The starting point for the ordering of screen media involves sending the basic information to the supplier. From this, the supplier can determine which media will best suit the application, eg:
- The type and size of material to be screened.
- The type and size of screen being used.
- Does the screen have camber?
- What type of clamping mechanism is fitted on the screen?
If the customer knows what meshes they require, the supplier simply needs information about hole size, wire diameter, dimension over hooks and the panel size required. The different meshes include:
- Woven Wire. Woven wire screens are constructed from high tensile woven wire material. The sizes vary but typically the smallest weaved are a 4mm aperture with 2.5mm wire diameter up to a 100mm aperture with 12mm wire diameter. Most size increments in between are catered for. A typical panel can be up to 1600mm in width and some suppliers may even deliver custom-made panels up to 1900mm wide.
- Stainless steel. The range of stainless steel mats can be woven into a range of weave patterns. Typically, stainless steel mats are available in sizes from 150 microns up to 25mm with a 2.15mm wire diameter. Stainless steel mats with smaller apertures are favoured in the processing of mineral sands.
- Rubber screen media. Rubber screen media is favoured in many applications where woven wire is found and is also used in wet screening applications. Rubber mats offer superior levels of impact and abrasion resistance and are generally available in the same sizes as woven wire screen media. They can also be fitted with the hooked edge which allows them to be fitted to many different styles of screening equipment.
- Self-cleaning screens. There is a range of self-screening screen media across the extractive industry that can keep blinding and clogging to a minimum. This will reduce carry-over and increase screening efficiency. Typically self-cleaning screens are used where material is wet or sticky. Applications are normally found in smaller aperture sizes.
- Piano wire screens. Piano wire screens are typically end-tensioned units and are normally available in smaller aperture sizes. Sizes range from 0.5mm to 16mm. This media is used mainly in screening of dry sand and is very effective. It is also used in screening of gravels.
- Polyurethane screens. Polyurethane screens are manufactured from high wear resistant materials for larger screen units. Typically, polyurethane media has a lower open area for a given size when compared to wire woven media but does offer a much longer life span of the media.
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These screens are available in a large range of sizes.
- Perforated plate. Perforated – or punch plate – screens are used in a number of applications, mainly scalping or primary screening. They are normally made of a wear-resistant material that has more abrasion resistance and a higher tensile strength than normal plate. Plate aperture sizes can be as low as 20mm with a 12mm plate up to a 200mm aperture on secondary applications.
- Accessories. To go with the broad range of screening media outlined above, some suppliers may offer a full range of screening media accessories, including capping rubber for camber bars, clamp bars, skirting rubber and spray nozzles for wet applications. These accessories form an important part of the range as they can assist the customer with the correct fitment of screen media.
Kieran Hawkes is the sales manager for OPS Screening & Crushing Equipment in Perth, Western Australia.
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