Bran is the hard outer layer of whole wheat and other cereal grains. It is present in and may be milled from any cereal grain, including rice, corn, wheat, oats, barley, and millet. Bran naturally contains significant quantities of starch, protein, vitamins, and dietary fiber. Because of these nutrient-rich qualities, bran is often used to enrich bread, muffins, and breakfast cereals to benefit those who wish to increase their dietary fiber.


Historically, bran and germ have been separated from the whole grain because the combination of an extended distribution cycle and the high oil content of bran caused the flour to become rancid. However, when bran is removed from the whole grain, the grain loses much of its nutritional value. Millers need to grind large quantities of multiple grains quickly. The challenge is that each grain must be ground to its precise specifications to reach the desired fineness appropriate for end-use.

Grain millers are also concerned about the flavor quality of their products. Retaining good nutritional value becomes inconsequential if the flavor quality is gritty, and the product is undesirable to the consumer. In the end, both the grind consistency and the flavor standard have to be optimized to achieve maximized profitability.


Prater's Classifier Mills (CLM) allow millers to grind multiple grains to their product specifications. Capable of grinding to a product size sub 1 % retained on 70 mesh, the CLM is perfect for grinding fibrous products with a narrow particle distribution curve like bran.

There are three stages taken when processing material through a Prater CLM. The initial grinding stage is similar to what is accomplished with the M Series Fine Grinding Mills. However, a secondary inlet provides additional air for the second stage internal air classifier wheel. This additional air also adds an element of cooling to the material being processed. Oversized particles that are larger than desired are rejected by the classifier and directed to the third stage, a separate part of the grinding rotor. This recycled material is ground again, then redirected to the classifier, allowing only properly sized product to exit the mill.

Company Overview:

At Prater, results come first. Our products work to serve your dry processing, powder, and bulk solids applications. With Prater's extensive line of equipment and systems, you will obtain your process's best possible results time after time. Each of our high-quality products is developed to serve each industry differently to provide the desired outcome of each processing application.

Each of our products carries the Prater guarantee of efficiency and durability while designed to adapt to serve the needs of various industry applications. Prater products are rugged and time-tested, providing the best results for materials processing. Whether you plan to feed, size, enlarge, weigh, or reduce your material, Prater products provide the Particle Management Solutions you seek.

Prater has been providing reliable particle management solutions since 1925. The company specializes in an extensive line of equipment and engineered systems, including lump breakers, hammermills, fine grinders and classifier mills, screeners/separators, air classifiers, compactors, minor/micro ingredient batching systems, and plant-wide automation/controls.