1. Screw speed
In the past, the main way to increase the output of an extruder was to increase the diameter of the screw. Although an increase in screw diameter will increase the amount of material extruded per unit time. But an extruder is not a screw conveyor. In addition to extruding the material, the screw also extrudes, mixes and shears the plastic to plasticize it. Under the premise of constant screw speed, the mixing and shearing effect of the screw with large diameter and large screw groove on the material is not as good as that of the screw with small diameter. Therefore, modern extruders mainly increase capacity by increasing the screw speed. The screw speed of common extruder is 60 to 90 rpm for traditional extruders. And now it has generally been increased to 100 to 120 rpm. Higher speed extruders reach 150 to 180 rpm.
2. Screw structure
The screw structure is the main factor that affects the capacity of the extruder. Without a reasonable screw structure, trying to simply increase the screw speed to increase the extrusion capacity is against the objective law and will not be successful. The design of a high speed and high efficiency screw is based on high rotational speed. The plasticizing effect of this type of screw will be poor at low speed, but the plasticizing effect will gradually improve when the screw speed is increased, and the best effect will be obtained when the design speed is reached. At this point, both higher capacity and qualified plasticizing results are achieved.
3. Gearbox
The manufacturing cost of a reducer is roughly proportional to its size and weight, provided that the structure is basically the same. The large size and weight of the gearbox means that more materials are consumed in the manufacturing process and the bearings used are larger, which increases the manufacturing cost. In terms of unit output, the lower motor power and the lower weight of the gearbox of a high speed high efficiency extruder means that the manufacturing cost per unit output of a high speed high efficiency extruder is lower than that of a normal extruder.
4. Motor drive
For the same screw diameter extruder, the high speed and high efficiency extruder consumes more energy than the conventional extruder, so it is necessary to increase the motor power. During the normal use of the extruder, the motor drive system and the heating and cooling system are always working. The same screw diameter extruder with a larger motor seems to be power hungry, but if calculated by output, the high speed and high efficiency extruder is more energy efficient than the conventional extruder.
5. Vibration damping measures
High-speed extruders are prone to vibration, and excessive vibration is very harmful to the normal use of equipment and the service life of the parts. Therefore, multiple measures must be taken to reduce the vibration of the extruder in order to increase the service life of the equipment.
6. Instrumentation
The production operation of extrusion is basically a black box, and the situation inside cannot be seen at all, and it can only be reflected through instrumentation. Therefore, precise, intelligent and easy-to-operate instrumentation will make us better understand its internal situation, so that production can achieve faster and better results.
Post time: Mar-01-2023