Sieving Process

On the surface the sieving process appears simple. There are complications starting with the nature of woven wire mesh. As with all woven products, the openings in the can become distorted.

The ASTM and the ISO have set standards for sieve construction and mesh tolerances. These fall into three certification categories. The first is construction conformance certification called working sieve states the sieve was constructed in conformance with one of these standards. The second is a certification of manufacturing conformance and a certification of the mesh tolerance called mesh certified. A third level of certification, mid-point provides a sieve in which the openings in the mesh fall in the middle of the standard. Each level provides a specified assurance of performance.

In addition, sieves for special purposes such as shaped holes, wet washing, very small openings and for use with specialize equipment are available.

Hengfeng has sieves in each of these levels and types therefore can provide expert and objective help in specifying and supplying your sieve needs.

Sieving History
Sieving which started in Egyptian times continues to be the basic most widely used technique to determine the distribution of particles in material. The classic sieve is constructed of a round metal frame with a center of woven wire mesh of specified opening sizes. Alternatives are a center of perforated metal or an electroformed center for smaller particles.