How to deal with labeling problems in beer label printing

At present, most of the beer labels in China use 65-80g/m2 single-sided coated paper. Wet strong paper, sprayed aluminum paper, printing methods for offset printing, gravure, label quality and label fiber orientation. Flatness, moisture content. Dimensional stability, curling time and other factors.

The specific requirement is that the paper fiber direction is perpendicular to the bottle body axial direction; the water content is about 5% to 7%; under the condition of humidity of 40% to 80%, the single label remains flat; the front and back surface curl height is not more than 3mm; The time for the back of the water to curl into a tube should be greater than 8 seconds. In addition to the above elements, the printing quality must meet the requirements of the wine label, otherwise it will bring difficulties to the labeling.

The Probable Quality Problems and Causes in Beer Labeling

1. The glue is uneven (the upper and lower sides have glue, there is no glue in the middle or glue in the middle and there is no glue on the left and right sides). The main reason is that the beer label paper is uneven and the positive and negative curl heights are more than 3mm.

2. Take off when taking the bid. The main reason is that the front curl height of the beer label paper is greater than 3mm, and air cannot enter between the label and the label during the labeling process. When the label is taken, the label appears double or multiple sheets.

3. The label is pleated or curled (very good when bottled, but the label is curled at the corners during transport). The main reason is that the moisture content of the label paper is low and the water rapidly expands.

At present, the technical level of most printing factories can meet the appearance requirements of beer labels. How to control the intrinsic quality of beer labels and meet the labeling requirements is a key process. From the above analysis we can see that the beer label is curled. The main cause of problems such as the skew angle is the low moisture content of beer labels. If the printing method is different from the post-press processing method, the printing quality needs to be controlled by controlling the moisture change of the beer label paper.

Change of Water Content of Beer Label Paper in Different Printing Methods

1. Offset labels are single sheets, single or multiple overprints complete the printing, the ink drying is mostly natural conjunctival solidification, due to the existence of ink and ink balance in the offset, so the water content of the label paper and print water content is basically the same.

2. The gravure label is web pre-dried, continuous multi-color overprint, and winding completed. After each color printing, the ink is dried and the solvent is volatilized and dried. After the label is dried many times, it will cause moisture loss.

From the rule that the paper is subjected to moisture elongation and drying shrinkage, the offset label is printed under the condition that the paper is “stretched”, and the gravure label is printed under the condition that the paper is “shrinked.” Therefore, if gravure is printed, The process of labeling the beer is not well-controlled, and the humidity of the finished product may be curled, resulting in labeling failures.How to solve the problem of changes in the moisture content of the gravure beer label to suit the bottle labeling requirements?

Gravure beer label considerations

1. Rewetting: Restore the moisture content of the label after printing;

2. Stereotype: adjust the amount of water in the rewetting process according to different paper properties;

3. Leveling: The finished sheet after cutting the web should be flattened;

4. Keep the air humidity in the production workshop.

In short, there are many factors that affect the labeling process. The above is just a little experience that the author has explored for years to learn from peers and communicate with each other.