During the printing process of the self-adhesive label, the quality problems that often occur are: the back surface of the label material taken by the self-adhesive label is dirty, the printing of the ink, flying ink and static electricity. These failures seriously affect the printing quality, and certain measures must be taken to eliminate them. So, what are the common problems in printing self-adhesive labels? Here, Dongguan Bowei Printing focuses on the four most common and most overlooked problems in self-adhesive printing

       1. The back of the sticker material is dirty

The ink imprinted on the label of the self-adhesive paper pickup sticks to the back of another printed sheet, causing the back to be dirty. To prevent the back surface from getting dirty, a duster is generally installed in the paper receiving part of the printing machine to disperse fine particles of calcium carbonate between the sheets. In addition, accelerating the drying of the ink, reducing the height of the stack of printed sheets, and placing paper with good ink absorption between the printed sheets, etc. can all inhibit the smear phenomenon.

2, through printing

Transparent printing of ink refers to the phenomenon that the front print can be seen on the back of the sticker. In order to prevent the ink from passing through, you can choose to print on the paper with high tightness, or increase the viscosity of the ink and reduce the printing pressure appropriately.

3, flying ink of printing ink

The phenomenon of small droplets of ink flying in the air is called "flying ink", which is also called ink fogging. It is the most common failure of self-adhesive labels in high-speed rotary letterpress printing machines. To mitigate the "flying ink" phenomenon, you can increase the humidity in the print shop and use conductive inks such as water-based inks.

4. Static electricity

During the printing process, the self-adhesive labels are not easy to separate, the paper on the paper receiving table is not uniformly received, or the paper on the paper feeding table is skewed and the overprinting is not allowed. All these may be caused by static electricity. To eliminate printing static electricity, generally install a static eliminator on the printing machine to ionize the air around the printing machine, thereby neutralizing the positive and negative static electricity on the paper. You can also spray the appropriate amount of water mist around the printing press or behind the impression cylinder to eliminate static electricity on the paper. In addition, increasing the humidity in the printing shop is conducive to the elimination of static electricity.