The twin-screw granulator can produce plastic products […]
The twin-screw granulator can produce plastic products and has good performance. When using, pay attention to the factors that affect the quality of plasticization, such as: aspect ratio, back pressure, etc., to prevent affecting the quality of its products. At the same time, we must always pay attention to its safety to prevent malfunction.
What are the main factors that affect the plasticization quality of the twin-screw granulator?
The main factors affecting the quality of plasticization are: aspect ratio, compression ratio, back pressure, screw speed, barrel heating temperature, etc. Let me introduce you one by one:
1. The ratio of length to diameter is the ratio of the effective working length of the screw to the diameter of the screw. Larger aspect ratio makes it easier to eat evenly; plastics with better thermal stability can use longer screws to improve mixing performance without burning.
2. The compression ratio is the ratio of the depth of the groove after the feed section to the depth of the first groove in the metering section. Considering the compressibility of the material, the degree of filling, backflow, etc., the product should be dense, heat transfer and exhaust.
3. Back pressure. Increasing the back pressure can increase the work done by the screw on the molten resin, eliminate unmelted plastic particles, and increase the density and uniformity of the raw materials in the barrel; the back pressure is used to increase the barrel temperature, and its effect is more significant.
4. The screw speed, the rotation speed of the screw directly affects the shear of the plastic in the spiral groove; the shallower screw groove of the small screw groove absorbs the heat source quickly, which is enough to promote the softening of the plastic during the compression period, and the frictional heat energy between the screw and the barrel wall is low. Suitable for high-speed rotation to increase plasticizing capacity.
What should be paid attention to when using twin-screw granulator?
1. There is an electrical interlock between the main motor and the oil pump motor, that is, the oil pump motor does not start, the main motor cannot start; the main motor does not stop, the oil pump motor cannot stop.
2. When the pressure of the machine head exceeds the set alarm value, the material pressure alarm signal light will be on and the machine will stop automatically.
3. There is an electrical interlock between the main motor and the feeding motor, that is, the main motor does not start, and the feeding motor cannot start; the main motor of the feeding motor does not stop, and the main motor cannot stop. The main motor control cabinet has over-current protection, which has been set before leaving the factory.
4. In addition, it also has a mechanical protection device, generally a nylon shear pin safety coupling. When the design torque is exceeded, the shear pin is cut off and the transmission box stops working.
5. The twin screw adopts variable frequency speed regulation, AC motor drive or DC speed regulation, DC motor drive. The deceleration and twin-screw drive are in the same box, with compact dimensions. The safety coupling equipped with shear pins can protect the screw and transmission box from damage due to overload.