Problems and Solutions

Problem

1. Too thick.
2. Dried out.
3. Wrong thinner.

Solution

1. Add thinner.
2. Clean cliche with thinner.
3. Use slower thinner or one suited to ink system.

Cliche

Problem
1. Insufficient etching depth.
2. Wrong screen ruling.
3. Surface physically damaged.

Solution
1. Produce new cliche with greater etching depth.
2. Test new cliche with different fineness of halftone screen.
3. Use new cliche.

Pad.

Problem
1. Too flat.
2. Surface roughened.
3. Pad swollen.
4. Surface too oily.

Solution
1. Use more tapered pad shape.
2. Replace pad.
3. Blow air on pad.
4. Clean pad (several times) or replace.

Substrate

Other

Problem
1. Pad is pushed onto cliche too strongly.

Solution
1. Decrease head stroke of pad.

If ink pulls on pad fibers during pickup, it is too thick and needs thinning.

Problem
1. Dried out on pad.
2. Too wet on pad, not tacky.

Solution
1. Use slower thinner.
2. Use faster thinner.

Cliche

Problem
1. Insufficient etching depth.
2. Etched too deeply.
3. Wrong screen ruling.

Solution
1. Produce new cliche with greater etching depth.
2. Produce new cliche with shallower etching depth.
3. Use new cliche with different fineness of halftone screen.

Pad

Problem
1. Wrong shape pad.
2. Surface roughened.

Solution
1. Use more tapered pad shape.
2. Replace pad.

Substrate

Problem
1. Soiled surface (grease, oil, perspiration, mold release agents..).
2. Surface insufficiently pre-treated (polyolefines).

Solution
1. Pre-clean objects.
2. Check pre-treatment, repeat as required.

Other

Problem
1. Print speed setting too slow.
2. High ambient (room) temperature.

Solution
1. Maintain uniform cycle time.
2. Optimal room temperature is
18 °C – 20 °C or
65 °F – 68 °F.

Incomplete or spotty deposit of ink by pad is referred to as “splitting.” It plays a minor role in a continuously
running process. The Problem
only arises when cycle times fluctuate or after short breaks. The pad deposits
the dried ink all at one time, producing an inconsistent image. Using fast thinners will decrease ink build-up
and improve ink deposition.

Problem
1. Too thin.
2. Transparent ink.
3. Wrong ink system.
4. Scanty ink transfer.

Solution
1. Reduce amount of thinner.
2. Use opaque color shade.
3. Use pad printing ink .
4. Locate defect in cliche or pad.

Cliche

Problem
1. Insufficient etching depth.
2. Areas not screened.
3. Areas not slanted.
4. Wrong cliche type.
5. Wrong screen ruling.

Solution
1. Use new cliche with greater etching depth.
2. Screen area.
3. Slant areas.
4. Use cliche which allows screen to be etched with it.
5. Test new cliche with different fineness of halftone screen.

Pad

Problem
1. Too flat.
2. Porous surface.
3. Too soft.

Solution
1. Use more tapered pad shape.
2. Replace pad.
3. Use harder pad.

Substrate

Problem
1. Soiled surface.
2. Dark substrate color.
3. Surface too rough.
4. Stress cracks (esp. on injection molded parts).

Solution
1. Clean surface with alcohol.
2. Double print.
3. Use harder, more tapered pad.
4. Use milder ink/thinner system or quick drying ink/thinner to avoid any disSolution
of substrate.

Other

Problem
1. Soiling from greasy residues on accessories (auxiliaries).
2. Doctor blade sags.

Solution
1. Clean cliche, doctor blade, etc. before installing.
2. Use harder or thicker doctor blade (or see cliche points 2 and 3).

This Problem
very often occurs in pad printing, and cannot always be solved satisfactorily. Due to the low
degree of ink transfer in pad printing, 100 % opacity cannot be achieved on many objects with only a single
printing, especially in the case of dark substrates. Increased hiding power can be attained by double or triple
printing or preprinting with white.

Cliche

Problem
1. Individual motifs not correctly aligned.

Solution
1. If motifs are all on one cliche, film must be corrected and new cliche must be produced.

Pad

Problem
1. Pads mounted off center.
2. Pads not same shape.
3. Pads not of same hardness.
4. Head stroke not same over cliche and substrate material.

Solution
1. Readjust pad.
2. Replace pads with ones of correct shape.
3. All pads should be of same Shore hardness.
4. Adjust head stroke.

Substrate

Problem
1. Material is pliable.

Solution
1. Switch to different material.

Other

Problem
1. Jig not perfect.
2. Carre, adjustable, or rotary indexing table inaccurate.
3. Mounting screws not tight.

Solution
1. Check for play in jig, refabricate as needed.
2. Check indexing.
3. Screws not properly tightened during initial setup; they become loose during printing operation. Tighten screws.

The simplest way to contain these deficiencies is to produce a new cliche with precisely registered film.

Cliche

Problem
1. Motif not aligned with cliche.

Solution
1. Hold film over finished print and compare; correct and produce new cliche as needed.

Pad

Problem
1. Wrong pad shape (pad too small).
2. Too soft or too hard.
3. Stroke force too great.
4. Stroke force on cliche and substrate not equal.
5. Touch down at wrong point.

Solution
1. Test different pad shape.
2. Test other hardnesses.
3. Decrease the head stroke.
4. Correct the head stroke.
5. Align pad to correct contact area.

Substrate

Problem
1. Very soft/pliable.
2. Material allows distortion.
3. Very deep recesses/depressions.
4. Edges in proximity to motif.

Solution
1. Cool objects before printing to harden material; inflate hollow body.
2. Switch to different material.
3. and 4. Use pad assemblies or jigs which compensate for depressed areas; produce special pad as needed.

Other

Problem
1. Unsuitable jig.
2. Work piece mounted at wrong angle.
3. Jig too unstable.

Solution
1. Modify jig so that substrate is supported in all print/contact areas.
2. Test correct angle using adjustable wedge.
3. Produce new jig.

Distortion means that a printed rectangle, for example, does not show any right-angled corners, and has more
the shape of a cushion. Distortion occurs primarily in very curved motifs or in motifs which are in proximity to
an edge of the area to be printed or of the substrate. It is often impossible to achieve a 100 % correction. It is
possible to make a wraparound print, but improvements with this method are also limited.

Problem
1. Too thick.
2. Too thin.
3. Too slow.

Solution
1. Add thinner.
2. Use new ink.
3. Use faster thinner.

Cliche

Problem
1. Poor etching.
2. Etching too deep.
3. Wrong cliche type.
4. Wrong screen ruling.

Solution
1. Examine cliche with magnifying glass, produce new cliche as needed.
2. Produce new cliche with shallower etching depth.
3. Replace with correct cliche.
4. Test new cliche with different fineness of halftone screen.

Pad

Problem
1. Too soft.
2. Wrong shape.

Solution
1. Use harder pad.
2. Test different shape.

Substrate

Problem
1. Soiled surface.
2. Not free of distortion. 3. Great differences in height.
4. Printing in proximity to edges.
5. Very structured surface.

Solution
1. Pre-clean with alcohol.
2. Switch to different material.
3. Use pad assembly or special pad.
4. Jig should support substrate adjacent to edges, to prevent pad from extending over edge.
5. Use hard, pointed pad.

Other

Problem
1. Jig unstable.
2. Fast cycle time with bulky pad.

Solution
1. Refabricate jig.
2. Reduce speed, adjust setting to delayed cycle in front position to prevent pad from wobbling during print stroke.

Blurred print is understood as the indistinct, hazy reproduction of lines or letters. This deficiency is often confused
with distortion.

Problem
1. Too thick.
2. Too thin.
3. Ink mixed insufficiently.

Solution
1. Add thinner.
2. Remix ink.
3. Mix ink well before pouring into ink trough.

Cliche

Problem
1. Wrong etching depth.
2. Wrong screen ruling.

Solution
1. Check etching depth, produce new cliche as needed.
2. Test new cliche with different fineness of halftone screen.

Pad

Problem
1. Surface too rough.
2. Wrong shape.
3. Oily surface.

Solution
1. Replace pad.
2. Test different shape.
3. Clean with alcohol or replace pad.

Substrate

Problem
1. Soiled surface.

Solution
1. Pre-clean with alcohol.

Other

Problem
1. Ink contaminated by grease, oil, silicone, etc.

Solution
1. Use new ink and keep accessories free of contaminants, or clean before use.

Problem
1. Too thick.
2. Too slow.

Solution
1. Use new ink.
2. Use faster thinner.

Cliche

Problem
1. Too deep.
2. Wrong screen ruling.

Solution
1. Produce new cliche with shallower etching depth.
2. Test new cliche with different fineness of halftone screen.

Pad

Problem
1. Rough surface.

Solution
1. Replace pad.

Substrate

Problem
1. Very slick, dense material structure.

Solution
1. Substrates where surfaces cannot be dissolved by thinner are esp. problematic (e.g., glass).

Other

Problem
1. Insufficient pretreatment or subsequent treatment.

Solution
1. Heat objects before printing, or ventilate them for thinner to evaporate faster.

During high speed printing operations, the last ink printed may be removed by next pad. This occurs particularly
on larger surfaces, where material cannot be dissolved by thinner, or with slower inks in connection with
carree or rotary indexing tables and linear belts. The Problem
hardly ever arises when adjustable tables are
used. The best Solution
is to pre-heat objects or dry them with cold or hot air at intervals during the printing run.

Problem
1. Too thin.
2. Wrong ink system.
3. Wrong color match (in custom colors).
4.Transparent ink.
5. Shade cannot be mixed.

Solution
1. Use new ink.
2. Use pad printing inks.
3. Check proportions or re-mix as needed.
4. Use more opaque ink.
5. In this case no Solution
possible.Test another ink system.

Cliche

Problem
1. Wrong etching depth.
2. Wrong screen ruling.
3. Wrong type of cliche.

Solution
1. Check etching depth or produce new cliche as needed.
2. Test new cliche with different fineness of half tone screen.
3. Replace cliche.

Pad

Problem
1. Wrong pad shape.
2. Surface too rough.

Solution
1. Use hard, pointed pad.
2. Replace pad.

Substrate

Problem
1. Dark substrate color.
2. Changing material types.

Solution
1. Try to attain thicker ink deposit by double printing.
2. See below.

Other

Problem
1. Only printed once.

Solution
1. Test double or triple printing.

This Problem
occurs frequently in pad printing. It is, however, often impossible to achieve the original shade,
as it cannot be mixed from the colors available in pad printing. To lessen the influence of the substrate color,
the options are to: pre-print using white, double print, or triple print to increase the opacity. Each method
does, however, have its drawbacks, and should be tested beforehand.

Problem
1. Too thick.
2. Ink build-up on pad.

Solution
1. Add thinner.
2. Use faster thinner.

Cliche

Problem
1. Etching too deep.
2. Wrong screen ruling.

Solution
1. Produce new cliche with shallower etching depth.
2. Produce new cliche with fine half-tone screen.

Pad

Problem
1. Wrong pad shape.
2. Surface too rough.

Solution
1. Use more tapered pad form.
2. Replace pad.

Substrate

Problem
1. Surface becomes charged with static electricity.

Solution
1. Install ionizing unit on printing press.

Other

Problem
1. Humidity too low.
2. Cycle time too fast.
3. Intermittent operation of machine.

Solution
1. Raise humidity to approx. 60 % – 80 %.
2. Reduce printing speed.
3. Regulate to constant cycle times.

Improvement can be achieved by grounding press. Splotches or spiderwebs most often occur with materials
such as polystyrene, polycarbonate, or acrylics.

Problem
1. Too thick.
2. Too thin.

Solution
1. Thick ink with fast thinner produces visible screen dots.
2. Thin ink with slow thinner (retarder) causes invisible screen dots.

Cliche

Problem
1. Etching too deep.
2. Wrong screen ruling.
3. Wrong cliche type.

Solution
1. Produce new cliche with shallower etching depth.
2. Depending on results desired, use finer screen for invisible screen dots or coarser screen for visible screen dots.
3. Use cliche type suited to screen type.

Pad

Problem
1. Surface too rough.
2. Wrong pad shape.

Solution
1. Replace pad.
2. Depending on results desired, use more tapered pad for visible screen dots or flatter pad for invisible screen dots.

Substrate

Problem
1. Surface too coarse/ very structured.

Solution
1. In this case, not the screen dots are visible, but the surface structure.

Other

Problem
1. Poor quality of artwork.

Solution
1. Check screen dot pattern on film or expose in new screen.

Screen dots are desirable for some prints, but not for others. Some photopolymer cliches cannot be produced
without a screen, or only with a certain type of screen. With steel cliches, the screen is only exposed in for
support of the doctor blade, to allow printing of larger motifs over an entire surface.

Problem
1. Too thin.
2. Too slow; ink smears.

Solution
1. Use new ink.
2. Use faster thinner and/or blow on pad.

Cliche

Problem
1. Etching too deep.
2. No graduated etching in fine motif.
3. Wrong cliche type.

Solution
1. Produce new cliche with shallower etching depth.
2. Only possible with strip steel/steel cliches.
3. Use different cliche type.

Pad

Problem
1. Surface too rough.
2. Wrong pad shape.
Solution
1. Replace pad.
2. Use more acute (more pointed) shape.

Substrate

Other

Problem
1. Head stroke set too deep.

Solution
1. Causes crushing; adjust head stroke.

This Problem
occurs with cliches having both a large surface and fine lines in one motif, because the surfaces
should be etched deeper and with screen, but the lines are to be etched flat and without screen.

Problem
1. Too thin.
2. Wrong ink system.
3. Transparent ink.

Solution
1. Use new ink.
2. Use another pad printing ink.
3. Use opaque ink.

Cliche
Problem
1. Etching too shallow.
2. Wrong cliche type.
3. Wrong screen ruling.
4. Motif not slanted.
5. Different etching depth.

Solution
1. Produce new cliche with greater etching depth.
2. Use different cliche type.
3. Test new cliche with different fineness of halftone screen.
4. Slant motif.
5. Produce new cliche with constant etching depth.

Pad

Problem
1. Wrong shape.
2. Too soft.
3. Surface too rough.

Solution
1. Use more tapered pad shape.
2. Use harder pad.
3. Replace pad.

Substrate

Problem
1. Surface structure too irregular.
2. Soiled surface. olution

Solution
1. Use hard, pointed pad shape.
2. Pre-clean objects, e.g., with alcohol.

Other

Problem
1. Doctor blade sags.
2. Only printed once.

Solution
1. Use stronger doctor blade, or screen areas or slant lines.
2. Double print or preprint opaque ink.

This deficiency is easily observed in prints where peripheral areas are acceptable, but coverage (hiding) worsens
progressively toward center. See also “Insufficient Opacity.”

Problem
1. Too thick.

Solution
1. Add thinner.

Cliche

Problem
1. Poor etching.

Solution
1. Examine cliche with magnifying glass; produce new cliche as needed.

Pad

Problem
1. Surface damaged.
2. Wrong shape.
3. Too soft.

Solution
1. Replace pad.
2. Use more tapered pad shape.
3. Use harder pad.

Substrate

Problem
1. Statically charged.
2. Contaminated with dust particles.

Solution
1. Install ionizing unit.
2. Pre-clean. objects, if necessary, using air hose (air jet).

Other

Problem
1. Soiled artwork.
2. Dust present when films are copied.
3. Unclean environment, dust circulating in surrounding air.

Solution
1. Checks films.
2. Produce new cliche.
3. Dust particles, which appear to be air bubbles, can be transferred by pad from substrate to ink.

This deficiency can be contained easily. If bubbles always appear in same place, Problem
will be found in cliche or pad. If position of bubbles shifts, Problem
is caused by dust particles or electrostatic charges.

Problem
1. Too thin.
2. Too slow.

Solution
1. Use new ink.
2. Use faster thinner.

Cliche

Problem
1. Etching too deep.
2. Wrong screen ruling.
3. Wrong cliche type.

Solution
1. Produce new cliche with shallower etching depth.
2. Test new cliche with different fineness of halftone screen.
3. Use different cliche type.

Pad

Problem
1. Too soft.
2. Too little volume.
3. Prints over edges.
4. Stroke force on cliche and substrate not equal.

Solution
1. Use harder pad.
2. Use larger pad.
3. Correct head stroke.
4. Correct head stroke.

Substrate

Problem
1. Very irregular surface.
2. Surface not sufficiently precleaned.
3. Material not smudge free.

Solution
1. Use pad assembly or special pad.
2. Pre-clean surface.
3. Switch to different material.

Other

Problem
1. Jig not fastened tightly enough.
2. Jig unstable.
3. Jig not precisely made, object has too much play.
4. Cliche not doctored cleanly.

Solution
1. Tighten fixture.
2./3. Produce new jig.
4. Sharpen or change doctor blade.

This deficiency often occurs when thinner is added during printing run, where ink and thinner are not properly
mixed.

Problem
1. Wrong ink system.
2. Wrong or no hardener.
3. Wrong/imprecise mixing proportions.

Solution
1. Only use ink system suited to substrate according to technical bulletin.
2. Corresponding hardener must be added to two component inks.
3. Weigh proportion of ink to hardener exactly.

Cliche

Pad

Problem
1. Oily pad surface.

Solution
1. Clean new pads with alcohol before use.

Substrate

Problem
1. Soiled surface (grease, oil, perspiration, mold release agents).

Solution
1. Pre-clean substrate with alcohol.

Other

Problem
1. Surface insufficiently or not at all pre-treated.
2. Curing (drying) time not observed.
3. Subsequent treatment of surface insufficient or lacking.

Solution
1. Check pre-treatment, repeat as needed.
2. Observe curing time as per technical bulletin.
3. Check subsequent treatment.

This Problem frequently occurs because the type of plastic material is unknown, or unsuitable ink systems are
used. The requirements for adhesion and scratch proofing are very different due to the respective demands
placed on the finished products.
It is expressly recommended that the printing material be checked under the respective conditions of use
before printing any production run.

Problem
1. Wrong ink system.
2. Insufficient ink transfer.

Solution
1. Use glossy ink.
2. Double print.

Cliche

Problem
1. Etching depth too shallow.
2. Wrong screen ruling.
3. Wrong cliche type.

Solution
1. Produce new cliche with greater etching depth.
2. Test new cliche with different fineness of halftone screen.
3. Use different cliche type.

Pad

Problem
1. Surface too rough.
2. Wrong shape.

Solution
1. Replace pad.
2. Use more tapered pad shape.

Substrate

Problem
1. Structure of material unsuitable.
2. Material unsuitable.

Solution
1. Structure of substrate influences result.
2. Ink looks matte due to stress cracks.

Other

Due to the thin layers of ink inherent in pad printing, it is generally not possible to attain as high a grade of
gloss as with screen printing.