Cylindrical Sealing Element Molding With Unwound Tooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing manufacturing processes for sealing elements with complex three-dimensional geometries, such as those used in rotary slide valves, are costly due to the need for complex injection moulding tools and post-treatment processes, resulting in high production costs and part prices.
Innovation Solution
A manufacturing process for a sealing element with an essentially rectangular basic shape that involves injection moulding or compression moulding in an unwound mould, followed by forming a virtually cylindrical contour, which simplifies the tooling requirements and reduces production costs by eliminating the need for complex slides and post-treatment processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a complex three-dimensional sealing element geometry is manufactured using conventional injection moulding with slides or post-treatment processes, then the sealing element can achieve the required cylindrical contour and sealing function, but the manufacturing cost and device complexity increase significantly
Solution Approach 1:
The sealing element is first formed in an unwound, flat state using a simple injection moulding tool without complex slides or post-treatment mechanisms. The cylindrical contour is then achieved by rolling up the flat sealing element after vulcanisation, performing the shaping action in a preliminary, simplified manner rather than attempting to form the final cylindrical shape directly during injection moulding.
Solution Approach 2:
The manufacturing approach transitions from attempting to form the sealing element in its final three-dimensional cylindrical shape directly during injection moulding, to first forming it in a two-dimensional flat state and then transforming it into the cylindrical shape through rolling. This dimensional transformation simplifies the moulding tool requirements while achieving the same final geometry.
2Manufacturing precision
If post-treatment processes such as punching or cutting are used to achieve the final sealing element shape, then the required precision and geometry are obtained, but the production time and manufacturing cost increase
Solution Approach 1:
The sealing element geometry is predetermined and formed during the initial injection moulding process in an unwound state, with all necessary features (openings, frame structure, sealing surfaces) already precisely defined in the mould. This eliminates the need for subsequent punching or cutting operations, achieving both precision and high productivity by performing all shaping actions in advance during vulcanisation.
3Shape
If complex injection moulding tools with multiple slides are used to manufacture the sealing element, then the required sealing element geometry is achieved, but the tooling cost and initial investment increase
Solution Approach 1:
The manufacturing process is segmented into two independent stages: (1) injection moulding of the sealing element in an unwound, flat state using a simple tool, and (2) rolling up of the vulcanised sealing element to achieve the final cylindrical shape. This segmentation allows the use of simple, cost-effective tooling for the complex geometry formation by separating the shaping functions from the forming functions.
Solution Approach 2:
The complex three-dimensional geometry is achieved by first forming the sealing element in a simplified two-dimensional flat state using inexpensive tooling, then transforming it into the final three-dimensional cylindrical shape through rolling. This approach creates complex geometry without requiring complex tooling by utilizing a dimensional transformation step.
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 process results in a cost-effective and easily controllable method for producing a virtually cylindrical sealing element that can be used in compact applications, such as rotary slide valves, while maintaining effective sealing properties and reducing material stress.
Implementation Method 1
For primary moulding, an elastomeric material is heated and moulded under pressure in a vulcanisation tool.
Implementation Method 2
an elastomeric material is heated and moulded under pressure
Implementation Method 3
moulded under pressure in a vulcanisation tool
Implementation Method 4
During the rolling process, elastic deformation by bending occurs in the first direction of extension
Data Source
AI summary
A method for manufacturing a sealing element with a rectangular shape. The sealing element has a first and a second direction of extension as well as two or more openings. The method is technically simpler and more cost-effective than known manufacturing methods since the sealing element is formed by an injection molding process or a compression molding process in an unwound mold, after which a cylindrical end contour is formed. A sealing element produced through the method and its use are also described.