How does colored thermal label paper work?

The working principle of colored thermal label paper is mainly based on physical and chemical reactions, and its operating mechanism is explained in detail as follows:

working principle

Color thermal label paper contains a latent dye inside, which is colorless at room temperature, so thermal paper looks no different from regular paper when not activated. When the temperature rises, the dark dye and acidic substance will melt into a liquid one after another, and the freely moving molecules will meet and react, thus displaying color on the paper. This process is exactly why thermal paper is named - the paper only changes color when the temperature reaches a certain level.

Required equipment

To achieve printing of colored thermal label paper, it is necessary to use it in conjunction with a thermal printer. The internal structure of a thermal printer is relatively simple, with the main components including a drum and a print head. Without ink cartridges or other printing consumables, the printing process relies on the print head to heat specific areas of the paper, triggering a chemical reaction of the latent dye to display the desired text or graphics.

Application scenarios

Color thermal label paper is commonly used in applications that require fast and convenient printing of labels, such as supermarkets, logistics, warehousing, and other fields. They can print labels containing color information for better product identification, classification, and management.

matters needing attention

Printing quality: The printing quality of thermal label paper is affected by various factors, including the uniformity of the thermal coating and the rationality of the chemical formula. If the coating is uneven or the chemical formula is unreasonable, it may result in uneven color depth or shortened storage time during printing.

Storage time: Due to the fact that the color on thermal paper is generated by chemical reactions, this color structure may not be stable enough. During the storage process, if suitable conditions are encountered (such as sun exposure, high temperature, or contact with other chemicals), the dye may revert back to its colorless form, causing the label to fade. In order to extend the storage time, many thermal paper manufacturers add a protective layer on top of the dye layer.

In summary, colored thermal label paper achieves printing function through the physical and chemical reaction between latent dyes and temperature changes, which has the advantages of speed and convenience. However, certain attention needs to be paid to printing quality and storage time.