10 Facts you might not know about laboratory test sieves
Fact No.1 Mesh number stands for number of wires per inch (25.4mm)
Woven wire sieves are sold either by mesh number or by the wire spacing. Mesh Number is measured as figure 1.
ASTM American standard uses mesh numbers and ISO/BS International and British standard more often uses wire spacing.
Fact No.2 8" is NOT 200mm
There is a slight difference between 8” and 200mm, or 12” and 300mm diameter. 8” is 203mm and 12” is 305mm.
So please remember 8” diameter test sieves and 200mm diameter test sieves will NOT nest with each other. It is the same for 12” and 300mm diameter.
Fact No.3 Not all aperture sizes are the same!
Both ASTM and BS/ISO allow tolerance for aperture size variation. The stainless steel weaving process for producing test sieves is remarkably accurate. However, it is important to understand the limitations to optimise more accurately the performance of a mesh. READ MORE ABOUT TEST SIEVE CALIBRATION AND ISO, ASTM TOLERANCE
Fact No. 4 Compliance Sieves, Inspection Sieves and Calibration Sieves have different tolerances
In the ASTM American standard, the permissible variations for test sieve cloth are different for the three types of test sieve. The tolerance of Inspection test sieves is the tightest, followed by Calibration test sieves and then compliance test sieves.
Glenammer regular compliance sieves all obtain the requirements of the Inspection sieves.
Fact No. 5 Intermediate receivers can make your testing more effecient
You can actually achieve two or more different testings while only operating the sieve shaker once by using intermediate receivers.
As show on Figure2, material A and material B can be tested at the same time, material A can be collected into an intermediate receiver and the material B into the receiver on the bottom.
Glenammer supply a full diameter range of intermediate receivers with an affordable price.
Fact No.6 The test sieves you use will NOT cut every particle to the principle size 100%
In most situations, the cutting point will be very close to the upper standard deviation but won’t be the exact principle size.
Therefore, you might get a more accurate result by using a slightly smaller test sieve aperture.
Fact No.7 Two different weaving technologies to make woven wire sieves
According to ASTM American standard, test sieve mesh size equal or greater than 75 micronmeters should be plain weave, and 63 micronmeters and or less can be supplied either twill weave or plain weave. Figure3
Fact No.8 Choose stainless steel sieves, choose the best
Laboratory test sieves can be made from stainless steel, brass, or bronze. However, stainless steel is the most suitable material to make laboratory test sieves. It is better than brass and bronze because it is much stronger, stable and environmentally friendly.
Food and pharmaceutical industries choose to use stainless steel test sieves rather than other material test sieves.
Fact No.9 Double mesh is definitely NOT a production error!
Have you noticed that some test sieves have double mesh? It is NOT a production error! For the very fine test sieve (under 90microns), large and heavy samples may cause the mesh to stretch and concave. The Glenammer production team put on a supporting mesh (with a larger aperture) to make the finer test sieve last longer for the users.
Fact No.10 Never use sharp objects to poke your sieves
When the particles are lodged in the woven wire mesh, brushes or sharp objects can cause damage affecting the result obtained from the test sieves. We would recommend using a nylon bristle brush to clean the mesh with a gentle circular motion from the underside. Ultrasonic cleaning is recommended for finer woven wire test sieves. READ ABOUT TEST SIEVE CARE AND CLEANING TIPS
1.BS410-1:2000 ISO 3310-1 International Standard Test sieves-Technical requirements and testing- Part1: test seives of metal wire cloth. (2000). Fourth edition 2000-07-15.
2.ASTM Standard E11-09 Specification for Woven Wire Test Sieve Clothes and Test Sieves. (2009).