The solvents commonly used for flexo inks include water, alcohols, and toluene. If the main solvent is water, it is called ink; while the main solvent is organic solvent, it is called solvent ink. In recent years, the domestic printing industry has begun to use ink and ink while introducing flexo presses. However, because few people used ink to print before, people used the term ink to refer to all printing inks. With the appearance of ink and wash, domestic related industries have agreed that Valley is called water-based ink. I think this kind of address is inaccurate. People usually say that oil and water are not compatible. In fact, oil is oil, water is water, and they cannot be rigidly linked together. If we analyze the word “WATER baseD INK†in English, it should be called water-based ink, water-based ink, or simply called ink-and-wash, so as to distinguish it from the traditional ink.
The ink used for flexo printing is usually a mixture of aqueous polymer emulsions, pigments, surfactants, water and other additives. Aqueous polymer emulsions used in inks are mainly synthetic emulsions of acrylic acid and ethylene styrene. Its role in the ink is mainly: the transmission of pigment carrier, provide adhesion, hardness, affect the brightness, drying speed, wear resistance, water resistance and other characteristics. This kind of emulsion can be divided into film emulsion and non-film emulsion. The former is used for inks printed on non-absorbent substrates such as plastics and metal coated materials, while the latter is often used in inks for paper and board printing. The role of the pigment is to provide the desired color. Commonly used pigments can be divided into organic pigments and inorganic pigments. For example, phthalocyanine blue and Litholol are organic pigments, while carbon black and titanium dioxide are inorganic pigments. Surfactants can also improve the stability of the ink. Obviously, water is the solvent of the ink system, which can change the viscosity of the ink, thus affecting the thickness of the ink in the printing and the drying speed of the ink.
It is worth mentioning that the development of ink-and-ink printing technology is the result of the mutual improvement of the improvement and development of printing presses, the development of plate-making technologies, and the development of ink-and-wash technology. For example, in order to improve the color overlay accuracy, the printing press manufacturing industry continues to improve the design and manufacturing technology of the printing press. The printing debugging can be performed by a computer, which is convenient and accurate. In order to obtain a higher definition, an anilox roller with a high number of lines and a small volume is gradually used in high-quality flexo printing. In order to meet the needs of high-line count (usually up to 600-800 lines) anilox roller, ink manufacturers need to produce high-strength, less than micron-grained ink, otherwise it will affect the printing effect. In the same way, high-quality printing also requires higher requirements for color separation technology, plate material selection, and platemaking technology.
Third, the prospects From the market, ink printing continues to expand. Packaging and printing is the main market for ink-and-wash applications. Ink and wash inks are also being used in decorating and printing (such as wallpaper printing), printing of books and newspapers, and other fields.
Book printing ink is one of the largest markets in the printing industry. The ink used for printing books is still based on solvent inks. The reason is mainly that the effect of using water and ink to print books and books is not very satisfactory. At least in the current circumstances, the quality of solvent ink printing cannot be achieved. The cause of this difference is not only the problem of ink, but also the problem of the cooperation of paper and printing presses. In recent years, many papermaking and ink-making plants have cooperated with printing machinery manufacturing to continuously improve the ink formula and improve the paper's water absorption performance. Through repeated trial printing, much progress has been made. I believe that as long as time passes, the application of ink and wash will have substantial breakthroughs in the printing of books and periodicals. Once ink and ink are used to meet the printing quality requirements, the publication of books and periodicals will be replaced by water and ink.
The use of ink and wash in newspapers and magazines has been used for at least 10 years. Because the paper used for newspaper printing has good water absorption properties, the use of ink in newspaper printing has come to the front of the book printing industry. The application of ink and wash in newspaper printing has evolved from the simple black ink to the color ink and overprint ink. There will be further development in this area in the future.
Anti-counterfeiting ink is a new area for ink ink development and application in the future. Due to the needs of anti-counterfeit packaging, anti-counterfeiting securities and cheques, anti-counterfeiting technology and ink-and-wash technology are being used to promote anti-counterfeit inks. Although sales of anti-counterfeit inks are small, they are relatively expensive due to high costs. Therefore, sales are still considerable.
In the United States today, due to the requirements of environmental protection and the development and improvement of ink-and-wash technology, ink-and-wash printing has been accepted by more and more printing companies. Quite a number of users have ordered manufacturers to use ink and wash when ordering products from a printing factory to show their support for environmental protection and their responsibilities to the natural environment. The air cleaning program implemented in California several years ago in the United States requires restrictions on the content of organic volatiles in the ink. This means that the pigment should be selected correctly in the formulation of the ink, and the pigment with high heavy metal ion content should be excluded as much as possible.
The promotion and application of digital printing technology may provide a new field for the development of ink-and-wash technology. According to statistics, the United States has accounted for 80% of the printing ink in corrugated box printing, paper and board printing, general plastic ink printing and gift paper printing. The improvement of ink-jet printing technology also makes flexo printing a reality instead of other traditional printing methods. In the next 10 years, the quality of ink printing will be further improved, and the amount of ink used will increase. Especially in the developing countries where the application of ink and wash is not yet common, the application of ink and wash will have greater development.