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The possible problems happened in the meiyu season(from May to June each year) for gravure or flexo |
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Solvent based Ink:
When we are print on the gravure or flexo printing
(
No matter how in the inside or surface printing) , the ink will absorb some dampness during the printing process and cause some problems in the meiyu season
as listed below
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Q1. The fluidness of printing ink is worse
In printing place, in order to avoid highly relative humidity, the temperature should be at
25°C and
the relative humidity should be between 45% and 55%.
Thus, the ink can avoid absorbing too much humidity from air and lost its fluidness.
Q2. The ink lost its adhesion
1.Carefully choose low water content of organic solvents and suppliers.
2.The container has to seal well after the solvent's dilution for preventing water's infiltration from sun and rain.
Q3.
The ink's adhesion is getting worse for printing material
For small size's printing, it should be add appropriate amount of slow-drying solvent for avoiding ink to absorb too many humidity from air and adding water's content of ink.
Q4. Viscosity rising of ink
1.
Control the temperature to
25°C and the relative humidity between 45% and 55%.
2.
Add the appropriate amount of slow -drying solvent.
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Gravure print's problems and solutions ==> Ink Thickening |
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A. Problems happen in printing process
While in the long time Printing, the printing ink's mobility will be decrease,
the viscosity rise adnormality
and the gloss decline
When print for a long time, the fluidness of ink will get worse, the viscosity of ink rises adnormally and the gloss of ink declines.
B.Reason
Off Central solvent in the ink tank or space volatile, because solvent absorption heat of vaporization, the temperature dropped to ink, so that the air and water vapor condensed to form dew. When mixed with dew off, especially the printing of small varicolored and high air humidity, the most vulnerable.
C.Solution
1. Use slightly slower dry solvent
2. Use Dehumidifiers to reduce the air's humidity
3. Add new ink or resupply the ink
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Gravure print's problems and Solutions ==>Ink albino or powdered |
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A.Problems happen in printing process
The printing surface has worse sheen, poor adhesion, and poor friction
B.Reason
1. When solvent loses its balance of solubility, the resin of ink can’t be dissolved and become cloudy,
gel, and precipitation.
2. The dilute solvent is overused.
3. When the printing ink dry on the surface of polymer with higher humidity, the vaporization will
reach fog condititon and then cause moisture. Then the surface of ink-film is getting tarbidty.
C.Solution
1. Replacement of dedicated solvent dilution
2. Use appropriate amount of dilution
3. Supply enough heat / dryer for vaporization, or switch to slow dry solvent.
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Gravure print's problems and Solutions ==>poor adhesion |
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A.Problems happen in printing process
Poor adhesion
B.Reason
1. Using the wrong ink or mixed with different types of ink
2. Worse plastic printing handling
3. Plastic's hygroscopicity, plastic own content surfactant or slip agent effects
4. Ink's albino or diluting
C.Solution
1. Carefully choose the correct ink. and tries to avoid the ink witch contains different types of ink
(the surplus ink should be marked with ink's name to prevent misuse)
2. The electronic discharge should handle appropriately, and do the examination of plastic’s adhesion
before plastic printing. The hygroscopicity plastic, PT, and the nylon membrane should do the
wet-proof management, and control the humidity in printing place.
3. The solvent should be selected and used carefully, and the humidity in printing place should
control appropriately.
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Gravure print's problems and Solutions ==>Blows the ink not good |
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A.Problem happens in printing process
The ink scraper can’t remove ink except marks, and then causes the dirty phenomenon.
B.Reason
1. Because the scraper’s abrasion or bad grinding, so the efficiency of ink scraping is lower.
2. The printing plate’s galvanization is not good or abrasion, which will damage its surface.
3. The printing ink contains coarse particles or impurities, which will damage its surface.
C.Solution
1. Carefully selects the scraper, replace, or grind it again.
2. Layout with light spinning paper mill, if out of center, should promptly adjust
3. The printing ink is filtered by sieve again or replaces the printing ink
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