How to Choose the Right Filter Cloth for Liquid Filtration
A step-by-step selection method used by buyers who get it right the first time.
A step-by-step selection method used by buyers who get it right the first time.
Filter cloth looks simple — a fabric that catches solids while liquid passes through. But order the wrong construction or fiber and you will see it within days: cloth blinding, premature clogging, solids bleeding through, or a fabric that swells and loses permeability in your specific chemistry. Most of these failures trace back to four decisions made before the order was placed. Get these four right and the rest is routine.
Woven filter cloth is made from monofilament or multifilament yarns interlaced in a pattern (plain, twill or satin). It gives you precise, consistent pore sizes, excellent cake release and easy cleaning — which is why it dominates plate-and-frame presses, belt filters and centrifuge duty.
Needle-punched filter cloth is a nonwoven felt: fibers mechanically entangled into a thick, porous mat. It holds far more dirt per square meter than a weave of the same weight, making it the standard for coolant filtration on grinding and machining lines, where the goal is progressive depth filtration rather than building a dry cake.
The fiber decides what the cloth can survive, not how fine it filters. Three fibers cover the large majority of industrial liquid duty:
| Fiber | Chemical Resistance | Max. Continuous Temp. | Typical Duty |
|---|---|---|---|
| Polyester (PET) | Good against most acids; poor in strong alkali | ≈ 130 °C | Coolant, process water, general industry |
| Polypropylene (PP) | Excellent across acids and alkalis; poor in solvents | ≈ 90 °C | Chemical process, plating baths, wastewater |
| Nylon (PA) | Good abrasion; hydrolyzes in strong acid | ≈ 110 °C | Food slurry, abrasives, mineral processing |
Typical industry values for reference — always confirm against your actual liquor chemistry.
A quick rule of thumb: if the liquid is above pH 10 for long periods, choose polypropylene. If it contains aromatic solvents, look beyond both. Temperature rarely rules out PET or PP in liquid duty, but hot caustic will destroy polyester quickly.
Bigger is not better and finer is not safer. A cloth rated far finer than your actual particle size will blind quickly; one rated too coarse lets the fines through and you pay for them downstream. Two numbers matter:
If you don't know your particle distribution, send us a description of the process instead: what machine, what slurry, what went wrong with the current cloth. From that we can usually land within one specification on the first try.
Two cloths with the same micron rating can behave very differently because of weave density and finishing (calendered, heat-set, singed). Calendering smooths the surface for better cake release; higher weight generally means longer life but higher pressure drop. The practical approach: keep a sample of your current cloth, note what you liked and disliked about it, and let us match or improve on those two numbers — permeability and weight — rather than guessing from a catalog.
Send us the machine type, liquor chemistry, target micron rating and roll width. We will come back within 24 hours with a recommended construction, a typical specification sheet and a price — and for trial orders we can supply cut pieces so you validate on your own line before committing to rolls.
Trial quantities and cut-to-size pieces are available for all liquid filtration fabrics.