The simple test sieve is the most basic and cost-effective type of particle size analyzer on the market. For this reason, it is an important weapon in the battle to maintain rigorous quality control standards. Due to its simple but highly effective design, this type of particle size analyzer plays an important role in many production facilities, including those found in the pharmaceutical, food processing, cosmetic, agricultural, and chemical processing industries.
In general, a particle size analyzer is used to determine the overall composition of dry granular materials (eg, cosmetic face powders or whole wheat flour). Additionally, fluids containing suspended solid particles, such as chemical grouts and household paint, can also be evaluated in this way. Regardless of the material being tested, a particle size analyzer is used to determine the size, shape, and distribution of the particles present in any given sample of that material.
Compared to other particle size testing options, the sieve test offers a number of distinct advantages. However, this method also has some drawbacks.
Advantages of using test sieves for particle size analysis
* Cheap. Thanks to their straightforward and straightforward design, test sieves are much less expensive than more sophisticated computerized models. This makes them the ideal solution for many manufacturers who need to monitor quality, without the need to invest in a high-end particle size analyzer.
* Produce Consistent and Reliable Results. Despite their simple design, test sieves can produce repeatable results regardless of when or where each test is performed. This is of great value to quality control managers who depend on the accuracy of these tests to maintain the integrity of the production process.
* Readily available. Thanks again to their simple design, test sieves are easy to obtain. This makes them very easy to replace when needed, with no loss of production time due to hard-to-find parts.
Disadvantages associated with the use of test sieves
* Depends on constant energy input. To perform a sieve test, the test sample must be “shaken” to separate the smaller particles from the larger ones. As a result, the only way to produce consistent and repeatable results using this method is to apply the same degree of “jolt” (energy) in all test scenarios. Mechanical sieve shakers are available to help alleviate this concern. However, there are currently no industry-wide standards governing the calibration of these units. Therefore, internal calibration standards must be developed and maintained by the facilities that employ them.
* Static electricity. Static electricity can cause fine particles to adhere to the wire mesh of the test sieve. This, in turn, can skew the results and lead to incorrect analysis data. Fortunately, the addition of talc, activated carbon, activated magnesium, or bourgeois clay can greatly reduce the impact of static electricity on the final test results.
Clearly, there are a number of advantages and disadvantages associated with using a simple test sieve for particle size analysis. However, many QA professionals have come to rely on them to maintain production standards in a wide range of environments.