Vacuum Insulation Panel Sealing for Thick Core Reliability

Solution Overview

Problem

Conventional vacuum heat insulating materials face issues with wrinkles, sealing defects, pinholes, and inadequate scratch and pierce resistance due to difficulties in heat sealing and pressure application, especially when using core members with larger thicknesses, which affect insulation performance over time.

Innovation Solution

The solution involves a vacuum heat insulating material with envelope members having gas-barrier properties and heat-seal layers, where uniform pressure is applied to heat-seal layers from outside to inside, extending the seal width to the edges of the core member, eliminating the need for folding and reducing the risk of wrinkles and defects, and using polyethylene terephthalate for surface protection to enhance resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional heat sealing methods are used on envelope members with core members, then sealing is achieved, but wrinkles and sealing defects occur due to difficulty in applying uniform pressure

Engineering Contradiction:

Improvesealing reliabilityVSAvoidsealing quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The envelope member is divided into a sealed portion (where heat sealing is performed) and a non-sealed portion (where the core member is exposed). This segmentation allows uniform pressure to be applied only to the sealed portion during heat sealing, preventing wrinkles and sealing defects while avoiding compression of the core member.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The envelope member has different structural characteristics in different regions: the sealed portion has heat-sealable layers suitable for heat sealing, while the non-sealed portion accommodates the core member. This local differentiation enables reliable heat sealing without compromising the core member or causing sealing defects.

Inventive Principle:

Principle #3Local quality

2Reliability

If pressure is applied to heat seal envelope members, then sealing is achieved, but the core member is compressed when using thicker core members

Engineering Contradiction:

Improvesealing reliabilityVSAvoidcore member thickness

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The envelope member is divided into a sealed portion (where heat sealing is performed) and a non-sealed portion (where the core member is exposed). This segmentation allows uniform pressure to be applied only to the sealed portion during heat sealing, preventing wrinkles and sealing defects while avoiding compression of the core member.

Inventive Principle:

Principle #1Segmentation

3Reliability

If folded portions are created in envelope members, then vacuum maintenance is improved, but manufacturing complexity increases due to difficulty in heat sealing

Engineering Contradiction:

Improvevacuum maintenanceVSAvoidenvelope structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The folded portion structure is eliminated by exposing the core member at the edges of the envelope member. The sealed portion is designed to extend to the edges of the core member, creating a simple planar structure that is easy to manufacture while still maintaining vacuum integrity through reliable heat sealing.

Inventive Principle:

Principle #2Taking out (Extraction)

4Reliability

If heat-seal layers are made wider in the peripheries, then vacuum deterioration is suppressed, but manufacturing difficulty increases

Engineering Contradiction:

Improvevacuum maintenanceVSAvoidheat sealing ease

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The envelope member is divided into a sealed portion (where heat sealing is performed) and a non-sealed portion (where the core member is exposed). This segmentation allows uniform pressure to be applied only to the sealed portion during heat sealing, preventing wrinkles and sealing defects while avoiding compression of the core member.

Inventive Principle:

Principle #1Segmentation

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 approach ensures secure, long-term reliable heat sealing with improved sealing performance, reduced pinholes, and enhanced resistance to scratches and pierces, maintaining insulation efficiency even with thicker core members.

Implementation Method 1

The heat-seal layers are heat sealed to each other by heating the entire envelope members to a temperature at which the heat-seal layers are melted

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 2

the heat-seal layers are heat sealed to each other by applying uniform pressure from outside to inside the envelope members

Methodology Applied

Scientific EffectCompression: Compression

Data Source

PatentUS8753471B2Vacuum heat insulating material, method of producing vacuum heat insulating material, and heat insulating box body using vacuum heat insulating material

Publication Date: 2014.06.17 PANASONIC HOLDINGS CORP

AI summary

Disclosed is a vacuum heat insulating material. Also disclosed is a heat insulating box using the vacuum heat insulating material. The vacuum heat insulating material includes a core member and envelope members having gas-barrier properties and including heat-seal layers. The envelope members are opposed to each other in such a manner that the core member is disposed between the heat-seal layers. The envelope members are entirely heated to a temperature at which the heat-seal layers are melted, and the heat-seal layers are heat sealed to each other by applying uniform pressure to the entire envelope members from outside to inside the envelope members.