How much drying do I need for my process?  

The amount of drying will be highly dependent on the goals of the project. Some converters would like to maximize line speed, others will want to minimize operating costs, and still others may want to increase access to the press deck.

Unless another opportunity exists, we will typically start out by designing the dryer to fit into the same space as the original dryer. We will then make modifications to the size of the dryer to keep in line with the goals of the project.

Based on our experience and the specifications of the processes, we will have a pretty good idea of how many air bars are required for an application. We try to design as much flexibility into the dryer system as possible, which includes making provisions to add air bars if additional drying is required in the future.

  Does the high velocity air disturb the inks or coatings on the web?  

Occasionally we will experience this in applications with heavier lay downs such as varnishes, adhesives, and flood coats. The impinging jet of air at the web will actually move the ink or coating around, causing visibly raised areas in the print or coating. This is more noticeable on the roll as it is being rewound. We more commonly refer to this as laning.

To address this, our standard Coater and Tunnel Dryers include a feature where the air bars can be adjusted closer to or father away from the web. By moving the first one or two air bars away from the web, laning can be avoided. This gives the ink or coating a chance to set before being exposed to the full intensity of the impinging air.

Does the high velocity air cause registration issues?

If the web is properly supported as it passes through the dryer, compressed air dryers will not affect the ability of the press to hold registration. This is more of a concern for converters that are running low-tension webs, in which case we will provide an idle roll opposite every dryer nozzle.