Thermal printing paper is generally divided into three layers: the bottom layer is paper base, the second layer is thermal coating, and the third layer is protective layer. Thermal coating or protective layer mainly affects the quality of thermal printing paper.
Thermosensitive coating: If the coating of thermal paper is not uniform, the color of the printed label will be different and the quality will be significantly reduced. If the chemical formula of the thermal coating is not reasonable, the storage time of the thermal printing label will be affected.
Protective coating: The protective coating can absorb part of the light that causes the chemical reaction of the thermal coating, slow down the deterioration of the printing paper, and protect the thermal components of the printer from damage. If the protective coating is not uniform, it will not only greatly reduce the protection of the thermal sensitive coating, but also cause the fine particles of the protective coating to fall off during the printing process, which will lead to the damage of the thermal sensitive components of the printer.
How to distinguish the quality of thermal label paper?
Appearance: If the paper is very white, it means that the protective coating and heat-sensitive coating are unreasonable and excessive phosphor is added, the better paper should be slightly greenish; if the paper finish is not high or looks uneven, it means that the paper coating is not uniform; if the paper looks very reflective, it also adds too much. The quality of phosphor is not very good.
2. Fire-baking: If the color on the back of the paper is brown after heating with a lighter, the heat-sensitive formula is not reasonable, and the time of preservation of printed handwriting may be shorter; if the black part of the paper has fine stripes or uneven color blocks, the coating is uneven. The paper of better quality should be black-green (with a little green) after heating, and the color block is uniform, and the color gradually fades from the center to the surrounding.
3. Contrastive identification of sunshine exposure: The printed paper is smeared with a fluorescent pen and then sunned in the sun (which can accelerate the reaction of the thermal coating to light). Which kind of paper darkens the fastest, indicating the shorter the storage time.