Encapsulated Window Seal with Molded TPE Lip
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Solution Overview
Problem
Existing encapsulated window assemblies for vehicles, such as sunroofs, face challenges in achieving a cost-effective, aesthetically pleasing, and simple manufacturing process while maintaining a reliable seal that is unaffected by thermal expansion and requires post-manufactured bulb seals, which increase labor and material costs.
Innovation Solution
An integral seal is molded around the peripheral edge of a dielectric substrate material, using thermoplastic elastomer (TPE) materials like SEBS, with a lip portion and engaging features that compress to exert a consistent sealing force against the vehicle body sheet metal, eliminating the need for post-installation seals and accommodating thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If post-manufactured bulb seals are used, then sealing reliability is improved, but manufacturing complexity and labor costs increase
Solution Approach 1:
The seal is integrated directly into the encapsulated window assembly manufacturing process, combining the seal formation with the window assembly production. This eliminates the need for separate post-manufactured bulb seals and their associated installation steps, thereby reducing manufacturing complexity while maintaining sealing reliability through the integral design.
Solution Approach 2:
The seal is formed as part of the initial window assembly manufacturing process rather than being added later. The molding process creates the seal structure in advance, preparing it for immediate engagement with the vehicle body opening, which eliminates subsequent installation steps and reduces overall manufacturing complexity.
2Reliability
If the seal is made rigid to maintain sealing force, then sealing reliability is improved, but adaptability to thermal expansion decreases
Solution Approach 1:
The seal is constructed as a flexible lip portion that can deform under compression. This flexibility allows the seal to adapt to thermal expansion and contraction of the window assembly while maintaining continuous contact with the vehicle body opening, ensuring reliable sealing across varying temperature conditions.
Solution Approach 2:
The seal transitions from a static rigid structure to a dynamic flexible element that can change shape in response to thermal forces. The lip portion's ability to deform and rebound provides continuous sealing pressure while accommodating dimensional changes in the window assembly due to thermal expansion.
3Reliability
If the lip portion is made longer to increase sealing contact, then sealing reliability is improved, but device complexity increases
Solution Approach 1:
The lip portion is formed with a curved configuration that naturally conforms to the contour of the vehicle body opening. This curved geometry provides extended sealing contact along the periphery without requiring additional seal components or complex structural features, achieving reliable sealing through elegant geometric design.
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
The solution provides a cost-effective, aesthetically pleasing, and reliable sealing solution that maintains a consistent sealing pressure, suitable for both fixed and movable sunroofs, reducing labor and material costs by integrating the seal directly into the manufacturing process and ensuring durability and flexibility.
Implementation Method 1
the lip portion of the seal is compressed such that the lip portion is moved toward the base portion of the seal while at the same time, the lip portion of the seal is exerting a sealing force against the portion of the body sheet metal
Data Source
AI summary
A encapsulated window assembly may be fixed or movable upon installation into an opening in a vehicle body, particularly a vehicle roof. In order to keep air, water and/or dirt from entering the passenger compartment of the vehicle, an integral seal is molded onto a dielectric substrate material. The seal, upon installation of the assembly into the vehicle body opening, effectively closes the gap between the edge of the window assembly and the sheet metal surrounding the body opening, without the need for a post-applied seal, for example, a preformed bulb seal.