The extruders are used in the production of many direct expanded snack and cereal. In such a cereal line, the dry ingredients are blended in a mixer and metered into the extruder along with the liquid ingredients.
The extruder is subjected to heat and shear to optimise the starch conversion according to the quality profile of the final product. Processing temperatures are precisely regulated through individual heating and cooling systems in each section of the extruder barrel.
Expansion takes place when the water in the extruder flashes off as the product is forced through the die.
The product shape is determined by a combination of the die aperture, expansion and the die cutter.
The product enters a belt dryer which reduces and stabilizes the moisture content. If a sweetened cereal is desired, the product may enter a coating unit for a liquid confectionery application, followed by a final drying procedure before packaging.