How to prevent bruises on the back of the card

How to prevent bruises on the back of the card

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How to reduce the smudging and scratching during card printing

In the card printing, there are often smears or scratches, especially glossy paper or PVC cards. How to overcome such ills has become an unavoidable problem for some high-end users. As a manufacturer of card printing machines, we are obliged to seek solutions for the users.

First analyze the root cause of the problem:

One. Paper feeding process.

The above-mentioned smudging or scratching phenomenon occurs in all the lower-feeding machines except the vacuum suction feeding mode, the main reasons are:

1. The lower paper feeding method (card) has a certain pressure on the lowermost card, and the lowermost card enters the printing cylinder and the ink that has not been dried before the last printing will fall to the back of the previous card;

2. For the same reason, when printing a hard card such as PVC, if there is a burr behind the card, it will scratch the back of the previous card;

3. If there are scratches or burrs on the platform of the paper feeding path, the card that is entering will also be scratched on the back side;

4. The double feed limit plate inlet is too tight, and the card that is entering will be scratched on the front and back sides;

5. If the edge of the paper feeder surface is not deburred, it may scratch the back of the card during the return journey.

Two. Paper exit process.

For the card machine without the characteristics of full-page printing, the scratches generated between the card and the scraper during the paper-out process are also very headaches. First look at the reasons:

1. The adhesion between the jam and the blanket cylinder is too large;

2. The scraper is dirty or has burrs.

Based on the above analysis, the following is a list of ways to eliminate or mitigate smear scratches:

 (1). Paper feeding process.

1. Do not add too much card to the carton at one time, and try to reduce the pressure;

2. When printing hard cards such as PVC, check and remove the edge burrs of the card;

3. Use a fine sandpaper to remove all raised burrs on the platform;

4. Before the printing, the inlet gap of the double feed limit plate must be adjusted;

5. Finely trim all the burrs on the edge of the feeder with fine sandpaper.

(2). Paper exit process.

1. Reduce the viscosity of the ink (add appropriate amount of varnish; add appropriate amount of viscous agent; add appropriate amount of edible powder); avoid excessive printing pressure; reduce the number of manual transfer before printing; wipe the blanket cylinder as much as possible after printing; The amount of water should not be too large; when printing, the heavy ink version should be printed as much as possible; try to use non-glossy paper.

2. Clean the scraper frequently; use a fine sandpaper to remove the raised burrs on the scraper.