What’s with Grinding:
Why Is Precise Particle Reduction So Important?

Grinding goes way, way back to the beginning of agriculture. Digestion of cereal grains requires breaking or dissolving the seed coat. How to do it? The simplest and quickest options are teeth… or tools.

For tools, from prehistoric grinding stones to modern milling equipment advancements have focused on improving particle size consistency, production efficiency, and final product quality.

D&D’s Accu-Grind™ system excels in meeting these goals.

Besides better digestion, why bother to grind?

Our system can grind whole grains and oil seeds to make meals. But it also can grind ingredients that are already in meal form to produce a processed meal of highly uniform particle size.

The D&D Accu-Grind system — with particle size choices ranging from ultra-fine (5/64-inch) to coarse (5/8-inch) — accommodates ingredients for a wide range of premixes and other products used directly by animal feed and pet food manufacturers as well as by other vendors who serve these industries.

Just a few of the products we custom grind on a regular basis:

• Beet pulp
• Linseed meal
• Soy hulls
• Porcine meal
• Others

Quality manufacture of most such intermediate and final products benefits from uniform particle size, where the size of individual particles of an ingredient should fall within a narrow range.

Why is uniform particle size an advantage?

Controlling the “Brazil nut effect”

You might not know the effect by this name, but you know the result. When you open a box of breakfast cereal or bag of snacks, big pieces are on top and little pieces are on the bottom — even though everything was well mixed when the box or bag left the factory.

That’s the Brazil nut effect — a form of “unmixing” of a dry, granular mixture.

This type of particle segregation occurs as particles of different sizes separate from a homogenous mixture. Bigger particles — like Brazil nuts — which may have the same or greater bulk density as other particles — like peanuts — tend to “float” to the top of the mixture.

The effect seems counter-intuitive, heavier particles ought to sink, right?

Scientifically, there’s a lot going on during the Brazil nut effect, which depends upon the shape of the particles and the container and many other factors.

Fortunately, D&D’s knowledge and experience over the years handling and grinding hundreds of different ingredients helps us avoid particle segregation in single-ingredient products as well as multi-ingredient blends and premixes.

Why customers appreciate good grinding

A quality grind — featuring precision particle reduction — contributes greatly to a quality blend, premix, and final product.

Even though everything going into the product may be acceptable — quality formulation, ingredients, etc. — nonetheless, inconsistent or highly variable particle size can lower its value in mixing and further processing and hurt the quality of the final product.

As our portfolio of ingredients and products expands, we must expand our knowledge of their grinding characteristics. Our expertise in precision grinding must keep pace with the increasingly diverse needs of vendors and customers in the animal feed and pet food industries.

Thanks for your interest! Please let us know what other topics you’d like to see in “Did You Know?” Email claytong@ddingredient.com