Plastic film printing and printing silver faults and solutions

1, paste version

Phenomenon: Gold and silver ink dry knots in the printed net pattern, the pattern is blurred after printing.

Cause: The ink dryness is too fast; the printing plate is not cleaned in time, so that the residual ink is solidified in the plate grain; gold and silver powder particles are too thick; mixed with sand, dust and the like.

Solution: Use high-boiling point solvents to reduce the dryness; clean the plate at any time, use gold or silver powder with ink of 1000 mesh or more; pay attention to keep the ink and the link material used to prevent dust from mixing. Filtering removes large particles from the binder and ink.

2, flash, spots

Phenomenon: large area solid bottom part, resulting in speckled pattern, poor luster; pattern edges spread out into hairy teeth.

Reasons: The pattern is too dark, the ink is too light, the solvent is too much, and the divergence is large; the static electricity of the plastic film accumulates, causing the ink to spread electrically.

Solution: The use of thicker ink; that is, with gold, silver ink, the amount of solvent should be less; to create a proper depth of pattern; eliminate plastic static phenomenon.

3, golden color light is not suitable

Phenomenon: Need blue light, printed after the blue light and so on.

Reasons: There are three kinds of gold, green light, red light, choose the wrong phase. Different manufacturers have different colors of pink and gold.

Solution: Choose good color according to the trademark requirements; pay attention to the difference of color shade produced by different manufacturers, and adapt to the requirements.

4, color gray

Phenomenon: Gold and silver are gray and dull.

Cause: Mixing with other ink colors; The used linking materials have strong oxidizing components or acids, alkalis, and sulfur components and they have a long mixing time.

Solution: Clean up the ink pump, piping, ink tank and printing plate in time, and find that the color string is replaced immediately. Use with the adjustment, and choose the resin material with low acid value and no oxidation. After printing, it is protected from attack by acids and alkalis.

5, escape

Phenomenon: The thin lines of the pattern are not clear or printed.

Reasons: The gold and silver inks are too dry. When printing, the speed is slow, and the fine lines are dried in advance; the pattern design is not properly matched. When large areas and lines are present, it is not easy to grasp.

Solution: Add a solvent with a high boiling point, latent heat of evaporation to slow down the drying rate, adjust the printing speed, and redesign the plate.

6, shedding

Phenomenon: The fastness of ink layer is very poor, and the particles of gold powder and silver powder are easy to drop or wipe off.

Reasons: Too little binder, too much solvent, almost mixed with gold powder and silver powder with solvent. Plastics are not handled well.

Solution: Use a high level of resin binder with appropriate solvents to the extent of use. To ensure that gold powder, silver powder coated with a solid layer of resin, fixed on the plastic film. Reprocess the film.

7, stick back

Phenomenon: After the plastic film is printed, the back surface is dirty, and when it is severe, the film will not be peeled off or the background image will be stuck.

Reason: The ink is slow in dryness, poor in dryness, or the nature of the resin and gold or silver ink in the background ink is not the same; the ambient temperature is too high, the printing speed is too fast, the pressure is too high, and the amount of hot air is insufficient; the plastic itself Sticky, especially some imported polyethylene film.

Solution: Increase quick-drying ingredients, use gold-plated, silver-linked materials to match the background ink, improve the ambient temperature, slow down, reduce the pressure, strengthen the air volume and thermal drying energy, make sticky plastic and not sticky Fighting and mixing.

Source: China Ink Technology Network