Category Archives: Heatset

Inadequate Drying

Ink is taking up too much water

Check ink/water balance.  Run proper amount of ink and water

Rollers are not properly conditioned or set

Thoroughly condition or reset the roller system.  (Improperly set or poorly conditioned rollers promote emulsification of ink.)

Fountain solution pH or conductivity is wrong

Adjust to manufacturer’s specifications

Heatset solvent range for proper volatilization is too high

Consult your Sun Chemical representative

Excessive ink thickness is being run

Consult your Sun Chemical representative about stronger ink

Web exit temperature is too low

Increase web exit temperature

Dryer temperatures are too high, inhibiting the ability of chill rolls to cool web efficiently

Decrease web exit temperature and check chill roll  efficiency

Marking is visible on chills or delivery equipment

Check web exit temperature from dryer and chill rolls.  Check cooling efficiency of chill roll system

Gloss

Print gloss is too low

Run a higher tack ink

Use a higher gloss ink

Reduce dryer temperature to minimum settings

Check chill roll system

Increase ink film thickness

Minimize water settings

Consult your Sun Chemical representative

Dot Gain

Rollers and pressures are improperly set

Reset rollers and pressures

Rollers or blankets are too soft

Condition or replace rollers or blankets

Ink is low in viscosity and/or tack

Consult your Sun Chemical representative

Ink color strength is too weak; ink film is too heavy

Consult your Sun Chemical representative

Ink is too receptive to water

Consult your Sun Chemical representative

Blankets are packed improperly, or too much pressure exists

Check packaging and pressure

Ink is piling

Consult piling section of this guide

Plate is poorly desensitized

Consult your pre-press department

Dampening system is dirty

Clean dampening system

Fountain solution pH or conductivity is out of balance

Adjust pH and conductivity to manufacturer’s  specifications

Slurring or doubling occurs in halftone

Check cylinder pressures, blanket tension and roller slip-page.  Check mechanical operation of unit

Plate is improperly exposed and developed

Consult your pre-press department

Chill Roll Condensation

Streaks appear on web or signatures. This is caused by ink resoftening due to solvent condensation on chill rolls

Check dryer and/or chill roll temperature. Use inks with lower boiling point solvents if possible. Consult suppliers of dryer, chill rolls and inks as necessary

Dryer temperature is too high, inhibiting the ability of chill rolls to cool web efficiently

Decrease web exit temperature

Marking appears on chills or delivery equipment

Check web temperature from dryer and chill rolls. Check cooling efficiency of chill roll system

Excessive ink film thickness is being run

Consult your Sun Chemical representative about stronger ink formulations

Blister

Dryer temperature is running too high

Reduce dryer temperature. Consult your Sun Chemical representative about ink drying speed

Moisture content of paper is too high

Run different paper. Run different paper lot or position number

Too heavy an ink film is being run

Consult your Sun Chemical representative about a stronger ink formulation