Heating or cooling metal rollers
Metal rollers with heat-transfer fluid circulation are designed for the most demanding production processes in the non-woven and plastic film industries: calendering, embossing, laminating, heat sealing, and thermal bonding.
The roller is developed according to the customer’s construction drawing, custom-built for the specific production line
Main features according to which the rollers are designed
- Outer diameter and effective width (working face)
- Surface finish
- Operating temperature and fluid temperature
- of circuits, spiral pitch and gap between turns, internal circuit capacity
- Fluid type, operating pressure, and flow rate
- Fluid inlet/outlet connections and vents
- Dynamic balancing
The geometry of the internal circuit is the element that determines the thermal uniformity of the roller’s surface, a critical parameter for the quality of the final product, which is why we support customers in designing the circuit according to the application, among the following solutions:
- Single spiral flow A single helical channel runs the length of the shell from one end to the other. A simpler and more economical construction solution, suitable for applications with less stringent thermal requirements; it can generate an axial temperature gradient between the fluid inlet and outlet zones, which becomes more pronounced as the roller length increases.
- Cross/double spiral flow This is the solution adopted in the roller described here: two helical channels running side by side in counterflow, distributed at a constant pitch over the entire effective length. In this way, the incoming “hot” fluid and the returning fluid are always adjacent along the entire axial length, mutually compensating the thermal gradient and maintaining a much more uniform surface temperature from one end to the other compared to the single-flow solution. This is the preferable configuration wherever surface temperature uniformity is a process requirement (film calendering, non-woven heat sealing, multilayer laminating).
Each configuration is sized according to diameter, effective length, required thermal power, fluid used, and target temperature uniformity, with verification of the minimum flow rate needed to ensure turbulent flow in the channel.
Each roller is engineered to customer specification: diameter, effective width, circuit type (single, double spiral, drilled), shell material and finish, feed connections, and rotary joint system can all be adapted to the existing production line or to a new project.
