The quality of the ink directly affects the quality of packaging printing
Published time:
2021-07-21
Ink is the main raw material for printing. Only by thoroughly understanding the structure and working principle of ink can high-quality prints be produced. In order to meet product quality requirements, printing plants must have a detailed understanding of ink properties when using ink to ensure that the printed products meet printing adaptability and various testing indicators. The main components of ink are colored pigments and binders. The colored pigments play a color-rendering role, forming a contrast with the color of the substrate to show the image on the substrate. Only by correctly understanding and recognizing the ink and adjusting the proportions of the various components of the ink can the ink achieve its required printability and usability.
Ink is the main raw material for printing. Only by thoroughly understanding the structure and working principle of ink can high-quality printed products be produced. In order to meet the requirements of product quality, printing plants must have a detailed understanding of ink properties when using ink to ensure that the printed products meet the printing adaptability and various test indicators.
The main components of ink are colored pigments and binders. The colored pigments play a coloring role, forming a contrast with the color of the substrate to show the image on the substrate. Only by correctly understanding and recognizing the ink and adjusting the proportions of the various components of the ink can the ink achieve its required printability and usability, and can the printing ink, printing plate, printing press, and substrate be coordinated to ensure the smooth progress of the printing process.
The following six items should be noted during the printing process:
1. Some inks, due to excessive thixotropy, have a high viscosity before the thixotropic phenomenon occurs, which easily causes ink clogging and plate smearing during printing. Therefore, a stirrer needs to be installed in the ink fountain to improve the ink flow and reduce the ink viscosity through stirring to prevent ink clogging and plate smearing. If the thixotropy of the ink is too high, the ink in the printing process will become thinner and thinner, and the ink color will become lighter and lighter, which is almost impossible to adjust. This kind of ink is not suitable for printing solid full-page prints, and this problem should be paid attention to during printing.
The inappropriate thixotropy of ink has a great impact on the printing quality. We found that in the printing process, when the temperature is low and the machine speed is slow, the ink in the ink fountain often shows poor transportation and abnormal ink supply, causing the ink color of the printed matter to become lighter and lighter, affecting the stability of the printing ink color. This is due to the poor thixotropy of the ink. Therefore, it is necessary to pay special attention to frequently stirring the ink in the ink fountain and maintaining continuous and uniform fluidity during the printing process to ensure the ink color quality of the product.
2. If the printing viscosity of the ink is too high, the viscosity will increase, and under the high-speed movement of the printing plate, the ink will generate a large impact force impacting the doctor blade. In this way, it is difficult for the doctor blade to smoothly scrape off the ink in the non-image area, which will cause plate fouling.
If the pigment distribution in the ink is uneven, or the resin in the ink does not wrap the pigment particles well, the pigment particles will reaggregate. These larger particles are very easy to form linear or stripe-shaped knife lines during printing.
Generally, the lower the printing viscosity of the ink, the less likely it is to cause plate fouling. Therefore, the printing viscosity should be adjusted in time during the actual printing process to improve the quality of the printed matter.
3. The fluidity of ink includes viscosity, adhesion, viscoelasticity, yield value, and thixotropy. It mainly depends on the properties of the pigment and binder, and its manufacturing process, among which the binder directly affects the fluidity of the ink. Three flow phenomena are mainly shown on the printing press:
1. When pouring from a container into an ink fountain, it is easy to ink, which is called good fluidity; otherwise, it is poor.
2. When outputting from the ink fountain, it is easy to ink, which is called good fluidity; otherwise, it is poor.
3. During inking, ink transfer, and inking, it is easy to spread, transfer, and transfer, which is called good fluidity; otherwise, it is poor.
4. The drying property of ink refers to the drying speed of the ink. It has two aspects: the slower the ink dries on the printing plate, the faster it dries on the substrate. Fast drying on the printing plate will affect the viscosity, rheology, and uniformity of the ink mark. Screen printing ink will cause clogging, also known as netting. Slow drying of the ink on the printed matter will affect the production speed. It can be said that ink that dries slowly on the printing plate and quickly on the substrate is a very good characteristic.
5. The fineness of ink refers to the degree of dispersion of pigments, fillers, and other solid powders in the binder. If the dispersion is not good, the ink will appear rough and not smooth, and the ink color density will not be enough. The fineness of the ink is different from the fineness of the solid powder. The latter refers to the basic particle size of the powder, which is very small. The basic particle size of the pigment is less than 1 μm. In fact, the pigment is in the form of aggregates of several basic particles adhering together. The better the dispersion in the binder of the ink, the smaller the particle size of the ink.
6. The coloring power of ink reflects the degree of dispersion of the ink and the amount of pigment in the ink. The higher the degree of dispersion of the pigment, the higher the concentration of the ink; the higher the pigment content in the ink, the greater its concentration. In addition to the pigment determining the concentration of the ink, the binder, filler, and auxiliary agents also affect the concentration of the ink to a certain extent. Ink concentration is one of the important indicators affecting printing quality. Ink is a hydrophobic colloid, which is a uniform mixture composed of pigments, binders, fillers, and auxiliaries. The binder is also the main component of the ink. It is the raw material that makes the ink fluid and has a certain viscosity. It plays a role in mixing the powdery pigments and other solid particles, and making the adhering pigments transfer and adhere to the printed matter, while also making the printed matter have a certain gloss.
Tag:
Previous page
Next page
Previous page:
Next page:
Share to
Main Products
Can't find the product you're looking for? Contact us!
If you need to consult our products, please leave your contact information to us, and we will contact you within 24 hours.
Business License