Ink Drying Trouble or slow drying of ink
Possible causes of these problems include:
- Excessive ink emulsification
- Old inks used
- Low temperatures in the printing room or low ambient temperatures where the printed materials were placed
Excessive ink emulsification is the cause of more than 90% of all such problems.
Drying can be improved somewhat for slow setting printed materials by placing them in a 25℃ to 30℃ environment with continual air movement, but this is not a surefire countermeasure so be sure to always print in accordance with the YUPO printing manual.
Preventive measures
- Use fresh inks designed for YUPO.
- Restrict dampening water to a point just before the plates become dirty. It is especially important to minimize dampening water for the first two colors. If possible, it is also effective to add alcohol such as IPA to make the water on the plate as uniform and minimal as possible.
- These problems tend to occur on sparsely printed materials, so it is important to include large solid elements in white areas on the plate as much as possible and to keep up the consumption and supply of ink on the rollers to keep the ink on the rollers fresh. It is also effective to use a "G drier" or an "X + Y = DRY drier" as necessary.
- Ink emulsification problems can occur if too much ink builds up at the print start up.
- To improve drying, it is effective to keep the temperature of the room where YUPO materials will be stored after printing at around 25℃ to 30℃.