The structure of the twin screw barrel feeding hopper is commonly used in ordinary hoppers, forced feeding hoppers and vibrating feeding hoppers.
This simple structure and low cost hopper is mostly used in small extruders to feed the extruder barrel. The feeding method of this hopper is to rely on the weight of the pellets themselves to fall freely into the extruder barrel. Therefore, during work, pay attention to avoiding the phenomenon of "bridging" of raw materials in the hopper, which affects the continuous feeding of the extruder.
Forced hopper feeding is mostly used in large extruders or when the extruded raw materials are powdered materials. The spiral motor is decelerated by a worm and worm wheel and then driven to rotate. A spring on the upper end applies a certain pressure to the spiral, so that the raw material is pressed into the twin screw barrel when the spiral rotates. When the material in the barrel is full, the back pressure of the pressed material will push up the screw and stop the barrel feeding. When there is no raw material in the barrel, the spiral is pressed down by the spring force and continues to rotate to feed the barrel.
This compulsory feeding method avoids the "bridging" phenomenon of raw materials in the hopper, and can ensure that the hopper continuously feeds the extruder barrel and ensures that the extruder continues to feed production.
The structure of the vibrating feed hopper is relatively simple, except that an electromagnetic vibrator is added to the ordinary hopper. When the extruder barrel needs to be fed, start the vibrator to make the hopper shake in the horizontal direction, the raw material in the hopper overcomes the frictional resistance between the hopper wall and the material, and slides down in the shaking and enters the extrusion inside the machine barrel.
The vibrating hopper is suitable for powdery or granular materials. The structure is simple, and it is not easy to cause the phenomenon of "bridging" of raw materials. The cost is low and it is very practical.