How to distinguish the use of ink by ink viscosity

1) The “sticky” ink with high viscosity and poor fluidity has good adhesion, large intramolecular friction or cohesion, strong adhesion and rapid fixation. How to distinguish the use of ink by ink viscosity

      Clear and round dots can be obtained by printing with “sticky” ink. Moreover, the “sticky” ink has good water resistance, is not easy to emulsify, has good “ink receiving”, is easy to dry, has smooth dots and bright ink color Saturated color and thick ink layer. Therefore, this ink is more suitable for the following situations:How to distinguish the use of ink by ink viscosity

(1) It is used for printing paper with good gloss and high surface strength, such as coated paper, glass paperboard, white paperboard, gold and silver paperboard and other paper with good smoothness and non absorbability. It is also suitable for “sticky” ink;How to distinguish the use of ink by ink viscosity

(2) Suitable for fine products with high screen cable, it is easy to obtain strong, clear and full color images;How to distinguish the use of ink by ink viscosity

(3) When printing gold, silver ink and fluorescent ink, it is also necessary to adjust the viscosity of the ink to make it strong adhesion and not dirty;How to distinguish the use of ink by ink viscosity

(4) For phosphorous flake pearlescent ink, it also needs to be printed with adjustable viscosity ink.How to distinguish the use of ink by ink viscosity

As the viscosity of the ink is an important factor affecting the dot transfer, in practice, the viscosity of the ink should be coordinated with the printing process according to the changes of different conditions, and appropriate adjustments should be made to increase or decrease the viscosity of the ink. In fact, the cohesion of the ink should be adjusted to meet the requirements of the actual printing conditions, The specific adjustment methods for increasing “viscosity” mainly include:

(1) Add an appropriate amount of tackifier, such as No. 0 inking oil;

(2) Add high viscosity resin oil to increase viscosity;How to distinguish the use of ink by ink viscosity

(3) Add an appropriate amount of high viscosity ink to increase viscosity.How to distinguish the use of ink by ink viscosity

Because the “sticky” ink with high viscosity has high cohesion and strong adhesion, it is not suitable to use in some cases. For example, when printing offset paper, whiteboard and other paper with low paper strength, printing speed is fast, ambient temperature is high, and the layout is mainly large and on the spot, it is necessary to use the ink with low viscosity. If the viscosity of the ink is too high, it is necessary to reduce the viscosity. The common methods of reducing “viscosity” are as follows:How to distinguish the use of ink by ink viscosity

(1) Add a certain amount of silicone oil;

(2) Add less than 2% and no more than 5% of viscosity reducer to reduce viscosity;

(3) Add high boiling point kerosene to reduce viscosity, and the dosage shall not exceed 10-20ml per kilogram;

(4) Add a certain amount of viscosity reducing substances such as corn starch and vaseline.

2) For the “thick” ink with high consistency but certain viscosity and adhesion, due to poor fluidity and poor ductility, the ink is paste like and not easy to level, the imprinted ink film is not easy to spread during printing, the graphic transfer is more accurate, not easy to deform, and the ink color is relatively bright and full. Therefore, the “thick” ink is more suitable for the following situations:How to distinguish the use of ink by ink viscosity

(1) It is suitable for printing products with large field, hollow words or small words. Because it is not easy to level and spread, hollow words or small words are not easy to paste;

(2) Suitable for printing products with large solid area and shallow dot, thick field can be obtained, and the dot is relatively clear and not easy to expand:How to distinguish the use of ink by ink viscosity

a. When the ambient temperature is high, the vehicle speed is slow, and the pictures and texts of the dot are mainly used, the ink is generally thickened appropriately for printing;How to distinguish the use of ink by ink viscosity

b. When the surface strength of the paper is high and the surface ink absorption is poor, the ink should also be thickened appropriately for printing.How to distinguish the use of ink by ink viscosity

In actual production, if there is no ink with corresponding consistency, or the consistency of the ink becomes smaller and can not meet the use requirements, then the “thickening” treatment should be carried out to reduce the fluidity of the ink. The specific “thickening” treatment methods are mainly as follows:How to distinguish the use of ink by ink viscosity

(1) Add NaOH and the amount is about 1% – 3%. This method takes effect quickly. It is a simple and effective method for ink thickening;How to distinguish the use of ink by ink viscosity

(2) Add tackifier, such as No. 0 inking oil, but pay attention to the appropriate amount, not too much;

(3) If the ink is not thick enough due to the influence of temperature, the original ink with the same hue can also be added to the ink.

3) The ink with low consistency and poor viscosity can be well extended under the mutual extrusion of ink rollers due to good flow, good transfer performance and easy to drop ink. How to distinguish the use of ink by ink viscosity

      In addition, the ink layer between each printing transfer surface can be quickly leveled and spread, and the imprinted ink film is flat and smooth. Therefore, in some cases, the ink consistency also needs to be reduced, such as:How to distinguish the use of ink by ink viscosity

(1) Poor paper quality, rough, large ink absorption, or low surface strength, easy to roughen and drop powder, such as the use of offset paper, book paper and whiteboard with poor printing;How to distinguish the use of ink by ink viscosity

(2) When the layout is mainly field and large color blocks;How to distinguish the use of ink by ink viscosity(3) When the workshop temperature is high and the printing speed is fast;How to distinguish the use of ink by ink viscosity

(4) The paper is damaged. If the ink is too thick, it may aggravate the damage. Therefore, the ink with greater fluidity should be used for printing.How to distinguish the use of ink by ink viscosity

The main methods to reduce ink consistency are:How to distinguish the use of ink by ink viscosity

(1) Add a certain amount of diluent, such as No. 6 ink blending oil with low viscosity and high fluidity. This method has a good effect, but the amount should be controlled, which generally does not exceed 10% of the amount of ink;How to distinguish the use of ink by ink viscosity

(2) Frequently stir the ink bucket, because the ink has thixotropy, its flow characteristics will be improved with the increase of stirring degree, so as to reduce the viscosity of the ink;How to distinguish the use of ink by ink viscosity

(3) Add less than 2% viscosity reducer.How to distinguish the use of ink by ink viscosity