Cover Strip Sealing Element With Cast-On Joint Stability
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Solution Overview
Problem
Existing sealing elements with elastomer strands connected via form-fit connections are labor-intensive to automate, prone to dimensional variations, and suffer from variable holding forces due to manufacturing tolerances, with the elastomer strand potentially moving longitudinally relative to the facing strip.
Innovation Solution
A sealing element featuring a facing strip made of metal or galvanized plastic, with a section produced by injection molding as a composite part of thermoplastic and elastomer, secured via an elastomer part in a vessel-like design with undercut features, ensuring a stable connection through thermal expansion matching and positive engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a form-fit connection is used to connect the elastomer strand to the facing strip, then the connection can be established without additional bonding processes, but the connection requires high labor input and is complicated to automate
Solution Approach 1:
The patent combines the elastomer strand and facing strip into a single coextruded composite profile, merging two separate components and their connection process into one integrated manufacturing step. This eliminates the need for separate form-fit connection processes and enables full automation through continuous extrusion.
Solution Approach 2:
The invention uses a composite structure where an elastomer strand is coextruded with a thermoplastic covering strip that integrates with the facing strip. This composite material approach allows the connection to be formed inherently during extrusion, combining the sealing function of the elastomer with the structural function of the thermoplastic in a single automated process.
2Ease of manufacture
If a form-fit connection is used to connect the elastomer strand to the facing strip, then the connection can be established without additional bonding processes, but dimensional variations in the parts to be joined complicate the connection process
Solution Approach 1:
By coextruding the elastomer strand and thermoplastic covering strip in a single process, the invention eliminates the need to join separately manufactured parts with different dimensions. The integrated extrusion process ensures consistent dimensional relationships between the elastomer and facing strip components, removing the tolerance accumulation problem.
3Ease of manufacture
If a form-fit connection is used to connect the elastomer strand to the facing strip, then the connection can be established without additional bonding processes, but the holding force of the connection varies depending on manufacturing tolerances
Solution Approach 1:
The coextruded composite profile creates an inherent mechanical interlock between the elastomer strand and thermoplastic covering strip, with the thermoplastic forming a integrated connection structure with the facing strip. This composite construction ensures consistent holding force by design, eliminating the variability caused by tolerance accumulation in separate part assemblies.
4Reliability
If an elastomer strand is connected to the facing strip, then sealing functionality is provided, but the elastomer strand moves longitudinally relative to the facing strip
Solution Approach 1:
The coextrusion process merges the elastomer strand and thermoplastic covering strip into a single integrated profile that is extruded directly onto the facing strip. This integration eliminates relative longitudinal movement between the elastomer and facing strip, as they become structurally unified through the thermoplastic connection elements formed during extrusion.
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
Facilitates high-quality, automated production with enhanced stability and reduced material stress, preventing longitudinal movement and cracks, while maintaining a strong bond between the facing strip and injection-molded components.
Implementation Method 1
A section, which is to be produced by injection molding, is connected to the facing strip by being cast onto the facing strip
Implementation Method 2
the shrinkage is equal to the shrinkage of the injection-molded portion of the sealing element until it cools to approximately ambient temperature. This advantageously prevents stresses or cracks in the material cast onto the facing strip
Data Source
Figure 1~3
AI summary
The invention relates to a sealing element (4) comprising a cover strip (6), in particular for sealing a window pane (3) at the inlet of a window channel into which the window pane can be retracted. According to the invention, a portion (7) of the sealing element (4), which portion is to be produced by injection moulding, is connected to the cover strip (6) by being moulded onto said cover strip (6). In a corresponding method according to the invention, the cover strip (6) is preheated such that its shrinkage is matched to the shrinkage of the moulded-on material, until said cover strip has cooled down to approximately the ambient temperature.