Vehicle Sealing Assembly EPDM TPV Co-Extrusion Bonding
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Solution Overview
Problem
Current sealing assemblies for vehicles, which combine thermoplastic vulcanizate (TPV) and ethylene propylene diene monomer (EPDM) rubber, face difficulties in bonding these materials due to the formation of oil on the surface of EPDM rubber, preventing effective adhesion.
Innovation Solution
A sealing assembly is created by extruding an EPDM-based sealing body with a bonding layer of TPV co-extruded onto an overmold region, followed by molding a second TPV layer to form channels for windows, facilitating chemical and mechanical bonding between the materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If TPV and EPDM rubber are combined in a single sealing assembly, then the sealing performance is improved, but the bonding between materials becomes difficult due to oil formation on EPDM surface
Solution Approach 1:
A primer layer is applied to the EPDM rubber surface to serve as an intermediary between the EPDM and TPV materials. This primer layer chemically bonds to both the EPDM substrate and the TPV overlay, enabling effective adhesion despite the oil formation on the EPDM surface that would otherwise prevent bonding.
Solution Approach 2:
The surface properties of the EPDM rubber are modified by applying a primer layer that changes the chemical and physical parameters of the surface. This treatment alters the surface energy and chemical composition to enable subsequent TPV bonding, overcoming the natural oil formation that creates bonding difficulties.
2Strength
If a multi-layer structure with bonding layer and molded layer is used, then the bonding between TPV and EPDM is achieved, but the manufacturing process complexity increases
Solution Approach 1:
The primer application and TPV molding operations are combined into an integrated manufacturing process. The primer is applied to the EPDM surface, and then the TPV material is molded over it in a continuous operation, reducing the number of separate manufacturing steps while achieving strong bonding through the multi-layer structure.
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 method allows for successful bonding and sealing between the EPDM and TPV materials, enhancing the sealing performance between vehicle windows and panels by ensuring a strong, durable interface.
Implementation Method 1
extruding an elastomeric material formed from an ethylene propylene diene monomer (EPDM) to form a sealing body
Implementation Method 2
co-extruding a thermoplastic vulcanizate (TPV) onto the overmold region of the sealing body to form a bonding layer
Implementation Method 3
molding a thermoplastic vulcanizate (TPV) onto the bonding layer to form a molded layer
Implementation Method 4
facilitating chemical and mechanical bonding between the materials
Implementation Method 5
facilitating chemical and mechanical bonding between the materials
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A sealing assembly for a vehicle comprises a sealing body extruded from an elastomeric material formed from an ethylene propylene diene monomer and having a base and first and second legs spaced from one another extending from the base. The base and the legs define an interior surface and a first channel for receiving a panel, and further define an exterior surface opposite the interior surface. The sealing body defines an overmold region opposite the first channel extending along a portion of the exterior surface of the sealing body. The sealing assembly further comprises a bonding layer of a first thermoplastic vulcanizate co-extruded onto the overmold region of the sealing body, and a molded layer of a second thermoplastic vulcanizate molded onto the bonding layer with the molded layer defining a second channel for receiving a fixed window of the vehicle. Also disclosed is a method for manufacturing a sealing assembly.