The Vacuum Coating Revolution in Feed Production

26 May 20209 min reading

In feed production there is a hidden revolution going on. Why are the biggest feed producers in the world using vacuum coating techniques? And why should you too? This article answers the questions why and how every feed producer could benefit from implementing vacuum coating techniques in their production line. For better feed, healthier animals, and less emissions.

Feed ProductionPeter RAEVEN Vacuum Coating Expert Dinnissen Process Technology

WHAT IS VACUUM COATING?  A BRIEF HISTORY In 1990 vacuum coating techniques were first introduced in the (aqua) feed production sector by Dinnissen Process Technology.

The vacuum coater originated as an evolution of the Dinnissen Pegasus Paddle Mixer. In mixing experiments carried out under vacuum conditions, high concentrations of liquid were sprayed onto feed pellets.

When the vacuum was removed, the liquid was sucked deep into the coated pellets. In this way, Dinnissen succeeded in gradually increasing the fat content of the pellets.

Compared to atmospheric systems, up to 80 % extra liquid could be added to pellets coming from the pellet presses.

The Pegasus Vacuum Coater enabled feed producers to apply liquid additives to and into pellets and extruded products, by creating a vacuum environment within the production process.

For the first time, feed producers were able to improve the quality and characteristics of their products drastically, without influencing the main processes, by adding functional additives like enzymes, vitamins, and drugs, end of line.

By using vacuum coating technology, the additives penetrated homogeneously into the entire pellet. This resulted in better, more nutritious feed and food, healthier animals, and less emissions.

Over the years, animal feed became less and less nutritious and therefore the addition of functional additives became more and more important. ‘Optimizing the recipe’; adding the exact amount of the right additives at the best possible moment to create an ever better product, became an art on its own.

A lot happened since 1990. Nowadays the Pegasus Vacuum Coater is used worldwide. Available options such as oversized hatches, hot-air treat ment and CIP cleaning make it suitable for many applications.

With the latest Pegasus Vacuum Coater you can quickly switch between recipes while still complying with the strictest hygienic requirements.


After years of developing, optimizing, and innovating, the benefits of using vacuum coaters speak for themselves: • More nutritious feed: Preservation of the action of functional additives such as vitamins, minerals, ameliorators, taste enhancers, yeast and enzymes. • Retention of taste and color of feed. • Energy-rich feed via the addition of high percentages of oil or fat, results in faster and better growth of animals. • Better feed leads to better digestion, which results in better growth. • Better digestion leads to reduction of nitrogen, ammonia, phosphate and/or methane emissions (feces). Hamex® Hammermill

• Healthier animals, and less loss of livestock. • Flexible production processes with sophisticated control programs allow producers to optimize the ‘recipe’ of their product to create an ever better feed. • Extremely precise and homogeneous dosing of (expensive) additives, micro dosing with a very high accuracy. • Applicable in different production settings: convenient, easy-to-use and easy-to-clean. • Adding functional additives at the right moment (end-of-line, preconditioning and pressure stage).


Vacuum coating technology allows producers of animal feed and aquafeed to create a vacuum environment within their production processes, enabling them to deal with a wide variety of challenges.

animal feed The process starts with creating a vacuum inside the vacuum coater, where after multiple layers of additives can be applied to the product. The Pegasus Vacuum Coater gently suspends ingredients homogeneously in the air while the vacuum unit creates a vacuum environment. The spraying functionality makes it possible to spray a precisely predetermined quantity of liquid onto the powders, pellets or granules. When air is then allowed to enter the mixing unit, the liquids are evenly distributed deeply into each particle. The ingredients being sucked deep into the particles through the vacuum, also has the effect of protecting them against crumbling. After this step, additional layers of top coatings or aromas are applied to each particle, which results in a high-quality extruded product. Often a thin layer of fat is applied to the granular feed material. This extra protective layer makes the material more elastic so that it breaks or crumbs less quickly. All this is done very fast, the entire batch process takes just a couple of minutes. Pegasus® Mixer


By using vacuum coaters, functional additives can be introduced in the final stages of the production process. Additives, including a wide range of substances such as oils, fats, vitamins, minerals, enzymes, prebiotics and probiotics, taste enhancers, yeast and other enhancers, can be added to powders, particles and granules.

Functional active ingredients can be processed as powders or liquids, and are always added in the vacuum coater after the heating and pressure stages.

This functionality of vacuum coaters ensures that heat-sensitive substances remain active after being added to the product. Another advantage of introducing functional additives in the vacuum coater, is that the (expensive) additives can be dosed extremely precisely and homogeneously.

The vacuum coating process not only preserves the action of functional additives, such as vitamins, minerals, ameliorators, yeast and enzymes, it also helps with retaining the taste and color of the product.

An additional advantage of vacuum coating is that pellets aren’t greasy on the outside anymore. This increases the flow out of the silo, prevents pollution, and reduces contamination at farms.


Vacuum coaters are used primarily for adding essential ingredients such as aromas, oils, vitamins, minerals and enzymes to granules and extruded products.

The Pegasus Vacuum Coater makes it possible to add precisely the right amount of powder or liquid to each granule, after which the additive penetrates deeply into the granule.

With the same technology, batches of solid as well as liquid ingredients can be mixed quickly and very homogeneously. The Pegasus Vacuum Coater is capable of adding much larger quantities of additives to powders, granules and granulates, than traditional production methods.

Additionally, it’s possible to quickly add several coatings (one after another) on granules and extruded products and to vary the effect of the vacuum process. For example, switching the vacuum on and off controls the depth to which the liquid additives penetrate into the granule.

The sophisticated control program makes it easy for producers to vary the vacuum settings and with it the injection of powders and liquids.

As a result, the vacuum coater is suitable for producing a wide range of products on a single production line. Varying with ingredients and switching between recipes is fast and convenient. This also applies to the production of small quantities.


• Energy-rich, non-sticky, and good running granules • Strong pellet, no dust, fewer recalls • Improved efficiency and feed conversion • Lower energy need for production • Possibility of adding components ‘end-of-line’ • Less odor emission, fat/oil is not overheated • Mixing / blending with vacuum processing capabilities • Highly accurate feeding, weighing and liquid dosing • No contamination and hygienic design for fast and easy cleaning • Suitable for fragile and extruded products • Optimum quality, safety and homogeneity of product, used by many premium brands

SPECS OF THE PEGASUS VACUUM COATER • Production capacity of up to 30 t/h per unit • Batch sizes from 10 up to 3000 l/batch • Fast mixing with double shaft paddle mixing technology • Low coefficient of variation • Fitted with vacuum tight exclusion valves that have a FDA-approved type seal, developed exclusively by Dinnissen


Dinnissen Process Technology has perfected the vacuum technology over the past years and made it suitable for many other applications. The Pegasus Lab Coater for example is a great addition to any research department. With this compact and easy-to-clean machine, testing several recipes becomes a much easier task as adding different ingredients and mixing small batches is possible within relative short amounts of time.


At Dinnissen we’re always looking for ways how the production process can contribute to producing an ever better product. That’s how 30 thirty years ago the first Pegasus Vacuum Coater was developed.

We also know that there are few production environments where the 'price' argument is as harsh as in animal feed & aquafeed markets. That’s why we constantly

challenge ourselves to come up with solutions that enables feed producers to maximize output at the lowest possible operating costs.

• How can we increase production capacity? • How can we improve product quality • How do we make sure that our machines keep running at all times? • How can we contribute to better feed? Less energy consumption? And less emissions? • How can we keep our own production and development costs low? • By asking ourselves these questions every day, we make sure that all our innovations are efficient and reliable. This applies to our vacuum coaters, as well as to our mixers, hammer mills and other machines.

For example, our Hamex Hammer Mill, developed for grinding a wide range of raw materials, such as protein products, barley, corn, wheat, soy Feed Productionmeal, and rape seed meal mixed with grain-replacing raw materials like corn gluten feed flour, tapioca, grain waste and citrus pulp. Optionally, the Hamex Hammer Mill is equipped with a fully automatic screen change system that allows changing while the rotor continues rotating. This saves feed producers about ten minutes waiting time per screen change.

Another example: Our Pegasus mixers are optimized for ultra-fast and optimal mixing of powders, pellets, granules and granulates, while at the same time reducing product damage and contamination to a minimum.

People know us from our innovative machines and turnkey solutions, but I believe that the reason why we became a global leader is not because of this.

It’s because we always kept in mind that we are not developing machines or production lines, but that we’re creating better feed, a better meal, pellet or granule.

Together with our customers, we work on creating high-quality nutritional feed that is good for animals, good for humans, and good for profit.


With more than 70 years of experience with industrial processes, Dinnissen Process Technology is a leading specialist in the process technology of powders, particles and granules.

From product intake, conveying and handling, feeding and weighing, mixing, milling, sifting and packaging.

Dinnissen Process Technology optimizes the performance and efficiency of entire production processes with customized solutions. All developed, manufactured, and tested in-house.

Articles in Cover Story Category
29 March 20205 min reading

Mycotoxin Risk Assessment in Feed Production

For an effective mycotoxin risk management, feed manufacturers should always consider a basic princ...

06 March 20227 min reading

A practical guide for evaluation of automation systems in feed industry

23 January 20188 min reading

Status of Feed Production in the World and Turkey

“Following the first feed production facility established in the United States of America in 1875 w...