How to control the temperature in the calender rolls
There are a lot of continuous production processes, using rotating cylinders for the most disparate functions:
- hot pressing
- packaging films
- modeling (embossing, flocking etc …)
- plastic or rubber molding
- refinement of food or pharmaceutical products
- Heating / cooling of films or products to make flakes
generically we call them calender rolls.
These processes produce or absorb heat, so the cylinders are maintained in temperature by heating or cooling them.
In order to achieve this result, the cylinders are hollow inside or in any case have channels, which are traveled by a temperature controlled fluid.
Depending on the required temperature level, the thermal fluid can be:
- pressurized water
- diathermic oil
The fluids are generally thermoregulated by temperature control units, already equipped with all the systems of circulation and expansion of the fluid, temperature probes and sensors and PID controllers.