Increasing Efficiency in Pet Food Production - Why You Should Think About Grinding

The main challenges pet food producers face in grinding today are:
 

• New high fat and protein rich recipes for optimal nutrition.
• Demand for fine uniform texture and well looking appearance requires fine grinding. 
• Increased energy cost decrease margines and grinding is one of the most energy consuming process steps.

Evolving Ingredients, Evolving Demands

Modern pet food recipes incorporate a growing variety of ingredients or higher meat and bone meal content causing unique milling challenges due to higher protein, fat, and moisture content. Premium pet food recipes often contain bone meal and meat content of more than 30% and a fat level higher than 8%.
 

Older hammermills struggle with these recipes, tend to clog when processing such components, leading to increased energy consumption and heat buildup. These issues not only drain more power but also degrade sensitive nutrients, compromise product quality, and necessitate more frequent maintenance.

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Fine Grinding and Extrusion Performance

Beyond the nutritional benefits, particle size has a significant impact on extrusion performance. Finer and more uniform grinding improves water absorption and starch gelatinization during the extrusion process. These factors influence the consistency, fineness, and bulk density of pet food. In addition, finer and more uniform grinding reduces wear on extrusion equipment, thereby reducing maintenance costs and downtime.
 

While fine grinding offers clear advantages in terms of nutritional value and processing, it also poses a significant challenge for hammer mills. Smaller screen sizes are required to achieve finer grinding, which often results in lower throughput and higher energy consumption. In addition, the risk of screen clogging increases and more heat is generated due to longer grinding times.
 

Excessive heat can break down sensitive nutrients and cause starch to gelatinize prematurely. This heat can also overheat mechanical parts and, in extreme cases, increase the risk of fire.
 

Many hammer mill systems were not designed for fine grinding. Older systems were designed for coarser grinding degrees, where a medium fineness was completely sufficient. Fine grinding requires higher rotor speeds, larger screen areas, optimized air flow, and intelligent process integration. Without these prerequisites, manufacturers are faced with rising operating costs, production losses, and unnecessary losses that have a direct impact on profitability.

The FD 32 Pro: Modern Hammer Mill Made for Pet Food Producers

Tietjen new FD 32 Pro hammer mill was designed to face these challenges and is engineered to address precisely these energy and process challenges. Key innovations include:
 

• Expanded 4.8 m² screen area: Allows high capacity grinding to feed the new generation of extruders with only one mill. This saves investment and operational costs 
   
• Reduced beater-to-screen gap: Minimizes screen clogging even with high-fat ingredients
   
• Variable speed drives: Permit optimized rotor speed, so the mill only uses as much energy as needed for each recipe
   
• Impact plates & modular screens: Shorter retention time of the product in the mill and screens that fit ideally for the product allow for faster grinding with less energy 
   
• Quick-change beater frame system and User-Friendly Design: Large sliding doors, easy beater change, and robust construction allow for long service life, further lowering downtime.
   

In sum, the FD 32 Pro is the next step in hammer mill design—a focus on energy efficiency, high-capacity fine grinding, and operational simplicity—helping pet food manufacturers turn modern processing into opportunities for sustainable, profitable growth. 

0.8 mm (20 -25 mesh) screens after grinding fat and protein rich pet food recipes

Due to its large size, the FD 32 Pro mill enables pet food producers to achieve both high throughput and fine particle size simultaneously when grinding pet food formulations. The throughput of the hammer mill complies with the requirements of the newest generation of high-capacity extruders.

The FD 32 Pro can process even protein- and fat-rich recipes through a 0.8 mm screen (roughly mesh size: 20 to 25) without clogging—something most mills cannot achieve without repeated stoppages or multiple machines.

Save More Energy with an Optimally Designed Grinding System

To achieve even greater improvements and maximize both energy and production efficiency, it is essential to rely not only on the high-capacity FD 32 Pro hammer mill, but on the entire grinding system. Looking at the grinding process as a whole opens up several opportunities for significant energy savings and operational improvements. 
 

Pre-crushing of coarse ingredients
By integrating a pre-crusher such as the CR900 from Tietjen, coarse ingredients (legumes or large pellets) can be pre-crushed before entering the hammer mill. The result is a more homogeneous product that requires less time in the hammer mill, reducing both residence time and heat generation.
 

Optimized aspiration and product transport save energy
Correctly designed aspirations contribute significantly to increasing process efficiency in hammer mills.
 

Improved product discharge
The extraction system supports the targeted removal of particles that have reached the desired fineness. Coarse components remain in the grinding chamber until they are sufficiently crushed. Insufficient extraction would also leave fine particles in the grinding chamber, resulting in reduced throughput, higher energy consumption, and unnecessary strain on the machine.
 

Thermal stabilization of the ground material
During the grinding process, frictional heat is generated, which can significantly heat up the ground material. Aspiration reduces this effect, as the air flow continuously cools the material. This prevents temperature-related damage to sensitive ingredients, helps to ensure consistent product quality and minimizes the risk of dust explosions.
 

The professional design and integration of aspiration is therefore a key factor for operational safety, energy efficiency and product quality in the hammer mill process.

Uniform product distribution
The feed device of a hammer mill performs several key tasks: it distributes the feed material evenly across the entire width of the mill in order to make optimum use of the impact and sieving surface, keep the wear uniform and use the drive power efficiently. For product mixtures with components of different weights and that are difficult to grind, the system automatically adjusts the feed rate—controlled by the motor load of the mill (load-dependent dosing)—so that the operating point always remains optimal. In addition, the feed system ensures the separation of foreign objects such as metal or stones to prevent damage to the mill and explosion hazards.
 

It also supplies the intake air for grinding. Tietjen has developed a new DA 376 drum feeder for the FD 32 Pro, which is specially designed for the mill and the properties of pet food and aquafeed. 
 

A magnet separates magnetic foreign matter, and the aspiration air is used for heavy material separation. The throughput is regulated by the speed of the drum.

Conclusion

Fine and homogeneous grinding is the key to producing high-quality premium pet food. 
 

With the specially developed FD 32 Pro hammer mill, Tietjen offers a powerful solution that combines maximum grinding fineness with high throughput thanks to innovative technology and is ideal for processing demanding, fat- and protein-rich recipes.
 

However, the overall system remains crucial for maximum efficiency and product quality: The optimal coordination of hammer mill, pre-crushing, aspiration, and regular maintenance results in energy-efficient operation, reduces downtime, and ensures a consistently high-quality end product. Those who rely on modern grinding technology from Tietjen and a well-designed system are ideally equipped for the pet food production in the future.

By Tietjen
Source: All Pet Food Magazine

This is Tietjen
We have been developing, designing, and producing hammer mills and size reduction technology in Germany since 1959. Complex customer requirements are our specialty: from first contact to design and delivery of the optimal plant, to after sales service, we are your competent partner for all types of impact grinding. We develop your grinding solution and take care of the implementation—worldwide.