Filter Element End Edge Sealing with Plastic Casing
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Solution Overview
Problem
Existing methods for connecting folded or pleated filter materials in the automotive sector face challenges in achieving a fluid-tight seal, particularly with multi-layer filter media, where fraying and leakage are common issues, especially when connecting end sections of filter bellows.
Innovation Solution
A method involving a molded or extruded plastic casing that encloses the end edges of filter material sections, ensuring a fluid-tight connection by using injection molding or extrusion processes, which completely seals the edges and prevents fraying, even with layers containing absorber materials like activated carbon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal clips or brackets are used to hold together two superimposed flat sections, then the connection is mechanically strong, but the connection is not fluid-tight and fraying occurs at edges
Solution Approach 1:
The patent applies a plastic coating that forms a flexible seal around the end sections of the filter material. This plastic sheath acts as a flexible shell that conforms to the bellows structure while providing a fluid-tight barrier, preventing both fraying and fluid leakage simultaneously.
Solution Approach 2:
The invention combines the filter material (such as paper or nonwoven fabric) with a plastic coating material to create a composite structure. The plastic component provides both mechanical reinforcement to prevent fraying and a sealed surface to prevent fluid leakage, achieving both strength and reliability.
2Area of stationary object
If the filter material is folded in a zigzag shape to form an endless bellows, then the filter surface area is increased, but the end sections become difficult to connect in a fluid-tight manner
Solution Approach 1:
The plastic coating forms a flexible sheath that can accommodate the zigzag folded geometry of the bellows while maintaining a continuous seal. The flexibility of the plastic shell allows it to conform to the complex three-dimensional shape without creating gaps or weak points in the fluid-tight connection.
Solution Approach 2:
The invention transitions from a two-dimensional flat filter material to a three-dimensional bellows structure with volumetric sealing. The plastic coating adds a third dimension by forming a sheath around the folded sections, creating a volumetric seal that maintains fluid-tightness despite the complex folding geometry.
3Reliability
If multi-layer filter media with absorber materials are used, then the filtration performance is improved, but the edges are more prone to fraying and particles may escape
Solution Approach 1:
The plastic coating acts as a protective flexible shell that encases the multi-layer filter media and absorber materials. This shell prevents the edges from fraying and contains the absorber particles (such as activated carbon) within the filter structure, eliminating the harmful effects while preserving the enhanced filtration performance.
Solution Approach 2:
The plastic coating serves as an intermediary layer between the multi-layer filter media and the external environment. It mediates the conflict between needing exposed absorber materials for filtration and preventing particle escape, by providing a sealed containment that allows the absorber to function while preventing harmful particle release.
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 provides a reliable, fluid-tight seal over the entire length of the edges, preventing fraying and leakage, and ensures that particles between layers do not escape, enhancing the durability and efficiency of filter elements used in vehicles.
Implementation Method 1
a thermoplastic material is melted and injected into a mold defining the shroud in an injection molding process
Implementation Method 2
injected into a mold defining the shroud in an injection molding process
Implementation Method 3
The liquid plastic material is then introduced into the interior of the tube 30. After cooling, a plastic coating 5 results around the end edges 4A, 4B and parts of the end sections 3A, 3B
Data Source
Figure 1~5B
Figure 5C~6
Figure 7
AI summary
A filter element (1) comprises opposing end sections (3A, 3B) of a filter material sheet (2) that are connected to each other in a fluid-tight manner, wherein a molded or extruded plastic casing (5) encloses the end edges (4A, 4B) of the end sections (3A, 3B). A method for producing a corresponding filter element (1) comprises the encasing of opposing end edges (4A, 4B) of end sections (3A, 3B) of a filter material sheet (2) with a plastic casing (5) so as to form a continuous bellows.