Graphic Design & Printing Technology- Allow the machine to run on standard working condition.
- Repack blanket or reduce cylinder pressure.
- Use a quick release blanket.
- Use better quality paper.
Ink problems
Emulsification
Emulsification is the mixing up of ink and dampening solution. In this process,
dampening solution is distributed evenly throughout the ink in small droplets.
Too large a proportion of dampening solution in the printing ink, or too low a
pH-value causes emulsification. Emulsified printing inks will increase drying
times, as well as increasing the risk of deposits.
Remedies:
- Set the ink and dampening balance correctly, and check on it continu-
ously throughout the printing process. - In case of emulsified ink, wash the rollers.
- Check the dampening solution, and change it regularly (the ideal damp-
ening solution has a pH-value from 4.5 to 5.5, and a temperature from
10°C to 15°C (50°F to 59°F).
Slow ink drying
It is a condition that occurs when ink fails to cure quickly, delaying multicolour
printing runs. This may lead to the rubbing off color of the print during post
press or during transport. Causes for slow drying are
- Fountain solution too acidic
- Insufficient amount of ink driers
- Wrong ink used with paper
- Low temperature in press room
Remedies:Check the pH of fountain solution, add driers to the ink, use ink
that is appropriate for the paper and raise the press room temperature to improve
drying ability.
Chalking
It is a condition in which dried ink gets easily rubbed off or is missing from the
sheet. Major causes of chalking are:
- Insufficient amount of ink driers
- Ink absorbed by the paper before setting properly
- Wrong ink used with paper