Analysis: The difference between printing ink and screen printing ink

Different printing processes do not have the same requirements for inks, and they must also add appropriate supplementary components to the inks to make them easier to use in specific applications. For example, offset inks have higher viscosity, good water resistance, and gravure printing inks are relatively thin. , good fluidity; screen printing inks must have good permeability.

The main difference between inks used in different printing processes is that the additives contained in the inks are different. This article will mainly focus on screen printing inks and pad printing inks.

In terms of substrate suitability, screen printing has great advantages, especially in the amorphous plastic hardware and direct consumer goods industries. Screen printing has been widely praised. However, there is no universal printing method in the world, and screen printing is no exception. In the area of ​​industrial printing on the surface of small areas and irregular substrates, silk screen printing encountered real troubles, and this trouble caused the birth of pad printing technology. It can be said that although there are great differences between pad printing technology and screen printing, the industries involved are very similar.

The earliest printing inks were replaced by screen printing inks. Practice has proved that there is absolutely no accommodation. However, inks used in different printing environments must have different applicability. For example, pad printing inks do not require users to have the permeability of screen printing inks, but they are required to have better thixotropy and surface dryness. To ensure that the transfer process from the steel plate to the plastic head and substrate is more accurate. The use of special pad printing inks will undoubtedly make it easier to improve the print quality.

MARABU pioneered the development of special pad printing inks. The effect of the additive keeps the surface tension of the ink within a constant range so that the ink transfer during the printing process remains absolutely consistent. The ink transfer process is closely linked with the nature of the print head. The surface tension of the print head is controlled within a similar range to that of the print ink. This appears to be a systematic project. The essential purpose is to improve the ink transfer efficiency. The Japanese have solved this problem from another angle. They installed a plastic head cleaning device on the pad printer. However, the installed plastic head cleaning device mainly controls the amount of ink transferred, and the transfer efficiency has not improved.

MARABU has 6 (actually 8) pad printing inks to choose from: GL, mainly used on metal, ceramic, glass surface, basically a two-component ink, need to add GLH hardener, TPR, is in SR The improved printing inks based on the series of screen printing inks, the materials that can be used by SR can make TPR in the printing process; the same reason, TPY is an improved printing ink based on PY series screen printing inks. TPU inks can be used on surfaces that are very difficult to print; TPT is a pad printing ink that is primarily used on pad printers: TPL is more stable and maintains good uniformity over long rubbing conditions. There are two kinds of TPP and TPS.

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

Material and ink selection Offset printing methods may not be so much trouble, because the printability of paper is very good, basically do not consider the adhesion problem, but the screen printing and pad printing is not so simple, silk screen printing and printing of a lot of printing materials It is not possible to use an ink instead. In order to be fully adapted to the market, ink manufacturers must produce a wide variety of inks. We can simply divide the printing materials into the following categories:

1. PP and PE, in the plastics family, PP, PE are two kinds of materials with very large amounts. The first is that they have very good physical properties, chemical resistance is very good, most of the solvents can not do them, so in the coating , cosmetics, plastic films and electrical products have a wide range of uses. But this is also the reason why they are difficult to print, because their constituent molecules are non-polar molecules. At present, prepress printing methods are commonly used for printing these two kinds of materials. The more common methods are flame treatment and high frequency processing. The Pl treated water produced by MARABU is actually a strong oxidizer, and the good adhesion of the ink is achieved by forming a rough surface on the surface of the oxidized material. The development of PP-free inks is also a goal of many manufacturers, and the technology is basically mature, but the non-handling inks are not well attached to PE surfaces. MARBU's PP series inks are free-handling inks.

In combination with prepress processing, the types of inks that can be used on the surface of PP and PE are many. We are talking about solvent inks here. For UV inks, prepress processing is also a must. At present, there are no UV inks that are free from treatment. It should be said that in the current printing technology field, it is difficult to achieve stable quality control by printing on PP and PE materials.

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

3. The substrates such as glass, metal and ceramics do not have any absorption properties on the surface, and the inks manufactured according to the conventional methods are difficult to work. In most cases, two-component inks are used.

Nowadays, more and more companies are engaged in printing screen printing. The ability to find inks suitable for customers' products means the ability to obtain orders. However, suppliers' information shows that they can fit this material. To determine whether they can really meet the requirements, the key is to perform tests as required. If the test results are not good, you may want to replace the ink. Sometimes you may get the wrong information and technology, so we must understand the test method, many inks can not achieve the printing method of the product, the wrong test method is an important reason for this result. If some problems cannot be solved, please contact the ink manufacturers in time. The important information provided in the previous description is to first understand what the customer's product is, and secondly to be familiar with the ink selection information, and then meticulously experiment until the customer is satisfied. In theory, there are no products that cannot be printed. In fact, many product printings are annoying to you. The key is whether there are enough test methods to solve them.

Dongguan Henghui Color Printing Machinery Factory Co., Ltd. is a large-scale integrated enterprise integrating R&D, production and sales. It is the largest manufacturer of special color printing machinery industry in China and a subsidiary company of Hong Kong Henghui (Holdings) Co., Ltd. The company's business scope includes: special printing equipment (printing machines, screen printing machines, hot stamping machines, thermal transfer machines, heat transfer machines, and drawing machines, printing machines, flame processing machines, UV furnaces and other peripheral equipment), vortexing Low-noise air compressors, agents of the world famous brand printing materials (Marabu Marabu ink, Apollo Apollo ink, Coates Gao Ink, Watts Wisdom squeegee) and international trade. The company is well-known in the special printing industry for its reliable quality, stable performance, various types and complete specifications. It is one of the world's largest and most powerful brands.