PET film is thin and easy to wrinkle PET film is prone […]
PET film is thin and easy to wrinkle
PET film is prone to generate large static electricity, which leads to quality problems such as blocking, ink dots, and knife lines during printing. In addition to the conventional method of removing static electricity, strengthening the temperature and humidity control of the workshop is an effective method.
When printing, a larger tension is required. The printing vacuum bag should use special inks that are resistant to high temperature cooking, and always pay attention to whether the film is static.
NY is easy to absorb moisture and deform, the tension is extremely unstable
The packaging film cannot be damaged when it is not printed; the environmental humidity should be tested before printing, and it is best to take dehumidification measures; the packaging film should be printed immediately after opening, and one process cannot be ignored at the same time-preheating, the preheating temperature is controlled at 50 ～80℃, printing equipment can be used flexibly without preheating equipment, and the first color group can be used as a preheating device; the tension should be properly reduced during printing; after printing, the packaging must be sealed and placed in the curing room for aging 2～ After 3 days, recombine as soon as possible.
The focus of control is ink
Whether printing PET or printing NY, the control focus is ink. It mainly includes the following two aspects.
1. Adjustment of ink printing suitability. Including adjustment of viscosity and color density. Can be adjusted with an automatic viscosity adjuster to improve work efficiency. The regulator can add solvent according to the preset value to keep the viscosity of the ink unchanged. However, the color density of the ink should never be diluted with a solvent, and it should be adjusted with a special diluent.
2. Strictly monitor the impact of active particles. After printing for a certain period of time, the ink will produce many active groups,these groups will combine with the chromium ions of the gravure cylinder, when these combinations appear in the shallow mesh part of the gradient version, their binding force will hinder the transfer of the ink, thus Cause blockages and flower spots. Vacuum bag manufacturers must not worry about the cost at this time, they can add an appropriate amount of activity retarder CHY-1 auxiliary agent.