A summary of the common faults in the printing of Gift Paper Boxes pearl ink, and all the problems such as sticky back and paste are solved.

A summary of the common faults in the printing of Gift Paper Boxes pearl ink, and all the problems such as sticky back and paste are solved.

1. Poor or no pearlescent effect

reason

1. The cells of the printing plate are too shallow or clogged, resulting in a dry plate phenomenon.

2. The ink viscosity is too high or too low, which does not match the speed of the printing machine.

3. The angle of the ink knife is too large or the pressure of the impression cylinder is too large.

Approach

1. The cell of the printing plate is generally 25~45μm, and the cell of the printing plate should be cleaned with a thinner.

2. Adjust the viscosity of the ink to match the speed of the printing machine.

3. Adjust the angle of the squeegee, generally 45° or reduce the roller pressure.

Second, sticky back, adhesion

reason

1. The pearlescent ink on the printed matter is not completely dried.

2. The coil tension is too large or the coiling length is too long.

3. Improper treatment of film corona or damp.

Approach

1. Add quick-drying diluent to the ink, or increase the power of the drying device to completely dry the ink.

2. Reduce the winding tension and shorten the curling length.

3. Re-process the film and prevent moisture.

3. Uneven printing of pearl ink

reason

1. The viscosity of pearlescent ink is too high and it is not easy to be evenly coated, causing uneven ink layer after imprinting.

2. Pearlescent powder is easy to precipitate.

3. Poor contact between the impression cylinder and the printing plate cylinder.

4. The percentage of pearlescent powder in the pearlescent ink layer is insufficient.

Approach

1. Reduce the viscosity of the ink and choose a suitable diluent.

2. Fully stir the pearlescent ink.

3. Increase the pressure of the impression cylinder or replace it with a new one.

4. Choose high-quality pearl powder and diluting agent to make the pearl powder account for 30%~35%.

Four, there is pearl effect but no luster

reason

1. The thinner evaporates too fast.

2. The temperature of the oven is too high or the cold air is too big.

3. The viscosity of pearlescent ink is too low.

Approach

1. A slow-drying thinner should be added to make it compatible with the speed of the printing press.

2. Lower the temperature of the oven or reduce the amount of cold air.

3. Increase the viscosity of the pearlescent ink and adjust it with the same gold oil.

5. Cut lines often appear

reason

1. The squeegee is notched or angled incorrectly.

2. The pearlescent ink has insufficient fineness or improper viscosity.

3. The cell of the printing plate is too deep.

Approach

1. Replace the squeegee or adjust the angle of the squeegee to scrape off excess ink on the layout.

2. Adjust the ink viscosity to match the speed of the printing machine.

3. Add two cold air ducts behind the printing plate to blow air to the plate.

Sixth, paste version, block version

reason

1. The ink dries too fast.

2. There are impurities mixed in.

3. The angle of the squeegee is incorrect or the distance from the impression cylinder is too large.

Approach

1. Add the corresponding diluent to the ink.

2. Pay attention to the sanitation of the surrounding environment and control the humidity in the workshop.

3. Adjust the distance between the angle of the squeegee and the impression cylinder to reduce the drying time.

Seven, pearl powder is inconsistent before and after printing

reason

1. The pearlescent ink has discoloration.

2. The pearlescent effect is inconsistent.

3. Uneven mixing and accumulation of pearl powder.

Approach

1. Control the drying of the first few colors of ink to prevent the first few colors of ink from being mixed into the pearl ink to cause color change.

2. The diluent should not be added to the ink pump separately, it should be added together with the pearlescent ink.

3. When stirring with an ink pump, it is also necessary to clean up the accumulation of pearl powder in time to prevent uneven coating.

8. Poor peel strength after composite printing

reason

1. The film corona treatment does not meet the requirements.

2. Adhesives and thinners are not compatible with pearl ink.

3. Uneven amount of glue during compounding.

Approach

1. Master the types of films and standards for corona treatment.

2. Choose the pearlescent ink to make it compatible with the adhesive.

3. Control the amount of glue, temperature and tension during compounding.

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