EV Battery Vents

• Robust structure does not damage easily like expanded PTFE material
• No change in airflow when handled
• IP rated for extreme thermal cycling
• Easy, flexible assembly – attach via ultrasonic, heat welding, overmolding, or a variety of other techniques
• Fully assembled
• Can be designed to act as a breather and safety vent
• 100% PFOA free – Compliant with (EC) 1907/2006 REACH / Regulation (EU) 2019/1021 POP

Porex Virtek® PTFE – Automotive / Oleophobic product range (hydrophobic & oleophobic)

Physical properties

When incorporating a sintered PTFE membrane into your product, it’s critical to understand the physical properties impacting the materials and functionality of the part including:

Understanding typical material properties will guide you in selecting the right polymer for your device’s function and operating conditions.  The above characteristics can be highlighted or downplayed based on your specific product needs.  Below is a chart that shows the common materials with their physical properties; however, this is not an exhaustive list.

• Air flow rate: the volume of air being delivered at a given pressure drop through a specific area. This is a critical measure for designing a venting membrane. One important thing to note – air flow rate will increase through the same vent as the pressure drop increases.
• Water entry pressure (WEP): the amount of water pressure required to have water break through the membrane. This is a critical measure when designing a water-resistant venting or filtering membrane.
• Operating temperature: the temperature range at which the part will be required to operate. For Porex Virtek PTFE membrane, this value is 260°C / 500°F continuous.
• Other key characteristics: Porex Virtek PTFE membrane is an extremely versatile material that is used in numerous markets and applications. Other application-specific characteristics that may be required for your application can include filtration efficiency, moisture vapor transmission rate, Gurley number, % reflectivity, and dielectric properties.

Chemical properties

Porex Virtek PTFE waterproof membrane is one of the most chemically resistant materials available in the market. There are only a handful of fluorinated acids that are not chemically compatible with sintered PTFE membranes, so it is always your safest choice if unknown chemicals may be in contact with the component.

Material options

Polytetrafluoroethylene (PTFE)
For applications in need of ultra-hydrophobicity, high-temperature tolerances, high chemical resistance, and excellent robustness, sintered and skived PTFE membrane technology is a perfect choice.

Using our wide range of customizable solutions, we work closely with your engineering team to define your specifications and select the best PTFE membrane for your application.

Additive options

Below are some common additives and treatments that expand the potential functionality of your PTFE membrane:

• Oleophobic treatment
• Polypropylene scrim support layer
• Adhesive backing
• Screen Printing

Geometric options

Porex Virtek PTFE membrane material begins as a 330 mm wide format (between 0.1 and 3.0 mm thick) and can be cut into porous PTFE sheets and other format options such as:

• Slit rolls (8 – 330 mm)
• Die-cut discs and various shapes
• Rotary-cut plugs and discs
• Cut discs “in web”
• Water jet cut shapes
• Zoned adhesive disc and other shapes
• Rods & molded or spiral tubes
• Thermoformed shapes
• Porous PTFE sheets

Our engineers can work with you to better understand your manufacturing process and determine which size, shape, and dimensions are the best fit for your application.

Assembly & converting options

Customizable assembly and converting options for sintered PTFE are endless. Some of the more common methodologies include:

• Thermal & ultrasonic welding
• Overmolding
• Die-cutting
• Press fit
• Pressure-sensitive adhesive (PSA)

To potentially decrease your assembly time and complexity, our engineers can work with you to better understand how your final product or device will be made. In many cases, we can combine multiple parts into one that is custom engineered.

If you require secondary processing of sheet and film products to meet your product design challenges, Porex also offers a Preferred Converter Program that can serve smaller order quantities.

Key Benefits

• High precision breathing and/or bursting for emergency degassing & pressure compensation in the event of thermal runaways
• Battery housing protection against intrusion of liquids, dust and dirt (IP67 class)
• Membrane can be bonded directly to the insert via ultrasonic welding, laser welding or insert-molding
• 100% Free of PFOA: Compliant with (EC) 1907/2006 REACH / Regulation (EU) 2019/1021 POP

Physical properties

When incorporating a track-etched membrane into your product, it’s critical to understand the physical properties impacting the materials and functionality of the part including:

• Air flow rate: the volume of air being delivered at a given pressure drop through a specific area. This is a critical measure for designing a venting membrane. One important thing to note – air flow rate will increase through the same vent as the pressure drop increases.
• Pore Size: the size of the voids in a porous media. Depending on the technology and material selected, pore sizes can range from 0.1μm to 10μm.
• Pore Density: the degree of compactness of the pores. Depending on the technology and material selected, pore density can range from 0.01M to 1,000M pores per cm².
• Operating temperature: the temperature range at which the part will be required to operate.

Chemical properties

Choosing the right polymer is important to ensure lasting functionality in your device. Below is a chemical compatibility comparison of PET material and sintered particles:

¹ Testing in Progress

² Based on Customer Validation

Material Options

• PET Track-Etched Membranes unlaminated​​
• PET Track-Etched Membranes laminated with PET/ PP non-woven material​
• Additional membrane materials available upon request​​

Additive options

Below are some common additives and treatments that expand the potential functionality of your TEM solution when using PET material:

• Hydrophobic treatment
• Hydrophilic treatment
• Bactericidal / bacterial static
• Oleophobic treatment
• Laminated support structure

For TEM solutions using PC material, hydrophilic treatment is available.

Geometric options

Our track-etched membranes are available in many different geometric options, including:

• Rollstock
• Pre-punched discs (OxyDisc)
• Self-adhesive pads (OxyPad)
• Pressure compensation units (OxySeal)
• Custom assemblies and modules

Our engineers can work with you to better understand your manufacturing process and determine which size, shape, and dimensions are the best fit for your application. We can even create custom assemblies and modules if needed.

Some of the more common methodologies for PET TEM include:

• Thermal, ultrasonic and laser welding
• Over-molding
• Die-cutting
• Pressure-sensitive adhesive (PSA)

To potentially decrease your assembly time and complexity, our engineers can work with you to better understand how your final product or device will be made. In many cases, we can combine multiple parts into one that is custom engineered.