Polypropylene (Poly-Pro) filter bags stand as a cornerstone in industrial liquid filtration, offering a robust balance of chemical resistance, high dirt-holding capacity, and cost-effectiveness. As a distributor and OEM for industry leaders like Fil-trek and Veolia, Purecowater provides high-performance Poly-Pro filter bags designed to tackle challenging solid-liquid separation tasks across diverse sectors.
Product Overview: Poly-Pro Felt Filter Bags
Polypropylene filter bags are typically constructed from 100% synthetic fibers using a needle-punch technique. This creates a felt-like media that functions as a depth filter. Unlike mesh bags that trap particles only on the surface, Poly-Pro needlefelt captures deformables and solid particles throughout the thickness of the media.
These bags are often finished with a glazed or singed surface treatment. This serves a critical function: it bonds the exterior fibers to prevent fiber migration into the clean filtrate, ensuring that downstream processes remain uncontaminated [rosedaleproducts.com](https://www.rosedaleproducts.com/industrial-filtration-bags).
Key Performance Specifications
When selecting a filtration solution, understanding the operational limits of the media is essential. Polypropylene is particularly valued for its broad chemical compatibility.
| Specification | Details |
|---|---|
| Material Construction | Needlefelt Polypropylene (PO/POG) |
| Filtration Type | Depth Filtration |
| Micron Ratings | 1 µm to 200 µm (Nominal & High Efficiency options) |
| Max. Operating Temperature | ~200°F (93°C) |
| Recommended Change-out Pressure | ~1.5 bar (approx. 22 PSI) [porefiltration.co.uk](https://www.porefiltration.co.uk/resources/articles/a-complete-guide-to-filter-bags-types-uses-best-practices) |
Chemical Compatibility Table
One of the primary reasons operators choose Poly-Pro over Polyester or Nylon is its behavior in acidic and alkaline environments. It is hydrophobic and resistant to bacteria.
| Chemical Type | Compatibility Rating |
|---|---|
| Strong Acids | Excellent |
| Strong Alkalis | Excellent |
| Organic Solvents | Good / Fair (Dependent on specific solvent) |
| Oxidizing Agents | Fair |
Standard Bag Sizing
Purecowater supplies Poly-Pro bags in industry-standard sizes to fit housing vessels from major manufacturers such as Fil-trek, Rosedale, and Eaton. Selecting the correct size ensures optimal flow rates and seal integrity [filtersource.com](https://www.filtersource.com/blog/a-guide-to-filter-bags).
| Bag Size | Diameter (Inches) | Length (Inches) | Typical Flow Capacity |
|---|---|---|---|
| #1 | 7″ | 16.5″ | Medium Flow |
| #2 | 7″ | 32″ | High Flow (Standard) |
| #3 | 4″ | 8-9″ | Low Flow |
| #4 | 4″ | 14″ | Low/Medium Flow |
Primary Applications
Due to the versatility of needlefelt polypropylene, these bags are utilized across a wide spectrum of industries. They serve as excellent pre-filters for membrane systems or as final polish filters for bulk fluids.
- Water Treatment: Removal of sediment, sand, and algae in pre-RO filtration.
- Chemical Processing: Filtering acids, bases, and plating solutions where resistance is key.
- Food & Beverage: Clarification of potable water, edible oils, and non-critical process fluids.
- Paints & Coatings: Elimination of agglomerates and skins in solvent-based or water-based paints.
Looking for specific micron ratings or custom bag sizes?
Whether you require standard Size #2 bags for high-flow housings or specialized rings and flanges (steel, plastic, drawstring), Purecowater can supply OEM-equivalent solutions.