printing tips

We are always available to help answer specific questions you might have to help your project run as smoothly and effectively as possible.  But here are some simple guidelines, tips and solutions that address issues that printings can encounter.

Infeed difficulties
Delivery difficulties
Curl (at the infeed)
Curl (at the delivery)

Wrinkles
Breaks
Waving after Printing
Folding defects: dog ears
Folding defects: wrinkles

 

Picking
Hickies
Set off (roll)
Set off (sheet)
Doubling (roll)
Doubling (sheet)

 

Our advice for storage and use

  • Dry, water free, temperate (15-25°C ; 60-75°F) warehouse
  • Do not store less than 10cm from the walls
  • Store the paper close to the press, 24 hours/m3/10°C
  • Unwrap the paper as late as possible
  • Repack the unprinted paper with angle protection
  • Air conditioned press room at 23°C (70°F) and 50% relative moisture

 

Issue: Infeed difficulties
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Solutions

  • Make sure that the paper has a stable temperature
  • Decrease air flow and suctions with lower grades
  • Check the side (cutting quality, linting)
  • Air the piles if necessary
  • Turn the piles up side down or front/rear
  • Limit the speed of the sheet on the frontal wedges

 

Issue: Delivery difficulties
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Solutions

  • Make sure that the antistatic bar (cleaning) functions correctly
  • Use antistatic garlands (coper ropes), even with low static level with earth connection
  • Our advice: look for the best position in relation to the circuit of the sheet (place the antistatic garland close to the break rolls - at the delivery of the press)
  • Adjust the air flow to obtain "wagon roof"
  • Insert adjusting blocks
  • Decrease dampening on sheet edge
  • Clean the powdering nozzles

 

Issue: Curl (at the infeed)
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Solutions

  • Return the piles up side down and/or front rear

 

Issue: Curl (at the delivery)
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Solutions

  • Adjust dampening water between the 2 sides of the paper
  • Our advice: the principle is to adjust the quantity of dampening water between the 2 sides
  • In perfecting printing, to reverse printing unit in relation of the inking

 

Our advice for storage

  • Dry, water free, temperate (15-25°C ; 60-75°F) warehouse
  • Do not store less than 10cm from the walls
  • Unpacking: storage close to the press before printing

 

Issue: Wrinkles
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Solutions

  • Adjust the web tension in the wrinkle area
  • Tape the rolls at the origin of the wrinkles
  • How to tape: pose of adhesive tape on the roller of the sheet on horseback on the edge of the strip. In case of very pronounced defect, spiral dressing of the inside of the band (strip)
  • Reverse the roll if possible
  • Our advice: during the setting up in order to prevent wrinkles, start with low tension and gradually adjust as the speed increases. Introduce ink when process is stabilized

 

Issue: Breaks
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Solutions

  • Identify the break area
  • Our advice: send us the samples
  • Check the side of the roll
  • Check and adjust the web tension
  • Check the cleanliness of the dryer
  • Avoid ink drops: use bandage ink eaters and increase damping on the web edge
  • Avoid water drops: fountain section condensation
  • Check the quality of the blades
  • Our advice: during the setting up, monitor the condensation on the chill rolls. Slice printing: open silicon rolls if necessary

 

Issue: Waving after printing
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Solutions

  • Decrease the silicon
  • Decrease inking
  • Decrease dryer temperature
  • Our advice: be careful of set off and maintain the temperature of the chill rolls at a minimum (12-14°C)

 

Issue: Folding defects (dog ears)
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Solutions

  • Control static electricity (increase silicon, use copper ropes, check antistatic bars, make sure the folding section is connected to the earth)
  • Check brushes, tapes, tucker blades, etc…

 

Issue: Folding defects (wrinkles)
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Solutions

  • Increase perforation in cross and machine direction
  • Change type of perforation

 

Issue: Picking
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Solutions

  • Print paper at the press room temperature (>15°C ; >60°F)
  • Increase dampening
  • Check and adjust the PH of dampening water between 4.5 and 5.5
  • Adjust the temperature of dampening water (10-15°C ; 50-60°F)
  • Decrease the pressure: mechanical pressure and blanket closing (Manila)
  • Decrease ink tack (change or elongation of the ink)
  • Our advice: if possible turn the roll (or the pile) and check the evolution of the picking according to the position of the role. During the setting up, let the ink rise up in temperature and increase the damping

 

Issue: Hickies
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Solutions

  • Print paper at the press room temperature (>15°C ; >60° F)
  • Decrease the inking tack
  • Hickies in solid printing: use halftone and decrease inking
  • Wash ink rolls
  • Our advice: put a brush roll on each side of the paper before the printing units

 

Issue: Set off (roll)
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Solutions

  • Adjust the dryer
  • Check the temperature of the chill-roll (maxi 15°C (60°F) on the first 2 rolls)
  • Increase the silicon
  • Adjust the air flow on the folding rolls and former
  • Adjust the inking (normally a lightweight paper needs less ink for the same level of optical density)

 

Issue: Set off (sheet)
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Solutions

  • Optimize ink loading
  • Increase the anti-set off powder
  • Increase the anti-set off powder
  • With IR dryer, decrease drying temperature

 

Issue: Doubling (roll)
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Solutions

  • Make sure that blanket tension is good
  • Decrease pressure on the paper: mechanical pressure and adjust the thickness of the blanket
  • Increase web tension

 

Issue: Doubling (sheet)
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Solutions

  • Use stabilized paper in temperature and humidity
  • Check the grippers
  • Decrease inking
  • Decrease the inking tack
  • Decrease/adjust the air flow between the units