Method for making an hermetically sealed overmolded plastic thermal bridge breaker with liner and wrapper for a vacuum insulated structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vacuum insulated refrigerator cabinet structures face challenges in maintaining an airtight seal and reducing heat transfer between the wrapper, liners, and thermal bridge, which affects the efficiency of the vacuum insulation and thermal performance.
Innovation Solution
A method involving the formation of a thermal bridge through overmolding a resin mixture in a mold, interconnecting the wrapper and liners, using a mold cavity with an inverse configuration of the thermal bridge, to create a hermetic seal and reduce heat transfer, while maintaining the vacuum insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the wrapper and liners are spaced apart to form a cavity for vacuum insulation, then thermal insulation efficiency is improved, but maintaining an airtight seal becomes more difficult
Solution Approach 1:
The thermal bridge breaker acts as an intermediary component between the wrapper and liners. It provides structural support to maintain the spaced-apart configuration for vacuum insulation while incorporating sealing surfaces and channels that enable reliable airtight sealing. The breaker's design allows it to mediate between the conflicting requirements of spacing for insulation and connection for sealing.
Solution Approach 2:
The thermal bridge breaker is formed from a resin mixture that combines multiple material properties. The composite material provides both the structural integrity needed to maintain spacing and the sealing capability to ensure airtightness. The resin formulation allows the breaker to simultaneously achieve mechanical support and hermetic sealing functions.
2Stability of the object's composition
If a thermal bridge is provided to interconnect the wrapper and liners, then structural stability is improved, but heat transfer between components increases
Solution Approach 1:
The invention extracts or removes the thermal bridge breaker material from the direct thermal path between the wrapper and liners. By positioning the breaker in a way that it interrupts the thermal bridge, the design maintains structural connectivity while eliminating the heat conduction path. The breaker is taken out of the thermal flow to prevent heat transfer.
Solution Approach 2:
The thermal bridge breaker introduces local quality variation in the structure. While the overall structure remains connected for stability, the specific region where the breaker is positioned has different thermal properties. The breaker creates a localized thermal barrier with low thermal conductivity, while other parts of the structure maintain their original properties for structural support.
3Reliability
If an overmolding process is used to seal the thermal bridge breaker to the wrapper and liners, then hermetic sealing is improved, but manufacturing complexity increases
Solution Approach 1:
The overmolding process merges the thermal bridge breaker with the wrapper and liners into a single integrated component. The resin mixture is molded directly onto the breaker, combining multiple parts (breaker, wrapper, liners) into one hermetically sealed assembly. This merging eliminates separate sealing steps and ensures airtight connections through the integrated molding process.
Solution Approach 2:
The mold cavity is pre-configured with an inverse configuration of the thermal bridge breaker geometry before the overmolding process begins. This preliminary preparation of the mold cavity ensures that when the resin is injected, it automatically forms the correct sealing geometry and integrates properly with the breaker and other components, simplifying the overall manufacturing process.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A vacuum insulated cabinet structure includes an exterior wrapper with a front edge extending around an opening thereof. At least one liner includes a front edge extending around an opening of the liner, wherein the liner is disposed inside of the wrapper with the front edge of the wrapper disposed around the front edge of the liner in assembly. A thermal bridge includes an outer coupling portion and an inner coupling portion. In assembly, the outer coupling portion is overmolded to a portion of the front edge of the wrapper, and the inner coupling portion is overmolded to a portion of the front edge of the liner to form a sealed vacuum cavity between the wrapper and the liner. The thermal bridge is formed in a mold in which the preformed wrapper and liner are partially disposed to form a unitary composite structure.