White Paper. Different sieving methods for a variety of applications
The determination and knowledge of the particle size distribution is an essential part of the quality control process for industrial products. Easy handling, low investment cost and high accuracy make sieve analysis one of the most frequently used procedures for measuring the particle size. This white paper gives an overview of the different sieving techniques and describes the necessary steps to ensure reliable results.
White Paper: Cryogenic Preparation of Sample Materials
A solid sample material should always be sufficiently prepared by size reduction and homogenization before it is subjected to chemical or physical analysis. Care should be taken that the analysis sample fully represents the original material and that the sample preparation process is carried out reproducibly. Most sample materials can be reduced to the required analytical fineness at room temperature by choosing a mill with a suitable size reduction principle (impact, pressure, friction, shearing, cutting).
White Paper: Ultrafine Grinding with Laboratory Ball Mills
How are nano particles produced? The “Bottom-Up” method synthesizes particles from atoms or molecules. The “Top-Down” method involves reducing the size of larger particles to nanoscale, for example with laboratory mills. Nano particles are produced by colloidal grinding which involves dispersion of the particles in liquid to neutralize the surface charges. Factors such as energy input and size reduction principle make ball mills the best choice for the production of nanoparticles.
Particle size analysis and particle size distribution are important criteria for the quality control of bulk materials. In a running production process, the results of a quality check must be available quickly to allow for immediate adjustment of the production parameters. Depending on the expected particle size and sample volume, different sieving methods and sieving machines are suitable for analysis. The method used for particle size analysis is primarily determined by the fineness of the material to be sieved. For dry sieving of samples with particle sizes below 40 microns, air jet sieving is the method of choice.
Mixer Mill MM 400: Upgrade of a True Multipurpose Mill
With the Mixer Mill MM 400 RETSCH has developed a true multipurpose mill which covers a huge range of applications, including classic mixing and homogenization but also more complex tasks like cell disruption via bead beating or mechanochemical processes.
The ease of use of mixer mills in general, combined with a wealth of accessories make the MM 400 the perfect choice for quick, safe and reproducible processing of small sample volumes.
The following situation is typical for many production plants: After a routine quality check, the production process is stopped or an already produced batch is suspended, because the analysis results were not within the relevant critical values. But does the tested product really deviate from the specifications? It is often not the product itself which causes irregular analysis results but a lack of understanding of the steps which come before the analysis.
Representative sampling of large sample volumes is an integral part of the physical and chemical analysis of bulk goods and has a decisive influence on the quality of the results. Extraction of a sample from the bulk is not always carried out in a way to ensure representativeness. This is a widespread flaw in the quality control process with a negative impact on the subsequent analysis results. RETSCH provides some convenient solutions which help to improve working conditions and thereby the quality of the sampling process.
Separation of large sample volumes with the AS 450 control
Particle analysis of large quantities of bulk goods is usually done by vibratory sieving. In most vibratory sieve shakers in the market the sieve stack is mounted on springs which oscillate vertically. However, to evenly distribute the material over the entire sieve surface, the so called 3D vibratory sieving as it is used in the AS 450 control is the most suitable method.
Sieving of agglomerating powders with the air jet sieving machine AS 200 jet
Air jet sieving is usually the method of choice for dry sieving of materials with particle sizes below 40 microns. However, it is also a faster alternative to vibratory sieving of materials of up to 250 microns.
Planetary ball mills meet and exceed all requirements for fast and reproducible grinding to analytical fineness. They are used for the most demanding tasks in the laboratory, from routine sample processing to colloidal grinding and advanced materials development.
With the new PM 300 RETSCH has developed a powerful tool which offers high sample throughput combined with ease-of-use.