How to solve smear or scratch in card printing

In the printing of the cards, it often encounters dirty or scratched phenomenon, especially glossy paper or PVC cards. How to overcome such disadvantages has become an unavoidable problem for some high-end users. First analyze the source of the problem:

one. Feeding process

For all the paper feeding methods other than the vacuum suction upper feeding method, the above-mentioned smearing or scratching phenomenon exists. The main reasons are:

1. Downward feeding mode The paper stack (card) has a certain pressure on the lowest card. The last printing card will go to the back of the previous card when the last printing in the printing cylinder has not dried yet;

2. For the same reasons as above, 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 any scratches or burrs on the platform of the paper feed path, back scratches will also be generated on the card being entered;

4. The double-feeding limit plate is too tight, which will cause the incoming card to be scratched on both sides;

5. If the surface of the feeder is not deburred, it may scratch the back of the card when it is returned.

two. Paper out process

For the card machine without the characteristics of full-printing, the scratches generated between the card and the scraper are also a headache. First look at the reason:

1. The paperboard and rubber roller have too much adhesion;

2. The scraper is dirty or has burrs.

Based on the above analysis, the following methods are listed to eliminate or reduce the phenomenon of smearing:

(one). Paper Feeding Process 1. Do not add too many cards to the card at one time, and try to reduce the pressure;

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

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

4.Be sure to align the inlet gap of the double-feed limiter before printing;

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

(two). Paper discharge process 1. Reduce ink viscosity (add appropriate amount of varnish; add appropriate amount of viscosity reducer; add appropriate amount of edible raw meal); avoid excessive printing pressure; reduce the number of manual transfer before printing; try to scrub after printing when shutting down Rubber roller; the amount of water should not be too large; color printing when the first reprint as much as possible; use non-glossy paper.

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