Sticker printing ink use and precautions

The performance indicators of label printing inks mainly include hue, fineness, saturation, gloss, adhesion, viscosity, and drying. These properties have a very important influence on the printing process and print quality. Here are some of the performance indicators highlighted.

(1) The stability of the ink viscosity is one of the prerequisites for ensuring the consistency of the quality of the printed matter. The high or low viscosity of the ink is not conducive to printing. Therefore, the control of the viscosity of the ink is very important. Generally speaking, in the printing process, as the moisture and solvent in the ink continuously evaporate, the ink viscosity will gradually increase, so the viscosity of the ink should be measured frequently, and the viscosity change record should be made and adjusted in time.

(2) The dryness of the ink also has a great influence on the label printing. Drying too quickly may cause the pattern to become lighter or even dry. If the drying is too slow, it may cause the ink to stick or the printed product to become dirty. In general, the drying speed of the ink should be compatible with the printing speed, the drying ability of the printing equipment, and the area of ​​the printing pattern.

(3) pH value control is very important for water-based label printing inks, and it is usually between 8 and 9. Changes in the pH of water-based inks can also cause changes in viscosity. Therefore, an appropriate amount of pH stabilizer is added to the ink at regular intervals during the printing process.

In general, the type of printing materials, printing methods and printing conditions, and customer's special requirements must be taken into consideration in selecting the printing ink for labels. Postpress processing, label use and usage conditions, cost, and other factors.

(1) The type and performance of printing materials is one of the most important factors in determining label printing inks. Different substrates need different inks. For example, paper labels can be printed using aqueous inks, while film labels are usually printed using solvent-based inks. In addition, it is worth noting that even the same type of printing materials may use different inks if they have different types, grades or surface properties.

(2) Printing methods and printing conditions are also one of the important factors affecting the selection of label printing inks. Different types of printing inks generally cannot be used or mixed, and the speed of printing, the type and performance of the printing equipment also have a certain influence on the choice of label printing ink.

(3) When selecting the label printing ink, we must fully consider the customer's requirements. Sometimes the customer may require the label to have some special effects, such as ice flower effect, sanding effect, anti-counterfeit effect, etc. At this time, it may be necessary to consider how to meet the special requirements of customers and products from the perspective of label printing ink.

(4) Does the label go through some special processing processes along with the product it is pasting? What are the special requirements? This also has a certain influence on the choice of labels. For example, in some products, the labels attached to them may be subjected to high temperatures or exposed to certain chemical reagents. This requires labels. Printing ink must have excellent high temperature resistance, chemical resistance, etc., otherwise it will cause the label deformation or damage.

(5) The use of the label and the use of the environment is also a factor that can not be neglected when selecting the label printing ink. For example, the label used on the daily chemical washing product usually requires the printing ink to have good acid and alkali resistance, oil resistance and the like. For another example, labels used outdoors are required to withstand the wind, sun and rain tests. Therefore, in the selection of label printing inks, it is necessary to pay attention to the performance of the ink in terms of light resistance, water resistance, high temperature resistance, and acid and alkali resistance.

(6) Cost factors. The goal of the company is to pursue the maximization of profits, which inevitably involves cost issues. In general, UV label printing inks have the highest prices, followed by water-based label printing inks, and solvent-based label printing inks have the lowest prices. Of course, the costs and costs of transportation, storage, etc. must also be considered.

Source: 21st Century Fine Chemicals Network