Rollers are widely used on many machines. And most of them do not need to be heated, but a few need.
How to design a proper heating roller is the basic skill that the engineer must master. Generally, the design of the most suitable heating roller needs to start from the following aspects:
First of all, we must know the application of heating roller industry and specific processes clearly. The common industries using heating roller are papermaking, printing, textile, rubber, plastic, chemical fiber, packaging, non-woven fabric, lithium battery, automobile, building materials, various composite materials and other industries. The common processes include preheating, drying, shaping, laminating, embossing, calendering, compounding, etc. The industry and process usually determine the general requirements of heating roller.
Secondly, it is necessary to know the basic process conditions when using the heating roller. For example, the product and its main physical and chemical properties; the width and thickness; the commonly used roller surface temperature and temperature accuracy; the speed of the production line; the working pressure; the installation method of the roller (single guide roller, steel roller or steel roller and rubber roller), etc.
Third, clear the mechanical requirements of the roller. Such as roller size (diameter, roller surface length, bearing position size); Roller surface treatment requirements (hard chromium, Teflon, ceramics, etc.); surface hardness, roughness, runout and other mechanical parameters of the roller.
Fourth, according to the above information, determine which heating method to be used. From the roller surface temperature, if the required temperature is very low (≤ 100 ℃), any heating method can be selected; if the temperature is between 100 ~ 160 ℃, water heating roller cannot be selected, but steam heating, heat transfer oil heating, electric heating and electromagnetic induction heating can be used. If the roller surface temperature is greater than 160 ℃, steam heating is usually not selected, because the steam temperature and pressure are strictly corresponding. For example, at 180 ℃, the steam pressure is 10bar. Due to the temperature difference on the roller surface, the roller surface temperature is generally not more than 160 ℃. If the roller surface temperature exceeds 250 ℃, subject to the performance of heat transfer oil, oil heating is rarely used. At this time, only electric heating and inducton heating can be selected.
From the use environment, if there are cleaning requirements, the steam roller and oil roller are not suitable; From the perspective of temperature accuracy, the accuracy of electromagnetic heating roller is generally higher, while the accuracy of heat conduct oil roller will gradually decline after long-term use; Considering from the external conditions, if there is no ready-made boiler for heating, or new boiler is not allowed, steam roller should not be selected.
After determining the heating mode, the follow-up design of heating roller is routine work. For ordinary users to choose heating roller, the above information is enough. In recent years, with the increasing demand for materials, the application of high-end electromagnetic induction heating roller is more and more common. The most important thing users need to do is to open their eyes and choose the most suitable manufacturer. At present, the leading technology enterprise of heating roller is still in Japan, but the gap between Chinese enterprises is getting smaller and smaller. From 2012 to 2013, Japan's well-known heating roller enterprises and Shanghai Lianjing company took two years to fight two intellectual property lawsuits. As a result, Shanghai Lianjing won. This made the latter famous for a time, and also quickly entered the center of the world's high-end roller industry. In particular, in recent years, Shanghai Lianjing's large-scale application of FCCL composite rollers has made China's heating roller (induction heating roller) at the forefront of the world for the first time.