[kalidindi]

nice explination ,well done

[Md.Rejuan Hossain]

Extrusion is a process in which the food is not only compressed, as in pelletization, but also ‘cooked’, which is why it requires higher levels of moisture, temperature and pressure than pelletization,f

[Vasanthi Jayakumar]

Nice explanation of Pelleting and extrusion. thank you sir

[Md Abdul Bari]

1. Pelleting

Process: Pelleting involves compressing ground feed ingredients into a pellet form using a pellet mill. The process typically involves:

1. Grinding raw materials.

2. Conditioning the feed with steam to increase moisture and temperature.

3. Compressing the mixture through a die to form cylindrical pellets.

2. Extrusion

Process: Extrusion is a high-temperature, high-pressure process where feed ingredients are forced through a die by a rotating screw in an extruder. The process involves:

1. Grinding raw materials.

2. Preconditioning the feed with moisture, heat, and steam.

3. Forcing the mixture through the extruder barrel, where it is subjected to high shear, pressure, and temperature.

4. Rapidly cooling or drying the product after it exits the die.2. Extrusion

Process: Extrusion is a high-temperature, high-pressure process where feed ingredients are forced through a die by a rotating screw in an extruder.

[Kim]

This is a good basic explanation of the two processes. Pelleting uses a limited amount of steam for heat and moisture addition in the conditioner and then relies primarily on mechanical pressure to push the granular feed into the die holes and then compress the feed into pellets. Extrusion takes a granular feed and first introduces much more steam in the conditioner to increase temperature perhaps to 100C and moisture to greater than 30-40% – the hot wet granular feed is then put into the extruder barrel where screw segments convey the material forward under ever increasing mechanical pressure further increasing the temperature which causes the granular material to melt as it is pushed to the exit die – due to the elevated temperature and pressure inside the extruder barrel water remains in the liquid phase – when the material exits the die the pressure immediately drops to atmospheric allowing moisture/water escape as steam – this explains the “puffing” seen in the extrudate and allows pellets to float.

[Bello Bashir]

The main difference between pelleting and extrusion in feed processing is that pellets sink, while extruded feed can be made buoyant

Pelleting

Compresses small particles into larger, solid pellets. This process involves passing the feed mixture through a conditioning chamber where steam is added. Pelleted feed has lower manufacturing costs, but pellets sink quickly, which can lead to higher feed costs and environmental impact.

Extrusion

Involves grinding and mixing ingredients, then cooking them with moist heat to a high temperature. The resulting mash is then pushed through a die to shape it. Extrusion can be used to make feeds that are buoyant, fast sinking, or slow sinking, depending on the needs of the species. Extrusion minimizes nutrient loss and improves digestibility compared to pelleted feed

[Kim]

Good basic explanation of the differences between the two processes. Extrusion is a much more costly process which is why it is used in special applications.

[Md. Osman Sheikh]

Nice explanation, Thank you sir

[Muhammad Zeeshan Asghar]

everyone please