Troubleshooting | Curling
The challenge of curling
In the printing press, the paper‘s surface is moisturised with fountain solution. This one-sided moisturisation can lead to a different surface tension on the paper‘s upper and lower side. The fibre of the paper begins to swell; paper edges may start to furl (curling). This effect can be additionally intensified by means of varnishing. There is an especially high danger of curling using non-coated paper. Uncoated substrates absorb more moisture and hence are more prone to curling.
Solving curling
Step by Step
1. Adjust your fountain solution
Reduce one-sided moisturisation and the effect of different surface tensions.
2. Pay attention to your production conditions
The reason: Climatic influences affect the printing process. Also check the storage of your substrates. Temperature differences between the pile and the production area should be balanced in advance (acclimation).
3. Adapt the surface tension
By means of varnishing the rear page after a one-sided printing, curling can be avoided. It is also possible to send the rear page of your sheets through the printing press with running dumping units.
4. Choose a coating with good anti-curling characteristics
Some coatings have been especially developed for the application on uncoated substrates. Due to their good anti-curling effect, curling is avoided. You achieve a good running behavior during further processing.
Your checklist
Influence factor: Fountain solution
Measure: Use less fountain solution
Influence factor: Substrate
Measure: Acclimation of substrate
Influence factor: Printing
Measure: Align surface tensions, e.g. by varnishing the rear page
Influence factor: Coating
Measure: Use a suitable alternative
Still have open questions? Contact us and we will support you with the application.
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