How Does Temperature Control Affect Rubber Extruder Performance?

The current Rubber Extruder temperature control method, generally in accordance with the sequence of measurement, regulation of the operation, the target control and so on programmed into a closed circuit for control. That is, to accurately measure the temperature of the control object, find out the error between it and the specified temperature, modify the amount of operation, so that the temperature of the controlled object to maintain a certain.

The screw of the Rubber Extruder consists of the threaded part, which is the working area, and the part that is connected to the drive. There are three types of threads: single head, double head and composite thread. Single head is mostly used for glue filtering and double head is mostly used for Rubber Extruder modeling with uniform discharge. The composite thread is single-ended at the charging end (for easy feeding) and double-ended at the discharging end, which provides even discharge and good quality.

With the expanding use of Rubber Extruder and the continuous development of extrusion theory, there are more and more types of screw and thread structure, such as those with primary and secondary threads, those with mixing section, and those with manifold divider type.

Influence of Temperature Control of Rubber Extruder

Usually, the hot feed Rubber Extruder is used to supply the rubber to the openers, which already has a high temperature and a high degree of plasticization. Therefore, the function of the hot feed Rubber Extruder is to further increase the temperature and degree of plasticization of the feed material and to achieve continuous extrusion.

In the hot feed Rubber Extruder barrel screw system, there is no significant change in the state of the rubber, at the same time, different types of rubber can be achieved by controlling the time and conditions of the openers to achieve the requirements of feeding rubber. Therefore, its control of temperature in the hot feed Rubber Extruder itself is not very strict requirements, so the hot feed Rubber Extruder rarely use temperature control devices.

The situation is very different with the Cold Feed Rubber Extruder, where the feed material is both cold and hard, and all kinds of cold and hard rubber materials need to be extruded by the Cold Feed Rubber Extruder itself to fulfill their extrusion process requirements. The processes from cold to hot, from hard to soft and from non-homogenizing to homogenizing go through distinct stages of change, each of which influences the other.

The temperature of each section of the Rubber Extruder plays a decisive role in the extrusion process when other operating conditions are constant. If the temperature of each section changes, the extrusion speed, extrusion temperature and expansion rate of the extrusion process will change, resulting in the destabilization of the extrusion operation and seriously affecting the quality of semi-finished products.

Temperature control method and its optimization for Rubber Extruder

In the pneumatic temperature control device, when the temperature measuring element detects the temperature of each section of the cold feed Rubber Extruder and converts it into a signal, which is input to the temperature display regulator. All the way to the measurement display part of the actual temperature display, all the way to the regulation part and set the temperature compared with the deviation value, the regulator is calculated according to a certain mathematical law after the output of a signal to control the heating system and cooling system.

When the measured temperature of the barrel deviates from the set temperature value, the pneumatic regulator sends commands to control the opening of the pneumatic actuators of the heating and cooling systems according to the size and nature of the deviation.

If the barrel temperature exceeds the set value, the opening of the pneumatic actuator in the cooling system is increased, and the cooling water flow rate is increased (even to the full flow rate), and at the same time, the opening of the pneumatic actuator in the heating system is reduced (even to the full closure), so as to reduce the temperature of the barrel to the set temperature value;

If the barrel temperature is lower than the temperature setting value, then reduce the opening of the pneumatic actuator of the cooling water system, so that the cooling water flow decreases (or even to zero), while increasing the opening of the pneumatic actuator of the heating system, increase the flow rate of the heating steam (or even increase to the full flow rate), so that the temperature of the barrel to the set value. Thus, the cycle of regulation to achieve the purpose of controlling the temperature in the electric (solenoid valve) regulation of the temperature control device is different from the above pneumatic regulation. The main difference is that the temperature regulator issued by the on-off signal, and often with a proportional nature.

When the measured temperature of the barrel is higher than a certain range of the set temperature value, the temperature regulator sends a signal to turn on the power supply of the electric actuator for controlling the cooling water system, and at the same time cuts off the power supply of the heating system, so that the temperature of the barrel decreases; when the temperature decreases and is lower than a certain range of the set temperature, the temperature regulator sends a signal to turn on the power supply of the heating system, and at the same time cuts off the power supply of the electric actuator for controlling the cooling water system, so that the temperature of the barrel increases. 

When the temperature drops below a certain range of the set temperature, the thermostat sends a signal to turn on the power supply of the heating system and cut off the power supply of the electric actuator controlling the cooling water system, so that the temperature of the barrel rises.

This repeated heating and cooling, so that the temperature value of the system tends to the set value, so as to realize the constant temperature control.

Rubber Extruder temperature control devices used in the early stages, often using media heating and pneumatic regulation methods. At present, it has basically used electric heating and solenoid valve regulation method to replace the traditional method, there are reasons:

1. Energy savings;

2. Simple structure;

3. Works reliably;

Electric heating temperature control device mainly has electric heating direct cooling open type temperature control device, electric heating direct cooling closed type temperature control device, electric heating indirect cooling closed type temperature control device and electric heating direct cooling high temperature closed type temperature control device.

Its circulation circuit consists of a circulation pump - body waterway - open water reservoir (with heater inside) - filter. A cooling water supply pipe with solenoid valve is installed on the water reservoir, and an overflow pipe is set at an appropriate position of the reservoir. When working, the circulating pump will input the warm water from the water reservoir into the body waterway for constant temperature heating of the body, so that the temperature of the body and the temperature of the warm water, at this time in the circulating circuit of the thermocouple will be detected in the temperature of the circulating water and converted into electrical signals into the controller.

If the detected temperature is higher than the set temperature, the controller will turn on the solenoid valve for controlling the supplementary cooling water, and at the same time cut off the power supply of the heater, so that the temperature of the water in the water reservoir will drop; if the detected temperature is lower than the set temperature, the controller will turn off the solenoid valve for supplementing the cooling water line, and at the same time turn on the power supply of the heater, so that the temperature of the water in the water reservoir will be increased, which will make the temperature of water in the circulating system increase. This continuously alternates to achieve constant temperature control of the Rubber Extruder.

concluding remarks

Rubber Extruder temperature control machine is characterized by simple structure, reliable work, low cost, but the circulating water temperature is low, generally below 95 ℃, it is not suitable for the Rubber Extruder that needs higher temperature heating, but it is feasible for the general Rubber Extruder heating temperature. As its circulating loop is open, its water temperature can only be lower than the vaporization temperature of water. If a higher temperature is required, it is necessary to use a closed hot water circulation temperature control device, which can increase the pressure of the circulating water, so that the boiling point of the water is increased, and its circulating water temperature can generally reach 130 ℃.

With the development of Rubber Extruder, cooling and heating system, temperature sensing element, pressure measuring element, product size measurement technology has been greatly developed, especially the introduction of computer technology, so that the Rubber Extruder's automatic control level has been greatly improved.