For quality control programs, test sieve analysis is imperative. The gradation of particles is critical to the way a product or material performs when put into use. Sieve analysis is the most common way to ensure particle size distribution. This is because it is the simplest, most cost-effective method for ensuring proper particle size. Since it can be performed on organic and non-organic materials of various sizes, including tiny particles, it is useful for an extensive variety of applications.
The Procedure
Aggregates such as manufactured powders, granite, crush rock, or other organic or non-organic granular materials can be used in gradation laboratory tests. A typical gradation sieve includes a nested column of wire mesh sieves. A weighed sample of whatever material is being tested is poured into the topmost sieve. It will have the largest openings. The sieves are graded so that each lower sieve will have smaller openings than the one above it. The column of sieves is placed on a device that produces a shaking movement, allowing materials to rest on each sieve according to its particle size. Each sieve is then weighed, and the sample weight on each sieve is divided by the total weight of the original material. This gives the percentage of various particle sizes in comparison with the total weight.
Results of Sieve Analysis
The results of sieve analysis tests are very useful for determining the properties of a particular aggregate. For example, asphalt or concrete mixes must contain a precise amount of specific-sized aggregates in order to function as intended. Sieve analysis is also useful for producing appropriately sized well screens for water production.
Additional Methods
There are many different ways that sieve analysis can be performed. The type of method used will depend on the aggregate that is being measured. For instance, if you need to measure long, needle-shaped, or fibrous materials, the horizontal sieving method may be the most fitting method to use. For this method, the sieve stack is moved in horizontal circles on an even plane. For fine, dry powders, the sonic sieving method is often used, which involves lifting the particles in the sieve and dropping the column forcibly. Within the column, oscillating air moves at a high frequency. Wet sieving, throw-action sieving, and air jet sieving are just a few other methods used to perform sieve analysis.
Calibration Services
In order to ensure quality control, it is important for laboratories that perform sieve analysis to calibrate the sieves that they use from time to time. Sieve calibration services are offered by professionals for both new test sieves and test sieves that are already in use. When seeking professional calibration services, it is imperative to choose a reputable calibration company that can assure a great amount of accuracy. An experienced company that performs many calibrations a year in a professional laboratory and that has a strong reputation for top-notch services will ensure the best results. Calibration services should be an integral part of your quality control program so that you can offer the most reliable products available.