Vacuum-Insulated Refrigerator Door Panel With Airtight Dual Skins

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional household refrigeration appliances face challenges in achieving effective thermal insulation due to the limitations of existing heat-insulating door panels, which often rely on insulating foam and do not maximize energy efficiency.

Innovation Solution

A heat-insulating door panel design featuring a plastic inner skin and a metal outer skin, connected airtightly to enclose an evacuated cavity, with the metal skin coated with plastic and the skins connected using adhesives or welding to create a sealed, low-emissivity environment, enhancing thermal insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If insulating foam is used in conventional door panels, then thermal insulation is provided, but energy efficiency is not maximized and the door panel thickness must be large

Engineering Contradiction:
Improveenergy efficiencyVSAvoiddoor panel thickness
Core Design Contradiction:
Loss of energyVSLength of stationary object

Solution Approach 1:

The patent changes the physical state of the insulation medium from solid foam to vacuum (gas removal), dramatically improving thermal insulation performance. The evacuated cavity eliminates conductive and convective heat transfer, allowing for thinner door panels while achieving superior energy efficiency compared to conventional foam insulation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts the gas molecules from the insulation cavity to create a vacuum environment. By removing the gas phase entirely, the insulation mechanism transitions from relying on trapped gas pockets (as in foam) to utilizing vacuum isolation, which provides superior thermal performance with reduced material thickness.

Inventive Principle:
Principle #2Taking out (Extraction)

2Loss of energy

If an evacuated cavity is created between two skins, then thermal insulation is improved, but manufacturing complexity increases due to airtight connection requirements

Engineering Contradiction:
Improvethermal insulationVSAvoidairtight connection structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent employs composite construction with an inner plastic skin and an outer metal skin (aluminum or stainless steel). The plastic skin provides airtight sealing capability, while the metal skin offers structural strength and aesthetic appearance. This material combination simplifies the overall manufacturing process compared to using单一 materials for both sealing and structural requirements.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent uses adhesive bonding instead of permanent welding or mechanical fastening systems. The adhesive allows for simpler assembly processes, accommodates manufacturing tolerances, and enables easier repair or replacement of skins if needed, reducing overall device complexity while maintaining airtightness.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Shape

If the outer skin is made of metal for valuable appearance, then aesthetics are improved, but production cost increases

Engineering Contradiction:
Improveappearance valueVSAvoidproduction cost
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The patent applies metal material (aluminum or stainless steel) specifically to the outer skin where aesthetic appearance is required, while using plastic material for the inner skin where structural and sealing functions are prioritized. This localized material assignment achieves the desired appearance value while controlling production costs by not using expensive metal throughout the entire door panel structure.

Inventive Principle:
Principle #3Local quality

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 design enhances thermal insulation by creating a vacuum cavity, allowing for a thinner door leaf and improved energy efficiency, while maintaining a valuable appearance and reducing production costs.

Implementation Method 1

enclose an evacuated cavity

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

enhances thermal insulation by creating a vacuum cavity

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP2427708B1Domestic refrigeration appliance, and heat-insulating wall of a domestic refrigeration appliance
Publication Date: 2018.08.01 BSH HAUSGERATE GMBH
  • EP2427708B1 patent drawingFigure 1~3
  • EP2427708B1 patent drawingFigure 4~5
  • EP2427708B1 patent drawingFigure 6

AI summary

The invention relates to a heat-insulating wall of a domestic refrigeration appliance, especially a door leaf of a domestic refrigeration appliance, comprising a first skin and a second skin which are rigidly connected to each other in an at least largely air-tight manner at the edges thereof and enclose an evacuated hollow space. The invention also relates to a domestic refrigeration appliance comprising a heat-insulating carcass that delimits a refrigeration space, and a door leaf that is mounted on the carcass. The carcass and/or the door leaf is/are designed like the heat-insulating wall.