Polypropylene Liquid Filter Bags

Polypropylene (PP) filter bags operate through depth filtration, where contaminants are captured throughout the multilayer PP felt rather than only on the surface. The fiber network provides progressive particle retention, allowing high dirt-holding capacity while maintaining stable flow rate. This makes PP bags ideal for water treatment, chemicals, paints, inks, oils, and general industrial liquid-solid separation.

PP felt can be enhanced through several surface-finishing processes, including:

• Anti-Static – reduces loose fibers and minimizes fiber shedding during filtration
• Water & Oil Repellent – compresses and stabilizes the fiber structure for improved filtration consistency
• PTFE Membrane – provides superior dimensional stability, minimizes shrinkage, and improves fine-particle retention

These treatments improve filtration accuracy, reduce fiber migration, and extend overall service life.

Omela conducts strict QA testing, including:

• Air-permeability and flow-rate performance testing
• Tensile-strength and fiber-shedding resistance checks
• Dimensional stability and heat-shrinkage analysis
• Chemical-compatibility evaluation for acids, alkalis, salts, and organic liquids
• Cleanability and CIP-compatibility validation
• Surface-finish and fiber-distribution inspection
• Verification of sealing-ring integrity (PP / stainless / steel / plastic)

These quality-control procedures ensure consistent filtration accuracy and safe use in sensitive liquid-processing systems.

Polypropylene filter bags are available in several bottom configurations to match different housing designs and flow requirements:

• Round Bottom – the most common design for standard liquid-filtration systems, offering stable flow and reliable dirt-holding capacity
• V-Shape Bottom – optimized for economical applications where reduced material usage and faster drainage are preferred
• Flat Bottom – provides excellent sealing contact, minimizes bypass risks, and delivers a clean internal profile ideal for hygienic or precision-filtration systems

The optimal bottom type is selected based on system pressure, hygiene standards, and the physical characteristics of the filtered liquid.

To ensure a secure, leak-free installation, polypropylene filter bags are available with several sealing methods:

• Needle Sealing – the most widely used method, providing reliable mechanical bonding for general liquid-filtration systems
• Hot-Melt Sealing – delivers a smoother, fused edge suitable for applications where minimal fiber release and enhanced sealing performance are required

All sealing options undergo mechanical-integrity testing to verify proper fit with standard industrial filter housings and to prevent bypass during operation.

Yes. Custom options include:

• Felt weight, thickness, and permeability
• Standard, multilayer, or reinforced polypropylene felt
• Surface finishing options such as singeing, calendaring, and heat-setting
• Custom seam types, including stitched or welded designs
• Multiple ring materials to match housing and chemical conditions
• Custom lengths, diameters, and configurations tailored to specific filter housings

These customization options ensure accurate fit, stable flow characteristics, and cost-efficient service life for your filtration system.