Piling

Problem:

Verify whether the pilling is defective paper coating or ink

Solution:

If defective paper coating, try a different batch of paper or lower the tack of the ink slightly, if necessary.

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Problem:

If the ink becomes over-emulsified/waterlogged, this changes the physical properties of the ink and results in poor transfer.

Solution:

Check that pH, conductivity, Brix level and temperature are to specification and try to run less water.

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Problem:

Ink roller train or ink fountain is too cool.

Solution:

Adjust form rollers to 72°-80°F (22°-26°C) and be sure ink fountain is 70°F (21°C) or above to ensure proper ink flow and transfer.

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Problem:

Inadequate or excessive blanket cylinder pressure and/or plate or blanket packing.

Solution:

Check blanket cylinder pressures and/or ensure that plate and blanket packing are all to manufacturer’s specifications.

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Problem:

Rollers are the wrong durometer or improperly set.

Solution:

Check roller settings, clean and condition / de-glaze rollers.

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Problem:

Ink film thickness may be too high or too low

Solution:

Verify densities are in normal range