The key of high gloss injection is mold temperature control system. Because the highest difference between high gloss injection and general injection is the control of mold temperature, and the requirement for injection molding machine is not high. The high light injection mold temperature control system is also known as the high optical mold temperature machine, which is coordinated with the general injection molding machine. It coordinates the action in the filling, pressing, cooling, and closing of the injection mold. The heating method on the mold surface is the key technology of the temperature control system. The surface of the high gloss dies mainly obtains heat through the following ways. The first is heat conduction based on heat conduction, such as the heat conduction through the oil, water, steam and electric heating element of the inner pipe of the mold to the mold surface; two is the heating mode based on the heat radiation, such as the direct radiation of the surface of the mould, such as solar energy, laser beam, electron beam, infrared light, flame, gas and so on; three The body's heat is heated, such as resistance, electromagnetic induction heating, etc., so that the surface of the mold itself generates heat. At present, the practical heating systems include the heat transfer machine of high temperature oil, the high pressure water temperature machine with high temperature and high pressure water, the steam heat transfer machine of steam heat transfer, the electric heating model temperature machine of the heat transfer tube, and the electromagnetic induction heating system and the infrared radiation heating system.

(L) a uniform heating or cooling pipe is designed inside the mold for the heat transfer of the high temperature oil. The heating system of the oil is achieved by the oil heating system. At the same time, it has the effect of cooling in the injection process. The maximum temperature is up to 350 degrees centigrade. Because the thermal conductivity of the oil is low and the efficiency is low, the oil and gas affect the quality of high light forming, but the effect is not ideal. But at present, the oil temperature machine is relatively common and has rich experience.

(2) high pressure water heaters with high temperature and high pressure water are designed internally with balanced pipes, and different temperatures are used at different stages. When heated, the hot water is heated at high temperature, and then cooled to low temperature cooling water to realize heating or cooling of the mold surface. If the water is pressurized, the temperature rise can reach 140~180 degrees centigrade, and the temperature rises quickly. The manufacturer of the temperature and temperature control system of high temperature and high pressure, such as oad's GWS system, is the best choice to replace the steam in the domestic market because the hot water can be recycled and the running cost is low.

(3) the steam model temperature machine of steam heat transfer is similar to that of high pressure water thermo machine. The pipe in the mold is designed to balance the steam, when the steam is heated, when the cooling is cooled to the low temperature water, the surface of the die is heated or cooled. (the compressed air is usually needed to dry the pipe before steam heating). The high temperature and high pressure steam heating system can make the maximum surface temperature of the mold reach 160 degrees Celsius. Because steam is smaller than water, its heat capacity is relatively small, and the relative heating time is longer. The steam surface temperature of 150 degrees C requires about 300 degrees of steam. However, due to the fact that steam is not recyclable in the production process, it is necessary to install boiler equipment and lay pipes, resulting in high operating costs.

(4) the electric heating machine with electric heating tube is used as the heat source of resistance heating element (electric heating plate, electric heating frame, electric heating ring, etc.), in which the electric heating tube is applied more, and it uses metal tube as the shell (including stainless steel, purple copper tube), and the core of the tube is uniformly distributed in the center axis of the tube (nickel chromium, iron chromium alloy), and its gap is filled. The magnesia sand with good insulation and thermal conductivity is compacted and sealed, and both ends of the nozzle are sealed with silica gel. The electric heating element can heat air, solid and various liquids. At present, the electric heating system directly installed in the mould has higher cost and the patent fee for mold design is required. The heating speed of the heating tube is faster, the control temperature range can reach 350 degrees C. After using this system, 15s can heat the mould temperature to 300 C, and then 15 s can cool the mold temperature to 20. But it is only suitable for smaller size products. Because the heating temperature of the heating wire is higher, the life of the die will be shortened.

(5) the high frequency electromagnetic induction heating system increases the temperature of the workpiece according to the electromagnetic induction principle. Because of the skin effect, the eddy current generated on the surface of the workpiece is strongest, but it is very weak inside and near the core. Therefore, this method can only heat the surface of the workpiece to the skin depth range, so the heating volume is small, the heating speed is faster and the heating speed is above 14 /s. For example, the heating rate of the system developed by Zhongyuan University in Taiwan has reached over 20 centigrade /s. After the surface heating is finished, it can be matched with the fast low-temperature cooling equipment to achieve the rapid heating and cooling effect of the mold surface and achieve variable die temperature control.

(6) infrared radiation heating system researchers are developing infrared radiation to directly heat the cavity. The form of infrared heat transfer is radiation heat transfer, which is transmitted by electromagnetic wave, without heat transfer medium, and has a certain penetration ability. Compared with other methods, it has the advantages of energy saving, safety, simple equipment and easy popularization. However, due to the bright metal, the absorption capacity of J red line is weak, and the heating speed is slow.

(7) the high temperature gas of the gaseous return system is used as the medium of fast changing the mold temperature. It can quickly and accurately determine the gas injection into the cavity before the filling stage. The temperature of the mould surface can be raised to about 200 C in a moment, and the high temperature area can be controlled near the surface of the mold, and the other parts of the mold will not be caused by the temperature JINGWAH. The coordination degree of an inch expansion. The technology does not need to modify the existing molds too much, but the mold manufacturing cost is low, but the sealing requirements are high. At present, there are still some problems to be solved in the temperature control system. First, the practical heating method is few, and it is more successful for steam and high temperature water heating, and the two is high gloss injection molding.