Vacuum Insulation Outer Packing Material to Prevent Bending Cracks
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Solution Overview
Problem
Existing outer packing materials for vacuum insulation materials tend to develop minute cracks when bent, leading to a degradation in thermal insulation properties, as they lack sufficient flexibility and stress distribution to prevent crack formation during bending.
Innovation Solution
The outer packing material is composed of a thermally weldable film and a gas barrier film, with a specific combination of tensile elasticity and thickness that ensures a product value of 3.0 MPa·mm^3 or less, and a push-in elasticity of the thermally weldable film of 0.8 GPa or more, which inhibits the generation of minute cracks when bent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outer packing material is made with conventional gas barrier film and thermally weldable film, then gas barrier properties and thermal welding properties are achieved, but the material develops minute cracks when bent, leading to degradation in thermal insulation properties
Solution Approach 1:
The patent changes the physical parameters of the thermally weldable film by controlling its push-in elasticity to be 0.8 GPa or more and adjusting the product of tensile elasticity and thickness to be 3.0 MPa·mm³ or less. These parameter changes enable the material to maintain both welding properties and crack resistance during bending operations.
Solution Approach 2:
The patent uses a composite structure consisting of a gas barrier film and a thermally weldable film with specific elastic properties. The composite material combines the gas barrier functionality of the first layer with the high push-in elasticity of the second layer, achieving both gas barrier properties and resistance to bending-induced cracks.
2Strength
If the outer packing material has high tensile elasticity and thickness, then strength is improved, but the product of tensile elasticity and thickness exceeds 3.0 MPa·mm³, causing crack generation during bending
Solution Approach 1:
The patent precisely controls the parameters of the thermally weldable film by setting the product of tensile elasticity and thickness to 3.0 MPa·mm³ or less. This parameter optimization allows the material to maintain sufficient strength while preventing excessive stress concentration during bending that would lead to crack formation.
Solution Approach 2:
The patent applies different quality requirements to different layers: the gas barrier film provides gas barrier properties, while the thermally weldable film specifically provides high push-in elasticity (0.8 GPa or more) to handle bending stresses. Each layer is optimized for its specific function rather than requiring all layers to have high tensile strength.
3Ease of manufacture
If the push-in elasticity of the thermally weldable film is low, then ease of welding is improved, but crack resistance during bending is reduced
Solution Approach 1:
The patent identifies push-in elasticity as the critical parameter for both welding performance and crack resistance. By setting push-in elasticity to 0.8 GPa or more, the material achieves optimal balance: sufficient elasticity for easy thermal welding while maintaining high resistance to bending-induced cracks through the same parameter adjustment.
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
This configuration maintains excellent thermal insulation properties by preventing crack formation in the gas barrier film during bending, ensuring the vacuum insulation material retains its insulating efficiency.
Implementation Method 1
the outer packing material is configured by a gas barrier film and a thermally weldable film
Implementation Method 2
gas barrier properties to inhibit gas from passing there through
Data Source
AI summary
An outer packing material for vacuum insulation material by having a thermally weldable film and a gas barrier film in this order; wherein the product of the tensile elasticity of the outer packing material for vacuum insulation material and the cube of a thickness of the outer packing material for vacuum insulation material is 3.0 MPa·mm3 or less; and push-in elasticity of the thermally weldable film is 0.8 GPa or more.