The application of self-adhesive label stickers has become more and more extensive, and with the increasing production, there have been some problems in production and processing. Some Logistics Waybills printing companies found that when the label sticker was folded, the skew of the label sticker was quite serious, the irregularity and skewness in the processing of the sticker label; and some problems caused by the dirty back of the sticker. So what are the reasons for the irregularity and smearing in the processing of sticker labels?

 

In the end, our Waterproof Adhesive Paper Roll Sticker Lables suppliers found the cause of the problem, which is summarized below.

First, the reason why the label sticker is not neatly folded and skewed and the solution

1. Reasons and solutions for irregular labels

The reason why the label sticker is not neatly folded is mainly the tension of the device. Unstable tension of the equipment will cause the position of the die cutter to oscillate before and after the die cutting process, resulting in uneven folding. The reason for this is that the folds are not uniform, and the folded label stickers are arranged in a zigzag manner. In this case, try to increase the running tension of the equipment. If there is a pressure roller in front of the die cutting station, be sure to press the pressure roller and ensure that the pressure on both sides of the pressure roller is consistent. Under normal circumstances, the above adjustments can solve this problem, but if it still can't be solved, you need to ask the equipment supplier to help solve it.

2. The cause and solution of the sticker label folding skew

The label sticker is folded and skewed in two cases, one for front and rear skew and the other for left and right skew. The front and rear skew is generally caused by an error in the diameter of the die cutter roll from the theoretical value.

The left and right skew is generally caused by the skew of the dotted knife. Sometimes the fold appears left and right skew. We can also clearly see that the dotted knife is cut obliquely. At this time, you only need to adjust the dotted knife to correct it. But one thing to note is that sometimes we visually observe that the dotted knife is positive, but the actual cut label sticker is oblique. This may be caused by the equipment die-cutting unit skew or the die cutter. The roller is skewed. If this happens, the device needs to be adjusted.

Second, the cause of the dirty back of the sticker and its solution

The ink printed on the sticker is printed on the back of the other sheet due to the sticker printed on the sticker, causing the back surface to become dirty. A dusting device is installed in the delivery portion of the printing press to disperse fine particles of calcium carbonate between the sheets. In addition, the drying of the ink is accelerated, the height of the printed sheet is reduced, and paper having good ink absorbability between the sheets is inhibited. The offset of the ink, the offset of the ink refers to the phenomenon that the front side of the sticker can be seen on the back side of the sticker, preventing the ink from being printed, and the printing of the paper with a large tightness can be selected, and the viscosity of the ink can be increased. Reduce printing pressure. The tiny droplets of the ink printed on the sticker are scattered in the air called “flying ink”, also called the fog of the ink. It is the most common fault of the self-adhesive label in the high-speed rotary letterpress printing machine. To slow down the "flying ink" phenomenon, you can increase the humidity in the printing shop and use conductive inks such as water-based inks. Static electricity is also the process of printing on self-adhesive stickers. The self-adhesive labels are not easy to separate, the paper on the delivery table is not aligned, or the paper on the paper-feeding table is skewed and the overprinting is not allowed. It may be caused by static electricity. To eliminate printing static electricity, a static eliminator is generally installed on the printing machine to ionize the air around the printing machine, thereby neutralizing the positive and negative static electricity on the paper. It is also possible to spray an appropriate amount of water mist around the printing machine or on the back of 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. The embossed printing sticker is used, and the printing plate is a photosensitive resin relief plate. The water-based ink or uv ink suitable for flexo is used to change the properties of the ink to adapt to the substrate change. This method is also applicable to Express Logistics Stickers printing.