Seal Lip Coating for Micro-Leakage Control
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Solution Overview
Problem
Seals with sealing lips experience micro-leakage due to increased wettability caused by surface treatment for improved adhesive properties, leading to lubricant escape and liquid penetration into sealed areas.
Innovation Solution
A partial coating is applied to the sealing lip, specifically in the functional area, to reduce wettability with polar and non-polar media, using materials like perfluorinated surfactants, fluoropolymers, or alkoxysilanes, which can be achieved through plasma treatment, to prevent film formation and droplet formation that contribute to micro-leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the surface of the sealing lip is activated to improve adhesive properties, then the sealing lip adheres securely to the supporting body, but the wettability of the sealing lip increases causing micro-leakage
Solution Approach 1:
The patent applies a hydrophobic coating specifically to the functional area (sealing surface) of the sealing lip, while leaving the connection area to the support ring untreated or differently treated. This local differentiation allows the sealing surface to maintain low wettability (preventing micro-leakage) while the connection area maintains high adhesion to the support ring, thus resolving the contradiction between adhesive strength and sealing reliability.
2Productivity
If the wettability of the sealing lip is increased to enable film formation in the hydrodynamic structure area, then the conveying effect is enhanced, but droplet formation occurs in the functional area causing micro-leakage
Solution Approach 1:
The patent differentiates the surface properties of different areas: the hydrodynamic structure area (in front of the functional area) is treated to have high wettability for enhanced conveying effect, while the functional area is coated to have low wettability to prevent droplet formation and micro-leakage. This spatial differentiation of surface properties resolves the contradiction between productivity and sealing reliability.
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
The coating effectively reduces micro-leakage by preventing the formation of closed films and droplet ejection, enhancing the sealing performance by maintaining a high contact angle with both polar and non-polar media, thus ensuring better containment of lubricants and protection against aggressive media.
Implementation Method 1
The sealing lip is at least partially provided with a coating to reduce the wettability with respect to polar and/or non-polar media
Implementation Method 2
the surface of the sealing lip is activated so that the sealing lip adheres securely to the supporting body
Data Source
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AI summary
The seal (1) has a sealing lip (2) partially provided with a coating (3) to control wettability of the seal with respect to polar and/or non-polar media, where the coating is formed in a functional region (4) or at a free end of the sealing lip. The sealing lip is produced from polytetrafluoroethylene compound or glass fibers. The coating is formed from a perforated surfactant particles, fluorine polymer or alkoxysilane using a plasma treatment, where the contact angle of the polar and/or non-polar media in the region of the coating is greater than 90 degrees.