Solutions for Press Problems,
   
Sheetfed Solution
 

PROBLEM

CAUSE

SOLUTION

Tinting - scumming 1) Ink too thin

2) Fountain solution is too acid

3) Incorrect ink/water balance

4) Plate incorrectly processed

1) Use an ink with more body (seek assistance from TRENAL)

2) Measure the pH of the fountain solution. If the pH is not between 5,0 and 5,5, re-adjust the fountain solution.

3) Clean up , and correctly re-adjust the ink and water.

4) Prepare and use a new printing plate

SET-OFF
in the delivery pile
1) Too much ink on the paper

2) Fountain solution is too acid

3) Ink doen not contain enough driers

4) Ink is too stiff;doesn’t penetrate into paper

5) Poor quality paper coating

6) Delivery pile is too high

7) Static electricity in pile is causing sheets to stick together

1) Use less ink, or a more concentrated ink

2) Re-adjust fountain solution to a pH of 5,0 - 5,5

3) Add GRAFO-DRIER to ink

4) Reduce the ink viscosity with a suitable reducer

5) Change paper for a better quality paper

6) Reduce pile height, and print smaller piles

7) Use a static eliminator

Hickies 1) Particles of dried ink or skin from ink can

2) Paper dust

3) Dust from overhead objects e.g. lights

1) Remove all skin or hard particles from ink before putting ink

into duct

2) Remove paper dust before running (clean edges of stack)

3) Clean all overhead objects in the work area

Misting
Ink flies off into admosphere of work place as a fine mist.
1) Ink too thin

2) Press speed too high

3) Inking rollers are old and damaged

4) Too much ink

1) Use an ink with more body (seek assistance from TRENAL)

2) Reduce press speed

3) Inspect rollers and replace damaged rollers

4) Reduce the ink film

Slow drying of ink on paper 1) Fountain solution too acid

2) Paper too acid

3) Insufficiant driers in ink

4) Ink not suitable for the type of paper

1) Re-adjust fountain solution to give a pH of 5,0 - 5,5

2) Replace paper with a different grade and more neutral pH

3) Add GRAFO-DRIER to ink

4) Contact TRENAL for technical assistance

Poor distribution of ink on paper 1) Ink too stiff or tacky

2) Ink rollers are old and damaged

3) Ink rollers are glazed

1) Add GRAFO-GEL to ink

2) Inspect rollers and replace damaged rollers

3) Remove glaze from rollers with TRENAL DEGLAZER

Piling on ink rollers 1) Ink too stiff or tacky

2) Ink has become emulsified with water

1) Add GRAFO-GEL to ink

2) Add WATER RESISTANT VARNISH V.950

Drying of ink on rollers 1) Too much drier in ink

2) Incorrect type of ink for work being printed

1) Reduce the driers in ink

2) Contact TRENAL for technical assistance

Picking of paper 1) Ink too tacky

2) Impression cylinder pressure too high

3) Poor quality paper

1) Add GRAFO-GEL to ink

2) Adjust and reduce impression cylinder pressure

3) Change to a better quality paper with higher pick resistance

2000 (C) All Right Reserved by Diamond Engineering Works.