If the ink can be fixed well, it is dried from the inside to the outside. In this case, although the ink surface can resist static pressure after solidification, the ink layer cannot withstand friction. Solve The Slow Drying Of Ink
The common ink for offset printing mainly depends on chemical reaction for drying. The oxidation and high polymerization of ink rosin is the role of desiccant and an important component of ink. Solve The Slow Drying Of Ink
If the ink is not dry enough to resist the pressure of the next color, the paper cannot print the second color. Solve The Slow Drying Of Ink
Worst of all, if the ink needs to be dried for a long time, the medium containing rosin will excessively penetrate into the paper, and the ink film lacks the ability to bind pigment, which may lead to white deterioration. The operator should know that this trouble is very complex. It is based on unbalanced factors such as ink, paper and printing conditions. Solve The Slow Drying Of Ink
Remedies
1. Temperature
As drying is one of the chemical reactions, the temperature can affect its drying speed. Control the temperature of paper or printing room if it is under abnormal conditions. From 60 ° F V less than 0 ° f is ideal. Solve The Slow Drying Of Ink
2. Desiccant
If the amount of desiccant in the ink is not enough, pay attention to its characteristics and amount, and add some desiccant to the ink. But adding too much desiccant is not recommended. (refer to note) Solve The Slow Drying Of Ink
3. Control wetting moisture
Too much wetting water will cause this trouble.
4. Moisture of paper
Too much moisture in the paper slows down the drying rate. In this case, it is best to add strong desiccant. Solve The Slow Drying Of Ink
5. PH value of water tank
Too much acidity of wetting water (low pH) will reduce the activity of desiccant. The suitable range of pH is from 5.0 to 6.0. At a minimum, the pH value should be maintained above 4.5. Solve The Slow Drying Of Ink
6. PH value of paper
For the same reasons above, it is very dangerous for the pH value of paper to be too low. When the pH of paper is too low, such as in non coated paper is lower than 4.5 and in coated paper is lower than 6.0, it is necessary to use strong desiccant or more ordinary desiccant than usual. Solve The Slow Drying Of Ink
7. Composition of sink fluid
It is known that some synthetic chemicals in water tank liquid can have adverse effects on drying speed. Solve The Slow Drying Of Ink If you find trouble after completing all the printing colors, you have to use up the oil to print again. Solve The Slow Drying Of Ink