Infrared Theory of Operation
The OXYTECH SYSTEMS™ Drying System uses a Programmable Logic Controller with an Operator Interface Touch screen controlled combination of heated air knife streams, radiated heat from short wave or medium wave infrared dryer panels, and air evacuation in order to produce quality results.
The Drying System consists of the following major components:
- Drying System Cabinet
- Air Evacuation Motor and Blower
- Operator Interface Touch Screen
Drying Cassettes include:
- Short Wave Infrared Panels
- Medium Wave Infrared Panels ( high intensity)
Theory of Operation Aqueous inks and coatings
The following describes the typical operating procedure for drying:
The printed web will pass under the first heated air knife where the laminar flow is disrupted allowing the short wave IR (SWIR) energy to heat the substrate to evaporate water from the ink, which accelerates the drying process. The web then passes under another heated air knife to further scrub the web and break the laminar flow. Infrared does not see thru the laminar layer. Then the web passes under the Medium Wave Dryer (MWIR). The medium wave energy heats the surface of the substrate further accelerating the evaporation of water from the ink. The web is then “scrubbed” by the last heated air knife that is crucial in setting up water-based inks. The printed web must be scrubbed of excess water, which is the main component of digital ink. The volume of air will determine the effectiveness of the scrubbing action, and heated air accepts moisture more readily than ambient or chilled air.
(MWIR) Dryers are used to compliment the effect of the (SWIR) Dryers. (SWIR) Dryers are not colorblind; light colors and metallic reflect heat while dark colors absorb. The effect on opaque or transparent ink is minimal, but the intensity of (SWIR) Dryers is required for high speeds.
(MWIR) Dryers are colorblind. They affect the ink, coating and varnish the same. However, they do not have much intensity, which is needed for high speed. The combination of (SWIR) and (MWIR) as with this drying system is a perfect balance to cover all situations. Presently we are using the highest watt density medium wave available in the industry.