Hard-Core Soft-Skin Seal Molding With Overflow Control
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Solution Overview
Problem
Existing methods for producing seals with a hard core and soft skin lack flexibility in adjusting the arrangement and shape of the core and skin during manufacturing, affecting functional and manufacturing advantages.
Innovation Solution
The method employs injection molding using the sandwich technique with an overflow device in the injection mold to control the propagation of skin and core components, allowing for targeted adjustment of the core and skin arrangement and shape, where the core is largely surrounded by the skin, and the core protrudes to form a breakthrough through the skin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an injection mold with a dividing wall or bluff body is used to produce a seal with hard core and soft skin, then the seal can be produced in a single operation, but the device complexity and difficulty of controlling material propagation increase
Solution Approach 1:
The patent extracts the function of controlling material propagation from the complex internal mold structures (dividing walls, bluff bodies) and relocates it to an external overflow device. This allows the mold cavity to remain simple while achieving precise control over where skin and core materials meet and overflow, resolving the contradiction between single-operation production and mold complexity.
Solution Approach 2:
The overflow device acts as an intermediary element that mediates between the injected materials and the final seal product. It controls the propagation and meeting point of skin and core materials without requiring complex internal mold structures, enabling precise material arrangement while maintaining simple mold design.
2Productivity
If an injection mold with a dividing wall or bluff body is used to produce a seal with hard core and soft skin, then the seal can be produced in a single operation, but the manufacturing precision of material arrangement decreases
Solution Approach 1:
The patent extracts the material propagation control function from complex internal mold structures and relocates it to an external overflow device. This allows precise control over where skin and core materials meet and overflow, significantly improving the manufacturing precision of material arrangement while maintaining single-operation production efficiency.
Solution Approach 2:
The patent replaces complex mechanical mold structures (dividing walls, bluff bodies) with a simpler overflow device system that achieves better control over material propagation. This substitution improves manufacturing precision by providing a dedicated control mechanism for material meeting points without the interference of complex internal structures.
3Manufacturing precision
If separate sprue channels are used to inject different materials into sealing lip carrier and sealing lip areas, then material segregation is achieved, but the device complexity and number of components increase
Solution Approach 1:
The patent merges the injection paths for skin and core materials into a single sprue channel system, eliminating the need for separate sprue channels. The overflow device then controls where these materials meet and separate within the cavity, achieving material segregation with simpler mold structure and fewer components.
Solution Approach 2:
The patent extracts the material segregation function from the sprue channel structure and relocates it to the overflow device. This allows a single sprue channel to supply both materials while the overflow device controls their separation and arrangement, reducing device complexity while maintaining manufacturing precision.
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 approach enables precise control over the core and skin arrangement, enhancing the seal's functional properties and manufacturability by optimizing the sealing and support characteristics while minimizing material complexity and component count.
Implementation Method 1
The seal is produced by injection molding in an injection mold with a cavity that corresponds to the outer shape of the seal, using the sandwich technique
Implementation Method 2
the spread of the skin component and the core component in certain areas of the cavity is controlled via the overflow device, in that part of the skin component and core component accommodated in the cavity overflows from the cavity as a material overflow into the overflow device
Data Source
Figure 1~3
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Figure 6a~6b
AI summary
The invention relates to a seal, which at least sectionally comprises a core (12) made of a hard plastic and a skin (14) made of a comparatively soft plastic. The seal is produced by injection molding according to the sandwich technology. The core (12) comprises at least one core end which passing through the skin (14), the end passing through the skin (14) to the outside to form an opening and/or passing through the skin (14) in a narrowing manner up to the edge of the skin without forming an opening. The production is carried out in an injection mold (110) that comprises a flash mold (110ku) abutting the cavity (110kv).