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#32
Subject: The benefit of an air dryer/ dehumidifier for the supply side of a coating machine.

I wanted to find out information on the benefit of an air dryer/ dehumidifier for the supply side of a coating machine. How much benefit is there in having something like this verses taking the air out of the atmosphere without a dehumidifier/ air dryer. Does the humidity in the atmosphere dissipate just because you are heating it to a high degree (195*F) or is the moisture still in the air that is going in through the supply fans and into the ovens to dry your product?


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#33

The benefits depend on a couple of factors.

#33
Author: Ed Cohen, AIMCAL
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Subject: The benefits depend on a couple of factors.

The benefits depend on a couple of factors. If water is the solvent being evaporated and most of the air is being recycled then the moisture will continue to build up in the drying air. Most dryers I am familiar with have about 90% of the air recycled and 10% new air. This can result in the moisture content of the drying air being variable which will influence drying. This can result in the dry point, location where coating is dry, varying and may result in having to adjust coating speed. The properties of the coating can also be influenced, if they are drying sensitive.

One way to get an insight into the effect of the moisture is to monitor the drying air for an extended period to determine range and if the variation is influencing properties.

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