The important role of the hottest nanotechnology i

The important role of nanotechnology in the field of printing

nanotechnology is a high-tech that was born and rose rapidly in the late 1980s. Its basic meaning is to understand and transform nature within the nano size (i.e. 0.1~100nm), and create new substances through direct operation and arrangement of atomic and molecular motion laws and characteristics. This means that people can produce extremely pure materials and colorful new products

characteristics of nanotechnology

"nano" is the translation of English nano meter. 1 nanometer is 1 billionth of a meter, which is only as long as 45 atoms. Nanostructures usually refer to micro structures with a size of less than 100 nm. At present, nanotechnology research mainly focuses on nano materials. Nano materials can be directly replaced by the self-contained bending indenter of the experimental machine instead of the pressure bar, and the material refers to the material whose grain size is in the range of 1~100 nm. The research shows that when the material particles enter the nano scale particles, they have the characteristics of quantum size effect, small size effect, surface effect and macroscopic quantum tunneling effect. Because the size of nanoparticles is close to the wavelength of light, and it has the special effect of large surface, its other characteristics, such as melting point, magnetism, optics, heat conduction, conductivity and so on, are often different from those of the material in the overall state

application of nanotechnology in printing

1 Nano paper

the fibers such as trees, bamboo and hemp used in traditional paper are relatively thick, while the coatings and fillers can become transparent, lighter and repairable with large particles, which makes ordinary paper afraid of water and moisture. Offset printing paper and electrostatic copying paper have waterproof and moisture-proof functions, but it is inconvenient to write. Nanotechnology is more and more widely used in the paper industry. At present, wood fiber can only be processed to the level of microns (100~1000nm). Because the cell diameter of wood is relatively coarse, the characteristics of wood may be changed by changing the cell structure and controlling the cell growth through wood nanotechnology. When wood is processed to the nanometer level, the original cell structure of wood will be destroyed, and the fiber tissue structure will change. Cellulose, hemicellulose and lignin can be separated by mechanical methods in the processing process, which can greatly improve the paddle making rate and reduce the environmental pollution caused by the paddle making and papermaking industry

in papermaking coatings, the application of nano calcium carbonate in the coating of white paperboard can effectively improve the performance of white paperboard. The addition of nano calcium carbonate is conducive to the improvement of several important performance indicators of the coating, such as IGT value, k n ink absorption, smoothness and so on

at present, the use of nanotechnology in the paper industry has begun to enter practical production. For example, Henan Yinge company and the Nanotechnology Research Institute of central China Normal University have successfully developed waterproof nanopaper by using the most advanced nanotechnology in the world to prepare nanostructured layers on ordinary paper. In addition to maintaining the original writing and copying functions of the paper, it also has the special properties of super hydrophobicity and moisture resistance, improving the printing surface strength and reducing the expansion rate that ordinary paper does not have

2. Nano ink

ink fineness is closely related to print quality. The better the fineness of the ink, the stronger the coloring power, and the clearer and fuller the dots of the printed matter. Nano scale transparent iron oxide series pigments, which have recently been rated as national key new products by the Ministry of science and technology, have been successfully developed in China. Nano metal particles can absorb all light waves and make themselves black. At the same time, they can also scatter light. Adding nano metal particles to black ink can improve the purity and density of black ink. On the other hand, after the surface of semiconductor nanoparticles is chemically modified, the medium around the particles can strongly affect its optical properties, which shows that the absorption spectrum has a red shift or blue shift. If they are added into yellow and cyan inks respectively to make nano inks, the purity of yellow ink and cyan ink can be increased, and the level of printed matter can be enriched. 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. Because they are highly fine, they have good fluidity and lubricity, which can achieve the effect of low pigment consumption but high coverage. If used in UV ink, it can accelerate the curing speed and eliminate the shrinkage and wrinkling of the ink film. Nano carbon ink is conductive and has a good shielding effect on static electricity. If ink is added, it can be made into conductive ink. If AG is made into nano scale in conductive ink instead of micron scale AG, 50% of Ag powder can be saved. This ink can be directly printed on ceramics and metals, and the ink film is thin, uniform and smooth; If Cu and Ni materials are made into 0.1~1 μ M, which can replace precious metals such as palladium and silver to conduct electricity. The combination of nano and anti-counterfeiting technology will open up another broad world of anti-counterfeiting ink

some nano powder particles can emit light by themselves, such as "－ n ≡ n －" nano particles, which can emit light by themselves in the dark for more than 12~24 hours after a few minutes of illumination. Its luminous intensity and maintenance time are more than 30 times that of traditional fluorescent materials, and the material itself is non-toxic, harmless, and does not contain any radioactive elements. Because nanoparticles have good surface wettability, they adsorb on the surface of pigment particles of ink, which can greatly improve the lipophilicity and wettability of ink

3. Nano ceramic roller

the so-called nano ceramics refers to ceramic materials with nano scale phase in the microstructure, which greatly improves the strength, toughness and Superplasticity of materials. As we know, laser engraved ceramic roller is widely used in flexographic printing, and it is considered to be the key to improve the quality of flexographic printing. Narrow width flexographic printing machines and UV ink flexographic printing machines have almost all adopted ceramic rollers. In terms of the development of flexo printing, ceramic rollers will eventually eliminate metal rollers. Cahn, a famous British material expert, pointed out that nano ceramics is a reasonable choice for solving bending specimens. 1) geometry: the maximum bending moment on the three-point bending specimen with circular section is only 1 point, which is a strategic way to determine the brittleness of ceramics. For the corrugated roller used in flexographic printing, when processing the corrugated roller with plasma thermal spraying process, it is required to spray a high-quality ceramic coating on the surface of the substrate. The coating hardness range must be hv300~1300, and the general porosity must be less than 1%. For the corrugated roller higher than 1200 line, the porosity must be less than 0.5%, and the coating structure should be uniform, high hardness, high density, etc. while the nano properties in nano ceramics improve the hardness, toughness and wear resistance of ceramics, This will lay the foundation for the embossing roller with excellent carving

in short, as a high-tech with rapid research and development in recent years, the application of nano technology in the printing field will continue to develop in depth and breadth like other fields

4. Nano packaging materials

nanotechnology carries out nano synthesis, nano addition and nano modification of packaging products to make them have new packaging characteristics such as nano structure and scale. In recent years, polymer matrix nanocomposites have been studied most. For example, compared with traditional plastic packaging materials, nanocomposite plastic packaging materials have significantly improved plasticity, wear resistance, hard strength and other properties. In addition, polyester PET and PBT nano plastics also have the characteristics of flame retardancy and pure barrier, which can replace PBT resin with higher price and meet the requirements of packaged food

reprinted from: Printing Art