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NEW WEB PRESSES


TROUBLE SHOOTING
and
SUGGESTED REMEDIES
(This table is courtesy of the Flint Ink Corporation)

Printing problems can occur as a result of many factors. The table below is offered as an assist and is not all-inclusive. If your problem is not listed or the suggested remedy is ineffective, please contact our services Department.

SYMPTOMS
PROBABLE CAUSE
SUGGESTED REMEDY
BLISTERING

A moisture explosion in the paper-looks like a bubble on both sides of web and generally in heavy coverage areas.

1. Oven heat is too high.

2. Excess dwell time in oven.

3. Defect in paper causing excessive moisture content, improper density or base.

4. Pigment strength of ink is too low, requiring more than normal to be carried in heavy coverage areas.

1. Reduce oven temperature. Consult ink manufacturer to provide ink that can be cured at a lower temperature.

2. Correlate press speed, web dwell time in dryer, and chill roll temperature to optimum performance levels.

3. Blistering may not occur across the full machine reel. Run roll from different paper machine position. Run a substitute stock. Consult paper manufacturer and reject if necessary.

4. Consult ink manufacturer to adjust pigment strength as needed.

BLOCKING

Undesired adhesion between printed signatures or sheets in a bundle or load causing them to stick together.

Refer to INADEQUATE DRYING section of this guideRefer to INADEQUATE DRYING section of this guide
DOT SHARPNESS

Printed halftone areas appear muddied and show higher values than the "Prog" proof show.

1. Too much form roller-to-plate, plate-to-blanket, or blanket-to-blanket pressure.

2. Doubled or slurred dots.

3. Ink body is too long and is squashing at the point of impression.

4. Ink is too water receptive.

5. Piling.

6. Plate was not sharp enough to compensate for normal dot spread from film to plate to press.

7. Improper ink/water balance.

1. Check settings and correct to proper pressure.

2. Adjust plate-to-blanket pressure. Make sure blanket is secure. Check press for roller slippage or mechanical stability at high speeds.

3. Consult ink manufacturer to provide stiffer ink.

4. Consult ink manufacturer.

5. Refer to PILING section of this guide.

6. Have cameraman and plate-maker co-operate in making sharper halftones, negatives, positives, and plates.

7. Adjust ink and water settings. Consult ink manufacturer.

INADEQUATE DRYING

Ink remains tacky during press delivery and bindery operations resulting in set-off, marking, or blocking.

1. Dryer temperature too low for speed of web. Insufficient solvent being released from ink film.

2. Ink film thickness excessive.

3. Inadequate evacuation of solvent vapours clinging to web as it leaves dryer.

4. Chill system not working properly; ink resins are not setting hard enough.

5. Stock is not porous enough or has too high water content.

6. pH/conductivity of fountain solution is incorrect.

7. Ink takes on too much water.

8. Plate dampening is uneven.

9. Ink film is only surface dried in oven and still wet underneath. After chilling ink solvent will work its way toward surface causing set-off. Most likely to occur with heavier than normal ink film thickness, very nonabsorbent stocks, or high oven temperature.

10. Ink films do not dry at normal dryer temperatures.

1. Increase dryer temperature to specification level.

2. Run less ink or consult ink manufacturer to increase strengths for this purpose.

3. Increase velocity of air in air-knife scavenger at dryer exit.

4. Lower chill roll temperature. Caution: Watch for chill roll condensation.

5. Switch stock to correct porosity or water content.

6. Adjust ph/conductivity to proper level. Refer to Flint Ink Corp. Technical Monograph TM84-5 on conductivity.

7. Consult ink manufacturer for proper adjustment.

8. Keep dampeners clean and free from accumulated dirt. Prevent drafts, check windows, vents, and forced air systems.

9. Reduce speed of press. Adjust oven temperature.

10. Consult ink manufacturer for inks that dry at lower temperatures.

GLOSS

There is a decrease in the normal reflection of light from the dried ink surface whether observed visually or read via glossmeter.

1. Paper too ink absorbent. Paper surface very rough and grainy. Paper has poor gloss.

2. Dryer temperature too high.

3. Press dampeners-too much water being introduced into inking system.

4. Ink film thickness too low.

5. Excessive ink vehicle penetration into web.

1. Consult paper manufacturer to obtain stock with more ink hold-out. Obtain stock having a smoother surface. Obtain paper with better gloss.

2. Consult ink manufacturer to obtain low temperature inks. Decrease press speed to allow decrease of oven temperature.

3. Cut back on amount of fountain solution used. Consult ink manufacturer to decrease water receptivity of ink.

4. Increase ink film thickness being carried on web.

5. Reduction of heat in dryer. Increase press speed to reduce oven dwell time maintain sufficient chilling capacity. Consult ink manufacturer, obtain inks with better hold-out.

HICKIES

Doughnut shaped or irregularly shaped white spots surrounding a small spot of ink.

DOUGHNUT SHAPED HICKIES:

1. Dried ink particles.

2. Flakes of inking rollers.

3. Glazed rollers.

4. Disintegration of dampener roller sleeves or rollers due to wear.

5. Foreign particles (dirt) from ceiling have fallen into press.

6. Loose paper dust on web.

1. Avoid dried ink skin when removing ink from cans or kits. Protect ink remaining in a can or kit from oxidation drying and formation of ink skin by applying a sheet of paper or plastic on top of it. Clean the press thoroughly and remove all dried ink in the fountain or on the rollers before inking up the press. Prevent the ink in the ink fountain from mixing with dried ink around the ink fountain edges. Prevent ink from caking on the ends of rollers by lubrication and manual washing. Use a leather covered or a grained rubber roller. This will pick up hickies that are passed on to the plate. Remove the leather-covered rollers and clean them thoroughly as needed.

2. Recondition the rollers and drums. Replace if necessary.

3. Use one of the specially formulated glaze-removing materials or remove the form rollers, and alternately scrub the form rollers and the drums with pumice powder and ink solvent to remove the glaze.

4. Replace suspect roller sleeves or rollers with new ones.

5. Vacuum clean the ceiling and everything overhead where dirt can accumulate. Paint the ceiling if necessary, or hang plastic sheeting over the press to catch the falling particles. Use a leather-covered or a grained rubber roller. This will pick up hickies that are passed on to the plate. Remove the leather-covered rollers and clean them thoroughly as needed.

6. Install vacuum sheet cleaner. Consult paper manufacturer.

INCONSISTENT COLOUR REPRODUCTION

Colour hues when printed do not match proofs.

1. Paper proofed on is not the same as that being printed. Paper being printed is more absorbent.

2 Excessive heat in dryer results in too much penetration of the ink resin, resulting in loss of gloss-ink is overdried.

3. Special, spot colour does not match proof.

1. Adjust ink film thickness to that of the proof. Consult ink manufacturer to adjust hue and ink hold-out to match the proof on the actual paper being printed on. Consult paper manufacturer to see if paper is available which more closely duplicates the paper proofed on.

2. Reduce dryer temperature. Increase press speed.

3. Consult ink manufacturer.

INK/WATER BALANCE

Frequent adjustments required on press to maintain print quality.

1. Excessive or insufficient dampening solution being run.

2. Fountain solution too weak or improperly mixed.

3. Improper dampening roller setting.

4. Improper ink form roller settings.

5. Improper ink fountain settings.

6. Weak ink, i.e. low colour strength.

7. Ink taking up too much water.

1. Reduce or increase dampener settings.

2. Check pH/conductivity and adjust accordingly. Refer to Flint Ink Corp. Technical Monograph TM84-5 on conductivity.

3. Re-set rollers. Be sure dampener form rollers are driven by the vibrator roller and not the plate.

4. Conduct ink stripe test to check form roller pressure.

5. Adjust the amount of ink at fountain. Allow adequate time for adjustment to take full effect.

6. Consult ink manufacturer for proper adjustment.

7. Consult ink manufacturer.

INK MILEAGE

More ink used per impression than normal.

1. Lack of control on colour densities.

2. Ink penetration into stock too rapid.

3. Improper ink and water balance.

4. Low pigmented inks.

5. Excessive waste at start-up of run.

6. Improper estimate of coverage from job to job.

1. Adjust colour densities to minimum, consistent with satisfactory print quality.

2. Consult ink manufacturer for ink with more hold-out. Change to less porous stock.

3. Reduce amount of water carried

4. Consult ink manufacturer for proper tinctorial strength.

5. Improve start-up procedures.

6. Establish ink usage history so that these figures can be used to more accurately predict ink usage.

MARKING

Streaks, tracks, or smudges on web due to mechanical contact.

1. Grater roller.

2. Web bustle wheels.

3. Improper air flow through oven causing web to flutter and make contact with oven apparatus.

4. Chill roll not cool enough.

5. Web temperature reached in the oven is not high enough to drive off sufficient ink solvents.

1. Install grater roller with sharper points. Increase pigment strength of ink so as to allow decrease in ink film thickness carried on web.

2. Move wheels so as to contact non-image areas only. If moving wheel is not possible, apply teflon tape to lessen abrasiveness of wheel surface.

3. Consult oven manufacturer for proper adjustment or adjust web tension.

4. Reduce chill roll temperature so that post-chill roll web temperature is 90°F or less. Recommended chill roll water temperature is 72-75°F. Caution: If chill rolls are too cold, condensation can occur. Reduce oven temperature to minimum necessary to get the web through chilling and press folding delivery operation.

5. If flame impingement drier used, adjuct flame tips to impinge properly. If high velocity forced air drier used raise circulating air temperature in oven until marking is eliminated. Caution: Remember paper will burn at 451°F and can scorch at lesser temperatures. Decrease press speed. Increase air velocity through oven so as to remove air and vapour layer clinging to moving web. Consult ink manufacturer to obtain faster drying ink.

6. Consult dryer manufacturer.

7. Consult paper manufacturer, change paper.

8. Raise air temperature circulating in dryer. Reduce press speed to increase dwell time in dryer. Increase air velocity circulating to help remove solvent vapour layer. Consult ink manufacturer, change to faster drying inks.

MISREGISTER

In the press running direction and side to side, after the press has been set for proper registration trouble arises when some condition prevents consistently good register.

MISREGISTER IN THE PRESS RUNNING DIRECTION:

1. One or more plates are cocked or are not properly set on their cylinder.

2. One or more plates are printing longer or shorter than the others.

3. Uneven blanket packing. If one of the printing units is not pulling the web fast enough, web tension between it and the following unit will build-up until the web snaps back, causing misregister.

4. Web tension is too low; the higher the tension, the better the register.

5. Web press tension changes during run because infeed tension changes.

6. Ink tack at the point of impression is too high causing the web to follow the blanket more than normal. This momentarily increases the tension in localised areas and as a result can affect running register.

7. Paper pile on blanket changes blanket diameter.

8. Paper roll out of round or having flat areas therein.

1. Plates should be handled more carefully on bending jig.

2. Transfer the packing from blanket to plate to shorten the print, or from plate to blanket to lengthen the print. Maintain good tension on the web.

3. Adjust blanket packing until the draws between the units are equal.

4. Increase the web tension in the infeed section of the press.

5. Equip presses with a constant-tension infeed.

6. Increase web tension. Reduce press speed. Consult ink manufacturer for tack reduction of ink causing problem.

7. Wash blanket more frequently. Change to paper that is more moisture resistant.

8. Constant-tension infeed will help. Increase distance travelled by the web between infeed and the first printing unit. Change to a roll that does not have problem.

MISREGISTER (Continued)

In the press running direction and side to side after the press has been set for proper registration, trouble arises when some condition prevents consistently good register.

MISREGISTER SIDE-TO- SIDE (more likely with wide webs 35+ inches):

1. Non-uniform moisture content across the web causes corrugation of roll, resulting in side-to-side misregister.

2. Welts caused by unwrapping rolls in a high humidity area and allowing them to stand for a long time. These welts will occur no more than 25 mils into roll. The small amount of corrugation will cause some side-to-side misregister just after splicing.

3. Paper varies in calmer across the web.

4. Web has slack edges due to moisture pick-up while in the roll.

5. Ink tack too high at point of impression. Refer to RUNNING DIRECTION MISREGISTER section of this guide, #6 under Cause.

1. Increase distance travelled by the web between the infeed and the first printing unit. The longer this distance and the higher the web tension, the more uniform the web will be. Use a preheater on the infeed and the first printing unit to dry the paper, even out the moisture content and flatten the web. Equip press with a curved roller to spread and flatten the web.

2. Remove outer 25 mils of paper. Do not unwrap rolls until just before going to press.

3. Consult paper manufacturer.

4. Keep rolls protected from atmospheric changes until they are mounted on the infeed stand. Increase distance travelled by the web between the infeed and the first printing unit. Increase web tension, stretching the web tends to tighten slack edges. Equip the press with a curved roller on the infeed to spread and flatten the web. Adjust the eccentric-mounted infeed roller to balance edge tension.

5. Refer to RUNNING DIRECTION MISREGISTER section of this guide, #6 under Solution.

MISTING/SLINGING

MISTING—Excessive amount of ink being thrown from ink train rollers described as fine droplets.

SLINGING—Ink being thrown from rollers in filaments.

1. Too much ink on rollers.

2. Improper ink and water balance.

3. Ink is too long in body.

4. Rollers are incorrectly set or in poor condition.

5. Roller train too hot.

1. Make press adjustment to decrease amount of ink carried or consult ink manufacturer to increase ink strength and carry less ink on rollers.

2. Adjust ink and water balance to proper setting.

3. Consult ink manufacturer.

4.Reset rollers based on manufacturer's specifications. Replace rollers if in poor condition.

5. Reduce temperature or increase flow of cooling water through ink train rollers.

MOTTLED SOLIDS

Printed solid area is not uniform (smooth) in appearance or density.

1. Stock has non-uniform surface formation.

2. Too much printing pressure.

3. Improperly set ink form rollers or rollers in poor condition.

4. Improper ink and water balance.

5. Blanket has not been changed for a long time and has become worn and rough in certain areas.

6. Poor ink transfer.

1. Get better grade of paper. Consult ink manufacturer to provide weaker ink and minimise penetrating tendencies.

2. Reduce printing pressure.

3. Check condition and reset ink form rollers to specifications.

4. Adjust to proper ink and water balance.

5. Replace with new blanket.

6. Consult ink manufacturer.

PICKING/LINTING

LINTING - pulling fibres from uncoated stock.

PICKING—lifting of the coating from coated stocks onto blankets plates, or rollers.

1. Too much water reaching paper.

2. Dampening solution concentration too high.

3. Paper surface trash, coating dust, slitter or trimmer dust.

4. Base stock picks.

5. Pressure set too high for ink/stock combination being used

6. Blanket is too tacky.

7. Ink is too tacky for stock being run.

1. Reduce dampener setting for proper performance.

2. Adjust dampening solution mix. Consult dampening solution manufacturer.

3. Make tape pulls from blanket, consult paper manufacturer.

4. If serious, reject paper; change to more lint or pick resistant stock.

5. Reduce impression pressure, repack to manufacturer specifications.

6. It blanket manufacture blanket or change it to a less tacky blanket. Check blanket wash.

7. Consult ink manufacturer to lower tack of ink.

PILING

Build-up of paper coating, lint, or ink on rollers, blankets, or plates.

PAPER:

Refer to PICKING/LINTING section of this guide.

INK:

1. Ink is waterlogged.

2. Ink is poorly ground, contains a coarse, heavy pigment.

MECHANICAL:

1. Improper packing of cylinders or rollers not set correctly

Refer to PICKING/LINTING section of this guide.

INK:

1. Reduce dampener settings. Consult ink manufacturer.

2. Consult ink manufacturer. Have ink reworked or reformulated.

MECHANICAL:

1. Check specifications and adjust if required.

PLATE BLINDING (LOSS OF IMAGE)

Part or all of image on plate does not take ink.

MECHANICAL:

1. Excessive amount of lint being deposited on plate.

2. Excessive plate-to-blanket pressure causing platewear.

3. Improperly set ink and dampening form rollers.

4. Abrasive particles destroying image.

CHEMICAL:

1. Too much acid in the fountain solution.

2. Too much gum in fountain solution.

3. Plate cleaners and/or scratch removers have dried on plate Image.

4. Detergent remains or has somehow entered the fountain system.

5. Ink will not adhere to image area due to excess amount of fountain solution being accepted by the ink.

6. Plate not completely developed.

MECHANICAL:

1. Refer to PICKING/LINTING section on this guide.

2. Re-set to specifications. Use packing gauge to check pressure.

3. Rollers could be too hard—check durometer. Also check setting; re-set if too much pressure exists.

4. Check ink grind, fountain solution, solvents, etc. Replace all contaminated material.

CHEMICAL:

1. Check pH/conductivity and reduce acid to proper amount. Refer to Flint Ink Corp. Technical Monograph TM84-5 on conductivity.

2. Re-etch plate and rub-up image areas with press ink. Drain fountain solution and refill with tap water. If image returns, replace tap water with fountain solution containing less gum.

3. Always rinse plate thoroughly and immediately after using such items.

4. Make sure that all parts that come in contact with cleaning detergent have been thoroughly rinsed before re-installing in press.

5. Reduce dampener setting to minimum, if problem persists consult ink manufacturer.

6. Plate was improperly developed with gum remaining on image areas—wash plate. If problem persists have plate remade.

POOR RUB AND SCUFF RESISTANCE

Printed ink film appears dry but exhibits poor rub and or scratch resistance when abraded.

1. Too much water run on job or paper contains too much water.

2. pH conductivity too high in fountain solution.

3. Ink not fully dry.

4. Poor paper coating integrity.

5. Roughness of paper surface creates poor rub between unprinted paper surface and printed paper surface (e.g. some dull coat type stocks).

6. Too much ink.

7. Ink is not properly formulated for rub resistance.

1. Reduce dampener settings. Change paper.

2. Very high pH/conductivity is indicative of too much acid in fountain solution which can retard or prevent drying of inks, adjust pH/conductivity accordingly. Refer to Flint Ink Corp. Technical Monograph TM84-5 on conductivity.

3. Refer to INADEQUATE DRYING section of this guide.

4. Consult paper manufacturer.

5. Consult ink manufacturer to provide ink with better rub resistance.

6. Lower level of ink carried.

7. Consult ink manufacturer for adjustment.

SCUMMING

The non-image area of a lithographic plate accepting ink in random areas.

1. Low alcohol or alcohol substitute content in dampening system.

2. Glazed blanket, ink rollers, or dampening rollers.

3. Excessive printing pressure.

4. Ink spreading into non-printing areas.

5. Plate improperly exposed to light after allowed to dry.

6. Improper ink/water balance.

1. Bring alcohol or alcohol substitute content to correct concentration.

2. Clean thoroughly and recondition per manufacturers' instructions.

3. Make on-press adjustment to proper pressures.

4. Consult ink manufacturer to assure ink is on-standard; reformulate if necessary.

5. Desensitize or remake plate.

6. Refer to INK/WATER BALANCE section.

ROLLER STRIPPING

Rollers do not accept ink.

1. Fountain solution too acid.

2. Too much water being run.

3. Desensitized metal vibrator rollers.

4. Glazed form roller.

5. Too much dampening solution being emulsified in ink.

1. Check pH/conductivity and gum concentration levels of fountain solution. Refer to Flint Ink Corp. Technical Monograph TM84-5 on conductivity.

2. Reduce dampener setting.

3. Clean rollers, copperize, wash thoroughly. Then ink rollers and wash again.

4. Remove rollers from press and de-glaze per manufacturer's procedure. Rinse thoroughly.

5. Consult ink and dampening solution manufactures.

TINTING/TONING

Fine particles of ink adhering to non-image areas of plate transmitted by press water dampeners.

1. Ink bleeding into fountain solution.

2. Improper fountain solution concentration.

3. Too much pressure between plate and blanket.

4. Improper setting of dampener or ink rollers.

5. Ink not sufficiently water resistant.

6. Plate improperly exposed, developed.

1. Check concentration of alcohol or alcohol substitute in fountain solution. Consult ink manufacturer.

2. Check pH/conductivity and adjust to proper concentration. Refer to Flint Ink Corp. Technical Monograph TM84-5 on conductivity.

3. Check and re-set to manufacturer's specifications.

4. Check and re-set to recommended manufacturer's specifications.

5. Consult ink manufacturer.

6. Check platemaking procedure; correct if necessary.

TRAPPING

Cannot achieve good colour balance or overall appearance.

1. Too much tack in relation to preceding ink.

2. Unequal press stability of inks. Ink tacks up quicker than preceding ink.

3. Ink strength not balanced properly.

4. Ink contains additive that creates a film on top of it that will not allow succeeding ink layers to adhere to it when printed.

5. Ink-water balance.

6. Poor ink release from blanket.

7. Improper register causing poor appearance.

1. Consult ink manufacturer. Reduce tack of the ink that is not trapping properly.

2. Consult ink manufacturer to adjust stability to be in line with previous colour(s).

3. Consult ink manufacturer.

4. Consult ink manufacturer.

5. Refer to MOTTLED SOLIDS section of this guide.

6. Consult blanket and/or ink manufacturer.

7. Refer to MISREGISTER section of this guide.

TINTING/TONING

Fine particles of ink adhering to non-image areas of plate transmitted by press water dampeners.

1. Ink bleeding into fountain solution.

2. improper fountain solution concentration.

3. Too much pressure between plate and blanket.

4. Improper setting of dampener or ink rollers.

5. Ink not sufficiently water resistant.

6. Plate improperly exposed, developed.

1. Check concentration of alcohol or alcohol substitute in fountain solution. Consult ink manufacturer.

2. Check pH/conductivity and adjust to proper concentration. Refer to Flint Ink Corp. Technical Monograph TM84-5 on conductivity.

3. Check and re-set to manufacturer's specifications.

4. Check and re-set to recommended manufacturer's specifications.

5. Consult ink manufacturer.

6. Check platemaking procedure; correct if necessary.

TRAPPING

Cannot achieve good colour balance or overall appearance.

1. Too much tack in relation to preceding ink.

2. Unequal press stability of inks. Ink tacks up quicker than preceding ink.

3. Ink strength not balanced properly.

4. Ink contains additive that creates a film on top of it that will not allow succeeding ink layers to adhere to it when printed.

5. Ink-water balance.

6. Poor ink release from blanket.

7. Improper register causing poor appearance.

1. Consult ink manufacturer. Reduce tack of the ink that is not trapping properly.

2. Consult ink manufacturer to adjust stability to be in line with previous colour(s).

3. Consult ink manufacturer.

4. Consult ink manufacturer.

5. Refer to MOTTLED SOLIDS section of this guide.

6. Consult blanket and/or ink manufacturer.

7. Refer to MISREGISTER section of this guide.

WEB BREAKS

Tearing of web as it travels through press— can occur anywhere on press from infeed to cutoff due to (1) paper defects, (2) press settings, or (3) ink.

PAPER:

1. Excessive tension on one or both edges of web due to loss of moisture and shrinkage.

2. Roll has dent or cut in end.

3. Fibre cuts, hair cuts, wire holes, wrinkles, slime spots foam spots, calendar cuts—Any one of these can start a tear.

4. Bad mill splices.

PRESS:

1. Web tension set too high.

2. Printing units or other press elements may be out of line. This is indicated if a proportionately large number of web breaks occur in one section of the press. An indication of misalignment of press elements is the presence of diagonal wrinkles in any span of web in the press.

INK:

1. Printing tack of ink is too high causing web to adhere to blanket and follow it causing a tear and subsequent web break.

2. Body of ink is too long allowing drippage from fountain nip onto web below. Web will follow blanket causing break.

3. Pigment strength of ink is too low causing ink fountain keys to be opened up too much. As a result ink will drip through ink fountain nip onto web below. Web will follow blanket causing break.

4. Ink slinging.

PAPER:

1. Keep rolls completely wrapped until ready to mount on roll stand. If the rolls are stored, make sure wrappings are undamaged.

2. If dent is not deep, sand or cut it out until edges of the paper are smooth. If the dent is deep, print down to the dent, stop the press, slab off the damaged portion of roll, resplice, and resume printing. If rolls are too badly damaged, consult paper manufacturer.

3. If defects are numerous consult paper manufacturer.

4. If problem is extensive, the paper mill should be contacted.

PRESS:

1. Decrease web tension.

2. Have the press alignment checked and corrected if necessary.

INK:

1. Consult ink manufacturer.

2. Consult ink manufacturer.

3. Consult ink manufacturer.

4. Consult MISTING/SLINGING section.

******************
TROUBLE SHOOTING GUIDE
For
OFFSET NEWSPAPERS
******************
SYMPTOMS
POSSIBLE CAUSE
SUGGESTED REMEDY
FLUCTUATION OF INK & WATER BALANCE
ink and water settings require constant adjustments during press run.
1. Poor maintenance of unit.

2. Excessive ink emulsification.

3. Improper concentration of fountain solution.

4. Density too high.

1. Check ink form roller settings to plate and drum. Check water form roller settings to plate. Check pickup roller to chrome roller (where applicable). Check speed settings on water motors. Check condition of rollers (deglaze if necessary).

2. Check with ink supplier.

3. Check fountain solution by adjusting to proper conductivity.

4. Check density with densitometer then reduce density and water to proper aim points.

FORMER BOARD & PIPE ROLLER BUILD-UP
Accumulation of ink and lint on former board and pipe rollers.
1. Improper ink/water balance.

2. Improper concentration of fountain solution.

3. Applying too much ink.

4. Improper maintenance—lack of sufficient cleanup.

5. Improper selection of ink for special stocks. 6. Insufficient penetration into newsprint.

7. Incorrect strength. NOTE: Additional solutions to correct Former Board & Pipe Roller Build-Up.

1. Adjust to proper ink/water balance.

2. Check fountain solution by adjusting to proper conductivity.

3. Reduce amount of ink.

4. Clean former board & pipe rollers on a regular basis.

5. Consult your Flint Ink sales representative.

6. Change to a more absorbent paper.

7. Reformulate. Use Teflon tape on the edge and nose of Former Board.

GREY & WEAK SOLIDS
Solids appear weak, lack density.
1. Improper ink/water balance.

2. Improper concentration of fountain solution.

3. Non-uniform dampening.

4. Lack of impression.

5. Loss of image area. NOTE: Additional solutions to correct Grey and Week Solids

1. Adjust to proper ink/water balance.

2. Check fountain solution by adjusting . to proper conductivity.

3. Check condition of brushes, flicker blades, etc., clean or replace.

4. Check blanket height.

5. See PLATE WEAR. Check for improperly set form rollers.

INK THROWING
Excessive amount of ink being thrown from ink train rollers.
1. Carrying too much ink on roller rain.

2. Improper roller settings or rollers in poor condition.

3. Improper ink/water balance.

4. Improper fountain solution concentration.

5. Low ink viscosity.

1. Reduce ink density.

2. Reset rollers based on manufacturer's specification. Replace if in poor condition.

3. Adjust to proper ink/water balance.

4. Check fountain solution and adjust to proper conductivity.

5. Reformulate.

LINTING
Accumulation of paper lint on plates, blankets, and/or ink train rollers
1. Tack of ink too high for type of paper used.

2. Excessive water settings.

3. Improper concentration of fountain solution.

4. Improperly packed cylinders.

5. Improper tension controls.

6. Excessive amount of lint on newsprint NOTE: Additional solutions to correct Linting.

1. Reduce tack of ink.

2. Adjust to lowest possible ink/water balance.

3. Check fountain solution by adjusting to proper conductivity.

4. Check & repack to manufacturer's specification.

5. Check specifications or modify, check rolls.

6. Consult paper manufacturer. On presses with roll stands, reverse the direction of unwind.

MOTTLED SOLIDS
Solid area not uniform in density.
1. Improper ink/water balance.

2. Excessive linting on blanket.

3. Improper blanket to blanket packing or blanket to plate packing.

4. Improperly set form rollers or rollers in poor condition.

5. Uneven dampening distribution.

1. Adjust to proper ink/water balance.

2. Reduce liming condition (see LINTING)

3. Check bearer to bearer packing with Colight or Baldwin gauge and repack manufacturer's specification.

4. Check condition and reset form rollers to manufacturer's specification. Replace if necessary.

5. Check condition of sock rollers, brushes, flicker blades, etc., clean or replace.

MUDDY APPEARANCE OF HALFTONES
Halftones lack sharpness in highlight areas.
1. Excessive ink being applied to the plate.

2. Poor materials for good reproduction.

3. Plate improperly processed.

4. Excessive dot gain.

5. Excessive linting.

6. Improper form roller settings.

7. Improper ink/water balance. NOTE: Additional solutions to correct Muddy Appearance of Halftones.

1. Reduce ink.

2. Determine reproduction process.

3. Recheck exposure using Grey scale (Stouffer scale).

4. Determine dot gain on press and plate.

5. See LINTING.

6. Adjust setting to manufacturer's specification.

7. Adjust to proper ink/water balance. Check for glazed blanket.

PAGE-TO-PAGE SET-OFF
Ink from printed side of page setting off an adjacent page of finished product.
1. Folder nip rollers improperly set.

2. Too much ink being used.

3. Improper concentration of fountain solution.

4. Improper ink/water balance.

5. Newsprint absorbency low. NOTE: Additional solutions to correct Page-to-Page Set-Off.

1. Adjust to manufacturer's specification.

2. Reduce amount of ink.

3. Check fountain solution & adjust to proper conductivity.

4. Adjust to proper ink/water balance.

5. Change to a more absorbent stock. Second fold rollers too tight.

PILING
Heavy accumulation of ink on either blankets, rollers, or plates.
1. Highly pigmented inks (i.e. metallic inks, opaque whites).

2. Roller not set properly and/or have high and low spots.

3. Excessive tack, or lack of lubrication in ink.

4. Improper packing of cylinders.

5. Tacky blankets. NOTE: Piling can also take the form of emulsified ink and can be controlled by using a minimum amount of ink and water necessary for the particular form.

1. Consult your Flint Ink sales representative to have the ink reduced in pigmentation and vehicle increased.

2. Set rollers to manufacturer's specification and/or replace any rollers that are uneven.

3. Reformulate ink where necessary.

4. Check specifications and repack if necessary.

5. Check blanket wash and/or blanket compatibility.

PLATE WEAR
Gradual loss of image
1. Improperly processed plates.

2. Ink and/or water form rollers improperly set.

3. Excessive linting.

4. Fountain solution too concentrated.

5. Improperly packed plate and blanket cylinders.

6. Running plates far beyond their capabilties.

7. Using extremely strong inks— starvation of image area.

8. Extremely poor grind of ink.

9. Form rollers too hard

1. Check plate developing process— include Stouffer scale. Check for excess Diazo on plate preventing complete development.

2. Adjust to manufacturer's specification.

3. See LINTING.

4. Check conductivity and reduce to proper amount.

5. Check with Colight or Baldwin gauge and set to manufacturer's specification.

6. Switch to higher quality plate which will result in longer plate life.

7. Reduce strength of inks so that plate will become more lubricated.

8. Consult ink manufacturer to check grind.

9. Replace form rollers.

POOR INK MILEAGE
More ink used per ton of newsprint.
1. Improper ink/water balance.

2. Excessive waste on start-up.

3. Low pigmented inks.

4. Ink penetration into stock too fast.

5. Different specific gravities of inks.

6. Newsprint too absorbent.

7. Ink density too high.

1. Adjust to proper ink/water balance.

2. Improve start-up procedures.

3. Increase strength of inks.

4. Reformulate ink with more holdout.

5. Consult your Flint Ink sales representative for specific gravity values of Ink.

6. If possible, change to a less absorbent paper. See STRIKE-THROUGH.

7. Reduce using a densitometer.

RUB-OFF
Printed surface has insufficient rub resistance.
1. Improper ink/water balance.

2. Too much ink density.

3. Improper concentration of fountain solution.

4. Poorly maintained equipment— especially rollers.

5. Difference in paper absorbency.

6. Switch to low-rub type inks.

1. Adjust to proper ink/water balance.

2. Reduce amount of ink.

3. Check fountain solution by adjusting to proper conductivity.

4. Better: housekeeping & maintenance.

5. If possible, use a more absorbent paper stock.

6. Consult ink manufacturer.

SCUMMING
The non-image area of a lithographic plate accepting ink. The plate generally must be replaced.
1. Plate not properly processed. (Test plate by honing non-image area with pencil eraser. If scum disappears in honed area, plate is the probable cause.)

2. Improper concentration of fountain solution.

3. Improper setting of dampener or ink rollers.

4. Ink with poor water resistance.

5. Condition of dampening system.

6. Plate not fully desensitised.

7. Plate exposed to unsafe light or excessive heat.

1. Remake plate and check plate-making process.

2. Check fountain solution by adjusting to proper conductivity.

3. Check and reset dampener and ink rollers to recommended manufacturer's specification—if rollers are old, check durometer.

4. Be sure that ink is on-standard; if necessary, reformulate.

5. Adjust, clean or replace sock roller, brushes, flicker blades, etc.

6. Recheck plate developing procedures.

7. Store plates under cool, dry and dark conditions.

SHOW-THROUGH
Ability to see reverse side of printed page.
1. Opacity of newsprint not sufficient.

2. Impression heavy.

1. More opaque newsprint, if possible.

2. Reduce impression.

SPITTING ON INJECTOR RAIL
Excessive ink spilling over edge of rail.
1. Improper ink/water balance.

2. Improper rail setting.

3. Improper concentration of fountain solution.

4. Improper ink train roller settings.

5. Page pack columns not properly zeroed.

6. Inappropriate canister pressure.

7. Inappropriate ink body and tack.

8. Ink set too high.

1. Adjust to proper ink/water balance.

2. Reset rail based on manufacturer's specification. (Bottom and Top)

3. Check fountain solution by adjusting to proper conductivity.

4. Reset rollers based on manufacturer's specification.

5. Reset page pack column to "O" according to manufacturer's specification.

6. Check for proper pressure.

7. Reformulate where necessary.

8. Reduce ink film thickness.

TINTING
During tinting, emulsified ink transfers to the printed sheet as background tint.
1. Improperly processed plates.

2. Improperly stored plate.

3. Improper ink/water balance.

1. Check age of Diazo coating, change batch if necessary, also check entire plate-making procedure.

2. Do not slip sheet plate after coating, keep away from moisture and humidity.

3. Tinting can be corrected by adjusting to proper ink/water balance.

TONING
Toning is an intense form of overall tinting. Emulsified ink particles that cause tinting now adhere more intensely to the non-image areas of the plate.
1. Improper concentration of fountain solution.

2. Ink bleeding in fountain solution.

3. Ink with poor water resistance (off standard).

4. Improper ink/water balance.

5. Improper setting of dampener or ink rollers.

6. Chemicals extracted from paper react unfavorably on press.

1. Check fountain solution by adjusting to proper conductivity.

2. Reformulate using non-bleeding pigment, if possible.

3. Be sure that ink is on-standard, if necessary, reformulate.

4. Adjust to proper ink/water balance.

5. Check and reset dampener and ink rollers to recommended manufacturer's specification—if rollers are old, check durometer.

6. Consult paper manufacturer.

STRIPPING
Roller or portion of roller does not accept ink.
1. Contamination by hydrophylic material on the roller.

2. Excessive emulsification of ink on the ink train.

3. Improper roller setting.

4. Improper concentration of fountain solution.

5. Copper worn off of ink drums.

6. Press chemicals in the dampening system.

1. Clean ink rollers thoroughly and re-copperize.

2. Adjust to proper ink/water balance.

3. Reset rollers to manufacturer's specification.

4. Check fountain solution by adjusting to proper conductivity.

5. Drum needs re-copperizing.

6. Revise press wash procedure.

STRIKE-THROUGH
Excessive ink absorbing into paper stock.
1. Newsprint too absorbent.

2. Change in basis weight of paper.

3. Insufficient ink holdout.

4. Too much ink.

1. If possible, change to a less absorbent paper.

2. Revert to original basis weight.

3. Reformulate ink for more holdout.

4. Reduce amount of ink.

Whatever your equipment needs fax or email us the details and thank you for considering

National Printing Equipment

 

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