Technical parameters of printing machine fountain solution (1) pH value

Technical parameters of printing machine fountain solution (1) pH value

Both low and high pH values of the fountain solution can cause printing problems, causing deep sanding in the blank area of the printing plate and even causing the image and text parts to "drop out" due to the dissolution of the photosensitive adhesive. If the pH value is too low, the acidity of the fountain solution will be too strong, which will prolong the drying time of the ink and easily cause the back of the printed matter to be scratched and dirty, resulting in poor printing effect when printing. If the pH value is too high, it will exacerbate the emulsification of the ink.

Therefore, it is usually best to mix the pH value of the fountain solution between 5 and 6. Of course, in order to increase and weaken the viscosity of the ink, the pH control of the fountain solution should also be treated differently for different papers. For non coated paper (double adhesive paper, writing paper, lightweight paper, etc.), due to the heavy shedding of hair and powder on the paper, the ink viscosity needs to be reduced. Therefore, the pH value of the fountain solution can be appropriately reduced. On the contrary, the pH value of the fountain solution can be higher. For on-site printing, the pH value of the fountain solution can be lower, while for dot printing, the pH value can be higher.

Technical parameters of printing machine fountain solution (1) pH value