Print product quality defects and causes

Print product quality defects and causes:

Color cast: The reasons may be poor quality of originals, inaccurate plate making, inconsistent control of printing conditions, good ink control steps, and non-standard viewing of sample stage light sources.

The color is dark, not bright; the reasons may be poor quality of the original, poor design of the plate making curve, low density of the color separating sheet, improper imprinting of the printing plate, insufficient printing pressure, aging of the printing machine, excessive amount of fountain solution, rough paper Whiteness is too low.

Text water: The reason may be that the positive density is lower, the film is more hazy, the shading is too light, the printing pressure is insufficient, the printing press is aging, the fountain solution is excessive, and the amount of ink is insufficient.

Paste plate: As the printing plate graphic part overflows the ink, resulting in the imprint on the substrate is not clear, it is a fault of the offset printing product.

Dirty plate: Ink is formed on the blank due to the poor wetting of the plate.

Falling out of print: The typography of the typographic plate becomes lighter, the area of ​​dots and lines is reduced, and even the ink affinity is lost.

The increase in the number of outlets: The area of ​​the printed-circuit web site is larger than that of the corresponding portion of the printing plate.

Stacking ink: Ink or other material deposits on the ink roller or blanket, forming a relief-like deposit, affecting ink and print transfer.

Deinking: The metal ink roller is eroded by the wetting fluid to oxidize and repel ink.

Ink emulsification: The phenomenon of the ink absorbing the wetting liquid during the printing process or the printing failure caused by the excessive absorption of the wetting fluid in the ink.

Lapping: During the printing process, the paper fibers, fillers or paints are peeled off or pulled off from the surface of the paper due to the fact that the ink is too tacky or the surface strength of the paper is different.

Printing failure: The general term that affects the phenomenon of normal production or print quality defects in the printing process.

Imprinting is not allowed: In the process of register printing, the overlap of the printed traces.

Ghost image: The double outline of the same color dots, lines, or text appearing on a print.

The back of the dirty: printing ink printed on the substrate, stuck to the back of another sheet, causing dirt.

Printthrough: Images printed on paper are visible on the back.