What is the thermal paper？

Thermal paper, also known as thermal fax paper, thermal recording paper, or thermal copy paper (referred to as thermal copy paper in Taiwan), is a processed paper with a unique manufacturing principle. High-quality raw paper is coated with a layer of “thermal coating” or thermal color change layer. This coating involves various compounds, including colorless dyes, commonly used fluorescent compounds, color developers, sensing agents, fillers, adhesives, stabilizers, and lubricants. The complexity of this process demands technical expertise.

Applications

Thermal paper finds application in fax machines, medical and measurement systems, internet terminal printing, and commercial activities. It is extensively used for trademarks, and sign codes (POS), with fax paper being the most widely used.

The thermal paper production process involves coating ordinary paper with powder particles and colorless dyes. When subjected to heat, a color-changing reaction occurs. However, the resulting color is unstable and fades easily, making document content challenging to recognize.

Commonly used lottery tickets are printed on thermal paper. While ordinary thermal paper is not suitable for long-term preservation, high-quality thermal paper can endure for 30 years or even longer.

Principle

The thermal coating of thermal paper mainly consists of colorless dyes or cryptochrome dyes and a color rendering agent. The composition includes various substances like crystalline violet lactone, fluorescent alkane system, dispersants, and top and bottom coating additives.

When thermal paper is exposed to temperatures above 70°C, the thermal coating undergoes a color change, starting a discoloration process. The quality of thermal paper directly affects the printing, preservation time, and lifespan of printers and fax machines.

Selection of thermal paper

Thermal paper is specifically designed for thermal printers and fax machines, but its quality varies. The lack of a national standard in many countries has led to confusion among users. Proper selection involves examining the uniformity of thermal coating, the formulation of the chemical formula, and the quality of the protective layer.

Thermal paper is commonly sold in rolls with specifications like 80mm × Φ60mm and 57mm × Φ50mm. Paying attention to the accuracy of these dimensions is crucial, as they directly impact the total length of the paper rolls.

Quality Identification

Identifying quality involves examining the appearance, conducting fire baking tests, and performing sunlight contrast identification. Unreasonable coatings, uneven finishes, and color changes during heating can indicate poor-quality thermal paper.

Hazard Prevention

Contact with thermal paper tickets often involves exposure to BPA (Bisphenol A). To minimize harm, individuals should minimize handling thermal paper, wash hands after contact, store thermal paper separately, avoid children playing with or saving tickets, and be cautious about direct contact with the oral cavity after handling tickets.

By adopting these practices, individuals can reduce potential health risks associated with BPA exposure from thermal paper.

Sunavin is a leading barcode factory, manufacturer, and supplier based in China. Our high-quality, cost-effective, and highly compatible products, such as thermal transfer ribbons and label papers, have gained popularity and achieved strong sales both domestically and internationally. We offer a comprehensive printing solution for our customers, collaborating with renowned brands like Zebra, TSC, Avery, Datamax, and more. Our product range includes a complete selection of barcode printers, barcode scanners, original and compatible print heads, printer accessories, and more.