A new patented, copper chill roll for cast film reportedly cools so much more efficiently than conventional steel rolls that it provides dramatically higher output for the same roll diameter or allows a smaller roll to be used for the same output.

A new patented, copper chill roll for cast film reportedly cools so much more efficiently than conventional steel rolls that it provides dramatically higher output for the same roll diameter or allows a smaller roll to be used for the same output. Thermal conductivity of the copper is so high that it cools with room-temperature water at 68 F instead of chilled water at 46 to 50 F, saving both equipment and energy costs. Using substantially warmer water also eliminates condensation at the roll ends for better quality film. The copper roll was invented by Derichs Maschinen- und Apparatebau GmbH in Krefeld, Germany. Cooling water runs through flat, multi-start spirals around the roll, separated by channels that add stiffness. A seamless copper tube is shrunk over the spiral-channeled inner body, and the copper is then plated with chrome or another surface coating. Derichs began building copper rolls in 2001. The first cast film maker to use a copper roll is Tetra Pak in Lund, Sweden. Derichs: +49 (2151) 306 950 . www.derichs-gmbh.de