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    Among the FAQ listed below you have not found what you were looking for? Then write us your question and we will reply as soon! info@comec-italia.it

    Q?
    Smudged image
    A.
    Probable Cause Possible Solution
    Pad  
    Too hard Use a softer pad
    Too small in relation to the image Use a larger pad
    Prints over edges Adjust the pad stroke and/or secure the fixtures
    Cliché  
    Depth too deep Make a new cliché
    Wrong type of cliché, may need screen Test a new cliché with a screen or use a different type of screen
    Ink  
    Too thin Add pure ink to thicken
    Slow drying Use a fast dying thinner
    Material  
    Very uneven surface Use special shaped pads or adjust pad position
    Other  
    Fixtures are unstable Redo them
    Q?
    Image appears blotchy
    A.
    Probable Cause Possible Solution
    Pad  
    Too flat Use a more pointed shape pad
    Porous, worn pad Replace pad
    Cliché  
    Etching depth is too shallow Make a new cliché with deeper etch
    Wrong type of etch Make new cliché with screened areas
    Ink  
    Too thick Add thinner
    Ink dried in etching Clean the cliché with thinner
    Material  
    Contaminated with oils Clean with alcohol
    Other  
    Machine speed too low Increase the machine’s speed
    Q?
    Fine lines begin to close up
    A.
    Probable Cause Possible Solution
    Pad  
    Too hard Use a softer pad
    Roughened porous surface Use a new pad
    Cliché  
    Etch depth is too deep Make a new cliché with lower etching depth or use pause to allow ink drying in the cliché
    First exposure of plate-making process too long-lasting Make new cliché with lower exposure time
    Wrong type of etch Use a different type of cliché with screened image area
    Ink  
    Ink too thin Reduce the amount of thinner
    Too fluid; ink smears out Use a fast dying thinner, or pause above cliché
    Material  
    Too smooth (e.g. glass) Clean thoroughly, to aid the ink cohesion
    Other  
    Pad stroke is too fast. Causes ink to be forced out of etched areas Reduce the speed of the pad stroke

     

    Q?
    Smears on edges of image
    A.
    Probable Cause Possible Solution
    Pad  
    Too flat Use a more pointed shape
    Cliché  
    Etch is too deep Redo a cliché with less depth
    Wrong type of screening or no screen Use a different screen
    Ink  
    Too thick Add more thinner
    Ink is drying too slow Use a fast dying thinner
    Material  
    Static charge Use a ionizer or increase humidity
    Other  
    Air moisture is too low Increase air moisture up to 60-80%
    Cycle time is too fast Reduce printing speed
    Pad pressure too high forcing ink outward Decrease pressure
    Q?
    Ink sticks to pad surface
    A.
    Probable Cause Possible Solution
    Pad  
    Too soft Use a harder pad
    Wrong shape Use a more pointed shape
    Roughened porous surface Replace with a new pad
    Cliché  
    Etch is too shallow Etch a deeper cliché if ink is drying on pad
    Etch is too deep Etch a new cliché with less depth, or use cliché pause to allow ink to partially dry on cliché
    Ink  
    Dried on the pad Use retarder or more thinner
    Too wet on the pad, does not film well Use a fast dying thinner or pause on the print stroke
    Material  
    Dirty surface (grease, oil, release agents, hand sweat) Preclean. Depending on the grade of dirtiness, with alcohol, if necessary. Wear gloves during printing
    Other  
    Room temperature is too high The room temperature is best at 18 – 20 °C
    Pad speed too low Increase speed in the case of ink drying on the pad
    Pad speed too high Use pause on print stroke in case of ink too wet to allow more drying time, or use cool/hot air
    Q?
    Mis-registration of colors in multi-color print
    A.
    Probable Cause Possible Solution
    Pad  
    Pads are not correctly assembled Adjust pads so as they pick up images in the exact same place
    Different shapes Use equally shaped pads
    Different hardnesses Use pads of the same hardness
    Cliché  
    Images are not in registration Re-register artwork and etch new cliché
    Ink  
    Image spreads more in one color than in others Correct ink viscosity to prevent incorrect dot gain
    Material  
    Parts collapse (e.g. plastic bottles) Use a more supportive fixture
    Other  
    Work piece fixtures are not stable enough Control. Make new fixtures if necessary
    Conveyor, feeder or turntable move inaccurately Set carefully the devices movement
    Fixtures are insufficiently attached Fasten fixture screws
    Q?
    Opacity of ink is inadequate
    A.
    Pad  
    Porous and rough Replace pad
    Too flat and soft causing insufficient ink release Use a firmer and more pointed pad
    Cliché  
    Etching depth is too shallow Etch a deeper cliché
    Wrong type of screen Test a new cliché with a different screen
    Wrong type of cliché Use a different type of cliché
    Ink  
    Ink too thin Thicken ink
    Ink not completely transferred Use print pause or air blower to partially dry ink for proper release
    Material  
    Image not brilliant enough due to darkness of parts Use double hit to lay down an additional ink layer
    Q?
    Distortion in printed image
    A.
    Probable Cause Possible Solution
    Pad  
    Wrong shape Use a different shape pad
    Too soft or too hard Use different hardness
    Image too close to pad edge Move or replace pad
    Cliché  
    Etched too deep Coupled with thin ink, the smudge caused is often mistaken for distortion
    Ink  
     Too thin + etched too deep Causes smudging (see above)
    Material  
    Moves or collapses Use special fixtures or appropriate pads
    Other  
    Unsuitable work piece fixtures Modify the fixtures to achieve support on all positions of the product
    Fixtures movement Check fixtures
    Printing on angles Change fixture grade
    Q?
    Uneven ink thickness
    A.
    Probable Cause Possible Solution
    Pad  
    Wrong shape Use a different shape
    Cliché  
    Wrong cliché type Use steel cliché to prevent ink “scooping”
    Wrong etching depth Make a new cliché controlling depth
    Wrong type of screen Test a new cliché with a different screen
    Wrong orientation Change cliché orientation
    Ink  
    Too thin Reduce the amount of thinner
    Too thick Add more thinner
    Insufficient mixing of ink and additives Mix the ink thoroughly before putting it into the inkcup.
    Material  
    Odd shaped surface Use suitable pad
    Other  
    Doctor blade too soft Use firmer doctor blade or convert to hermetic inkcup system
    Q?
    Color transfer between pads on multi-color jobs
    A.
    Probable Cause Possible Solution
    Pad  
    Porous, worn surface Replace pad
    Cliché  
    Etching is too deep Etch a new cliché with less depth
    Wrong percentage and DPI of screen Test a new cliché with a different screen (higher DPI screen for smaller areas & details)
    Ink  
    Ink contains too much thinner Add more pure ink
    Ink is drying too slow Use a fast drying thinner, blow air, or use pad delays/pauses to give inks time to dry
    Material  
    Very smooth surface. Substrates which cannot be notched by the thinner (e.g. glass) are especially problematic Use hot/cool air on part during the print, or use pauses before printing
    Substrates contaminated with oils Clean parts before printing.

     

    Q?
    Small pinholes are apparent
    A.
    Probable Cause Possible Solution
    Pad  
    Surface is damaged Replace pad or place it so that damaged area won’t interfere with image
    Pad is too flat Use pointed shape pad
    Too soft Use a harder pad
    Cliché  
    Bad etching due to error or dust during exposure stage Redo the etching
    Ink  
    Ink is too thick Add more thinner
    Material  
    Rough surface Use a firmer pad
    Dirty parts Clean them before printing
    Other  
    Ink contaminated with silicone or oils Replace with new ink
    Q?
    Ink does not meet adhesion requirements
    A.
    Probable Cause Possible Solution
    Pad  
    Too much silicone on surface Clean new pads with alcohol before use
    Cliché  
    Etched too deep Redo a deeper cliché
    Ink  
    Wrong type of ink Use the suitable ink according to the technical data sheet
    Probable need for two-component ink Use two-component ink with hardener
    Incorrect ratio of ink to hardener Remix ink with correct ratio by weighing ink and hardener
    Material  
    Dirty surface Pre-clean with alcohol
    Other  
    No/insufficient pretreatment Check pretreatment procedure. If necessary, repeat it
    Polymerization time not respected Let the pieces stand for longer time before testing
    No/insufficient after-treatment Use heat tunnel and in some situations do the flame treatment
    Q?
    Blurred print or sharpness problem
    A.
    Probable Cause Possible Solution
    Pad  
    Too soft Use a harder pad
    Wrong shape Use a different shape
    Cliché  
    Inaccurate etch Make a new cliché
    Etching is too deep Etch a new cliché with less depth
    Wrong type of cliché Use the suitable cliché type (e.g. steel in place of polymer).
    Wrong type of screen Test a new cliché with a different screen
    Ink  
    Ink is too thick Add more thinner
    Ink is too thin Reduce the amount of thinner.
    Slow drying Use a fast drying thinner or cliché pause
    Material  
    Dirty surface Pre-clean
    Rough, grainy surface Switch over to other material, if possible, or try a harder pad
    Printing near edges Fixtures must support the pad to prevent slippage
    Other  
    Work piece fixtures are not stable enough

     

    High speed causes pad vibration

    Make new fixtures

     

     

    Decrease speed. If necessary, pause the pad at front position before releasing the ink to avoid vibrations of the pad during printing