The nine properties that ink has

Thixotropic

The thixotropy of ink means that the ink becomes thin as soon as it is stirred and rubbed, and its fluidity increases. After standing for a while, the ink will return to its original thicker state. In the process of printing and transferring ink, after the friction between the ink fountain and the rubber roller, the temperature rises, and the fluidity and ductility also increase, until after the ink is transferred to the printed sheet, the external force disappears, and the fluidity thereof Reduced ductility, followed by thinning and thickening, to ensure the clarity of the printed ink. If the thixotropy of the ink is too large, it can easily cause problems such as blocking of ink and stencil printing. As the printing process progresses, the ink becomes more and more dilute, and the printing ink is printed more and more frequently, resulting in unclear images and printing. problem. If the thixotropy of the ink is too large or too small, it will have a bad influence on the printing. The printing requires the ink to have an appropriate thixotropy.

2. Viscosity

Viscosity refers to a property that prevents the flow of a fluid substance and is a measure of the ability of fluid molecules to interact to produce a relative movement between molecules, that is, the resistance to fluid flow. If the viscosity of the ink is too high, the transfer of the ink during the printing process is not easy to be uniform, and the printed sheets are likely to be sticky, and the ink and the ink are unevenly distributed. The paper paper powder is pulled off to make the printing surface paste or bloom; if the ink viscosity is too small, It is prone to slip, resulting in print marks, as well as blotting, ink emulsification, dirtiness and other undesirable phenomena.

3. Liquidity

Fluidity means that the ink will flow like a liquid under its own gravity. It is determined by the viscosity, yield value, and thixotropy of the ink. It is also closely related to temperature. The fluidity of the ink affects the ink transfer between the ink tank, the ink fountain, the ink roller and the substrate, thereby affecting the printing effect. The ink with high viscosity has poor fluidity; the ink with low viscosity has good fluidity.

4. Dryness

The ink should have good drying performance. Drying the ink too quickly or too slowly will affect the printing process control and print quality. If the ink dryness is too slow, the printed matter is likely to cause the back surface to be dirty during the process of deposition, and the adhesion phenomenon will occur in severe cases; the print will be dull and even powdered. If the ink is dried too fast, the fluidity of the ink is difficult to control during the printing process, which causes the ink roller to pile up and transmit ink. The ink is inconsistent, the paper is peeled off, and the ink film is crystallized. It also destroys the ink. Roll surface performance.

5. Fineness

The fineness of the ink refers to the size of the pigment (including the filler) particles in the ink and the uniformity of the distribution of the pigment particles in the binder. The ink with poor fineness is liable to produce quality problems such as ink transfer and ink unevenness, ink buildup, wear plates, and poor color rendering during the printing process. The fineness of the ink is relatively good and its concentration is relatively large, and printing is also relatively clear. If the fineness of the ink is poor, the dots of the printed dots are likely to become hairy and battered, and the printability of the printing plate is also low.

6. Coloring power

The color strength of the ink determines the depth of the hue of the ink. When the coloring power of the ink is large, the printing hue is darker; on the contrary, the printing hue is shallow. The ink with high coloring power consumes a relatively small amount of ink in printing, and the ink quality is also relatively good. On the contrary, the ink with a small coloring force uses a relatively large amount of ink and the ink is relatively light.

7. Yield value

The yield value is the minimum shear stress required to start the flow of liquid. An ink with a large yield value has poor flowability; an ink with a low yield value is liable to cause haziness and unclear printing dots.

8. Lightfastness

In the role of light under the influence of light, the relative change of color light is called lightfastness of the ink. In fact, inks that do not change color are not. Under the effect of light, the color of any ink will change more or less. Good light fastness ink, bright color of the printed product, the dot on the layout is full and solid, full of three-dimensional, and long-term preservation. The poor lightfastness of the ink, the printed ink is prone to fading and discoloration.

9. Acid and alkali resistance and alcohol resistance

Acid-resistant, alkali-resistant, and alcohol-resistant inks, with brightly printed inks, clear layout, and clear dots. Printing inks with acid, alkali, and alcohol resistance are basic requirements for packaging products, such as printed soaps, sodas, or food products. The ink used must have good acid and alkali resistance. In addition, the varnish contains alcohol solvents, so products that need to be coated must be considered to use alcohol-resistant inks in order to avoid adverse effects.

Understanding and understanding the performance of the ink helps to improve the printing quality.