PTFE Fabric Combinations
PTFE membrane can be applied to a large variety of fabric substrates depending on the particular application. Contact a Baghouse.com representative to help you to determine which combination of fabric and PTFE membrane is the best fit your particular process environment. Below is listing of several popular PTFE / Fabric combinations:
|*Sensitive bag-to-cage||**Fair with chemical- or acid-resistant finishes||***Must oversize bag for shrinkage above 450°F (232°C)|
|Max Continuous Operating Temperature||170°F (77°C)||265°F (130°C)||275°F (135°C)||375°F (190°C)||400°F (204°C)||356–500°F (180–260°C)||500°F (260°C)||500°F (260°C)|
Need chemical resistant or high temperature filters?
PTFE membrane is impervious to many harsh chemical compounds and high temperature processes. However to ensure filter life, a substrate fabric needs to be selected that also has the same durability, and withstand the stresses associated with normal Baghouse operation e.g. start-up, shutdown, dewpoint changes, temperature variations, etc. Popular choices for high temperature applications include felt and woven PPS (Torcon®/ Procon®), standard and acid resistant aramid fabrics (Nomex®), P-84, and fiberglass. PTFE membrane can withstand temperatures up to 500°F (260°C).
PTFE membrane filters also are useful in high humidity environments. When moisture enters into a gas stream, it often times causes dust particles to become “sticky” and form agglomeration, which is a serious operational problem in many dust collection systems. With PTFE membrane filter bags, accumulated particles are easily cleaned from the surface, leading to less non-permeable dustcake formation, which increases pressure drop.
Differential Pressure (Pressure Drop) Advantages of PTFE Filters
How does the use of PTFE membrane Baghouse Filters Result in Lower System Pressure Drop?
Pressure drop in a Baghouse occurs for two factors that make it more difficult for air to pass through the filter:
1. The dustcake characteristics (thickness, density, composition, etc.)
2. The amount of particulate matter that is embedded within the fabric.
Initial pressure drop on fabric filters in general is not a reliable guide for how the filter will operate under load conditions. The addition of PTFE membrane to standard filter fabrics will on average lower initial permeability from 30-60 CFM to 5-15CFM (depending on the fabric substrate and type of PTFE membrane). Under normal conditions Baghouse.com PTFE membrane filters will operate at 0.5in pressure drop at a 6:1 air-to-cloth ratio. With time additional dustcake formation will lead to pressure drop increase.
However due to non-stick characteristics of PTFE, cleaning of the filters is easily accomplished. This will allow for a consistently low pressure drop to be maintained, which in turn results in lower energy consumption, high output, and reduced compressed air for cleaning cycles.
Specifications and performance results are subject to change and cannot be guaranteed in exact figures. Results may vary in your application. Please discuss your needs with your Baghouse.com representative.