One the biggest challenges for original equipment manufacturers (OEMs) in automotive manufacturing is ensuring reliable operation and long-term performance of equipment. Liquid and particulate contaminants, pressure build-up, temperature fluctuations and harsh environmental conditions can have devastating effects on sensitive components resulting in costly maintenance, downtime and part failure. What is the best line of defense? Are there new technologies available that provide an effective solution? Let's explore some options.
Components that are especially vulnerable include:
- Automotive lighting an lamp housings
- Electrical motors
- Electronic control units and enclosures
- Battery vents
- Fluid reservoirs
An effective solution - membrane vents
Many OEMs use membrane vents. Membrane vents are designed to equalize pressure and reduce condensation while preventing ingress of liquid and other contaminants to keep automotive components and devices operating properly.
When selecting membrane vents, it is important to review the following performance testing data:
- Air Permeability - is a measure of the rate of air flow per unit area through a membrane at a specified pressure. The higher the air permeability, the lower the water entry pressure.
- Wet Mullen Burst - is a type of water entry pressure test that measures a membrane's hydrophobicity. It is the pressure required to force water through the membrane. The higher the recorded pressure, the higher the protection against water entry.
- Oil Repellancy: this test evaluates a membrane's resistance to wetting by a selected series of hydrocarbons of differing surface tensions. The oil repellency grade is the highest numbered test liquid that does not wet the membrane surface. The better the oil repellency grade, the higher the resistance to staining by oily fluids and the better the protection.
Another important factor to consider when selecting membrane vents is the reputation of the manufacturer and the quality of customer service they provide. Additional attributes to look for include:
- Rapid response times
- On-time delivery guarantees
- Technical service
- Application support
- Engineering expertise
Vents made from expanded polytetrafluoroethylene (ePTFE), such as aspire® membrane laminates, are particularly effective for automotive applications. aspire membrane vents combine high water entry pressure with high air permeability to exceed automotive manufacturing requirements. The membranes are laminated to polymer meshes to provide the physical stability required for integration into automotive components and throughout operation. Proprietary oleophobic chemistry provides the level of ingress protection necessary to ensure long-term performance of automotive equipment.
- Protects against dust, water and oil penetration.
- Reduces stress on seals for longer component life.
- Improves reliability and extends product life.
- Performs well in challenging engine compartment applications.
- Chemically and thermally stable.
- Maintains a high level of air permeability even after exposure to contaminants.
- Coating of individual fibers within the micro-structure forms an effective barrier against water leaks.
- Membrane vents are offered as die cut parts, with or without slicone contact adhesive applied to the outer border, or in a range of dimensions as slit rolls.
- PTFE vents are compatible with heat and ultrasonic welding, using standard methods and tooling to a range of housing substrates.
Choosing the best membrane vent solution for automotive applications takes careful evaluation. Considering services and support the manufacturer provides, performance data and the effectiveness of the technology are key factors to ensure reliable, long-term operation of automotive components.
Article contributed by Sarah Propp, engineering manager, Parker Performance Materials.