Application of Nanotechnology in Corrugated Printing (Part One)

1. Nano ink

The manufacture of corrugated boxes is inseparable from the packaging and printing. Nanoparticles play an increasingly important role in the packaging and printing industry. Nano inks are compatible with all aspects of performance. Many of the products (especially food) packaging and printing have very high requirements for sterilization, preservation, etc., while the traditional ink and packaging materials are a blank in this respect. Nowadays, the natural basic materials have been transformed with nanotechnology, and with the application of nano ink printing, they can exert an amazing bactericidal effect. Adding nano silver powder to the fresh-keeping packaging materials can accelerate the release of ethylene from the oxidized fruits and vegetables foods. Ethylene content in the package, to achieve a good effect of preservation. Since silica and titanium dioxide exhibit strong anti-ultraviolet light and catalytic performance at the nanometer scale, the nano-modified ink synthesized by special processing chemical reactions can generally improve its light fastness by 2-3 grades and heat resistance. And the attachment fastness has obviously improved. Adjust formula, can be made of environmentally friendly ink; add heat, light and other materials, can also be made of security ink.

Nanoparticles can also be used instead of chemical pigments to make printing inks. This production system uses uniform nanoparticle printing inks. The resulting ink is brightly colored with pure hue and is non-toxic and tasteless. The application prospects of nano inks in offset printing, gravure printing and flexo printing to produce color cartons and cartons are very broad. In addition, the use of nano inks can also significantly improve the quality of printed products. In prints (especially high-end color prints), product quality and ink fineness, purity have a great relationship. Only small, high purity inks can print high quality prints. Therefore, improving the ink purity and fineness is also an important part of the research of new inks. The fineness of the ink refers to the size of the pigment (including filler) particles in the ink and the uniformity of the pigment and the filler distributed in the binder. It not only affects the quality of printed products, but also affects the printing rate of printing plates. The practice of the process shows that the color printing products used in the net printing or the field layout contains small Yin characters, Yinxian, the printing process is easy to appear dirty quality problems, on the surface, may be considered ink consistency is not good, too much viscosity , too much ink or too much pressure and other reasons. The real reason is that the ink particles are too thick. The fineness of the ink has a direct relationship with the pigment, the nature of the filler and the size of the particles. In general, inks made with inorganic pigments (not including carbon black) have poor fineness and relatively coarse particles, which are closely related to the rolling process of the ink. The more the ink is ground during the rolling process, the more uniform it is, the greater the contact area between the pigment particles and the binder, the finer the ink particles, and the better and more stable the printing performance. Obviously, the fineness of the ink is closely related to the quality of the printed matter. For example, in the case of a printed anilox version, there are no shortage of 1-4% dots in the high-profile and intermediate tone of the layout, if the ratio of ink particles to the dot area is closer However, it is easy to make outlets emptiness or spread, or even the printing defects that are not smooth. Therefore, the finer the ink, the more clear and full of dots on the printed matter. In addition, the finer the ink, the greater its concentration, the stronger the coloring power, and the higher the product's print quality. The coarse particles of inks and pigments have a large coefficient of friction during the printing process, and the printability of the printing plate is low. In addition, coarse-grained inks are also prone to paste and ink deposits during printing, as well as uneven distribution of ink and ink. The fineness of the ink can generally be judged by naked eye observation, that is, the surface scraped by the ink knife, if it is smooth. A uniform visual effect indicates that the ink is fine. If the surface of the scraped surface appears as a small layer or a coarse layer of particles, the fineness of the ink on the surface is poor. In addition, it is also possible to use a small amount of ink layer on the coated paper, and then use another layer of paper to grind the ink layer until the ink layer is dragged to a very thin, it is still very smooth, indicating that the fineness of the ink is good. If traces of the ink layer appear, it is obvious that the traces of pigments and fillers caused by the coarse particles in the ink indicate that the fineness of the ink is not good enough. Of course, the above is only judged by experience, and the accuracy of the judgment has certain limitations. . To achieve standardized, data-based judgment, only rely on fineness meter to determine the size of pigment particles in order to more accurately detect the fineness of the ink. The specific method of measuring the fineness of the ink with a fineness meter is to dilute the sample ink to a certain degree, place it in the deepest part of the fineness meter, and then use the scraper to treat the groove movement (to maintain a constant speed) to the shallowest point. The ink particle size can be seen at the scale marks on both sides of the groove. In addition, the size of the ink pigment particles can also be observed using a microscope.

How the fineness and purity of the ink is sensitive to the quality of the printed crystal. To print high-quality products, we must have fine-grained, high-purity inks as guarantees. Therefore, a correct understanding of the relationship between ink fineness, purity and print quality, deeper understanding of nano inks, and development of higher quality nano inks are of great significance to the printing industry.

Because nanomaterials refer to the material itself being ultra-small and ultra-fine. Based on the various characteristics of nanomaterials, applying it to the ink system will bring a huge boost to the ink industry. In 1994, the XMX Corporation of Massachusetts, USA, has successfully obtained a patent for the production of nano-sized homogeneous particulate raw materials for inks. Then, XMX prepared to design a commercial production system, using this patent, select the appropriate volume of nano-particle raw materials to get a variety of ink pigments, and no longer rely on the old traditional production of inks required chemical pigments. According to another report, the nanoscale transparent iron oxide series pigments that have recently been awarded as national key new products by the Ministry of Science and Technology have been successfully developed. It will have an important impact on the upgrading of traditional pigments, mainly used in nano-ink, nano-water coating materials. The typical needle particle size of this material is 45 nm on the long axis and 6-7 nm on the minor axis. It has good dispersion, crystallinity and weatherability, high brightness and strong coloring. Its successful development has great significance for the replacement of traditional Chinese pigments, especially for the production of nano-inks, but also to greatly improve the quality of ink.

(to be continued)