Open mixer is a kind of roller-exposed rubber mixing machine used by rubber factories to prepare plasticized rubber, mixed rubber, or heat-mixed and shaped. The main working parts of the open mill are two hollow rollers or drilling rollers that rotate in opposite directions. The equipment on the operator's side is called the front roller, which can be moved back and forth horizontally by manual or electric action, so as to adjust the roller distance and adapt to the Operation requirements; the rear roller is fixed and cannot be moved back and forth. The size of the two rollers is generally the same, and they are reversed relative to each other at different speeds. The raw rubber or rubber material is rolled into the gap between the two rollers with the rotation of the rollers, and is subjected to strong shearing effect to achieve the purpose of plasticizing or mixing.

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Open mills are also used in plastic processing and other sectors. The open mill is the abbreviation of the open plastic mill. In the plastic products factory, people are used to calling it a two-roll machine. The open mill is a kind of plastic mixing equipment that has been used earlier in plastic products production plants. In the calender production line, the effect of the open mill before the calender and after the mixer is to knead and plasticize the evenly mixed materials, so as to supply the calendered plastic products with a more uniform molten material. When producing cable material, the open mill can directly smelt and plasticize the powdered material mixed according to the formula into a molten material, and then press and mold it into a sheet-like belt, so that the pelletizer can cut it into granules. In the floor leather production line, it can directly supply the bottom coating with mixing and plasticizing for the cloth leather. It is also possible to recycle the recovered waste plastic film (sheet) on the open mill. The open mill handles the temperature control problem: the accuracy of the temperature is directly related to the results of the research and development of the ingredients, and the heating methods generally selected are electric heating mold heating and oil heating.

1. Coiled electric heating of open mill: the power of a single heating wire can reach 2.1KW. The temperature difference between the two ends of the effect is more than ten degrees, and more are dozens of degrees. The main reason is that the heating wire cannot be closely matched or is not in contact with the inner wall at all, forming a hollow dry burning. Using this method is mainly manifested in the deformation of the heating wire after being dried for a period of time, difficult to replace, and temperature inequality. However, because the power of the heating wire is relatively large and the structure is relatively strong, it is not easy to be burned out.

2. Single-headed rod electric heating tube of open mill: A single-headed rod with a single heating wire has a diameter of 19.8 and the power is normally 1.7KW. In this way, the temperature is relatively uniform, and the accuracy can be ±2°C. The disadvantage is that the heating speed is slow and the power is small. If the power is increased, the heating tube can be easily burned out, which increases the replacement time and frequency.

3. Special heating molds are used for the open mill, and three-stage heating pipes are equipped inside. The power can reach 3.6KW. If it reaches 2.7KW, the pressure on the heating wire is greatly reduced. Due to the deep drilling of the special mold, the hole and the heat are tightly matched. It can ensure a longer life of the heating tube, and the temperature accuracy of the drum surface is ±2℃ or higher.

4. Thermal circulation heating method of open refining machine oil: use high temperature oil for heating, and circulate the high temperature oil through the high temperature oil pump, so that the high temperature oil circulates in the drill hole drum, and reaches the temperature balance at both ends of the open mill drum. It can greatly reduce the error of the temperature at both ends, improve the accuracy of the refining product, and then win the market competitiveness.