Mold heating tube (single-head heating tube) has the characteristics of simple molding device, small investment in equipment, simple mold structure, etc. It is still one of the most popular production methods in today's highly developed mechanized and automated production. However, there are many key skills in the mold design for compression molding. The heating, heat preservation, cooling and clamping structure of the mold are an indispensable part of the composite mold design. The structural design directly affects the appearance and internal quality uniformity of the product, and also affects the molding efficiency of the product. What should we consider when designing?
Steel heating is a heating method that must be used in the design of almost all plastic molding molds. It can be designed in various forms such as one-way wiring and two-way wiring. The material can be seam pipes, seamless pipes, stainless steel pipes, etc., and the characteristic is heat loss Small size, high thermal efficiency, simple wiring, can be designed as 220V or 380V according to needs, and the wiring is flexible and diverse. However, due to the limitations of its materials and processing technology, it is necessary to pay attention to its oriented characteristics in the mold design.
1. Leads:
(1) The temperature of the lead wire is too high: the temperature of the lead wire should be less than 400℃.
(2) Poor working environment stability: When the working environment stability is poor, the processing technology of the inner lead wire should be selected, and the lead wire is soft and not easy to break.
(3) After installation, if the lead part of the heating tube is easy to be worn during normal operation, a metal hose lead can be used.
2. Heating tube:
(1) Whether the power setting is reasonable: Whether a reasonable power load is selected according to its actual situation (high power load requires imported materials and imported technology), if the power load is too high, it will cause the heating tube to burn out.
(2) During the use of high-watt density single-head electric heating tube, due to its rapid heating and poor heat dissipation conditions, it often causes the external stainless steel tube body of the electric heating to burn, oxidize, and deform, which causes the internal heating element-the electric heating alloy wire to melt due to high temperature air burning. , Resulting in the shortening of the life of the single-head electric heating tube itself, so a good single-head electric heating tube not only requires good production quality, but also requires the material and processing aperture of the mold (the closer the aperture and the tube diameter, the better), the suitable aperture is not only convenient for changing the single head In addition to the electric heating tube, it is also conducive to the heat conduction between the two, thus prolonging the service life of the electric heating tube of the heating tube itself.
(3) The precision of the deep hole processing of the mold should be paid attention to. Do not drill at both ends, because the junction cannot be tightly closed and there are large pores, which causes poor heat dissipation of the heating tube and uneven temperature of the heated body.
(4) It should be noted that the magnesium oxide powder at the outlet end of the electric heating tube should not be infiltrated by pollutants and moisture in the use place to prevent leakage. It is best to reserve 5mm outside the mold.
(5) The electric heating tube should be used when the machine is turned on. It is best to preheat for 5 minutes, so as to avoid the risk of electric leakage due to humid air or water seeping into the tube. The electric heating machine must be equipped with a grounding wire.
(6) The electric heating tube should be fixed to protect the heating area from leaking and burning. Avoid using heat conductive mud to avoid carbon deposits in the inner hole and electric leakage, and it is not easy to replace the electric heating tube in the future.
3. Safety protection:
(1) When the heating tube is working, the surface temperature is very high. When dry burning in the atmosphere, attention should be paid to the exposed heating parts to prevent short-circuit, fire and other accidents.
(2) When using the heating tube, pay attention to keeping the insulation and dryness of the outlet part to prevent leakage, and it is best to do grounding protection. In the case of high-power use, an effective grounding protection must be done.
4. What you need to know is:
(1) The heating tube usually has a long cold end at both ends, which cannot play a heating role.
(2) The power design of the heating section should not exceed the limit of 10 watts/cm as far as possible. Such as 30 cm long heating tube, the power should not exceed 300 watts as much as possible. If the design power exceeds this limit, the surface load of the heating tube will be high, and the steel tube will be susceptible to oxidation and corrosion, causing a short circuit.
(3) For mold design with a temperature higher than 250°C, it is difficult to use a heating tube.
Soldering iron core is usually used as a kind of mold heating tube, which is characterized by high power per unit length (usually a soldering iron core with a diameter of 10mm and a length of 8cm can reach an output power of 150 watts), durable, safe, and not easy to form a breakdown short circuit , Can be buried by drilling blind holes, the disadvantage is that it is difficult to customize the design, and it is fragile and broken when dismantling and replacing.
In the circuit design, insurance measures such as insurance and air switch are indispensable. The operation site must be kept clean and tidy, with good insulation, and be diligent in checking electrical faults during operation to prevent unnecessary danger.
The above is the design and use of the mold heating tube that I have introduced to you. I believe this introduction will enable you to purchase the most cost-effective mold heating tube (single-head heating tube)!
In the selection process, customers need to select the most suitable heating element according to the actual environment and requirements of the equipment. Our company has been engaged in the heating pipe industry for more than ten years, and can be designed according to the drawings (voltage, power, size) provided by the customer or by our technicians according to the conditions you need. After confirming to you, the final order is placed.