Consumables
Drying double-sided coated continuous webs “gravity free”
Thursday 29. May 2008 - Venti Oeldes newly developed flotation dryer simplifies and accelerates the drying process. Drying double-sided coated materials is possible. The result is high-quality coatings.
The innovative development by Venti Oelde of an flotation dryer for the printing industry allows double-sided printed or coated paper and foil webs to be dried simultaneously from above and below in one work process. A reduced scale model can be seen at the drupa.
Innovative on the market
Until now, the entire process had to be interrupted after drying the first side. The reverse was then coated in a second pass. Now a web printed or coated on both sides can be dried in one work process. The new technology has consigned the time consuming work of cleaning the transport rollers to the past.
With the flotation drying process the material has no direct contact with the plant. It hovers on a cushion of air. Intelligently arranged air nozzle heads release precisely the amount of air required to avoid any unwanted contact. At the same time, hot air flows out of the offset arranged nozzle heads to ensure that the upper side is also dried.
A technical tour de force
If airborne drying is to be possible at all, it is very important to have an exact and even air distribution and flow behaviour, which is why the nozzle heads have a specific geometry. The relevant weight of the material, and that of the relevant coating, need to be taken into account since it drops as humidity drops. To set the plant up precisely for this, Venti Oelde uses complex calculation programs for flow simulation. Experiences from other industrial sectors were of great benefit to Venti Oeldes specialist in this case.
Flexible use based on modular design
The fully functional units are each 3 meters long and can be connected in series as modules depending on the required output. This makes the plant particularly flexible.
The complete coating line from one source
Of course, all the necessary components, such as gas burner or thermal oil plants, control equipment, noise and heat insulation, the supply and exhaust air systems and, if requested, a filter system, a solvent oxidation plant and a heat recovery system, are included.
Since the customers also usually inquire about technologies relating to winding and unwinding as well as coating processes, Venti Oelde cooperates in the design with specialised partner businesses. As a result, complete plants, including the downstream and upstream components, can be supplied from one source.
From the pilot project to the prototype plant
The new development again underlines Venti Oeldes innovative power and market awareness: the plant was developed in response to a concrete customer inquiry and can now be adapted and deployed for all conceivable applications.
This year a test plant will be put into service in Dormagen, in North-Rhine Westphalia, where interested customers can try out the airborne dryer with their materials and coatings. The plant is being created in cooperation with a partner company which is responsible for the technical components for winding and unwinding as well as coating processes. Interested parties can put their names down with Venti Oelde.