Extrusion type expansion is the process of extruding the material forward with the driving force of the extruder screw. The material is subjected to mixing, stirring, friction and high shear force to obtain and accumulate energy to reach high temperature and high pressure, and to expand the material.

Extrusion is a technology that expands food through the combined effects of moisture, heat, mechanical shear and pressure. It is a short-time processing process with high temperature and high pressure. When the material containing a certain amount of moisture enters the sleeve through the feeder, it will be transported forward with the rotation of the screw. When the material is gradually subjected to the resistance of the machine head, it will be compressed. Through the calendering effect and absorbing the heat from the outside of the barrel, And the high temperature and high pressure produced by the strong stirring, mixing and shearing of the material between the screw and the sleeve, so that the material becomes a molten state in the extrusion cavity, the densely arranged micelles in the starch tissue are destroyed, and the starch is produced. The starch (β-starch) is converted into cooked starch (α-starch), that is, starch gelatinization is formed. At this time, the water in the material is still in a liquid state. When the molten material enters the high temperature and high pressure zone in front of the molding die, it is in a completely fluid state. Finally, it is extruded with the die hole to a normal temperature and pressure state. The volume of the sol starch in the material also instantly expands, causing a lot of bursts in the food. Microporous, rapid expansion of volume, thus forming puffed food with loose texture.

Features:

1.Good variability

2.Large production capacity

3.low cost

4.Variety of product shapes

5.Hygiene, low nutrient loss, high digestion and absorption rate

6.High energy utilization

7.Easy production of new food

8.There is almost no loss of nutrients in food ingredients