The "rainbow protective film phenomenon" is due to the fact that the protective film substrate needs to undergo a high temperature during the hardening treatment, and in the high temperature treatment, the molecular structure of the protective film substrate surface is unevenly distributed to cause scattering, resulting in the generation of rainbow stripes. The higher the strength of the hardening treatment, the more difficult it is to control the rainbow.
The presence of rainbow lines can affect the transparency and visual effects, while the high-quality mobile phone protective film is difficult to see the rainbow pattern with the naked eye. Rainbow pattern is actually the product of hardening treatment. The higher the strength of hardening treatment, the more rainbow pattern of mobile phone protective film, the best hardening effect is 3.5H to 3.8 without affecting the visual effect. Between H. Exceeding this hardness range is either falsely reported or the rainbow pattern is obvious.
The production of rainbow pattern has a great relationship with the PET substrate itself. At present, domestic filmmakers are basically produced by multi-layer coextrusion method. There are at least three layers and uneven thickness, which is easy to cause light refraction. , forming a strip of "grain" like a rainbow.
In addition, when the PET substrate is subjected to surface hardening treatment, it is also susceptible to coating equipment and curing materials. If the equipment and materials are improperly selected, it is easy to cause uneven surface coating and thereby generate rainbow stripes.https://www.snpefilm.com/