Filter Cloths 101: Common Fabric Types
The Importance of Selecting the Appropriate Fabric Type for a Given Application
Filter press cloths can be manufactured from many types of materials including polypropylene, polyester, cotton, nylon and felt. Fabrics are usually selected based on the nature of the slurry being dewatered in a given application. Because filter presses are used across a wide range of industries, the characteristics of the suspended solids in a slurry can range from oily to fibrous to highly abrasive. The pH and temperature can also greatly vary.
The most common filter cloth materials are described below.
Common Filter Cloth Materials
Polypropylene
Polypropylene is the most common material. It has strong resistance to acid and alkali alike. A satin finish added to the fiber can allow for easy cake release. “PP” is a top choice for a wide range of applications, and is by far the most popular material.
Latex borders can be applied to a non-gasketed cloth to provide a better seal under pressure.
Nylon
This durable fiber is often chosen for its long life in the face of abrasives. Though higher in cost, nylon blends offer such durability that the higher cost can be justified by longer service life.
Polyester
Often chosen when sustained operating temperatures are over 180 degrees, or when oxidizing agents are present.
Air Permeability Testing Matches Filter Cloth Fabrics to Specific Applications
By using a Frazier® Air Permeability Tester, M.W. Watermark™ is able to determine the air permeability of a particular filter cloth fabric, utilizing the ASTM D 737-96 standard test method for textile fabrics.
How does it work?
A sample is placed on the machine and air is drawn through the fabric. The rate of air flow passing through a fabric sample is adjusted to find an air pressure differential between two fabric surfaces. The air permeability of the fabric can then be determined by this air flow rate. The test results are reported in CFM, or Cubic Feet per Minute.
Efficiency of filtration media is directly related to air permeability. By testing the air permeability of a filter cloth fabric, our lab technicians are able to determine the filtration characteristics and determine if a given fabric is ideal for a customer’s particular dewatering application.
Learn more about our Laboratory Services.
Additional Online Resources
Visit our Filter Cloths 101 webpage for more information, including FAQ’s and cloth installation videos.
Or, visit our Filter Cloths main product page to download our product guide.
Contact Us Today
Contact a member of our Sales and Service Team to discuss your particular filter press application.
About M.W. Watermark
M.W. WATERMARK wants to make a difference. We are passionate about the world’s water. We are innovative, focused on customer service and always try to exceed expectations. We are an environmentally conscious company with people who are energized, encouraged and inspired to make a difference on our planet by helping to keep our shared, finite water supply clean and usable for generations to come. We build amazing, custom water and wastewater treatment equipment. Together, we can make a difference.