Valmet’s latest solution for bulk-saving is double-pass cooling calendering. This new patented technology improves the calendering results compared to usual production conditions. With conventional roll nip, the best calendering results are achieved when the web is cool and stiff, like in pilot trials. With double-pass cooling calendering technology, pilot-type conditions are brought to production-level, by cooling down the web before the calendering nip.
Raw material savings with higher bulk
Compact design - easy for rebuilds
Double-pass cooling calendering enables the production of more lightweight end products without compromising functional and visual properties. This will lead to a substantial reduction in energy and raw material usage.
Web cooling is enabled by cool dry air blown on both web surfaces. Thanks to the compact design of this new technology, double-pass cooling can be retrofitted to practically any production line.
The dry air is blown on the web with the OptiDry Chill air web cooling units. OptiDry Chill double pass units presented on the left cool the web twice longer than the conventional cooling units on the right. For each 10 °C of lower web temperature, you'll get ~1 %-unit higher bulk!
Double-pass cooling technology complements Valmet's bulk-saving calendering offering, which includes the revolutionary metal belt calender as the ultimate lightweighting solution. With double-pass cooling technology, it is possible to get almost half of the metal belt calendering benefits with lower investment costs.
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