1) polyester fitler cloths series

Polyester Filtering Fabrics Series, which made of polyester fiber (PET), can be divided into PE staple fabrics, PE long thread fabrics, and PE monofilament fabrics. These products possess the properties of strong acid-resistance, fair alkali-resistance, and good performance at the temperature of less 130℃. They can be widely used in pharmaceutical, non-ferry melting, chemical industrial, for the equipments of frame filter press, centrifuge filter, vacuum filter, etc. The filtering precision can reach less than 5 microns.

2) polypropylence fitler cloths series 

Polypropylene Fabrics Series, which made of polypropylene fiber (PP), can be divided into PP staple fabrics, PP long thread fabrics, and PP monofilament fabrics. These products possess the properties of acid-resistance, alkali-resistance, small specific gravity, the melting point 142—146 degree, and normal working temperature maximum 90. They are mainly used in the precision chemical, dye chemical, sugar, pharmaceutical, alumina industrial, for the equipments of frame press filter, belt filter, blend belt filter, disc filter, drum filter etc. The filtering precision can reach less than 1 micron.

3) polyamide filter cloths series

Polyamide Fabrics Series, which made of polyamide fiber (PA), can be divided into PA staple fabrics and PA long thread fabrics. These products possess the properties of weak acid-resistance, alkali-resistance, high mightiness, specific gravity of 1014g/squ.mt, melting point of 215—250 degree, and operating temperature maximum 130. They can also be divided into PA6 series and PA66 series, and the later performance is better than the former. They are mainly used in the chemical, coal mine, building materials, melting industrial, for the equipment in the strong alkali operating conditions, such as frame press filter, disc filter, and centrifuge filter. The filtering precision can reach less than 5 microns.

4) poly-vinyalchol filter cloths series

Poly-vinyalchol filter cloth is made of Poly-vinyalchol filber (PVA). At present, we can produce poly-vinyalchol staple fabrics only. The products possess the properties of alkali-resistance, high soften point （220—230 degree）,small elongation, and good moisture absorption. They are mainly used for frame press filter.

5)Filter Presses

Press cloths cover a wide range of filter press designs from single cloth, drape over cloths, duplex or barrel-neck cloths and caulk-in cloths. Although the designs are different, the basic filtration function is the same whether it is an old plate and frame or a new recessed chamber, caulk-in automatic press with diaphragm squeeze. Filter presses are batch filters, operating under pressure to separate solids from liquids. The solids may be the product or they may be a contaminant. Either way, the solids are filtered on the face of the plate-mounted cloth, the chamber fills to capacity, the flow is stopped, the cake is dropped and the press is closed to begin the cycle again.

6)Disc Filters

Rotary disc filters use sector or disc bags, wedged shaped bags designed to fit which makes up the rotating disc. Disc filters are continuous process, vacuum filters, frequently found in the metal mining, metal ore beneficiation and coal cleaning industries.Disc filters rotate in a vat of slurry, rotate into the pan, pick up solids, dry and then release those solids. In most cases, the solids are the product, which is augured off the rotating disc by screw conveyor.

7)Pressure Leaf Filters

Pressure leaf filters are batch filters using a round or rectangular wire frame (leaf) dressed with sewn filter cloths. The individual leaves are mounted on a manifold which is inside a vessel. Slurries or solutions to be filtered are pumped into the vessel and each leaf and filter cloth separate the solids from the liquids. The filter has to be cleaned using a sluice bar or hoses and the solids are dropped out. Generally the solids loading is light and the filter is used as a polishing or clean up filter, sometimes with a filter aid such as diatomaceous earth.Because the cake discharge system is relatively ineffective, a good surface on the filtration side is critical. These filters require a fine balance of flow and efficiency to achieve reasonable life and to minimize the time required to achieve the desired turbidity of the solution. Most commonly used filter media are monofilaments with filter aid or felts without filter aid.

8)Belt Filters

Horizontal Belt Filters (HBF) are different from RDFs and RDVFs in that there is no pan. Instead, slurry is pumped onto the horizontal belt surface just ahead of multi-stage dewatering, drying, treating and washing. The final filter cake is discharged using gravity, wires or doctor blades. The belt can be backwashed after cake discharge and before returning to the slurry pick up zone.In all cases above, the original materials used were woven fabrics, ranging from lightweight multi-filaments to heavy mono-filaments weighing up to 40 oz/yd2 or 1350 g/m2. Depending on the type of filter, the discharge system, the product and the process, a very wide range of textiles have been used in these filters with life varying from a few weeks to multiple years.

9)Drum Filters

Rotary Drum Filters (RDF) operate under a high vacuum, rotating a drum into a vat of slurry, dewatering and drying as the drum rotates out of solution and over to the cake discharge side. The filter media is caulked onto the drum and stays in the same place. De-watered and dried filter cake is discharged on the back side using gravity, air blow back, doctor blade or counter-revolving roll. Of these, the doctor blade can cause the most wear on the cloth.

Rotary Vacuum Drum Filters (RVDF) also operate under high vacuum with a drum which rotates in a pan. However, in this design filter, the filter cloth comes off the drum and travels to a discharge system such as a doctor blade, cooch (helix) roll or gravity. After backwash, the cloths return to the pan to repeat the process. The RVDF filter cloth is held on the drum with edge guides using rope, coil springs or molded rubber (PIP) edging. Typical cloth closures are manual sewing, Velcro, clipper lacing or zippers (or a combination of those methods).

In all cases above, the original materials used were woven fabrics, ranging from lightweight multi-filaments to heavy mono-filaments weighing up to 40 oz/yd2 or 1350 g/m2. Depending on the type of filter, the discharge system, the product and the process, a very wide range of textiles have been used in these filters with life varying from a few weeks to multiple years.

10)Liquid filter cloths

Liquid processing equipment, unlike dust collectors, comes in many shapes, sizes, designs and methods of separating solids from a liquid.The major types of equipment, their design and their filter cloths are discussed in 5 major sections: Filter Presses Disc Filters Pressure Leaf Filters Belt Filters Drum Filters

in addition there are tray filters, tilting pan filters, vessel filters, candle filters, molded or pleated filters, all handling everything from phosphoric acid to swimming pool water. Many of those filters do not use conventional woven or felted media and are not discussed in depth. However, your BWF America staff person or sales engineer can help.

Contact us for assistance regarding the wide range of liquid processing equipment and filter media used in that equipment.