How to use the screen mesh correctly?
(1) Conversion of mesh size and aperture: Taylor indexing is based on 200 mesh mesh size 0.074mm.
So 100 mesh: 200*0.074mm÷100=0.148mm
325 mesh: 200*0.074mm÷325=0.045mm
(2) The screen mesh is the size of sieve pore, and the wire diameter of the screen refers to the diameter of the braided wire;
(3) The mesh number is the number of mesh holes in the length of 2.54 cm (1 inch), and is simply referred to as the mesh. For example, 50 mesh means that there are 50 holes in 1 inch and 500 holes in 500 mesh. The higher the mesh number, the more the holes are. In addition to the apertures representing the screen, it is also used to indicate the particle size of the particles that can pass through the screen. The higher the mesh size, the smaller the particle size.
(4) The particle size of the powder is called the particle size. Due to the complexity of the particle shape, there are usually several representation methods such as sieve size, sedimentation particle size, equivalent volume particle size, and equivalent surface area particle size. The sieve size is the size of the sieve through which the particles can pass through the screen, and is expressed as the number of sieves in the screen of 1 inch (25.4 mm) width, and is therefore referred to as "mesh". At present, there is no uniform technical standard for powder particle size at home and abroad, and each enterprise has its own definition and representation method of particle size index. Screen specifications in different countries and different industries have different standards, so the meaning of “mesh” is difficult to unify.
(5) At present, the calculated diameter of the equivalent volume particles is used internationally to represent the particle size. Expressed in μm or amm.
(6) The correct choice of screen is very important.
Example
1: The material sieved by the customer is soy protein. The material has less abrasiveness and the service life of the screen can reach more than 6 months. At this time, the standard of the screen is finer. Because the sieve diameter of the filament diameter is higher. For example, the customer specifies a 60-mesh screen. The screen standard selected by A is a hole diameter of 0.3 MM and a wire diameter of 0.112 MM. At this time, the mesh of the measuring screen is 61.6 mesh and the sifting rate is 53%; the selected screen standard is a hole diameter of 0.28. MM, wire diameter 0.14MM At this time, the mesh of the measuring mesh is 60.5 mesh screening rate is 44%; C is 0.25MM according to the national standard, the wire diameter is 0.125MM, and the permeable screening rate is 44%; this time is also a model The sieve machine, the sifting rate difference is 9%, the difference in output is very clear.
2: The material screened by the customer is silicon carbide. At this time, the coarse wire screen of the abrasive grade must be selected because of the abrasiveness and particularity of the material. There is no reason for negotiation at this time.