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Tackiness of ink & Acidity of Dampening Solution

Tackiness of Ink: High ink tack can make it difficult for the ink to transfer from the ink duct to the rollers, requiring continuous stirring. It can also lead to increased print waste and significant variations in ink density, affecting print quality. High tack might affect ink mileage due to increased key opening and the need to run over the ink density. Severe ink fading can occur, especially when new, high-tack ink lots are running on all towers. Ink being too hard to fetch from the bucket and stir in the ink duct is a common issue with high tack. "Patchy printing" and overall high black ink density can be observed with high ink tack. Excessive Acidity of Dampening: Scumming Cause : The excessive acidity eats away at the protective coating on non-image areas of the printing plate, making them susceptible to ink adhesion. Result : Ink appears on areas where it shouldn't be, leading to a dirty or dirty background. Plate Blinding Cause: The acid damages the ink-receptive...
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Showthrough and Strikethrough

#  S howthrough is a common print defect that is generally found in offset lithography.  Paper opacity is responsible for this type of phenomenon while ink absorption and penetration through the paper results in the visibility of printing on the reverse side of a sheet of paper under normal lighting conditions termed as showthrough. Reasons:-   This printing problem occurs in thinner papers with less pulp to create opacity.  Less fiber makes the paper more transparent.  The main reason behind the showthrough problem is the combination of ink and paper.  Tackiness of ink and excessive acidity of dampening   #  S trikethrough is similar to the showthrough print problem where the main reason is the penetration of ink through the paper or the substrate. Generally, in porous or uncoated paper this type of problem arises because of the excessive absorbent nature of paper which allows the ink vehicle to penetrate.  Moreover it can also occur ...
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Horizontal strips on a CTP (Computer-to-Plate) printing plate

  Horizontal strips on a CTP (Computer-to-Plate) printing plate can be caused by several factors: Laser Intensity Issues : If the laser intensity is not properly calibrated, it can cause uneven exposure, leading to horizontal striping. Developer Problems : Issues with the developing process, such as incorrect developer concentration or temperature, can result in uneven development of the plate. Plate Quality : Defects in the CTP plate itself, such as inconsistencies in the coating or material, can cause horizontal striping. Mechanical Issues : Problems with the CTP machine, such as misalignment or mechanical wear, can lead to uneven exposure or development. Ensuring proper calibration of the laser, maintaining the correct developer concentration and temperature, and regularly inspecting the CTP machine and plates can help prevent these issues.
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Mechanics of Paper Webs in Printing Press

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Web Break Prevention & Diagnosis

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Effect of Blanket Tension and Squeeze Pressure on Slur and Doubling

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Physical Testing of Paper

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