Printing ink wet and solution
Printing ink wet and solution
Printing ink wet Reasons and Solutions:
Reason one: the ink layer is too thick, the paper speed is too fast or the UV light irradiation time is insufficient
Method: When matching ink, the color of spot color UV ink is darker, so that the bottom layer of printing ink is thoroughly dried by deep ink thin printing. At the same time, also must ensure the appropriate paper speed and adequate UV light exposure time to ensure the drying effect of ink.
Reason two: UV lamp power shortage UV lamp power shortage, the main performance:
All UV lamps are beyond their useful life, and while they can continue to work, their power has been greatly reduced. (Replace the UV lamp with a reasonable power configuration. After replacing the UV lamp, you need to return the timer to zero and maintain the cleanliness of the UV lamp.)
Methods: First of all, the enterprise must have a complete and effective UV lamp use management system, to ensure the UV lamp effective work, timely replacement has exceeded the service life of the UV lamp.
Reason three: ink over the shelf life or excessive ink additives
If the ink is past its shelf life, poor drying of the ink may occur after printing due to the failure of the photoinitiator in the ink. It is often necessary to add additives such as adjusting ink oil and removing adhesive in ink. If the proportion of additives is too high, it may lead to UV ink too thin and cause poor drying.
Methods: In the shelf life of the ink recommended UV ink additive ratio in the summer is not more than 3%, in the winter is not more than 8%.
Four reasons: different colors of UV ink drying degree
Methods: According to the drying characteristics of different colors of UV ink, reasonable arrangement of printing color sequence, printing ink is difficult to dry, then printing ink is easy to dry, which can solve the problem of poor ink drying to a certain extent.
Reason five: cots density is too low
New equipment is more prone to ink drying failure. Because the density of the roller is too low to absorb UV ink in the photoinitiator, resulting in ink drying phenomenon.
Method: The simplest way is to replace the cots; The cots can also be removed, in UV ink oil soaking 12 to 24 hours, when the saturation state is difficult to absorb UV ink in the photoinitiator.
