The hottest new concept inks

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Several new concept inks

with the continuous improvement of printing quality requirements, higher requirements are also put forward for inks. Today, with the rapid development of science and technology, various inks continue to appear and are used in general printing, special printing, anti-counterfeiting printing and other fields. They not only require good print quality, but also meet a variety of special needs such as environmental protection, anti-counterfeiting and so on. Therefore, the emergence of magnetic inks, fluorescent inks, photochromic inks, thermotropic inks and so on has made the development of the printing industry leap to a new height. Next, we will briefly introduce the characteristics and uses of several high-tech special inks

I. nano ink

we know that the fineness and color purity of ink have a great impact on the quality of printed matter. To print high-quality products, we must have ink with good fineness and high color purity. The fineness of ink refers to the size of pigment (including filler) particles in the ink and the uniformity of pigment and filler distribution in the binder. It not only affects the quality of printing products, but also affects the print resistance of printing plates. Process practice shows that the conversion time of the pattern plate or upper and lower temperature used in color printing products: meet the specifications and experimental methods within 15 seconds. In the field, areas with small negative words and lines in the layout are prone to paste and dirty layout during the printing process, which leads to printing quality problems. If the operator does not carefully check and analyze, he may fall into the wrong operation, thinking that the ink consistency is inappropriate, the viscosity is too large, the ink volume is too large or the pressure is too large, and blindly make wrong adjustments. However, this is caused by poor ink fineness. The fineness of ink is directly related to the properties of pigment, filler and particle size. Generally speaking, salty inks made with inorganic pigments (excluding carbon black) have coarse particles. This has a lot to do with the rolling process of ink. The more times the ink is ground in the rolling process, the more uniform it will appear, the larger the contact surface between the pigment particles and the binder will be, the finer the ink particles will be, and the better and more stable its printing performance will be. Take the printing plate as an example, the 1-40% of the high-profile and middle tone on the plate is very common. If the proportion of ink particles to the dot area is close, it is easy to make the dot empty or fluffy, and even the printing defect of rough dots appears. Therefore, the higher the fineness of the ink, the clearer and fuller the dots on the print

the fineness of ink is low, the particles of pigment are coarse, the friction coefficient is large in the printing process, and the printing plate's printing resistance is low. During printing, it is also easy to produce plate pasting, ink accumulation, and uneven ink transmission and distribution. Generally, the fineness of the ink can be judged by visual observation, that is, if the surface scraped by the ink knife shows a smooth and uniform visual effect, it indicates that the fineness of the ink is good; if there is a small or granular rough layer on the scraped surface, the fineness of the ink is poor. In addition, you can also use coated paper to dip a little ink layer, and then use another piece of paper to polish the ink layer. When the ink layer is dragged to a very thin layer, it is still very shiny, indicating that the ink fineness is good. If there are traces in the ink layer, it is obvious that the traces are caused by the coarse particles of ink pigments and fillers. Of course, the above is only based on experience, and the accuracy of discrimination has certain limitations. In order to realize standardized and data-based judgment, only by relying on the fineness meter to measure the size of pigment particles, can we accurately detect the fineness of ink. The method is: dilute the sample ink to a certain extent and place it in the deepest part of the fineness meter. Then use a scraper to control the groove to move (keep a constant speed) to the shallowest place. The size of the ink particles can be seen at the scales on both sides of the groove. You can also use a microscope to observe the size of the ink pigment particles

nanotechnology is an emerging technology. Nano is a unit of length, M. the research object of this technology is mainly nano materials. Nanomaterials have now begun to penetrate all fields. In 1994, Xmx, a Massachusetts company in the United States, successfully obtained a patent for nano-sized uniform particle raw materials used in the manufacture of inks. Using nano materials as ink pigments or fillers can greatly improve the fineness of ink. Moreover, because nano materials have some characteristics that conventional size materials do not have, some inks with new characteristics can also be obtained

nowadays, with the help of high and new technology, various components in ink (such as resin, pigment, filler, etc.) can be made into nano raw materials. In this way, because it is highly fine and has good flow and lubricity, it can achieve better dispersion, suspension and stability, less pigment consumption, high hiding power, good gloss, fine resin particle size, continuous film formation, uniform and smooth, thin film, and clearer printing image. If used in UV ink, it can accelerate its curing speed, and eliminate the shrinkage and wrinkling of the ink film due to the fine and uniform dispersion of the filler. In the printing ink of glass ceramics, if the inorganic raw materials are composed of nano fineness, it will save a lot of raw materials and print more refined, beautiful and high-quality images

studies have shown that some optical properties of the particle surface of some nanoscale materials will change after chemical modification, which is manifested as red shift or blue shift of the absorption spectrum. Experiments show that the light absorption of CdS nanoparticles has a significant blue shift, and the light absorption of TiO2 nanoparticles has a large red shift. Accordingly, if they are added to yellow and cyan inks respectively to make nano inks, their color purity can be improved. Using nano ink with specific nano particles to copy and print color prints will enrich the layers, make the tones clearer, and greatly improve the performance of image details. In addition, the color of some materials will change at the nanoscale, which makes it possible for the ink manufacturing industry to no longer rely on chemical pigments, but to choose appropriate volume of nanoparticles to show different colors

nano carbon ink has conductivity, which has a good shielding effect on static electricity and prevents the electrical signal from being interfered by external static electricity. If it is added to the ink, it can be used to make salty conductive ink, such as high-capacity integrated circuits, modern contact panel switches, etc. In addition, if AG is made into nano scale instead of micron scale Ag in conductive ink, 50% of Ag powder can be saved. This conductive ink can be directly printed on ceramics and metals. The ink film is thin, uniform and smooth, and has good conductivity. If Cu and Ni materials are made into 0.1~1 μ M, which can conduct electricity instead of precious metals such as palladium and silver

in addition, some organic nano materials have their own light-emitting groups and may emit light by themselves. The printing products printed with the ink added with this nano material do not need the irradiation of external light sources, and can be recognized by the human eye by its own light emission. It can also achieve a good effect for anti-counterfeiting printing. The graphic printing products used for outdoor large-scale advertising spray painting or night reading do not need external light sources, which can not only save energy, but also greatly facilitate users

because nano materials generally have good surface wettability, in the process of manufacturing ink, as long as a certain amount of nano materials are added, they are adsorbed on the surface of pigment particles in the ink, which can greatly improve the wettability of the ink and ensure the stability of the whole ink dispersion system, so as to greatly improve the printability of the ink

in electrostatic copying, replacing the widely used non-magnetic toner with magnetic nano toner can eliminate the ferromagnetic particles currently used as magnetic carriers, and make a single component copy developer, which can save raw materials and improve the copy quality

it is believed that with the further development of nano material technology, more nano materials with different characteristics will be known and used by people

II. Cationic ink

in recent years, UV curing (UV) technology is playing an increasingly important role in printing. The most important feature of UV curing is that it can improve the printing stability (in terms of drying) and shorten the time waiting for oxidation drying in the printing process. At present, UV technology has blossomed in the web relief printing, flexographic printing and offset printing markets. Now, there is a new type of ink - cationic ink. This kind of ink has increased the guarantee for improving the environmental protection and quality of flexographic printing

compared with free radical system, cationic ink has the advantages of low volatility and low odor, which can be said to be a good environmental protection ink. The smell of free radical ink is a headache, which is harmful to the health of operators and the environment. Cationic inks (low volatile inks) have great advantages in this regard, and now they can even be applied to some food packaging industries. Cationic ink can also be attached to plastic sheet base. Cationic ink and coating light show particularly good adhesion to corona treated substrates, which is the most critical of all advantages

compared with free radical inks, cationic inks have the characteristics of medium curing speed (which is slightly inferior to free radical inks), secondary curing (about 24 hours), no oxidation prevention, light humidity effect, generally micro, no shrinkage, excellent plastic adhesion, etc

although in terms of curing speed, free radical inks can be dried under high-speed printing, the curing speed of cationic inks is slightly behind. However, recent research and development have shown that the improved cationic ink can also adapt to the printing of 150~200m/min

the advantage of secondary curing is that when the printed matter is output from the printing machine, the ink film looks as if it has been cured, but some parts still do not react (not dried out). The cation curing technology can continue to react until most of the materials connected with the oil suction chamber and the oil discharge chamber respectively react in the process of change. In contrast, free radical inks can only be completely dried after exposure to UV light. This process will lead to higher volatilization, especially for the unreacted low molecular weight components. Cationic ink has small shrinkage, so it has good adhesion characteristics

in the current situation of growing calls for green environmental protection, the packaging and printing industry is more environmentally friendly products. Food packaging shall comply with cepe standard in industrial standards. In terms of ink, we should constantly solve the content of harmful substances such as lead, benzene, aromatic compounds, ethyl glycol and so on in the ink, so as to ensure the safety of food and supplies and the health of printers. Judging from the achievements of the ink industry, the achievements are still very encouraging. In 1974, the lead in the ink and pigment was removed: in the late 1970s, the fibrinolytic agent (ethyl glycol) was removed; in the early 1980s, the toluene in the food packaging instructions was removed: in the late 1980s, the related benzidine yellow pigment: in the early 1990s, the use of benzoic acid plasticizer was reduced, etc. In the initial stage of cationic ink development (the mid-1980s), the content of some of the above harmful substances did not meet the industry standards, but after continuous improvement, the content of these harmful substances finally reached the industry standards. For example, benzene, in the cationic ink produced now, its content is very low, and it can't be detected by using ordinary analysis technology. Many test results of printing products and printing environment also showed that no benzene was found. Although some customers have no intention of using cationic ink at present, it shows great advantages in the printing process and is bound to win the public praise of customers

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