Vacuum Insulation Core Structure Without Binders or Curved Fibers

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Solution Overview

Problem

Existing vacuum heat insulating materials face challenges with heat insulating performance due to bulky core materials with curved strands and the use of binders in non-woven fabric manufacturing, which can decrease thermal resistance and maintain a vacuum level effectively.

Innovation Solution

The use of linear first fibers and crimpable second fibers, where the second fibers are easily pressed by the first fibers to align orthogonally, eliminating the need for binders and enhancing the core material's shape and thermal insulation by suppressing heat movement through the thickness direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If curved strands are used in the core material, then the core material can be formed with bundled fibers, but the core material becomes bulky and heat insulating performance deteriorates

Engineering Contradiction:
Improvecore material structureVSAvoidheat insulating performance
Core Design Contradiction:
ShapeVSLoss of energy

Solution Approach 1:

The invention changes the geometric parameter of the fibers from curved to substantially straight, which eliminates the bulkiness caused by curved strands while maintaining the bundled fiber structure. This parameter change directly reduces heat transfer paths and improves heat insulating performance without sacrificing core material formability.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If binders are used to bundle glass chopped strands, then non-woven fabric can be manufactured, but contact heat resistance decreases and heat insulating performance deteriorates

Engineering Contradiction:
Improvenon-woven fabric manufacturingVSAvoidcontact heat resistance
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The invention extracts and eliminates the binder component from the non-woven fabric structure. By using substantially straight glass chopped strands that can be mechanically interlocked or entangled, the patent removes the thermal bridge created by organic binders, thereby maintaining contact heat resistance and heat insulating performance while still achieving effective fiber bundling.

Inventive Principle:
Principle #2Taking out (Extraction)

3Stability of the object's composition

If curved strands are engaged to form bundles, then the core material can be structured, but heat moves more easily in the thickness direction

Engineering Contradiction:
Improvefiber bundle structureVSAvoidheat insulating performance
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The invention changes the fiber configuration parameter from curved to substantially straight, which shortens the heat transfer path length and reduces the number of fiber-fiber contact points that act as thermal bridges. This maintains the bundled structure for stability while significantly improving heat insulating reliability.

Inventive Principle:
Principle #35Parameter changes

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 improves the heat insulating performance by reducing heat transfer through the fibers, maintaining a high vacuum level, and reducing the need for costly binder materials, thus enhancing the thermal resistance and manufacturing efficiency.

Implementation Method 1

a core material (2) and an outer covering material (3) accommodating the core material (2), wherein the core material (2) includes a plurality of web-shaped fiber bodies (4) laminated in a thickness direction of the vacuum heat insulating material (1), and each of the fiber bodies (4) includes a plurality of first fibers (5) and a plurality of second fibers (6), and the plurality of first fibers (5) and the plurality of second fibers (6) are mixed with each other in the fiber bodies (4)

Methodology Applied
Scientific EffectVacuum insulation: Vacuum

Implementation Method 2

the second fibers can be easily pressed with the first fibers while the deformation of the plurality of first fibers is suppressed. Thus, the direction of the plurality of first fibers can be brought close to a direction orthogonal to a thickness direction of the vacuum heat insulating material, and the direction of the plurality of second fibers can also be brought close to the direction orthogonal to the thickness direction of the vacuum heat insulating material

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP3534054B1Vacuum thermal insulating material, method for producing vacuum thermal insulating material, and apparatus for producing vacuum thermal insulating material
Publication Date: 2021.11.03 MITSUBISHI ELECTRIC CORP
  • EP3534054B1 patent drawingFigure 1~2
  • EP3534054B1 patent drawingFigure 3~4
  • EP3534054B1 patent drawingFigure 5~6

AI summary

Provided is a method of manufacturing a vacuum heat insulating material, including: a fiber supply step of supplying a plurality of first fibers (5) having linearity and a plurality of second fibers (6) having crimpability onto a conveyor (13); and a compression step of compressing, after the fiber supply step, the plurality of first fibers (5) and the plurality of second fibers (6) on the conveyor (13) to obtain a continuous fiber body (10) including the plurality of first fibers (5) and the plurality of second fibers (6).