To be successful in the business of material size reduction, achieving a certain particle size and/or shape is key. In order to determine that, you have to measure particle size distribution (PSD)…but what does that mean? PSD is a method of determining the size characteristics of particles. There are multiple ways to make that determination.
In the Sturtevant lab, our engineers and machines can measure particle size distribution of low micron powders using a wet/dry laser analyzer, fine powders using wet/dry sieves, and particle shape using microscopy, blaine/surface area, bulk density, and moisture content.
Ultimately, Particle Size Distribution (PSD) is important because it helps define the physical and chemical properties of a material. It is related to the strengths of aggregate materials, the reactivity of chemicals and the surface area of pigments, pharmaceuticals and cosmetics where uniformity is crucial.
D-Values
To describe particle size distributions, the most commonly used methods are D values.. D10, D50 and D90 are used to represent the midpoint and range of the particle sizes of a sample.
D10 equals the diameter where 10% of the sample particles mass are made up of smaller particles, D50 is where 50% of the sample mass is of smaller particles. D50 is also called the mass median diameter because it divides the sample equally by mass.
D-values rely on the assumption that particles are generally spherical, but unfortunately this isn’t always the case. When particles aren’t spherical, attributes can be assigned to determine the ‘equivalent sphere’. These attributes can be equal weight, volume, surface area or length, etc. However, milling materials sometimes results in particles taking on a more spherical shape. (This is, of course, dependent on the material.)
Sturtevant is in the business of Perfecting Particle Size
Sturtevant is in the business of material size processing equipment for particle size reduction and has been since 1883. In fact, we are the leading family-owned manufacturer of material processing equipment including our patented Micronizer® jet mill which can produce sub-micron sized particles, FCM an air-swept impact mill with integral classifier, Simpactor® and Infestroyer, centrifugal, pin-type impact mills and three types of high performance air classifiers that separate fine and coarse particles with precision and accuracy.
Sturtevant custom engineers its mills to suit the widest range of applications, extending beyond the traditional mineral processing markets into chemical, pharmaceutical, cosmetic, pigment, food, fly ash beneficiation, aggregate, animal feed, and air pollution control industries.
Whether you know exactly the particle size and D value ranges you need or whether you need assistance in determining what particle size will best work for your application, Sturtevant can help.
Contact us, to chat about your PSD needs for your application.