Liquid filter bags are common filter elements used to remove impurities or suspended solids from liquids, improving liquid purity. They are frequently used in stainless steel precision filter equipment such as bag filters, effectively removing impurities and suspended solids while protecting machinery from contamination. Liquid filter bags come in various structural forms, mainly categorized by the filter media molding method into three types: needle-punched felt filter bags (polyester PET, polypropylene PP, polytetrafluoroethylene PTFE), meltblown nonwoven filter bags (polypropylene PP), and monofilament mesh filter bags (polyamide PA). Models include No. 1, No. 2, No. 3, No. 4, and No. 5 filter bags. These filter bags feature acid and alkali resistance, high filtration performance (achieving filtration efficiency of over 99.9%), and reusability, making them widely applicable for filtering inks, resins, paints, adhesives, industrial water, seawater, petrochemical raw materials, chemicals, and alcoholic beverages.
Three Common Types of Liquid Filter Bags
PP Meltblown Liquid Filter Bags
Nylon Monofilament Filter Bags
Needle-punched felt filter bags
- PP Meltblown Liquid Filter Bags
These filter bags mainly consist of three layers: a pre-filtration layer (removing large particles), a primary filtration layer (composed of micropores: trapping effective particles), and an outer layer (preventing fiber shedding). The filter bags are characterized by a fiber-free surface, prevention of foaming, and a large filtration area, enabling efficient interception of smaller particles. Polypropylene meltblown liquid filter bags are mainly available in standard size 2 bags with pore sizes of 10μm, 25μm, and 50μm. They are highly effective in filtration applications requiring extremely fine particles to pass through, and are suitable for filtration of food, beverages, pure water, chemicals, and coatings.
- Nylon Monofilament Filter Bags
Nylon monofilament filter bags are made from filter media woven from single nylon fibers, with a welded or stitched structure. They have good compressive strength, are not easily deformed, have a smooth surface, are easy to clean, and can be reused. They are suitable for applications with low precision requirements, such as coarse filtration or pre-filtration, as well as liquid filtration applications with high impurity content.
- Needle-punched felt filter bags
Needle-punched felt filter bags(PP/PE/PTFE series) are made of 100% ultra-fine pure fiber needle-punched felt, featuring a three-dimensional deep filtration structure. They are highly fluffy, with internal convoluted layers, providing excellent air permeability and high dirt-holding capacity. They effectively capture fine solid and colloidal particles without easily clogging. The felt surface undergoes high-temperature heat treatment and singeing/calendering to prevent fiber shedding and contamination, and to avoid excessive clogging and shortened lifespan caused by traditional rolling processes. Filter bags are available in various materials such as pure polypropylene, polyester, and polytetrafluoroethylene to meet your different filtration needs.