How does the small roll of thermal label paper work?

The working principle of small roll thermal label paper is the same as that of large roll thermal paper and ordinary thermal paper, which are based on the principle of thermal chemical reaction. The following is a detailed explanation of how it works:

First, the basic structure of thermal paper

Thermal paper is a kind of processing paper, and its manufacturing principle is to coat a layer of "thermal paint" (thermal discoloration layer) on high-quality base paper. Thermal label paper is generally divided into three layers, the bottom layer is the paper base, the second layer is the thermal coating, the third layer is the protective layer (some thermal paper may not have a protective layer). The main influence on its printing and preservation quality is the heat-sensitive coating or protective layer.

Second, the key components of the thermal coating

Key components in thermal coatings include colorless dyes (or leuco dyes) and color developing agents. Leuco dyes are colorless at room temperature, which makes thermal paper look indistinguishable from regular paper when not heated.

Third, the working principle

1. Heating process:

When thermal paper is passed through a thermal printer, the surface of the print head has a number of tiny semiconductor components that can heat specific areas of the paper depending on the text or graphics that need to be printed.

2. Chemical reaction:

At the moment of heating, the temperature of the surface of the thermal paper rises rapidly, causing the leach dye and the color developer (if any) to melt into a liquid one after another. At this point, the molecules that can move freely meet and immediately react, forming a colored product.

3. Color display:

As the chemical reaction progresses, the surface of the thermal paper gradually shows the required text or graphics. These colors can be blue, fuchsia, black, etc., depending on the type of leuco dye used.

4. Print complete:

Driven by the roller, the thermal paper continues to be transmitted forward to complete the entire printing process. Finally, a heat-sensitive label with clear text and graphics is printed.

Fourth, precautions

Storage life: After a document or label printed on thermal paper is stored for a period of time, the writing on it may gradually fade. This is because the colored products formed after the reaction of leach dye and color developer are not stable and are easily affected by environmental factors.

Environmental impact: Thermal paper may come into contact with chemicals in the environment during storage, or encounter conditions such as sun exposure and high temperatures, which may cause the handwriting to fade.

Purchase suggestion: When purchasing thermal paper, you should choose the right material and type according to your own use scenario and needs. For example, for labels that need to be stored for a long time or exposed to harsh environments, thermal paper with better quality and greater stability should be selected.

In summary, the working principle of the small roll of thermal label paper is based on the thermal chemical reaction, which makes the dark dye react with the color developer and show the color by heating. In the process of use, it is necessary to pay attention to the impact of storage period and environmental factors.