Address
31 York Road, North End
Port Elizabeth
South Africa
Contacts
Email: admin@imvusainks.co.za
Phone: +27 (0) 41 492 3347
INCIDENTS:
3. Double print: Abnormal pressure force and dots blurred.
4. Binding of the plate: Deterioration of the printing areas and/or graining areas (non- printing areas).
10. Creasing: Deformation of the substrate, mainly at the tail end.
11. Powdering: The ink solids remain on the surface.
12. Poor trapping: Ability of one ink to be accepted by another when it is not yet dry (this phenomenon only applies to wet-on-wet printing).
13. Curling: Excessive deformation of the printed material in the stack (excessive curling beyond 4cm/m).
14. Mottling: Irregular appearance (mainly on solid print areas).
15. Linting: Loose paper accumulated on the blanket.
16. Piling / Buildup: Ink build up on image areas of the blanket
18. Phantom effect: Reappearance of the previous print run or the print run underway but out of shift.
| CAUSE | SOLUTION |
|---|---|
| Paper too fragile (poor coating or poor structure). | Change the paper, dilute the ink or use a more suitable ink (less tack). Add Anti Tack Compound (3 % max.) or Arctic Thinner 501 (3% max.). |
| Restarting after a prolonged press stoppage. | Spray Rototack start-up aerosol over the rollers.
Apply a little thinner (Artic Thinner 501) onto the rollers. Clean the rollers. Clean the blankets. |
| Print shop temperature too low. | Dilute the ink before restarting printing. |
| Excessive dampening. | Reduce the dampening. |
| Excessive blanket / paper pressure. | Check the blanket / cylinder pressure, the counter pressure and the cylinder coverings. |
| Blanket has too much “affinity” for the ink. | Apply talc on the blankets. |
| CAUSE | SOLUTION |
|---|---|
| Substrate stored incorrectly. | Before printing: store in the original packaging at a temperature of around
20°C and a relative humidity of 60 %, for a period determined by the temperature in relation to the volume of the stack. During printing: between runs, do not hesitate to cover pallets to avoid deformation phenomena. |
| Excess or irregular use of anti set-off powder. | Adapt the quantity of anti set-off powder and its particle size to the job in hand. Clean the powder spray nozzles. |
| Excess water, principally on the paper edges. | Reduce or adjust the uniformity of the dampening. |
| CAUSE | SOLUTION |
|---|---|
| Substrate deformed before printing. | Change the substrate.
Avoid important relative humidity and temperature variations between the storage and printing areas. Place the paper in the print shop several hours before printing. |
| Blanket not tight enough. | Retighten the blanket. |
| Excess pressure. | Check the cylinder coverings.
|
| Slack impression cylinder or transfer cylinder clips.
| Adjust the clips (wear on the heels of the clips).
|
| Tack of the ink too high. | Add Anti Tack Compound (3% max.) or Arctic Thinner 501 (3% max.) to the ink. |
| CAUSE | SOLUTION |
|---|---|
| Abrasive particles from the paper coating deposited on the blankets. | Pre-lacquer the substrate. If possible, place the first group under pressure only with the dampening. |
| Pre-sensitised plate exposed too long to light. | Rework the plate. Protect the plate during print runs and apply gum during press stoppages. |
| Quality of the plate unsuited to the length of the print run. | Properly oven treat the plates. |
| Form rollers incorrectly adjusted (pressure too high). | Adjust the roller settings.
|
| Excess plate cylinder / blanket cylinder pressure. | Adjust the pressures. Check the cylinder coverings. |
| Excessive hardness of rollers. | Deglaze the rollers with Roline Arctic Deglazer or change them. |
| Abnormal movement of form rollers (with certain presses, equipped with form roller movement, it is recommended to use special high quality or oven treated plates). | Change the bushes or rollers. |
| Abusive use of hicky removal systems (delta effect). | Use the system sparingly (less than 1 minute). |
| Water too acid. | Adjust the pH to obtain a fount solution within the norms. |
| Water too hard. | Check the water hardness. |
| CAUSE | SOLUTION |
|---|---|
| Paper surfacing or coating fragile. Incorrect ratio between surface tension of fount solution / surface energy of plate (ST < SE). |
Improve the transfer of the fount solution by checking its dosage and, if necessary, add a transfer improving agent. Rework the plate. |
| Paper too alkaline. | Readjust the water / ink balance. |
| Oxidation of the plate due to insufficient or incorrect gumming. | Clean the plate with a de-oxidising solution followed by light gumming. |
| Dampeners clogged up. | Check / clean the dampening rollers and the dosing units. |
| Partial swelling of the blanket due to excessive use of deglazer. | Change the blanket. |
| Temperature too high in the inking rollers (ink becomes more fluid). | Reduce the temperature and the print speed, change the ink and restart the print run. |
| Excessive inking. | Reduce inking. Use an ink with higher colour strength. |
| Tack of the ink too low. | Use a more tacky ink. |
| Ink too diluted. | Open a new tin of ink. |
| Ink too siccative. | Use a less siccative ink. |
| CAUSE | SOLUTION |
|---|---|
| Poor dimensional stability of the paper (paper fibre in wrong direction) and excess water. | Always print the substrate with the paper fibres parallel to the cylinders. |
| Blanket tension incorrect. | Retighten. |
| Unsuitable cylinder coverings. | Adapt the cylinder coverings to rectify them if possible. |
| Clips loose due to incorrect adjustment and / or tacky ink. | Adjust the clips. |
| Paper deformed after several print runs and / or high inking level. | Reduce inking. |
| CAUSE | SOLUTION |
|---|---|
| Optical Density too high, out of standard. | Print using the Brunner standard, for example, or print using two printing units. Reduce inking. |
| Poor ink distribution. | Adjust the form rollers of the printing unit. |
| Incorrect Dampening. | Adjust the fount solution. |
| Excess water. | Adjust the water / ink balance. |
| Deformation of the stack due to heavy loads. Stack too high | Adapt the height of the stack according to the inking level and paper weight. Do not stack up pallets. |
| Not enough anti set-off powder. | Adjust the amount of anti set-off powder. |
| Particle size of the anti set-off powder not adapted to the substrate. | Adapt the particle size to the weight of the paper / cardboard. Use Arctic Vanesse or Arctic Vanesse 15μm anti set-off powders. Take account of post printing operations (varnishing, laminating). |
| IR lamps at incorrect temperature. | Adjust the temperature of the IR lamps as a function of the prin- ting speed, substrate grammage and whether printing on both sides. Recommended temperatures: Top side: maximum 35°C Reverse side: maximum 30°C. |
| Magnetisation of the paper. | Use a suitable anti-static system. Properly earth the press. Humidify the print shop. |
| Handling of the stack after printing. | Descend the loader slowly. Handle the stacks carefully. |
| Unsuitable ink. | Change the ink / substrate. Consult the supplier |
| Ink too emulsified. | Wash the printing unit and re-start with minimum dampening. |
| CAUSE | SOLUTION |
|---|---|
| Substrate too acid (destabilisation of the water / ink balance). | Check the pH of the fount solution. Change the substrate. |
| Fount solution too acid. | Check and adjust the fount solution |
| Excessive inking.
| Reduce the amount of inking. |
| Excessive dampening. | Reduce the amount of dampening. If necessary, clean the inking train so as to completely eliminate the emulsion and restart with less dampening. Check the pressure of the dampening rollers. |
| Wrapping or film covering too rapid (air oxidation ofthe ink film insufficient). | Allow inks to dry completely before wrapping or covering in film. |
| Ink too emulsified. | Find the correct ink / water balance. |
| Ink does not dry correctly. | Add Triple Drying Agent (1 % max. since too much drying agent can inhibit drying). |
| Ink not adapted to the substrate | Consult the supplier. |
| CAUSE | SOLUTION |
|---|---|
| Poor quality paper (linting, coating lift off). | Change the paper or reduce the tack of the ink with Anti Tack Compound (3% max.). Carry out a run without inking. |
| Accumulation of ink on the dampeners and / or thedampener form rollers. | Wash the dampening rollers. Prevention: replace the first form roller with an anti-hicky roller. If re-guillotining the paper, square it up well, and avoid making a reject cut. |
| Ink used from opened or incorrectly protectedcontainers. | Protect opened tins correctly with cellophane or by spraying Anti-drying A11 and remove the surface skin. |
| Skin on the ink when container opened. | Change the container of ink.
|
| CAUSE | SOLUTION |
|---|---|
| Paper wrapped before printing.Excess paper hygrometry. | Check the storage of the paper. Store the paper in the print shop before printing. |
| Deformation of the paper on first print run due to toomuch inking or an ink with too high tack. | Reduce the tack of the ink during the second print run. Use Anti Tack Compound or Arctic Thinner 501. |
| Clips incorrectly adjusted on the margin or wheelsincorrectly adjusted (pressure too high). | Adjust the clip settings to regular pressures. Reduce the wheel pressure settings. |
| Blanket not sufficiently tight. | Retighten the blanket. |
| CAUSE | SOLUTION |
|---|---|
| Paper too porous, causing the ink binder to separatefrom the pigment.
| Apply a primer coat. |
| Ink viscosity too low. | Use a higher viscosity ink. |
| Drying of ink too slow. | Use a more siccative ink. Consult the supplier. |
| Dampening water too acid, leading to longer dryingtimes. | Adjust the fount solution. To mask the phenomenon, apply an overprint varnish. |
| CAUSE | SOLUTION |
|---|---|
| Unsuitable colour sequence. | Adjust the colour sequence: Print low colour deposits before high colour deposits (e.g. Violet = 75 % Red and 100 % Blue ⇒ Print the Red first). In the case of poor trapping, dilute the second colour (e.g. Violet = 100 % Red and 100 % Blue ⇒ Dilute the Blue with a suitable thinner). |
| CAUSE | SOLUTION |
|---|---|
| Problem with the paper.Curling of the sheet parallel or perpendicular to thedirection of the press (central region of the parent roll,foudrinier table, dryer). | Change the paper. |
| Hygrometry too high or important change in the hygrometry. | Check the storage conditions. |
| Unsuitable blanket hardness. | Use a blanket with a harder surface. |
| Excessive dampening. | Reduce the dampening. |
| Ink too tacky. | Reduce the tack with Anti Tack Compound (3 % max.). When printing large solid areas, print a light screen first (base print), which then allows the thickness of the ink film to be reduced on a second print run. |
| CAUSE | SOLUTION |
|---|---|
| Paper has irregular smoothness. | Change the paper. Change the ink. |
| Excess dampening, which has the effect of reducing the tack. | Adjust the dampening to the minimum. |
| Ink too emulsified. | Change the ink. |
| Lack of pressure (piling). | Adjust the pressure settings. |
| Ink from previous prints deposited on the blanket. | Dilute the ink of the previous printing units that are being trans- ferred. |
| CAUSE | SOLUTION |
|---|---|
| Binding or surfacing of the sheet of paper insufficient. | Print a solid print area with transparent white ink without dam- pening. Carry out a run without inking. Change the paper. |
| New or badly washed blanket that is too adherent. | Wash the blanket correctly and apply talc. |
| Excessive pressure between the blanket cylinder andthe counter pressure cylinder. | Adjust the pressure settings |
| Ink too tacky. | Reduce the tack with Anti Tack Compound (3 % max.). |
| Non uniform water supply to blanket. | Adjust the water meteringspeed settings.
|
| CAUSE | SOLUTION |
|---|---|
| Spalling of the paper coating by the fount solution. | Change the paper. Slightly increase the dampening. |
| pH of the fount solution too acid. | Adjust the pH of the fount solution |
| Irregular dampening. | Increase the speed of the dampening tank roller. |
| Incorrect water / ink balance. | Check the water / ink balance. Slightly reduce the alcohol level. |
| Ink too sticky. | Soften the ink with Arctic Thinner 501 (3 % max.). |
| CAUSE | SOLUTION |
|---|---|
| Irregular ink deposition. | Incorrect imposition. Check the form roller movement. Adjust the pressure settings.
|
| CAUSE | SOLUTION |
|---|---|
| Worn blanket. | Change the blanket. Even if the blanket seems to be clean, its compressible layer may be altered and the phantom image may appear later. |
| Form rollers incorrectly adjusted on inking rollers. | Adjust the pressure settings of the form rollers on the inking rol- lers. |
31 York Road, North End
Port Elizabeth
South Africa
Email: admin@imvusainks.co.za
Phone: +27 (0) 41 492 3347
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