Pet Food and Aquafeed Production: Handling Oil-Coated Pellets – Advantages of Pendulum Bucket Elevators

In pet food and aquafeed production, product quality is influenced by much more than formulation, extrusion, or pelletizing. One of the final and most valuable processing steps is oil coating, which enhances nutritional value, improves palatability, and increases the overall quality of the finished product.

However, once the coating process is complete, a new challenge begins.

How Can Oil-Coated Pellets Be Conveyed Without Compromising Quality?

Between the coating drum and the packaging line, pellets pass through multiple conveying stages. Each transfer point has the potential to affect product integrity, making the choice of conveying equipment just as important as the coating process itself.

Why Are Oil-Coated Pellets More Sensitive?

After coating, pellets no longer have a dry surface. Instead, they become:

• More slippery
• More vulnerable to impact
• More susceptible to surface abrasion
• More sensitive to friction

These characteristics are particularly evident in premium pet food and aquafeed products with high oil inclusion levels.

Common Challenges During Conveying

Pellet Breakage

Mechanical impacts during conveying may cause pellets to crack or fracture. Broken pellets increase fines generation, reduce product appearance, and negatively affect packaging quality.

Damage to the Oil Coating

Oil coating represents a significant value-adding process. Excessive impacts and friction may remove part of the coating, resulting in:

• Uneven oil distribution
• Reduced product consistency
• Lower visual quality

Dust Generation

Broken pellets produce dust and fines. Besides product losses, excessive dust may:

• Increase cleaning requirements
• Affect plant hygiene
• Place additional load on dust collection systems

Product Segregation

A mixture of whole pellets and fines can reduce product uniformity, leading to inconsistent packaging quality and lower customer satisfaction.

Why Conveying Equipment Matters

In many production facilities, considerable investment is made in extrusion, drying, and coating systems, while conveying equipment is often viewed simply as a means of transportation.

In reality, coated pellets may be conveyed multiple times before reaching storage silos or packaging lines. Every transfer point influences final product quality.

Why Pendulum Bucket Elevators Make a Difference

Pendulum bucket elevators operate on a fundamentally different principle than conventional bucket elevators. Instead of relying on centrifugal force for discharge, the buckets remain suspended throughout conveying and gently tip at the selected discharge point.

This controlled discharge principle can help:

• Reduce pellet breakage
• Protect oil coatings
• Minimize dust formation
• Preserve overall product quality

Flexible Plant Design with Multiple Discharge Points

Another significant advantage of pendulum bucket elevators is their ability to discharge products at multiple locations.

Using a single elevator, products can be directed to:

• Different storage silos
• Multiple packaging lines
• Separate processing systems

This flexibility simplifies plant layouts while reducing the number of transfer points.

Typical Applications

Pendulum bucket elevators are particularly suitable for handling:

• Pet food
• Aquafeed
• Oil-coated pellets
• Extruded feed
• Coffee beans
• Breakfast cereals
• Pasta
• Nuts
• Seeds

Conclusion

Oil coating is one of the most valuable stages in pet food and aquafeed production. Preserving that quality during conveying is equally important.

Selecting the appropriate conveying system can help reduce product damage, protect the coating, minimize dust generation, and improve overall process efficiency.

For fragile, high-value products, gentle conveying should be considered an integral part of the production process rather than simply a transportation step.

To learn more about the differences between belt, chain, and pendulum bucket elevators, read our technical guide: Types of Bucket Elevators.

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