Application Effect Of Several Commonly Used Polish Oils For Self-adhesive Labels

Self-adhesive labels several commonly used varnish application effect

Printing varnish on the surface of printed self-adhesive materials is a relatively common post-print finishing process for self-adhesive label production. According to incomplete statistics, about 50% of the current wet glue and self-adhesive labels will use the varnishing process.

Varnish printed on the surface of self-adhesive labels can not only protect the printed ink surface and increase the brightness of the label surface, but also enhance the waterproof performance of the label, thus providing a good moisture-proof effect. In addition, some varnishes with special effects, such as printable varnishes, matte varnishes and scented varnishes, can also make the label have more functional properties. In this article, I will share with you some common types of varnish for self-adhesive labels and the application areas, hoping to give readers some inspiration.

Types of varnish and application areas

At present, there are various types of varnishes available in the market, if divided from the drying method, it can be divided into two categories: water-based varnish and UV varnish, of which, water-based varnish is mostly dried by hot air, while UV varnish is mainly dried by UV light curing. High friction resistant varnish, waterproof varnish, anti-slip varnish, reverse varnish, fragrance varnish, anti-static varnish, tactile varnish and food packaging varnish. Here, I mainly introduce several common varnish application effects from the perspective of usage.

1. Universal Varnish

Self-adhesive labels are made of a combination of surface material, glue and backing paper, and the expansion rate of the label's surface material and backing paper will be different when absorbing or losing water, so the self-adhesive label will be curled after absorbing or losing water because of the difference in the expansion length of the surface material and backing paper. The main function of general-purpose varnish is to increase the gloss and brightness of printed products, but also has a certain waterproof effect, printing varnish on the surface of self-adhesive labels can prevent the label from curling due to the influence of environmental humidity.

For example, some paper-type stickers in the air humidity environment after labeling, the label will absorb the moisture in the air will elongate, appear after labeling label drums, folds and other problems, and after the varnish label due to the light oil on the moisture in the air has a certain barrier effect, labeling after the impact of air humidity is smaller, so it is not easy to appear these problems.

In daily life, we will often see some side food seasoning or lubricant barrel label surface is very smooth, these labels are often printed generic light oil, the purpose is: on the one hand to make the surface of the label more smooth, bright, on the other hand, so that the label has a certain waterproof effect, to ensure that the label will not appear after labeling expansion and wrinkling problems.

2. Matte oil

The biggest difference between ordinary matte oil and glossy oil is: after the matte oil, the printed surface will show a matte frosted effect. This effect is especially suitable for some special design effects, such as some wine, cosmetics labels, in order to highlight the design pattern of the product grade design matte effect, and this effect is often achieved in the printing process is through the matte oil. In addition, matte oil also has a certain waterproof effect.

3. Printable varnish

Ordinary varnish is not suitable for printing on such a varnish surface because it contains silicone oil additives and the surface is relatively smooth, and the printed information is easy to fall off. However, in the actual application process, many labels need to print information on the varnish surface, such as food labels, pharmaceutical labels, etc. need to print the production date, batch number and other information on the varnish surface. Printable varnish can be printed on the surface of the material after printing variable information on its surface, this is because printable varnish can form a high surface energy varnish layer on the surface of the material suitable for printing, so that the printed information can be firmly attached to the label surface.

4. Rub-resistant varnish

Anti-friction varnish is a kind of varnish that can make the surface of printed products very smooth. There are some label products need anti-friction performance, which is because the labeled bottles boxed transport process will be due to vibration friction, if the anti-friction performance of the label is not good, it is easy to lead to the label printing pattern is worn flowers, wear off, such as some cosmetics or wine products, need to often long-distance transport to reach the stores, in the long-distance transport process in the box of bottles rubbing against each other is easy to destroy the label surface pattern.

This situation requires the use of friction-resistant varnish, this varnish contains more silicon additives, so after printing can form a relatively smooth varnish layer. Because the label surface is protected by a very smooth varnish layer, so it greatly improves the friction resistance of the label.

5. Reverse varnish

If you want to make a grainy effect on the printed surface, such as a raindrop effect, or a coarse grain frosted surface effect, then you can use reverse varnish to achieve. Reverse varnish is a kind of varnish that has been applied on a large scale only in recent years, and this varnish consists of two kinds of varnishes: surface varnish and base varnish.

In the process of use, the two varnishes printed on the label surface at the same time will produce a chemical reaction, forming a kind of granular varnish layer on the surface of the print, and the size and thickness of the particles can be adjusted according to needs. As can be seen, reverse varnish is a very special varnish, completely free of silicon additives, varnish effect is determined only by its own chemical properties. Because the reverse varnish can play a very good decorative effect, so in recent years is very popular with the majority of end users.

6. Scented varnish

Some cosmetics or high-end food need to be labeled with a fragrance, and this fragrance often needs to be similar to the fragrance of the product itself. This can be achieved by using fragrance varnish. The principle of scented varnish is to add microcapsules containing fragrance to the varnish, after printing, the microcapsules will remain on the surface of the label, and once squeezed or rubbed, the microcapsules will break and release the fragrance.

There are many kinds of scented varnishes, such as various fruit flavors, flower flavors, etc., which are often used for food and cosmetic labels. In recent years, some children's books have also started to use scented varnish, such as lavender flowers printed on the screen of children's books, if then printed with lavender scented varnish, then the children will be released through friction when reading the book, this design is very popular with children.

7. Anti-static varnish

In the printing of some film material labels may produce a very strong static electricity, to the printing and post-die cutting process caused a lot of trouble. In order to eliminate the problem of static electricity on the finished label, you can choose to remove static electricity varnish. The varnish contains anti-static additives, which can effectively eliminate the static electricity on the surface of the material after printing, thus achieving the ideal anti-static effect.

8. Tactile varnish

The so-called tactile varnish refers to the varnish will be automatically raised after printing on the surface of the material, and has a distinct tactile sensation when touched by human hands. When you need to achieve a clear bump effect on the surface of the label, you can use the tactile varnish.

Tactile varnish is currently available in two ways: screen printing and flexographic printing, where the screen printing ink layer is thicker and the touch is more obvious. Tactile varnish is mainly used to produce some special design labels, such as some labels printed with Braille is more suitable for the use of this varnish.

9. Food grade varnish

Traditional varnish can not be in direct contact with food, but only indirect contact with food, but in recent years the application of food-grade varnish is more and more. The main component of food-grade varnish is ethyl ester wax, which meets the current domestic and international requirements for food-grade packaging, so that it can come into direct contact with food. In the past, PE lamination was mainly used for this kind of packaging products, but now PE lamination can be replaced by food grade varnish.