Power saving automatic zoned dryer apparatus and method

A power saving method of regulating temperature of printed or coated surfaces of substrates exposed to infra-red (IR) heating as they move along a substrate path in a printing press, comprising the following steps:

• moving a succession of printed substrates along the substrate path;
• providing an IR heater comprising a plurality of separately controlled IR heating zones, each zone running longitudinally along and extending laterally across part of the substrate path;
• heating a plurality of longitudinally extending, laterally spaced heated areas on a surface of the printed substrates corresponding to the heating zones as the substrates pass under the IR heating zones of the IR dryer;
• sensing the temperature of the heated areas of the substrate surface;
• and
• adjusting the output of the heating zones in response to the sensed temperature of the heated areas of the substrate surface corresponding to said heating zones.

A power saving method of regulating temperature of differentially heatable areas of surfaces of printed substrates exposed to infra-red (IR) heating as they move along a substrate path in a printing press;

• comprising:
• moving a succession of printed substrates along the substrate path;
• providing an IR heater head assembly spaced from the substrates, the heater head assembly having a plurality of IR heating zones with adjustable outputs, each zone running longitudinally along and extending laterally across part of the width of the substrates;
• operating said plurality of IR heating zones while substrates are moving along the substrate path;
• generating signals representative of temperatures of portions of the substrates corresponding to heated areas of the surfaces of the substrates passing under the IR heating zones;
• adjusting and controlling output of the IR heating zones in response to said signals in order to selectively maintain temperature of the surface of the substrates passing under the IR heating zones within a desired range of temperature despite absorption of different amounts of IR energy in areas of the substrates passing under different heating zones;
• whereby printed substrates having a more even temperature profile are delivered.