Typical Drying Issues
The majority of drying issues in the industry today can be categorized as either Picking Issues (A.K.A. “Tracking”) or Blocking Issues (A.K.A “Offsetting”).
Picking is a term that refers to loosing part of the printed image as the material travels through the press, and is typically caused by insufficient between color drying. Picking can be immediately identified through visual inspection of the printed image, looking for build-up on idle rolls that come in contact with the printed side of the web immediately after the dryer, odor, scratch tests, or tape tests.
Blocking is similar in appearance to picking, but is not usually discovered until the roll has sat for 24 hours and is being unwound during the slitting process. As the roll is unwound, part of the printed image will stick to the backside of the next winding in the roll. This is either caused by insufficient between color drying or insufficient final drying at the end of the press. Unfortunately it is very difficult to know that job will block while it is being printed.