European paper and paperboard company M-real, a provider of wood fiber-based solutions for consumer packaging, communications and advertising end-uses, reports that a Metso PowerDry Plus air dryer installed at its Simpele BM 3 plant in Finland fulfilled all of the company's expectations with regard to run-ability, drying capacity and effect on surface quality.
The dryer was placed as a first dryer after the coating station and gives an excellent finish to the board surface.
Production manager Mika Leino from the Simpele mill says the company made several tests with different infrared dryers before plant personnel learned about the PowerDry Plus air dryer. Mill personnel found the air dryer so interesting that they decided to run similar tests with it. Tests at the pilot machine at CTC Raisio in Finland and at the mill showed superior results in printing quality compared to results with infrared dryers.
Leino reports that the startup was a success thanks to the air dryer's superb run-ability and simple control. The dryer fulfills the guaranteed drying capacity with its 842°F (450°C) impingement temperature and 60 m/sec impingement velocity. The dryer has operated flawlessly since startup, and tests have shown that its optimal drying capacity improves the print quality. According to M-real, the evaporation starts immediately from the coating surface and there is no unnecessary heating of the base paper. This means less roughening of the fibers as well as better binder concentration and uniformity. The high drying capacity offers quick solidification of coating and optimal surface quality.