UV glazing is a surface finishing process of packaging and printing industry in common. UV light oil FOLDINGCARTON printing enterprises (especially in Japan and Europe and the United States and other countries and regions have export business FOLDINGCARTON printing enterprises) often encounter such problems: UV glazing on prints, the abrasion resistance and adhesion of the UV varnish coating on the poor, especially printing using ink for metal (gold ink and silver ink printing and UV glazing, this phenomenon is particularly prominent.

In general, color box printing enterprises often by replacing the UV light oil to solve the problem. In fact, we should not be only will limit our thinking on the replacement of the UV light oil, but should be divergent thinking, thinking will be converted to change color box production process or adjust the relevant process parameters.

Solution

Conventional corrugated box production process route for engraving and cutting, printing, bottom UV oil, a UV surface oil and mounted corrugated, die - cutting, pasting box. After repeated experiments, the method will improve the corrugated box production process are summarized as follows.

(1), UV printing ink and paper plate + online glazing UV. Tests show that this process can greatly enhance the UV light oil in UV metallic ink on abrasion resistance and adhesion, but metal UV ink in the market is rare and need to custom, expensive and printing must also use UV printing machine. In general, small FOLDINGCARTON printing enterprises are not UV printing machine, so the production process apply only to FOLDINGCARTON printing enterprises, widespread promotion of little significance.

(2) plate making and printing, screen printing, paper cutting ordinary UV glazing. This production process can solve the problem of poor wear resistance and adhesion in metallic ink on UV light oil, but the screen printing UV light oil with high cost, and environmental performance than water-based light oil UV. In addition, a lot of FOLDINGCARTON printing enterprises have fully automatic screen printing machine, only the production of low efficiency of semi automatic screen printing machine, so this production process can only for in part FOLDINGCARTON printing enterprises, not worthy of popularization.

Finally after repeated verification, we made clear the idea to solve the problem: the use of high wear resistant UV face oil to improve the wear resistance, and by adjusting the process parameters or replace the material to ensure the UV bottom oil adhesion. As a result of the two polish, light oil film thick, the high wear resistance of UV oil surface wear more security, the next step just efforts to solve the critical factors, printing ink and UV oil affects the UV oil adhesion.

Solution measures

In solving the problem, we first need to understand the customer requirements of color box and detection method.

The wear resistance of (1) detection box UV light oil, methods are as follows: (1) if the box needs of shipping, the actual declaration is used when the carton installed a box of the actual product, or installed a box weight specifications and the actual product is consistent with the product model, on the transportation simulation test machine, vibration test and Taiwan) on Vibration for more than 2 hours, the box surface without obvious UV light oil coating or ink falling for qualified; 2 Box samples on high friction tester, with weight of 22n rub back and forth 80 times (weight and number can be based on customer requirements), with no obvious UV light oil or ink drop as qualified.

(2) detection box UV oil adhesion, methods are as follows: 1. 3M transparent tape firmly attached on the surface of the box, and then to a 45 degree angle to the direction of quickly, forcibly torn tape, to stick out UV varnish coating or ink layer is qualified; II with a Hb pencil core box UV varnish coating on the table surface force back and forth strokes, to cross out UV varnish coating or ink layer is qualified.

Current market sales of silver ink contained in the silver structure mainly has two: a close to circular granular structure; another a kind of is similar to the lamellar structure of the "scale". The former is more conducive to the adsorption of UV at the end of oil, the latter is more able to show the ink of the metallic luster and texture. At present, the market structure of Jin Mozhong gold powder was only a similar "sheet structure scales". Therefore, UV base oil in the gold ink on the adhesion than in the silver ink is much worse, it is also more trouble to solve. I also learned: better adhesion in oily metal ink on the UV base oil than the water base oil UV. However, in the use of the improved technology of UV base oil is oily, but the metal ink adhesion on the issue is still not resolved, so we have to focus on improving the metal ink.

In the detection box UV oil adhesion we found: 3M transparent sticky tape out not only UV light oil coating, and part of the ink layer. In addition, we also found that after conventional printing process and metal ink completely dry, when the fingers gently across the surface of the printed matter, will leave a thin layer of metal powder on the finger. We judge: probably not in metal ink binders. So we add some transparent ink in the metallic ink, again the test found that the adhesion of UV bottom oil in metal ink has been significantly improved, but is still not up to the requirements of customers. In this regard, we will add a transparent ink for quick drying varnish, as a result, bottom UV oil on the metallic ink adhesion problem basic solution. But quick drying varnish added to dilute the metallic ink color, resulting in printing color have changed little, and therefore must in metallic ink add a little four-color ink for redeployment. In addition, after UV glazing the 3 processes, mainly FOLDINGCARTON moisture content will affect the wear resistance of the UV light oil.