Calendering is a manufacturing process in which a material is passed between a series of heated rollers (a calender). Through the pressure and heat of the rollers the material is made smooth, dense and of even thickness. It is a way of producing sheets and rolls with a constant thickness and a tight surface.
How it works
The material — for example a rubber or plastic mass — runs through several stacked, rotating rollers. The gap between the rollers sets the final thickness; the heat makes the material pliable so it spreads evenly. This produces a level sheet without air pockets, which is then cooled and rolled up.
Application
In construction, calendering matters in the making of materials supplied as sheet or roll: bituminous roofing membranes, EPDM roofing membranes, plastic films and vinyl or linoleum floor coverings. The even thickness produced by calendering is important for the watertightness and reliability of a roof covering, for instance.
Points to note
- The even thickness is key to the watertightness of a roofing membrane
- The quality and thickness of such rolls are already fixed in the factory; only the installation on the roof or floor is up to you
Related terms
- Bitumen
- EPDM
- Roof covering
- Plastic
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