The dandy roll improves quality on Fourdrinier wire machines up to 1,000 m/min. The key feature is the patented self-supporting honeycomb with a large open surface.
The honeycomb is easy to clean and prevents undesirable ring marks in the paper due to its special design. The dandy roll works by being immersed into the free suspension and lightly wrapped by the wire. By unwinding the dandy roll wire on the top side of the web, the latter is smoothed. The intake pressure causes the stock water to penetrate the dandy roll fabric into the interior of the dandy roll. The flow is thus oriented in such a way that freely floating fibers in the suspension reach the fabric and are deflocculated there. The combined steam-water spray tube, the simple adjusting unit, quick retraction and heated chamfers are some of the other tried and tested features of the well-engineered dandy roll device.
Water that is centrifuged out of the dandy roll into the outlet is securely caught with a drop collection device, which can easily be retrofitted onto the dandy rolls of other manufacturers.
Dandy rolls are used in the wire section just before the suction devices or just after the first suction devices. They improve formation and smooth the top side of the web.