Twin-screw extrusion puffing machine

2023-01-03

Twin-screw extrusion puffing machine is a multi-screw extrusion puffing machine, is developed on the basis of the single-screw extrusion puffing machine, in the barrel of the twin-screw extrusion puffing machine, side by side placement of two screws, so called twin-screw extrusion puffing machine. According to the relative position of the screw can be divided into meshing type and non-meshing type, meshing type can be divided into partial meshing type and full meshing type; according to the direction of rotation of the screw can be divided into the same rotation and reverse rotation two types, reverse rotation can be divided into inward and outward two.

The nature of the pressure zone of the twin screw is different, as the material is rotated by the screw in the inner cavity of the sleeve, creating a high pressure zone and a low pressure zone. Obviously, the material will flow in two directions from the high-pressure area to the low-pressure area: one is with the direction of rotation of the screw along the inner wall of the sleeve to form the left and right two C-shaped material flow, which is the mainstream of the material; the other is through the gap between the screw engagement part of the formation of counter-flow. The reason for this is that the left screw pulls the material into the gap, while the right screw pulls the material out of the gap, resulting in a "∞" shape, changing the direction of the material flow.

This not only helps the mixing and homogenisation of materials, but also makes the screw groove between the grinding (i.e. shear) and rolling effect, the effect of calendering, this effect is much smaller compared to the reverse screw calendering effect. Of course, the calendering effect is small and the material wear and tear on the screw is reduced. The material is thus conveyed, sheared, mixed and heated by the barrel shell, cooked under high temperature and pressure, and finally extruded out of the barrel.