Quick answer: Polypropylene is the default filter cloth material because it resists most acids, alkalis and solvents, tolerates temperatures up to about 90 °C, releases cake cleanly and costs less than PA, PET or PTFE. Choose another fibre only when the slurry is above 90 °C, strongly oxidising, or needs finer particle retention than PP monofilament can give.
1. Overview of core elements
1. Material mechanism: Polypropylene fiber has a hydrophobic structure and can remain stable in a pH 2-12 environment to avoid chemical corrosion.
2. Pore size and retention: The filtration level covers 5–20 μm, which can accurately intercept fine solid particles.
3. Structural strength: tear strength ≥ 250 N, supporting secondary pressing pressure of 0.6-1.0 MPa, ensuring long-term circulation without damage.
2. Typical applications and measured data
Printing and dyeing wastewater:
Case: A printing and dyeing factory in Jiangsu used 800×800 mm polypropylene filter cloth. After 1200 hours of continuous operation, the moisture content of the filter cake dropped from 75% to 43%, with no obvious pulling or clogging.
Chemical pickling liquid:
Comparative test: After 500 cycles of polypropylene filter cloth, the liquid flux still remains at 85%, while that of polyester filter cloth only remains at 60%.
Mine tailings dewatering:
Effect: 5 μm filter cloth can intercept >98% of tailings powder, and the solid content of the filter cake is stable at more than 30%.
The above cases not only verify the reliability of polypropylene materials under high-corrosion and high-load conditions, but also highlight its cost advantage with a cleaning and maintenance cycle of up to 800-1200 hours.
3. Selection Process and Maintenance Guide
1. Working condition analysis: Preliminarily determine the filter cloth material through particle size distribution and chemical composition testing.
2. Pressure and temperature matching: Select the corresponding thickness and model based on the equipment’s pressing pressure and operating temperature.
3. Life assessment: Develop a filter cloth replacement and backwashing plan based on the frequency of on-site operation and maintenance.
4. Regular maintenance: Use a combination of backwashing and chemical cleaning to prevent fiber clogging and performance degradation.
Related products & guides: Versatile Filter Cloth (Custom) · Filter Press Membrane Plates · Benefits of Diaphragm Filter Press
Frequently Asked Questions
Why is polypropylene the most common filter cloth material?
Polypropylene resists most acids and alkalis, is strong yet low cost, releases cake easily and handles temperatures up to about 90°C, which suits most industrial slurries.
How long does a polypropylene filter cloth last?
With correct selection and regular washing, PP filter cloth typically lasts several months to over a year, depending on slurry abrasiveness, chemistry and cycle frequency.
Related products & guides
For general background, see filter press technology. Browse our full filter press product range or contact our engineers for a configuration recommendation.
Polypropylene filter cloth: key figures
| Property | Value |
|---|---|
| Stable pH range | pH 2–12 |
| Filtration rating | 5–20 μm |
| Tear strength | ≥ 250 N |
| Squeeze pressure supported | 0.6–1.0 MPa |
| Temperature limit | about 90 °C |
| Cleaning and maintenance cycle | 800–1200 hours |