With the emergence of new consumption scenarios, patterns and formats, quality and personalized consumption have become fashionable. More and more users are pursuing personalized packaging products, and labels are also being given personalized styles. Special inks, due to their special nature, can greatly enhance the functional and decorative effects of self-adhesive labels. Therefore, more and more special inks are being applied to self-adhesive labels. In this article, we introduce several special inks and their application in self-adhesive label printing machines, hoping to further stimulate the innovation vitality of label products.
Thermochromic ink refers to ink that can change color under changing environmental temperatures. Generally, thermochromic ink is divided into two types: reversible and irreversible. Reversible thermochromic ink refers to ink whose color changes with changes in environmental temperature. Once the temperature returns to a normal range, the ink color can also return to its original color. Irreversible thermochromic ink refers to ink whose color changes with changes in environmental temperature and cannot be restored to its original color even if the temperature returns to a normal range. In addition, reversible thermochromic ink is further divided into high temperature and low temperature types, where high temperature reversible thermochromic ink changes color with temperature increase and low temperature reversible thermochromic ink changes color with temperature decrease.
Generally, thermochromic ink has a critical temperature point at which the ink begins to change color. When the temperature exceeds or falls below this critical point, the ink will gradually change color, and this process is a gradual process rather than an instantaneous one. For example, a reversible thermochromic ink that is originally red will turn colorless when the environmental temperature reaches 60°C.
For self-adhesive labels, irreversible thermochromic ink is used more commonly. For example, some hospitals need to use high-temperature labels on medical supplies that require high-temperature disinfection to ensure that the relevant items have indeed been subjected to high-temperature treatment. This label contains irreversible thermochromic ink and changes from colorless to black during high-temperature treatment. When the staff sees the change in color of the label after treatment, they can determine that the item has undergone high-temperature disinfection.
Metallic ink refers to ink that can create a metallic texture effect after printing. Generally, metallic ink comes in gold and silver. Metallic ink is often used in label design to create a metallic texture effect and is commonly found on the packaging labels of food and industrial products. Compared to aluminum foil, metallic ink is lower in cost and higher in cost-effectiveness. Aluminum foil material is more suitable for displaying large-area metallic solid effects, while metallic ink is more suitable for displaying relatively complex pattern effects.
Currently, there are many popular types of metallic ink on the market. According to the printing method, metallic ink can be divided into relief printing, flexographic printing and gravure printing metallic ink. Among them, the effect of gravure printing mirror metallic ink is the best and can even achieve a effect close to that of aluminum foil material or gold stamping, but this ink usually uses solvents as carriers, and its environmental protection effect is not ideal. Relief printing and flexographic printing metallic ink are relatively more environmentally friendly, but the metallic effect printed on them is not as good as that of gravure printing metallic ink.
Fluorescent ink is a kind of ink made by blending bright fluorescent pigments. The printing effect of fluorescent ink is very bright and eye-catching, making it easy to attract attention. Currently, there are letterpress, flexographic, and screen printing fluorescent inks on the market. Fluorescent ink is usually used in cosmetic labels, warehouse logistics labels and dangerous warning labels.
When fluorescent ink is used on cosmetic labels, it can be combined with special designs to help people find products at a glance among numerous commodities, thereby attracting the attention of consumers and playing a good shelf effect. In some warehouses where lighting conditions are limited, efficient turnover requires workers to quickly find the corresponding goods. Labels printed with fluorescent ink are especially eye-catching, and even if placed in an environment with poor lighting, people can easily identify them. Therefore, they can be used as tags for storing warehouse goods. Similarly, because fluorescent ink is very bright and has a strong reminder effect, it is also commonly used for printing dangerous warning signs to remind workers of the placement of dangerous goods and dangerous locations on mechanical equipment.
Glow-in-the-dark ink contains photoluminescent pigments that can absorb and store light energy, so that the ink can continue to emit light in dark environments. This ink is often used on lifesaving channel warning labels, such as emergency exit signs used by cinemas, etc. Normally, the photoluminescent pigment on this label will absorb the light energy in the environment and store it. In case of emergencies such as power outages, the label can guide people to escape safely by emitting light.
In recent years, some cosmetics and alcohol products have also been trying to use glow-in-the-dark ink. For example, some liquor label designs feature a bright moon, and glow-in-the-dark ink can be used to print the moon. In a darker environment, the moon will emit light, thus having a good decorative effect.