Why do you need varnish for self-adhesive labels?

Why do you need varnish for self-adhesive labels? I believe that a large number of users will find it strange. Just yesterday, a customer who printed stickers in Shenzhen also asked, just to talk about it today. Among them, the self-adhesive label glazing is mainly to beautify the printed matter, protect the printed matter, enhance the publicity effect of the printed matter and improve the practical value of the printed matter.

The surface of the self-adhesive label after glazing appears smoother, resulting in uniform reflection of the incident light and a brighter ink layer. Glazing is the surface coating of label paper with varnish. Before final processing of the print after printing, take appropriate measures to protect the surface of the sticker or cardboard print. The printed matter is covered with a bright film on the surface after glazing. Its application range includes: packaging and decoration paper products, such as paper bags, envelopes, trademarks, etc., after glazing, it can beautify and protect the goods. Common quality issues in self-adhesive UV glazing are:

1. After glazing, after a period of time, the product turns yellow and red, changing the color;

2, the surface of the product is not bright; pleats or streaks;

3, the glazing surface is sticky, not smooth;

4, the glazing layer is not strong, the ink is lost, there are bubbles, pitting and so on.

Solutions to the problem:

1. Use high quality, effective period of varnish;

2, reasonable control of the amount of varnish, neither too little nor too much, pay attention to the leveling effect;

3, pay attention to the printing quality of the bottom ink, it is required to print the ink amount, print it, and do not dry out;

4. Correctly adjust the viscosity of the varnish according to the actual condition of the glazing surface;

5. Correctly adjust the surface tension of the varnish to make it smaller than the surface tension of the ink, and add a solvent or surfactant with low surface tension;

6. Avoid crystallization of the ink layer and surface treatment if necessary;

7. Adjust the relationship between machine speed, glazing oil and drying energy.