⚙️ Technological Process

Extrusion Process

Extrusion is a thermodynamic process in which raw material passes through an extruder under high pressure and temperature, resulting in an expanded, sterile and highly digestible product.

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100–3.000 kg/h Line capacity
110–160 °C Process Temperature
95–98% Protein digestibility
Nula patogena Sterilan proizvod

What is extrusion and how does it work?

Extrusion is a thermo-mechanical processing method in which raw material (flour, grain mixtures, protein concentrate or soy) is fed into the extruder where the screw compresses the mass and increases pressure and temperature. At the outlet die, the mass suddenly expands and dries, producing a porous, easily digestible granulate.

The high temperature (110–160°C) destroys pathogens, anti-nutritional factors and bacteria, ensuring a microbiologically safe product with extended shelf life without preservatives.

1

Raw material preparation

Grinding and dosing of components — flour, proteins, premix

2

Conditioning

Addition of moisture and steam to prepare the mass for extrusion

3

Extrusion and expansion

The mass passes through the screw at 20–100 bar and expands at the outlet

4

Drying and coating

Moisture is reduced to ≤10%, with optional oil and flavour coating

🔑 Key advantages of extrusion

  • Elimination of pathogens and salmonella — sterile product
  • Deactivation of anti-nutritional factors in soy and legumes
  • Protein digestibility increase up to 98%
  • Expanded texture — ideal density for floating in aquaculture
  • Adjustable granule shape and size (interchangeable dies)
  • Longer shelf life without preservatives
  • One extruder — multiple products by changing the die
Extrusion pressure
20–100 bar
Temperature
110–160 °C
Raw Material Moisture
18–25 %
Moisture output
≤ 10 %

When is extrusion used?

Extrusion is indispensable in the pet food industry, aquaculture and soy processing.

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Pet food
Dry granulated food for dogs and cats. Extrusion delivers a crunchy texture and sterility without preservatives.
Dog food Cat food Keksi
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Fish and aquaculture
Floating and sinking pellets for fish and crustaceans. Density is precisely controlled to match feeding behaviour.
Fish Shrimp Floating pellets
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Processing of soy and legumes
Soy toasting by extrusion eliminates anti-nutritional factors and increases protein digestibility for animal feed.
Soy Pasulj Sunflower

Extrusion Machines

AM Tehnolog offers single-screw and twin-screw extruders for different raw materials and capacities.

Technology Lines sa ekstruzijom

Complete lines in which extrusion is the key processing step.

Key parameters of the extrusion process

Factors that determine the quality and characteristics of the extruded product.

🌡️
Extrusion temperature
110–160 °C
Lower temperature = denser, less expanded granule. Higher = greater porosity and floatability in water.
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Raw Material Moisture
18–25 %
Optimal moisture for conditioning. Too much moisture reduces expansion, too little causes overheating.
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Granule size
1–20 mm
Diameter depends on die opening. 1–3 mm for fish feed, 6–12 mm for dog and cat pellets.
Specific energy
60–120 kWh/t
Depends on protein and fat content. Soy requires higher energy for complete inhibitor deactivation.
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Cylinder pressure
20–100 bar
Controls granule expansion and density. Higher pressure gives a denser, harder product.
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Protein digestibility
95–98 %
Thermal treatment breaks down anti-nutritional factors and increases protein bioavailability.

Planning an extrusion line?

Our team of technicians will help you choose the right extruder for your raw material and planned capacity.