Dairy & Nutrition

Hygienic Design Feeders, Components and Conveying Systems for Sanitary Applications

The production of dry dairy powders and infant/baby formulas requires extremely sanitary design of the equipment as well as high accuracy in the precise addition of ingredients to the formula blend. The system provided must also offer the versatility to handle a wide variety of difficult flowing and temperature-sensitive ingredients, including vitamins, nutrient additives and even probiotics. In addition, depending upon the type of process and the processing environment, the equipment must be able to be cleaned by either wet or dry cleaning methods. The hygienic designs provided by Coperion and Coperion K-Tron are easily adaptable for all of these requirements.

Products and ingredients may include: milk powder, whey powder, lactose, casein, cheese powder, infant formula, maltodextrine, probiotics, vitamins, baby food


  • Global systems engineering group with extensive application experience for the entire milk powder processing line ensures optimal design with an emphasis on product safety, quick product changeover and increased efficiency
  • Highest sanitary design according to the current guidelines and regulations
  • Innovative, custom engineered Coperion rotary and diverter valves ensure reliable, long-term and safe operation
  • Equipment and system designs in accordance with a wide variety of regulatory standards
  • Coperion is an active member of the European Hygienic Engineering and Design Group (EHEDG) and therefore the latest developments and directives are directly incorporated into design of all components
  • Coperion K-Tron line of feeders provides maximum accuracy for adding high value ingredients like vitamins and probiotics
  • Extensive material handling expertise for even the most difficult flowing dairy powders like lactose and maltodextrin

Application Examples

Coperion K-Tron feeders over mixer in infant formula application
Coperion K-Tron feeders over mixer in infant formula application

Feeding and conveying in infant formula production

This product application sheet outlines the process solutions available for feeding and material handling of dry infant formula and milk powders.  Both the dry blend and the wet blend process including spray drying are described, with specific options available for the most efficient process design and equipment choices. In addition, full details are given with regards to the wet and dry cleaning procedures used for these processes.

Download the application sheet for more info:


Handling Inclusions in Ice Cream

The ice cream manufacturing industry is highly susceptible to fluctuating costs in value added ingredients as well as product quality affected by the percentage of these ingredients in the mix. Ingredients added to the semi frozen ice cream base mix are typically called “inclusions”. Inclusions can be comprised of anything from marshmallows to chocolate chips to coconut flakes. Coperion K-Tron feeders are used to accurately dispense the percentage of these high value inclusions in the mix, in order to control ingredient costs as well as improve product quality. This application sheet describes the application and defines the equipment designed for this sanitary operation.

Download the application sheet for more info:

Coperion K-Tron Process Probiotics

Handling Probiotics

Global use of probiotics has steadily increased over the last 10 years, mainly in dairy products such as yogurts and yogurt beverages. However, even more recently, the introduction of probiotics in a powdered microencapsulated form for nondairy foods such as infant formulas, health food bars, breakfast cereals, snack foods, dry pet foods, and even chocolate has become commonplace in the food and petfood marketplaces. This growing trend in the use of probiotics can be attributed to the increased media exposure emphasizing that intestinal balance is critical to obesity management, cancer prevention, as well as improved overall immune system health.

Due to the delicate nature of the probiotic organism, the introduction of probiotics to the food processing or packaging stages requires special attention. The probiotic must be treated carefully during all stages of food processing to ensure that the probiotic viability is not affected and the overall efficacy is maintained. Coperion K-Tron loss-in-weight (LIW) feeders and sanitary vacuum conveying systems are used in the highly accurate introduction of probiotic powders to continuous mixers, as well as for the contained transfer and LIW batching to the final packaging container.

Download the application sheet for more info:

Coperion spray drying process flow for milk powder production

Spray Drying Milk Powder

In the wet blending/spray drying process, ingredients are blended with water in large batches and then pumped to a heat exchanger for pasteurization. The pasteurization step ensures that any harmful materials which may be present in the batch are destroyed. This step also has the advantage of ensuring uniform distribution of the ingredients.

After pasteurization the liquid is homogenized and the product may be concentrated by passing it through an evaporator or sent directly to the spray dryer. As shown in the flow diagram, the product is then atomized in the spray dryer. As droplets of product are fluidized in the dryer, water is evaporated and then dry powder deposits on the spray dryer bottom, where it is discharged with a sanitary Coperion rotary valve to a fluidized bed. There the product is typically dried further and cooled. The outlet air from the spray drying chamber still carries product (fines) which is normally ducted into cyclones and bag filters after the spray dryer. From there the product is discharged with Coperion rotary valves into the fines return line. The fines can either be transported with pneumatic conveying to the fluidized bed or back to the top of the spray dryer for agglomeration purposes. The actual conveying path is selected by the Coperion WYK diverter valve. After the fluidized bed, the finished powder passes through a sifter and is then pneumatically conveyed to storage silos or packaging lines, where it is deposited into bags or where it is canned.

Conveying & Metering Lactose

Lactose powder often presents a problem when used in a convey system with rotary valves. Typically, the valves will get caked with the lactose powder and layers of lactose or “hardened sheets” will build up on the valve rotor and housing. These extremely difficult layers on the valve pockets will then cause the valve to  squeal and eventually block. The specially designed valves by Coperion are specifically designed and engineered to address this issue and prevent this buildup and squealing.

Comprehensive Product Range

Feeding Equipment


Coperion K-Tron feeders provide the highest accuracy for both batch and continuous blending operations, at rates as low as 50 g/h! Both loss-in-weight and gain-in-weight batching techniques are available, depending upon the accuracy required. High value ingredients such as probiotics can be safely and precisely added to the formulation in accordance with the application recipe. In addition, multi-feeder operations can accurately dispense each of the components to the blender, assuring a safe and efficient automated blending operation.

Volumetric and gravimetric feeders

Material Handling

Hygienic Components for Safe and Efficient Transfer

Whether dry blending or using a spray drying process, Coperion components such as rotary and diverter valves provide the highest degree of hygienic design. Components are available in both EHEDG and USDA certified designs and provide durable and reliable operation for the dairy powder process. Coperion offers special components that can be cleaned in the process without need for dismantling. This also reduces the risk of external contamination in the process. Coperion hygienic rotary valves are designed such that the rotor stays in the housing during CIP and discharges the washing liquids by rotating. Retention-free design including special CIP-gaskets at the inlet and outlet as well at the sideplates assure that no product or liquid remains anywhere. Tests at authorized institutes (EHEDG) have proven that the components are absolutely clean.

Process Equipment

Plants & Systems

Sanitary Systems Design for Material Transfer

In both the wet and dry blending processes for dairy powder and infant formula manufacture, Coperion and Coperion K-Tron pneumatic conveying systems and material handling components are utilized for the  transfer of the raw ingredients prior to blending as well as transfer of the final blended/spray dried product prior to packaging. The conveying systems provided by Coperion K-Tron include both positive pressure and vacuum, dilute and dense phase and are designed with the highest sanitary standards with options for wet or dry clean operations.

Plants & Systems
Coperion service technician


Superior Global Service

Our global service personnel possess extensive material handling and process design knowledge for these special hygienic applications and are available 24/7 to assist you with your dairy powder process needs.

After Sales Service

Frequently Asked Questions

What are differences between Cleaning-Out-of-Place (COP) and Cleaning-in-Place (CIP) when it comes to rotary valve and diverter valve design?

Extremely stringent hygienic and purity requirements are very important when processing dairy powders.  It is often necessary to clean and inspect production systems regularly in order to meet the increasingly stringent specifications of the dairy and infant formula industries.  Wet cleaning is recommended when the product is perishable or products are changed frequently.  Milk powder and baby food are typical examples of products in which dry cleaning is often no longer sufficient.  The inside of hoppers, conveying pipes and bulk materials components are cleaned according to a specified procedure with cleaning media, such as weak acids or lyes and water.  For this reason it is imperative that all equipment in the production process can withstand the cleaning media.

There are two different cleaning methods used in the industry

  • Cleaning-Out-of-Place (COP)
  • Cleaning-in-Place (CIP)

Download our technical paper on CIP/COP for more information on each of these cleaning operations and how the design of the components is critical based upon the cleaning method. It discusses the design differences in detail of both rotary and diverter valves for each of these cleaning methods.


Play video
This 3D animation demonstrates Coperion's ZRD Hygienic rotary valve. The rotary airlock is designed for sanitary, pharmaceutical, food and chemical applications where contamination is a concern, and frequent cleaning is required.

Function principle of WYK diverter valve for CIP cleaning

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