Heatset Oven Troubleshooting - Chalking

Definition:  The heatset oven is drying the ink, but a powder-like substance is deposited afterwards leaving setoff.  Additionally, this is accompanied by a reduced gloss appearance in the ink.

Problem:  Oven temperature is too high.
Description:  The ink reaches a point where solvents evaporate and leave the pigment and resin behind.  This is referred to as the flash-point.  However if the ink is cooked beyond that, the resins that help set the ink will lose their binding properties and break down.  This in turn will leave the pigments with very little to bind to.  To diagnose, hold your hand against the web where it is safe after the dryer and chills for a few seconds.  If a powder-like substance is left on your hands, you are over-cooking your ink.
Solution:  Reduce oven temperature.

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1 comment:

  1. Anonymous6:53 PM

    Excited about getting a final design from the printer, however, when the printed piece arrived,all the photos had a grayish green tint to them, much of the color was off the mark and a powder like substance was coming off the paper. Paper is newsprint.