The quality of thermal label paper can be judged by the following methods:
Observe the appearance:
Color: Good quality thermal paper should be slightly green, not too white. If the paper is very white, it may be that too much phosphor has been added, which may affect the quality and storage time of the paper.
Finish and uniformity: Observe whether the surface of the thermal paper is smooth and uniform. If the surface is not uniform, it may indicate that the thermal sensitive layer and protective layer are not good enough during production, and the paper quality may be poor.
Fire test:
Heat the back of the paper with fire and observe the color change after heating. If the paper appears brown after heating, it may indicate that the heat-sensitive formula is not reasonable and the storage time may be short.
Good quality thermal paper should appear black and green after heating, and the color block is uniform, and the color gradually fades from the center to the four sides. If the black part of the paper has pinstripes or uneven color spots, it may indicate an uneven coating.
Comparison and identification of sunlight exposure:
Apply the printed thermal paper with a highlighter and place it in the sun. The faster the paper turns black, the shorter its shelf life is likely to be.
Professional tests (if conditions permit) :
Sensitivity test: Use a professional sensitivity tester to test the sensitivity of thermal paper to ensure that it meets the requirements.
Brightness test: Use white balance light source to test the brightness of thermal paper to ensure clear printing effect.
Heat resistance test: Simulate the actual printing situation to test the resistance of thermal paper at high temperatures.
Storage stability test: Test the storage stability of thermal paper under certain environmental conditions.
Through the above method, the quality of thermal label paper can be comprehensively evaluated, so as to choose high-quality thermal paper suitable for their own needs.