Plate cleaning – a key factor in increasing reusable plate life
Applying best practices for plate cleaning is essential for the re-use of plates to maintain print performance on press. Sue Kutay, Global Product Manager, guides you through the best practices.
Plate Cleaning – A Key Factor in Increasing Plate Life
Applying best practices for plate cleaning is essential to maintaining print performance with re-used plates. It is best to clean as soon as possible after the press run is done, and only store dry cleaned plates to ensure the best possible results on subsequent runs. Automatic or manual cleaning methods are both effective.
Dried ink or ink residue on fine reverse lines and halftone areas can be difficult to remove, and may require excessive scrubbing or use of aggressive chemicals that can damage the plate.
- Solvent ink starts to dry once the press is stopped, due to evaporation of the solvent alcohol components.
- Water-based ink residue left on the plate surface, after prolonged dry time, can be even harder to clean.
- Dirty plates are more susceptible to surface cracking during storage.
Checklist for cleaning your FLEXCEL NX Plate:
- Prior to mounting, check the back and front of the plate for contamination. Clean with isopropyl alcohol and/or use a lint roller to collect any particulates.
- Manually clean a stationary mounted plate with a soft horsehair bristle brush. Do not attempt to clean the plate while the press is running.
- Clean the plate immediately after use – before the ink can dry on the surface – with one of the recommended clean agent or solvent blends.
- When manually cleaning the plate, use gentle pressure and either a soft horsehair bristle brush or soft sponge. DO NOT use rags or shop towels.
- After the plate is cleaned, it should be rinsed thoroughly to prevent residual cleaning agent or ink from drying on the plate.
- Gently blot the plate with a lint free towel to remove any residual cleaning agent or solvent.
- Dry the plate completely before storage and/or stacking plates.
Recommended cleaning agents for different inks on FLEXCEL NX, SR and NX Ultra Plates
| Solvent based inks | Water-based inks | UV inks |
|---|---|---|
| Isopropyl alcohol (isopropanol)
Solvent blends |
Water
Water with mild liquid detergent |
Isopropyl alcohol (isopropanol)
Solvent blends |
Recommended cleaning solvent blends for FLEXCEL NX, SR, and NX Ultra Plates
| Type of solvent blend | Maximum concentration* | Type of solvent blend | Maximum concentration* |
|---|---|---|---|
| Diethylene glycol | 100% | Benzyl alcohol | 5% |
| Dipropylene glycol | 100% | Octyl alcohol | 5% |
| Ethyl alcohol | 100% | Acetones | <5% |
| Ethylene glycol | 100% | Cyclohexane | <5% |
| Glycerine | 100% | Heptane | <5% |
| Isopropyl alcohol | 100% | Hexane | <5% |
| Normal butyl alcohol | 100% | Methyl ethyl ketone | <5% |
| Normal isopropyl alcohol | 100% | Methyl isobutyl ketone | <5% |
| Normal propyl alcohol | 100% | VM&P naptha – 3% aromatic | <5% |
| Propylene glycol | 100% | Lactol spirits 9300/9500/45/50 – content 9-32% aromatic |
<3% |
| Triethylene glycol | 100% | Benzene | <1% |
| Methyl glycol | 50% | Ethyl benzene | <1% |
| Ethyl acetate | <20% | Toluene | <1% |
| Isopropyl acetate | <20% | Xylene | <1% |
| Normal propyl acetate | <20% |
*Follow manufacturer’s direction for diluting chemical concentrations safely, and for using plate cleaners.
Sue says:
It is best to clean as soon as possible after the run is done and only store dry cleaned plates to ensure the best possible results the next time on press. Dirty plates are also more susceptible to surface cracking, limiting plate re-use. Automatic and manual cleaning methods are both effective.
Sometimes the situation arises where you may need to clean a plate during long run. In this situation you should always first stop the press, then gently clean the plate using a soft horsehair bristle brush and approved cleaning agent.
Applying best practices for plate cleaning is essential for the re-use of plates to maintain print performance on press. It is best to clean as soon as possible after the run is done and only store dry cleaned plates to ensure the best possible results the next time on press. It is recommended to protect the print surface by interleaving the foam sheets used in the plate box when stacking plates. Dirty plates are also more susceptible to surface cracking, limiting plate re-use.
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