Causes and solutions of common failures of heating tube of mold temperature machine

The function of the mold temperature machine is to heat or cool the mold and maintain its working temperature to ensure the stability of the quality of the injection molding parts and optimize the processing time. The mold temperature machine is divided into water temperature machine and oil temperature machine. In the injection molding industry, mold temperature plays a decisive role in the quality and injection time of injection molding parts. The heating of the mold temperature machine is mainly carried out by the heating pipe. In the actual heating process, the heating pipe of the mold temperature machine often has some faults, including the heating pipe is not hot, the heating pipe is burnt out and the heating pipe is overheated. What are the reasons for these and how to solve them? Please see the specific analysis below.
Reasons and solutions for non-heating of the heating tube of the mold heater:
Because the heating tube of the mold temperature machine is composed of three or more groups, one or more groups in the heating tube are burnt out, resulting in the power reduction of the heating tube and the slow heating. At this time, the only way to solve the problem of slow temperature rise of the mold heater is to replace the heating tube again.
The second reason for the slow temperature rise of the mold heater may be the size mismatch. For example, a 2000-ton injection molding machine with a clamping force uses a 6-kilowatt mold heater to heat. The way that the calf pulls the cart will certainly lead to the slow heating of the mold temperature machine. The only way to solve this problem is to buy a high-power or use multiple mold heaters to solve the heating problem.
Due to the long use of the mold heater, the pipeline silts up, affecting the flow and heating performance. Due to the influence of water quality on the water mold heater, the scale will adhere to the outer wall and inner diameter of the heating pipe for a long time, affecting the heating efficiency. Because the oil quality of the oil mold heater will be coking due to high temperature heating, long-term failure to clean will lead to poor heating. In addition, there is also a lot of room for the application of mold temperature machine in the die casting industry. Uneven or inappropriate mold temperature will lead to the instability of the casting size, and the deformation of the casting will be ejected during the production process, resulting in defects such as thermal pressure, mold sticking, surface depression, internal shrinkage cavity and hot bubble, especially in the manufacturing of magnesium alloy and aluminum alloy; So don't neglect the maintenance of the mold temperature machine!
Reasons and solutions for the burning of the heating tube of the mold temperature machine:
The quality of the heating tube of the mold temperature machine is poor; As for the quality problem of the heating tube of the mold temperature machine, the nickel-chromium alloy heating tube imported from Sweden is adopted, which is particularly lengthened to reduce the load per unit area, which not only ensures the product quality, but also extends the service life of the heating tube. The whole tube is in the form of a central inserted flange, with beautiful appearance and convenient disassembly
Dry burning occurs; The dry burning phenomenon is caused by misoperation. When the mold temperature machine is started, and the motor and heater are started at the same time, the heater will start to work immediately: the heating temperature rises, because the motor has just started and the water or heat transfer oil has not been injected into the machine, the heater has no heat transfer medium, which leads to direct dry burning. Such work for a long time shortens the service life of the heater and makes the heater often easy to break
Although some manufacturers have designed a scheme for this purpose. The circuit board has two buttons, namely, the motor start button and the heater start button. This requires the operator to start the motor button first, and then operate the heater button after the water or heat transfer oil is completely replenished. Although this can prevent the heater from drying out, this operation needs to be completed by people, and the operation is not very user-friendly, so it needs to wait for a period of time before processing, Many operators often turn on two buttons at the same time for convenience, which will not meet the design intent of the mold heater manufacturer and will not be able to protect the heater
To solve this problem, the mold temperature machine adopts the function of heating delay, that is, when the mold temperature machine is started, the unit automatically replenishes heat transfer media such as water or heat transfer oil. When the heat transfer media is detected to be replenished, a start signal is sent to the heater, and the heater starts to work, so as to prevent the heater from dry burning. The unit is also equipped with a pressure controller. If the pressure is too low, it means that the flow of heat transfer media is insufficient, and dry burning may also occur. At this time, the unit starts to alarm, Through two aspects of technical improvement, the problem of dry burning of heating tube was solved from the root
When using the mold heater, it is also necessary to pay attention to a problem that is easy to be ignored. It is about to leave work. The operator directly closes the mold heater in order to save time. This problem occurs. When the heating tube is working, the surface temperature can reach 600-700 ℃. Suddenly closing causes the heat transfer medium to contact with the heating tube in a static state, which will cause the heat transfer medium to adsorb on the surface of the heating tube, and over time, it will also damage the heating tube, The most direct manifestation is the decrease of the heating rate of the mold temperature machine
Causes and solutions of overheating of mold temperature machine
1. The solenoid valve (or other control valve) controlling the cooling water is burnt out and is always closed. When cooling is needed, the cooling water cannot enter, resulting in high temperature.
2. The thermostat is faulty. The mold temperature controller outputs signals to control the operation of the electric heating tube. If there is a problem with the temperature controller, when the temperature reaches the set value, the temperature controller will not send a signal to stop the heating of the electric heating pipe, and the temperature will rise all the time, causing overheating.
3. The temperature control equipment is an exothermic process. The power of the mold temperature machine cooler is too small, and the cooling capacity is less than the heat absorption capacity of the heat transfer medium in the temperature controlled equipment, which leads to the phenomenon that the temperature of the heat transfer medium is too high and can not fall down.
4. The electrical part is not set in place. If there is a problem with heating, you can replace a heating tube.