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.
Related Products
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Standard Filter Bag Overview
Allied Filter Systems Ltd manufactures high quality liquid filter bags to fit standard size filter vessels, as well as custom designed products where requested. The constituent materials have been chosen for their purity, consistent high quality and repeatable performance.
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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.
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Fully Welded Filter Bags
All seams are welded rather than sewn, and combined with our positive sealing moulded Welseal (polypropylene or polyester) welded ring, no process liquid can bypass through needleholes caused by the sewing process or around a traditional metal ring.