 1:
The patent uses a composite structure combining expanded polyethylene (EPE) and expanded polypropylene (EPP) layers bonded directly to each other. EPE provides excellent cushioning and energy absorption, while EPP offers high elasticity and shape recovery. This composite material approach resolves the contradiction by combining materials with complementary properties to achieve both impact resistance and shape recovery.
Solution Approach 2:
The patent specifies foam density between 1.2 pcf and 8 pcf for the expanded layers, optimizing the balance between softness for cushioning and firmness for structural support. By controlling density parameters, the material achieves both compliance for impact absorption and rigidity for shape maintenance.
2Device complexity
If a single expanded core with expanded skin is used, then the structure is simple, but the product is prone to dents under impact
Solution Approach 1:
The patent creates a composite laminate structure with multiple expanded layers (EPE and EPP) directly bonded together without adhesives. This multi-layer composite provides superior dent resistance compared to single-layer structures, while the direct bonding method keeps the manufacturing process simple and avoids additional bonding layers.
Solution Approach 2:
The expanded core is divided into multiple functional layers with different densities and properties. The first expanded layer and second expanded layer are segmented to perform different functions: one provides primary cushioning while the other provides structural support and dent resistance, achieving enhanced protection without significant complexity increase.
3Strength
If adhesive or bonding layer is used to attach expanded layers, then the bonding strength is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The expanded layers are designed to bond directly to each other through their inherent surface properties and compression during lamination. The material itself provides the bonding mechanism through heat and pressure during manufacturing, eliminating the need for separate adhesives or bonding layers. This self-bonding approach maintains strong bonds while simplifying the manufacturing process.
Solution Approach 2:
The bonding function is merged into the lamination process itself. The expanded layers are compressed and bonded simultaneously during the same manufacturing step, combining the structural assembly and bonding operations into one process. This eliminates the need for separate bonding operations and reduces manufacturing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The expanded laminate provides excellent impact resistance and cushioning, preventing dents and shock, and can be used in various products like snow boards, surfboards, and luggage, effectively distributing forces and protecting against damage.
Implementation Method 1
The first and second expanded layers are directly bonded to upper and lower surfaces of the plastic sheet
Implementation Method 2
the expanded laminate of the present invention effectively distributes and cushions impacts, forces and shock
Data Source
AI summary
An expanded laminate material includes a plastic sheet and two expanded layers. The plastic sheet has upper and lower surfaces and a thickness of between about 0.05 and 1 mm. The first expanded layer has upper and lower surfaces, a foam density of between about 1.2 and 8 pcf and a thickness of between about 1 and 8 mm. The lower surface of the first expanded layer is directly bonded to the upper surface of the plastic sheet. The a second expanded layer has upper and lower surfaces, a foam density of between about 1.2 and 8 pcf and a thickness of between about 1 and 8 mm. The upper surface of the second expanded layer is directly bonded to the lower surface of the plastic sheet. The first and second expanded layers comprise a material selected from the group consisting of expanded polyethylene and expanded polypropylene.