On the composition and material of ink and the cho

·Talking about: ink composition, material and ink selection

printing is defined as the industrial reproduction process of transferring ink to the surface of the substrate through various pressures to form graphics and text. Traditional printing takes the printing plate as the intermediate carrier of graphics and text, so that the graphics and text area and blank area are separated by various means, and then the ink is transferred to the product surface, and digital printing leaves the printing plate aside, Directly transfer the pictures and texts in the computer to the product surface, and the evolution of technology is moving in the fastest direction, but it seems that printing has no sign of abandoning ink

composition of ink

content is the most fundamental purpose of printing, but to transmit content, color plays a very important role. There are many things that can express color in nature. Ink experts first think of pigments and dyes with long storage life and bright colors

neither pigments nor dyes can be directly printed on the product surface. The reason why pigments and dyes can firmly adhere to the product surface should be attributed to resin. Most of the resins are solid. Most of the resins in the ink are not pure resins, but mixtures formed by dissolving into solvents

inks are composed of pigments, resins and solvents. All printing inks cannot lack the above three components

pad printing ink and screen printing ink

different printing processes have different requirements for ink, and appropriate supplementary components must be added to the ink to make it easier to use in specific occasions, such as offset printing ink has large viscosity, good water resistance, gravure printing ink is relatively thin, and good liquidity; Silk printing ink must have good permeability

in general, the main difference between the inks used in different printing processes lies in the different additives contained in the inks. This paper will mainly talk about silk printing inks and pad printing inks

in terms of the suitability of the substrate, silk printing has great advantages, especially in the non stereotyped plastic, hardware, electronics and direct consumer goods industries, silk printing has been widely praised. However, there is no universal printing method in the world, and silk printing is no exception. In the field of industrial printing with small area and irregular substrate surface, silk printing encountered real trouble, which led to the birth of pad printing technology. It can be said that although pad printing technology and silk printing are very different, their industrial fields are very similar

the earliest pad printing ink was replaced by silk screen printing ink, and practice has proved that there is nothing absolutely unsuitable. However, when the ink is used in different printing environments, there must be different adaptability. For example, for pad printing ink, users do not require it to have the permeability of silk screen printing ink at all, but they will require it to have better thixotropy and surface dryness, so as to ensure that the transmission process from steel plate to rubber head and substrate is more accurate. Using special pad printing ink will undoubtedly make it easier to improve the printing quality

marabu took the lead in developing special pad printing ink. The surface tension of the ink is kept in a constant range through the action of additives, so that the ink transfer in the printing process is absolutely consistent

the process of ink transfer is also closely related to the properties of the pad printing head. Controlling the surface tension of the pad printing head within a range similar to that of the pad printing ink seems to be a systematic project, and the essential purpose is to improve the ink transfer efficiency. The Japanese solve this problem from another perspective. They install a glue head cleaning device on the pad printing machine. However, the installation of a glue head cleaning device is mainly to control the transfer amount of ink, and the transfer efficiency has not been improved

marabu has 6 kinds (actually 8 kinds) of pad printing inks to choose from: GL, which is mainly used on the surface of metal, ceramics and glass. It is basically a two-component ink, which needs to add GLH hardener and TPR. It is a pad printing ink improved on the basis of SR series silk printing inks. All materials that SR can make can make TPR in the pad printing process; Similarly, TPY is a pad printing ink improved on the basis of Py series silk printing ink. TPU ink can be selected for the surface of materials that are very difficult to print; TPT is a pad printing ink mainly used on the oil cup pad printing machine: TPL has better stability and can maintain good uniformity under long-term friction. The other two are TPP and TPS

it is worth noting that silk screen printing ink and pad printing ink are completely universal, but additives need to be added to change the printability. Therefore, when there is no special pad printing ink, silk screen printing ink can be used instead

color of ink: primary color, spot color, standard color

the color of nature is rich and colorful, and it is impossible to show it all with ink. There are two methods to copy color in printing: one is to directly mix spot color for printing, and the other is to print through four-color superposition

four colors are copied according to the superposition principle of four pigments in CMYK color model. Generally speaking, four color reproduction technology can basically reproduce the colors we require. Four color reproduction technology is usually used for layered originals

the replication advantage of four-color ink lies in the hierarchical manuscript. For most advertising design and creativity, as well as industrial printing, the use of spot color is a very common phenomenon. Spot color can better reflect the designer's ideas, and it is easier to prevent infringement. Theoretically, spot colors can also be matched with primary tones, but that will not only make it difficult to match the hues completely, but also increase the possibility of wasting ink. Therefore, the color reproduction of printing technology includes two reproduction technologies. One is that it tends to replicate color with four-color ink, which is mainly used when the original is hierarchical, and there is superposition between colors. Primary color printing is the most difficult technology in printing technology because it involves complex chromatics and the principle of dot synthesis. 600kN horizontal tensile testing machine 1000KN horizontal tensile testing equipment is for the test piece length of 500~3100mm. How to control the point change from the original to film, printing plate and substrate is the core link of primary color printing technology

spot colors are used in situations where colors do not overlap with each other. Due to the extremely rich pigments in nature, there are many kinds of spot color inks- Spot color in the general sense refers to all colors except the primary color, and there are infinite spot colors by implication. Pantone company of the United States formulates the standard color of ink spot color, and prints the color card commonly used today according to the produced spot color ink

no one can tell what red is, but if you tell you Pantone color card number, you will easily find this kind of ink. Whether the ink manufacturer can produce ink according to the standard color card is related to the vital interests of users. Choosing the ink color is an important content. Although the four-color printing technology is difficult to master, it seems very simple to choose the primary color ink, because the ink manufacturer produces only one set of four-color ink. In contrast, the choice of spot color ink is much more troublesome. If the designer happens to use a certain standard color to express his design idea, and you also happen to purchase this kind of ink, then you can only choose this kind of ink, but fewer and fewer designers will do so, and the boss may not allow him to do so, because it is easier to get, and it is also simple to counterfeit. Mixing ink is also based on the subtraction method in chromatics, but to quickly mix accurate colors, theory and experience are equally important

material and ink selection

offset printing and other printing methods may not be so troublesome, because the printing adaptability of paper is very good, and there is basically no need to consider the problem of adhesion, but silk printing and pad printing are not so simple. There are many printing materials for silk printing and pad printing, and it is impossible to replace them with one kind of ink. If ink manufacturers want to fully adapt to the market, they must produce a variety of inks

we can simply divide the printing materials into the following types:

1. PP and PE are two kinds of materials in a very large amount in the plastic family. First of all, they have good physical properties and good chemical corrosion resistance. Most solvents can't do anything about them, so they are widely used in coatings, cosmetics, plastic films and electrical products. Now law enforcement departments have blind spots, but this is also the reason why they are difficult to print, because their constituent molecules are nonpolar molecules. At present, prepress processing is widely used in printing these two materials, and the more common methods are flame processing and high-frequency processing. The PL treated water produced by Marabu company is actually a strong oxidant, which forms a rough surface on the surface of oxidized materials to achieve good adhesion of inks. The development of treatment FREE PP ink is also the goal of many manufacturers, and the technology is basically mature, but the treatment free ink can not adhere well on the PE surface. Marbu's PP series inks are free of treatment

combined with prepress treatment, there are many kinds of inks that can be used on PP and PE surfaces. What we are discussing here is that it dissolves and destroys fixtures: agent based inks. For UV inks, prepress treatment is also necessary. At present, there is no UV ink free of treatment. It should be said that in the current printing technology field, it is difficult to achieve stable quality control when printing on PP and PE materials

2. ABS, PC, PVC, PS, as and other polar materials are easy to print. Most of these materials can be printed without prepress treatment. This part of ink is the strength of all manufacturers

3. Glass, metal, ceramics and other substrates do not have any absorption properties on the surface, so the ink made by conventional methods is difficult to work. In most cases, two-component ink is used

now more and more enterprises are engaged in moving and printing silk screen printing. Whether they can find ink suitable for customers' products means the ability to obtain orders. However, the supplier's information shows that it can be suitable for this material. To determine whether it can really meet the requirements, the key is to test according to the requirements. If the test effect is poor, you may wish to replace the ink. Sometimes you may get wrong information and technology, so you must understand the test method. Many inks cannot achieve the printing method of products, and the wrong test method is an important reason for this result. If some problems cannot be solved, contact the ink manufacturer in time

the important information provided in the previous description is that we should first understand the material of the customer's product, then be familiar with the selection information of the ink, and then conduct careful tests until the customer is satisfied. Theoretically, there is no product that cannot be printed. In fact, many product printing annoys you. The key is whether there are enough experimental means to solve it