Jet mill

About: Jet mill is a research topic. Over the lifetime, 803 publications have been published within this topic receiving 5686 citations.

Ultrafine grinding using a fluidized bed opposed jet mill: effects of feed load and rotational speed of classifier wheel on particle shape.

Abstract: Circularity, aspect ratio, modelx, and pellips were employed to study the effects of process parameters, namely varying feed loads and rotational speeds of the classifier wheel, of the fluidized bed opposed jet mill on the shape of the micronized particles produced. The Shapiro–Wilk statistical test showed that 80.0% of the shape distributions of the four descriptors were not normal. Therefore, the Kruskal–Wallis test, which is a nonparametric statistical test, was employed to analyze the data. Micronized particles were more spherical and less elongated, as indicated respectively by higher median circularity and lower median modelx values when compared to unmilled lactose. These descriptors were able to indicate that the particles had been micronized. When feed loads of 250 and 350 g were used, increasing the rotational speed of the classifier wheel was found to bring about a decrease in span values of all the shape descriptors, indicating that the micronized particles were more uniform in shape. ...

Milling of Organic Solids in a Jet Mill. Part 1: Determination of the Selection Function and Related Mechanical Material Properties

Abstract: The particle size distribution of pharmaceutically active materials and other fine chemicals determines the performance of the final product to a large extent. Often milling of these particles is necessary. It is not possible to determine the milling conditions solely on the basis of the particle size distribution of the starting material, because the (mechanical) properties of the material also determine the desired milling conditions. It is often not possible to optimize milling conditions experimentally because the amount of material available is frequently highly limited. A theoretical approach towards predicting the best milling conditions is needed. The purpose of this study was to develop a method to predict the desired milling conditions given a specific (organic) solid material. The selection function and the breakage distribution function are usually the starting points in modeling the milling process. The selection function is the parameter that includes the material and mill properties. Dimensional analysis made it possible to correlate the selection function with material properties. A set of theories available in the literature enable prediction of the material properties. For different compounds (lactose, paracetamol, a steroidal compound, and two heterocyclic compounds) the selection functions were calculated. The calculations predict differences: lactose reduces slowly in size, while one of the heterocyclic compounds shows the most intense fracture.

Apparatus for coating jet milled particulates onto a substrate by use of a rotatable applicator

Abstract: A film coating apparatus and feed system therefor which comprise: (a) a feeder for dispensing a particulate material at a substantially uniform rate; (b) a jet mill which receives the particulate material from the feeder, wherein the jet mill processes the particulate material by breaking up particle agglomerations and by dispersing substantially uniformly the particulate material into a carrier fluid to result in a processed particulate material; (c) a substrate coating assembly comprising a rotatable applicator; and (d) a tubing having a material receiving end to receive the processed particulate material from the jet mill and a material feeding end to dispense the processed particulate material to the substrate coating assembly, wherein the feeding end is adjacent the surface of the applicator.

Effect of Different Milling Methods on Distribution of Particle Size of Rice Flours

Abstract: Two different methods (Sieve shaker, Elzone particle size analyzer) were used to investigate rice flour particle size obtained by various milling method. Results of Elzone particle size analyzer were more effective than Sieve shaker in determining particle size, and the distribution of particle size of rice flours was affected by the type of the milling methods used. A rice flour, prepared in a Pin mill had a particle size range of mesh, and 30.38% of the sample was in the particle size range mesh. A rice flour, prepared in a Colloid mill had a particle size range of mesh and more of flour particles appeared in the range mesh than any other particle size. A rice flour, prepared in a Micro mill had a particle size range of mesh, and 41.62% of the sample was in the particle size range over 500 mesh. A rife flour, prepared in a Jet mill had a finer flour particle size was over the particle size range 500 mesh. The finer rice flour gave the highest L value and the lowest a value. The wet-milled flour particles were observed as a cluster of starch granules and the particles of rice flour (dry-milling) were observed as fragment of rice grains. Scanning Electron Photomicrographs revealed that visual differences in structure between milling methods, and similar results with Elzone particle size analyzer method in particle size.