When it comes to micro filtration, woven wire and screens is one of the material that is used for filtration. It doesn’t matter whether the pores are the size of a fist of a human being or microscopic, the job of a filter mechanism is to provide with strong, flexible and resistant to any kind of corrosion. There have been filtration media that is made up of metals and have been used as the form of sheets and tubes. However, the greatest form of Filter Media from metal is with woven wire or perforated sheets. Such filter media benefits in providing high strength, corrosion, and abrasion resistance. The best part about metal woven wire and screens is that is can be made with varied openings (apertures).
The Filtration Industry also encourages filter medium made up of plastic materials that serve equal strength and provides an appropriate aperture. Having said this, plastic wire screens or sheets have higher corrosion resistance. The use of metallic media is used for separation of solid particles according to their size. It further aids in a screening of gas or liquid flows during the finer filtration processing.
What Happens In The Coarser?
It is a micro filtration process. There are a variety of materials based on the dry classification operations that are used for coarse filtration. This coarse filtration largely depends upon the size and shape of the openings in the mesh or the sheet. Based on the classes of media, there are three broad classes of media such as –
1. Woven wire meshes
2. Sheets perforated with a variety of holes
3. Elements made up from performed materials that include rods or bars.
In this article, the concentration will be on woven wire and screens and its study at large.
What Is Woven Wire And Screens After All?
These are the metal screens that are made from round plain weave wire. There is high weave durability in a just one-notch Woven Wire Screen. It also features unchangeable mesh size with multi-notch ones. It is mainly used for lateral or longitudinal tension. The material thus used is abrasion-resistant, highly durable spring steel and one can see the use of manganese steel in the making of woven wire and screens. The mesh roughly rages from 1, 0 mm while the wire Ø 6, 3 mm. The weaving of the wire is the traditional old principle where warp wires are set along the loom while the weft wires are across it. The final product comes in the form of a woven mesh that is a further process in varied ways to enable the filtration process easily. For a layman, wire cloth or gauze is the words that are easily identifiable with woven meshes of finer grades of wire. Sieving of flour is majorly done with square mesh cloths.
Kinds of Wires Meshes
Based on the shape of the apertures and zero aperture filter cloths, the mesh can be distinguished accordingly. While the former utilizes plain weave with single wires of the same width for the warp and weft in order to get the rectangular apertures. They are majorly in square shapes. The usages of such meshes are widely seen for sieving and sizing operations.
The latter on the other hand uses wires pressed closely together with a space as little as air to pass is then made in a number of more complex weaves. They are known as Dutch twills. The Dutch twills can be majorly seen used in pressure and vacuum process filters.
How Does Woven Wire Mesh Function?
Each warp or weft wires bend so that it can pass over another wire. It is this crimping of the wires that aids in weaving process at large. However, one has to be vigilant that the crimp must be imposed on the wire up to a certain thickness before it is assigned to its designated position. The crimping of the wires also benefits of holding the crossing wires in place if the wire mesh moves or vibrate.
The interesting part of such kind of woven wire is it can be made from any metal that is ductile enough to form a wire. However, most preferred metals remain phosphor bronze, nickel chrome stainless steels, aluminium alloys, copper, mild steel etc. For high-temperature duties, nickel, nickel-chrome alloys, and titanium are used while Inconel, haste alloy, Incoloy etc. is used as special alloys.
Factors That Show The Dependency Of The Wire Size
The size of the wire largely depends upon the alloy used in the making of the mesh. Therefore not every mesh can be used for kinds of filtration purpose. It depends upon the operating temperature, degrees of corrosion and abrasion etc. You will, therefore, find that finer wire diameters made up of aluminium or brass, copper is used only for light duties. But take the example of stainless steel that is used for up to 15m.
Use of Woven Wire Cloth
Woven wire cloth has been largely used for filtration for over a decade. It is available in all kinds of materials and mesh sizes. There are many sets of test sieves available that match according to the standard ranges of mesh sizes. These can be supplied in standard-sized holders that fit into one another. It is made to an extent so that it can be held in the frame of a shaker machine. It is this reason that the design of the mesh holder plays a vital role as it is necessary that the mesh must be held fast and taut.
Types of Weave
The filtration process largely depends upon the types of weave.
1. The square mesh has weft wire passing alternately over and under each warp wire. Since the opening is in the shape of square or rectangular it is known as plain or double crimped weave. It is moderately satisfying in strength that ranges from 10 to 60 Mesh.
2. Twilled weave has each weft wire progressing one wire at one time but alternately crossing over two as well as fewer than two warp wires. It produces a marked diagonal pattern hence. It is for this reason that has more strength.
3. Dutch or Hollander weaves have warp and weft of different width. To get plain Dutch weave, the warp wires must be thick. But if the wefts wires are thicker, and then reverse plain Dutch weave may be received.
Let Us See What Sintered Wire Mesh Offer
For the stability of the mesh, there needs to be a constant crimping of the individual wires in mesh and achieving absolute stability by sintering the mesh. For multi-layer meshes, sintering wires are the apt option.
Role of Perforated Plate Sheets
These sheets are strong and rigid and by far the strongest woven wire cloths. It is widely acceptable for finding particular applications I strainers, coarse, filters or screens. Since to the size of the screen, openings are controlled in the manufacturing process, perforated Metal Strainers are excellent for consistent performances.
There are several aspects to be noted while selecting the right woven wire and screens to get the right results. Look forward to this space for more information on filtration industry and its moves.