The uneven coating of the thermal paper will result in darker colors in some areas and lighter colors in some areas, which will obviously reduce the printing quality. If the chemical formula of thermal paper is not suitable, the storage time of thermal paper will be very short. Good thermal paper can be stored for 5 years after printing (at room temperature and out of direct sunlight). There is now a long lasting thermal record that can be stored for up to 10 years. But if the thermal coating paper is not suitable, it can only be stored for a few months.
Although there are more than a dozen chemicals used in these pigments, there are at least the following: leuco dyes, many, most commonly used fluorescents; Dyes account for less than 20%, typically using bisphenol and p-hydroxybenzene formic acid. Sensitizers account for less than 10%, including benzenesulfonic acid amide compounds; fillers account for less than 50%, usually using calcium carbonate (particles); adhesives account for 10% or less, such as polyvinyl acetate; stabilizers, such as diphenyl terephthalate; lubricants, etc. Therefore, the process is difficult and the requirements are high.
When thermal paper is heated, leuco dye reacts with the manufacturer to produce pigments, so when thermal paper is used to receive marks and printed on a fax machine or directly on a thermal printer, the image and publications. Due to the variety of leuco dyes, the colors of writing also vary, such as blue, purple, black, and so on.
Thermal paper has been used for many years. While thermal papers still have many important functions, some of them are gone. During its life, other popular materials, thermal paper, have undergone many improvements, removing some of the constant thinking. An important reason is that the document is still in the printing process after printing. Although fax machines now use white paper, many people still believe that thermal paper is printed before and after rolling. However, consider accepting a long-term food receipt. This is written on thermal paper, but do not roll it.