9 can not be partially polished, because the uv oil on the ps version of the ink separation characteristics.
10 It is easy to apply light locally by cutting the blanket.
11 When the coating is thin, the ink tank can be used for polishing.
If the shop temperature is below 20°C, the coating thickness can be adjusted by adding thinner.
Sixth, the correct use of uv coating oil
The uv oil is not conjunctiva, just like cooking oil does not form a dry film on the air surface. Uv oil sees UV light, such as sunlight, arc welding, and curing light immediately. General fluorescent lamps, incandescent lamps, sodium lamps and other lighting sources do not cause curing. Uv oil contains photoinitiators and thinners, which have a certain stimulating effect on human skin.
In view of the uv oil has the above characteristics, should pay attention to the following points when using:
1 uv oil normal use temperature is 50 °C ~ 55 °C, use a constant temperature water bath to heat the oil cycle, so that the viscosity to meet the design requirements, is conducive to leveling and rapid curing.
2 uv oil passes through the uv lamp irradiation area. When the temperature is 50°C~60°C, it cures quickly and has strong adhesion. But not the lower the temperature under the uv light the better.
3 The glazing machine is placed in a position where the sun cannot reach directly. Otherwise, the uv light oil is solidified on the coating roller. If it cannot avoid direct sunlight, the red and black curtains are used to block the light.
4 When glazing, uv oil will disperse the ink on the glazing material into the uv oil, so that the varnishes can be colored, and they can be used after being filtered and precipitated, and they need not be discarded.
5 When glazing, uv oil should be washed off immediately with soapy water, otherwise skin redness and blistering will occur.
6 uv oil viscosity varies with the type of polishing machine, should be based on models selected special coating oil. If you do not reach the required viscosity of the glazing machine, you can reduce the viscosity of the thinner or stick it with a tackifier. This method will lose uv light oil curing speed, brightness, adhesion and so on.
7 uv oil flows to the rotating part of the drive shaft, and it will stick to the shaft at high temperature, affecting the transmission, so pay attention to cleaning the shaft head.
According to the nature of the surface of the substrate, choose a special light oil, such as gold cardboard oil, pet oil.
Seven, uv curing time
Theoretically, it can be rigorously calculated how many photons of the uv-cured material can be cured per unit volume, and the photochemical reaction rate does not take much time. However, the addition of a polymerization inhibitor to the uv oil or ink delays the polymerization time (ie, the curing time) after the photochemical reaction has a direct relationship with the photoinitiator and the polymerization inhibitor.
General uv light oil or ink formulations will be selected within the curing time 0.1 ~ 0.2s. However, the specific time after the formula is determined depends on the following factors:
1 coating thickness
The surface of the coating cures quickly, but the surface layer cures and absorbs ultraviolet light strongly. The intensity of the ultraviolet radiation decays exponentially, lowering the curing speed. Therefore, the coating is cured quickly and slowly.
2 UV intensity
When the intensity is high, the curing time is short, and vice versa.
3 Add solvent
Adding thinners to uv light oils, such as ethanol, slows the curing process.
4 Ambient temperature
Coating temperature of 50 °C ~ 70 °C is the ideal ambient temperature. The uv mercury lamp contains a large amount of visible and infrared components, providing the coating surface with ambient temperature. Therefore, designing the curing machine is not as good as the surface temperature of the material. (To be continued)