How to distinguish the use of ink by ink viscosity

In the packaging and printing industry, various inks are often used, but different inks have different functions, and the use of different inks is distinguished from the viscosity

1.

Therefore, this ink is more suitable for the following situations:

(1) It is used for printing paper with good gloss and high surface strength, such as coated paper, glass cardboard, white cardboard and other papers, as well as gold and silver cardboard and other paper with good smoothness and non-absorbing properties.

(2) It is suitable for printing fine products with high screen lines, and it is easy to obtain strong, clear and full-color images;

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

(4) For the pearlescent ink in the form of phosphor flakes, it is also necessary to adjust the viscosity of the ink printing coating online coatingol.

Since 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 changes in different conditions, and appropriate adjustments should be made to increase or decrease the viscosity of the ink.

To adapt the ink viscosity to the requirements of actual printing conditions, the specific "viscosity" adjustment methods are as follows:

(1) Add an appropriate amount of tackifier to increase the viscosity,

(2) Add high viscosity resin oil to increase viscosity;

(3) Add an appropriate amount of high-viscosity ink to increase the viscosity

Due to the high cohesion and strong adhesion of the "viscous" ink with high viscosity, it is not suitable for use in some cases, such as: printing offset paper, whiteboard paper and other papers with low paper strength, the printing speed is fast, and the ambient temperature is high.

Common ways to reduce "stickiness" are as follows:

(1) Add a certain amount of silicone oil;

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

(3) Add high boiling point kerosene to reduce viscosity, and the dosage should be controlled within 10-20ml per kilogram;

(4) Add a certain amount of cornstarch, Vaseline and other viscosity reducing substances

2.

(1) It is suitable for printing large solid, hollow characters or products with small characters.

(2) It is suitable for printing products with large solid and shallow dots, which can obtain thick solid, and at the same time, the dots are relatively clear and not easy to expand:

a.
When the ambient temperature is high, the speed of the vehicle is slow, and the dots are mainly used for graphics and texts, it is generally appropriate to thicken the ink for printing;

b.
When the surface strength of the paper is high and the surface ink absorption is poor, the ink should be properly adjusted for printing
.

In actual production, if there is no ink of the corresponding consistency, or the consistency of the ink becomes smaller and cannot meet the requirements of use, then a "thickening" treatment should be carried out to reduce the fluidity of the ink
.

The specific methods of "thickening" treatment are mainly:

(1) Add NaOH, the amount of addition is about 1%-3%, this method works quickly, and it is a simple and effective way to thicken ink;

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

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

3.
The ink with small consistency and poor viscosity, due to its good flow, can be well extended under the mutual extrusion of the ink rollers, with good transfer performance, easy to ink, and the ink is in the ink layer between each printing transfer surface It can quickly level and spread, and the imprinted ink film is smooth and smooth.
Therefore, in some cases, it is necessary to reduce the consistency of the ink, such as:

(1) The paper is of poor quality, relatively rough, large amount of ink absorption, or low surface strength, easy to be brushed and powdered, such as the use of poorly printed offset paper, book paper, whiteboard paper, etc.
;

(2) When the layout is dominated by solid and large color blocks;

(3) When the workshop temperature is high and the printing speed is fast;

(4) The paper is damaged.
If the ink is too thick, the damage may be aggravated.
Therefore, ink with higher fluidity should be used for printing
.

The main ways to reduce ink consistency are:

(1) Add a certain amount of diluent

(2) Stir the ink fountain frequently, because the ink has thixotropy, and its flow characteristics will be improved with the increase of agitation, thereby reducing the viscosity of the ink;

(3) Add viscosity reducer below 2%
.