Sunkun Technology Service hotline
(+86)0755-28995058
(+86)0755-28995058
UV light oil when using the matters needing attention
1. The use of UV lamp
UV irradiation light source usually use high pressure mercury lamp or metal halide lamp, electrodeless lamp as well), the output power is commonly 80 ~ 120 w/cm, can ensure that UV light oil curing time is less than 0.5 seconds. , the service life of the UV lamp is replaced general work 1000 hours to check in time. UV light may cause harm to the skin and eyes, should be covered to prevent the illuminate of UV light on the human body; While eliminating air after UV light irradiation to produce ozone damage to human body, pay attention to strengthen ventilated smooth production environment; Under the pale yellow light working environment is suitable for production.
2. Not suitable for easy penetration of paper (such as rough surface offset paper) for processing
Because the UV light oil of low molecular material easy to infiltrate into paper, caused the paper to darken, soaked, even at the same time also can affect the UV light oil coating gloss. This kind of circumstance, should speed up the UV glazing, and increase the number of UV lamp irradiation. In order to prevent infiltration phenomenon, can be the first print coating a layer of thin bottom cheap oil, to avoid phenomenon of infiltration coating UV light oil.
3. The adhesion (or UV light oil coating not dry)
Main reasons:
(1) the coating is too thick, should reduce the coating thickness and viscosity, for some special artistic effects, such as wrinkles, crystal coating layer too thick, so under the same power source of irradiation time is relatively long, on the one hand, influence of UV light oil curing, reduce the moisture content of paper is relatively on the other hand, can make the paper brittle break easily, affect the wear resistance of UV light oil reservoir, more important is the illuminate of too long time can make the temperature rise, such as fire accident. At this point can use two quick UV light curing method, the traffic jam printing quality to be removed in a timely manner.
(2) the UV lamp power shortage or aging (UV lamp life generally about 1000 hours, more than curing efficiency will decrease the time), UV lamp should be changed to the rated power.
(3) oil polish expired, should stop to use.
(4) the coating weight reduction, reduction of single glossy film layer.
(5) improve glazing coating processing temperature, make the film completely cured.
4. Poor adhesion
Main reasons:
(1) the printed ink layer crystallization or improper use, such as ink additives and antiskid agent should improve the printing process, no or less ink additives;
(2) the UV light oil viscosity is too low, should be adjusted polishing machine and improve gloss oil viscosity;
(3) the improper use UV light oil type, make the scratch resistance of UV light oil coating is bad;
(4) high UV light radiation curing excessive;
(5) the printed ink layer to thoroughly dry glazing, is also the cause of glazing coating adhesion is poor;
(6) for the BOPP film print for UV glazing, because of the thin film surface not enough corona treatment, UV light oil reservoir caused by poor adhesion, easy to fall off.
5. UV light oil in black ink, white ink, shoot the light blue ink layer on curing
In black ink, white ink and light blue ink printed on the layer of light oil, often appear all sorts of unexpected problems when printing ink light initiator of pigment and light oil absorption of the same wavelengths of UV light, both the UV light energy limited competition, and UV light oil curing is the need of energy, so the influence of the curing light oil is bigger, may cause light oil curing not thorough. Solution: increase the UV lamp power, the right amount increase UV lamp headlamp unit, clean light reflector to increase the irradiation of UV light energy, UV improve the robustness of curing.
6. White UV glazing layer, low crosslinking density
Mainly is thinner, improper use, because alcohol solvent evaporation speed, when the environment temperature is higher, thinner, or should be changed to switch to ester diluent or dedicated thinner.
7. UV glazing layer of yellow
UV light oil yellow after curing have commonly:
(1) of the main causes of UV light oil storage time is too long, itself has become yellow, especially the inferior UV light oil yellowing phenomenon is more serious, must be replaced suitable UV light oil;
(2) excess UV light irradiation, UV light oil curing excessive, so to moderately reduce the UV light source power or less UV chy-tech, speed up the glazing.
8. UV polishing glossiness is poorer
Main reasons:
(1) the paper quality is poor or rough surface, oil absorption quantity is big, should switch to high smoothness of paper printing;
(2) uneven coating or glazing oil dilution is too thin, low viscosity, glazing machine can be adjusted accordingly, to improve gloss oil viscosity;
(3) print too much powder, affect the gloss of UV glazing.
9. UV glazing appear streaks, foaming, wrinkling at the membrane surface
Main reasons: (1) the high gloss oil viscosity values, thinner should be added, reduce gloss oil viscosity value;
(2) large amount of oil glazing coating, appropriate decrease coating:
(3) the glazing oil ink layer on the surface of a print wettability is poor, should be replaced or matching suitable UV light oil;
(4) in the polishing processing technology conditions don't match with oil polish eligibility, poor flowing property, adjust the process parameters, make its matching with glazing oil eligibility;
(5) when cutting, die-cutting, decrease as far as possible in the location of the UV glazing design.
10. Pay attention to the effective protection of operating personnel
(1) in the UV glazing, UV light can cause skin and eye damage, so want to cover, to prevent the illuminate of UV light on the human body;
(2) the UV light oil need special detergent or ethyl acetate cleaning, use gasoline, kerosene are hard to wash off. Should pay attention to the skin protection of operators, otherwise the skin will be affected by the stimulation of UV light oil, casual, redness, pimples, peeling, even splash on the skin immediately with soap and water is rinsed clean and in a timely manner to be removed;
(3) after air by UV light irradiation at the same time produce ozone has certain harm to human body, should pay attention to strengthen the production environment is ventilated smooth, conditional, operators each for 2 hours, UV glazing production operation to force arrangement to the well ventilated outdoor 10 ~ 15 minutes rest by turns.
11. Preservation and use of UV light oil
(1) UV light oil should be stored at low temperature or ventilation shade, shelf life usually are 1 year;
(2) if stored at high temperatures, it's easy to deterioration or hardening;
(3) the UV light oil won't mix with ordinary glazing oil use, adjuvants can also use special UV light oil adjuvant, brand different unfavorable also mix;
(4) adhesion fastness of UV light oil varies between species class printing, when change the new substrates, must test to confirm the adhesion performance, first batch glazing again;
(5) the UV light oil is suitable for the working environment in the yellow light production.