Other Filtering Related Items:
Sewn Filter Bags in Polyester/Polypropylene/Nylon
Filter Bag Adapters: 4" and 7"
Stainless Steel Filter Bag Housing: Size1, Size2, Size4
Welded filter bags offer some advantages over sewn filter bags:
Our welded filter bags have a durable plastic flange with handles for easy removal from a filter bag housing. The welded seams completely eliminate the possibility of unfiltered liquid bypass occurring due to needle holes. The result is a tighter seam with higher filtering efficiencies and improved finished product yields. The fused edges of the welded bag also provide a fiber-free finish which essentially eliminates any fiber migration from the bag to the working fluid. There is no possibility of silicone contamination since there are no threads. Need large quantities of bags? Call us for special discount pricing.
All filtration and screening involves limiting the passage of various sized solids by means of a barrier or fabric or media. This is done in two ways, by depth filtration using graded density material called felt or by surface filtration using filament woven material called mesh. Wovens, in turn have two basic varieties: multifilament and monofilament. In any application, variables such as flow volume, solids loading, shape and density of contaminants and other factors make this an inexact science. A general description of separation methods of media is helpful.
This is a filtration media made from a matrix of small fibers. One side is heat bonded to provide a uniform surface free of fiber loss. Contaminant particles are contained within the media by inpingment and entrapment. "Porosity" is defined by nominal micron ratings (1, 5,10,25,50,100,200) indicating the largest particle that can pass through, in general, and reflecting an increase in the density.
| FELT | |
| ADVANTAGES | DISADVANTAGES |
| High Flow Rate | Cannot be cleaned |
| Low Cost | Inexact filtration |
| Easy disposal of solids in bag | Variable performance |
| High solids capacity | |
This is a filter media having a "Teflon" microporous membrane applied to a base of polyester felt. This results in a nonstick surface which allows for a contaminant "cake" to build and slough off or be removed by cleaning.
| PTFE Coated Felt | |
| ADVANTAGES | DISADVANTAGES |
| Consistent filtration | High cost |
| Extended life | Lower flow rate |
| Sub-micron potential | Low solids capacity |
This is a two-dimensional square-woven fabric used for light filtration and general purpose screening. Consistently woven using a given number of threads per inch, its filaments are comprised of small fibers, twisted into threads. It is generally made of polyester polymer. "Porosity" is defined in broad divisions of hole size, measured in microns (i.e. 100, 150, 250, 400, 600, 800)
| PEMU (Polyester) | |
| ADVANTAGES | DISADVANTAGES |
| Low Cost | Moderate accuracy |
| Disposable | low solids capacity |
| Can be used to prescreen | not as strong as NMO |
| Moderately Cleanable | blinding of hole |
NMO - MONOFILAMENT MESH (NYLON)
A two-dimensional square of woven mesh fabric used for lower solids or higher accuracy screening and classification of solids. Made from a smooth uniform, one piece extruded thread woven into a screen with high accuracy and consistency. Used for exact separation. "Porosity" is defined by a hole size in microns, with greater variety than multifilaments (i.e. 25, 50, 75, 100, 120, 150, 175, 200, 250, 300, 400, 500, 600, 800).
| NMO (Nylon) | |
| ADVANTAGES | DISADVANTAGES |
| Strong | Blinding |
| Very cleanable | High Cost |
| Accurate | Low solid capacity |
Stainless steel filter bags offer excellent corrossion resistance and consistant filtering. The mesh is made of a stainless steel screen which has welded seams to make into the form of a filter bag for easy use. The filter bag can easily be cleaned and reused many times. The ring is made of stainless steel as well as the dual hanging strap. The metal mesh of this bag is much stronger than plastic filters (Polyester/Polypropylene/Nylon) and can withstand higher pressures as well as more weight when used in filter applications.
These bags are rated in mesh. Mesh is a measurement of number of holes per thread while micron is the measurement of the hole size. Use the chart below to determine the approximate micron size for each stainless steel mesh bag. These conversions are only approximate.
| Mesh To Micron Conversion | |
| Mesh | Micron |
| 100 | 149 |
| 120 | 125 |
| 150 | 100 |
| 180 | 82 |
| Comparison of Filter Bag Types | |||
| Filter Media | Micron Range | Advantages | Disadvantages |
| Polyester | 1-600 | Inexpensive, Good chemical resistance | Cleaning degrades filtering capabilities |
| Nylon | 10-1000 | Light Weight, Flexible, Cleanable | Not enough strength for high flow or pressure applications |
| Polypropylene | 1-100 | Special chemical resistance | Cleaning degrades filtering capabilities |
| Stainless Steel | 80-149 | Cleanable, Strong, Good Chemical Resistance | Expensive, may react with some acids/alkali |
