Sewn Needlefelt Filter Bags

Traditional sewn needlefelt filter bags are a versatile and cost effective media providing a high solid holding capacity for both non-deformable and deformable, gelatinous particles. By means of a depth filtration mechanism, particles penetrate and are captured throughout the depth of the filter media.

They are available in the range of 1 – 200 microns with a nominal (60-70%) efficiency.

Polypropylene and polyester are the most widely used, and have a calendered or singed external surface finish to eliminate migration into the filtrate. Manufactured from 100% virgin fibres, the constituent materials have been chosen for their purity, consistent high quality and repeatable performance.

Where polypropylene or polyester are not able to be used for reasons of chemical compatibility or temperature, we also off a range of Nylon, M-Aramid, and PTFE felts.

Sewn Polypropylene and polyester needlefelt filter bags are manufactured with a sewn ring, a welded centre seam and a sewn bottom.

Nylon, m-aramid, and PTFE felt filter bags have an all sewn construction.

A comprehensive choice of sealing rings are available to suit the needs of the application :

  • 7” or 4” galvanised Steel rings (or stainless steel) which fit universally into all filter housings. Polypropylene rings and stainless steel bands are also available. As standard, these products feature integrated lifting handles.
  • Custom designed positive sealing Santaseal moulded ring, for applications where high temperature or chemical resistance properties are required.

All filter bags are manufactured to ISO 9001 quality standards and under food safe and silicone free conditions to minimise any possible contaminations.

Chemical Compatability Guide

Media / Collar Type Acids Alkali Solvents Oxidants Recommend Maximum Operating Temperature (*C)
Polyester Good Good Excellent Poor 140*C
Polypropylene Excellent Excellent Good Excellent 93*C
Nylon Fair Good Excellent Fair 110*C
M-Aramid Good Good Excellent Excellent 200*C
PTFE Excellent Excellent Excellent Excellent 260*C
Santoprene* Excellent Excellent Excellent Excellent 200*C


Bag Size Diameter (inches/mm) Length (inches/mm) Surface Area (m2) Volume (l) Maximum Flow Rate (m3/hr)*
1 7″/180mm 17″/430mm 0.25 11.0 20
2 7″/180mm 32″/810mm 0.50 20.0 40
3 (1M) 4″/104mm 9″/230mm 0.07 1.9 6
4 (2M) 4″/104mm 14″/360mm 0.12 3.2 10

*Flow rate depends on factors such as filter media type, micron rating, and fluid being filtered. All dimensions are nominal.