What changes will circular colored copper plate labels undergo under ultraviolet irradiation?

Circular colored copperplate labels may undergo various changes under ultraviolet irradiation, mainly influenced by ink, paper, and special coatings or processing techniques that may exist on the label. The following is a detailed analysis of these changes:

1、 Ink changes

Fading:

Under the action of ultraviolet radiation, pigment molecules in ink may decompose due to photochemical reactions, resulting in a gradual fading of color. Light colored inks such as pale yellow, emerald green, and lake blue, as well as the yellow and red colors used in four-color printing, usually fade quickly. However, due to the relatively stable nature of pigments, the fading speed of cyan and black is relatively slow.

Color change:

In contrast to fading, some inks may experience color darkening or changes under UV irradiation. This is usually due to certain components in the ink undergoing chemical reactions under the action of light, generating new color substances.

2、 Paper changes

ageing:

Long term exposure to ultraviolet light may cause cellulose and other organic molecules in paper to break due to photochemical reactions, leading to paper brittleness and reduced strength. This aging phenomenon is more pronounced on paper with softer texture and stronger UV absorption ability.

Color change:

Some additives or dyes in paper may undergo chemical reactions under ultraviolet radiation, causing changes in the color of the paper. For example, paper containing lignin is prone to yellowing under prolonged exposure to ultraviolet radiation.

3、 Changes in special coatings or processing techniques

Fluorescent ink anti-counterfeiting changes:

If fluorescent ink is used for anti-counterfeiting treatment on the label, under ultraviolet irradiation, these fluorescent inks may emit specific colored light, thus playing a role in anti-counterfeiting. However, prolonged exposure to ultraviolet radiation may also lead to a decrease in the performance of fluorescent ink, affecting its anti-counterfeiting effect.

Changes in photosensitive anti-counterfeiting:

The photosensitive anti-counterfeiting technology uses light irradiation to change the anti-counterfeiting pattern. Under ultraviolet irradiation, photosensitive anti-counterfeiting labels may display colorless patterns, or make the original patterns shiny, discolored, etc. This change is usually reversible, meaning that the pattern gradually disappears or returns to its original state when the UV irradiation stops.

4、 Comprehensive impact

The comprehensive changes of circular colored copper plate labels under ultraviolet irradiation depend on the combined effects of ink, paper, and special coatings or processing techniques. These changes may include color fading, discoloration, paper aging, and changes in anti-counterfeiting effectiveness.

In order to extend the lifespan of the label and maintain its good visual effect, it is recommended to avoid prolonged exposure to strong ultraviolet light during use. If long-term outdoor use is required, one can consider choosing ink and paper materials with UV resistance, or using special coatings or processing techniques to improve the weather resistance of labels.

In summary, circular colored copperplate labels undergo various changes under ultraviolet irradiation, which have a significant impact on the visual effect and service life of the labels. Therefore, in the design and use process, it is necessary to fully consider the impact of ultraviolet radiation and take corresponding measures to reduce its adverse effects.