Application of Nanotechnology in Corrugated Printing (Part 2)

Studies have shown that after chemical modification of the surface of the nano-semiconductor particles, the medium around the particles can strongly influence the optical properties, which is reflected in the red-shift or blue-shift of the absorption spectrum. Experiments show that there is a clear blue shift in the light absorption edge of Cds nanoparticles and a large red shift in the absorption edge of TiO 2 nanoparticles. Accordingly, if they are separately added to the yellow ink and the cyan ink to make the nano ink, the purity of the yellow ink and the cyan ink can be greatly increased. The use of nano-inks with specific nano-particles to reproduce printed color prints can make the print layer richer, the tone more vivid, and greatly enhance the ability to represent image details, resulting in high-quality prints.

Today, with the help of high technology, various components (inks, pigments, fillers, etc.) in ink can be made into nano-scale raw materials, so that they can achieve better flow and lubricity due to their high degree of fineness and good lubrication. The dispersion and suspension are stable and the amount of pigment is low, but the hiding power is high, the gloss is good, the resin particle size is fine, the film formation is continuous, uniform and smooth, the film layer is thin, so that the printed image is clear, if used in UV ink, may cause faster Solidification speed, at the same time eliminate shrinkage and wrinkling of the ink film due to the fine and uniform dispersion of the filler. In glass-ceramic inks, if the inorganic material is nanometer-sized, it will save a lot of raw materials and print more beautiful images. A huge change has been made in pigments for the ink manufacturing industry. It no longer depends on chemical pigments, but rather selects the appropriate volume of nanoparticles to present different colors. Because some substances are at the nanometer level, the color of the particles is different, or the color of different substances is different. For example, Ti02 and Si02 are white in the nanoparticles, Cr203 is green, and Fe203 is brown. There are also inorganic nanomaterials such as nano-A1203 with good fluidity, if added to the ink can greatly improve the wear resistance of the ink film. Nano-scale carbon ink is conductive, has a good shielding effect on static electricity, to prevent electric signals from being disturbed by external static electricity. If it is added to ink, it can be made into conductive ink, such as large-capacity integrated circuits, modern contact panel switches, etc. . In addition, if Az is made into nano-scale instead of micro-sized Ag in conductive ink, 50% of Ag powder can be saved. This conductive ink can be directly printed on ceramic and metal. The ink film is thin and even and smooth, and the performance is very good. it is good. If the Cu, Ni material made of 0.1-1} xm ultrafine particles, it can replace palladium and silver and other precious metals conductive. In addition, some nanopowder particles themselves have luminescent groups and may emit light themselves, such as "N,N,N" nanoparticles. These new nano-luminescent materials can emit light in the dark for more than 12 to 24 hours after a few minutes of illumination. Their luminous intensity and maintaining time are more than 30 times that of traditional fluorescent materials, and the materials themselves are non-toxic, harmless, and non-toxic. Contains any radioactive element, its stability and weather resistance are excellent. Can be used endlessly. The printed matter printed with the ink added with this kind of nanoparticles does not require the irradiation of an external light source, and can be recognized by the human eye only by its own light emission, and it can also achieve a very good first-line anti-counterfeiting effect for security printing. The printed matter for outdoor large-scale advertising printing or night-time reading does not need external light sources. It not only saves energy, but also greatly facilitates users. Also, since nanoparticles have good surface wettability, they are adsorbed on the surface of the pigment particles in the ink, which can greatly improve the ink's lipophilicity and wettability, and can ensure the stability of the entire ink dispersion system. Nano-particle nano inks have greatly improved printability. It is believed that with the further development of nanomaterial technology, there will be more nanomaterials with different characteristics that will be recognized and used by people. Applying these nanomaterials to ink manufacturing, special inks with different uses can be obtained. The printing of confidential documents, the printing of various anti-counterfeit printings, and the printing of various handicrafts can all achieve exceptionally good results.

In practical verification of pigment nanocrystallization, the color appearance of nanometer pigments is far darker than that of submicron pigments. The main reason is that the particles of the pigments are large and the light will break through, and the light will scatter and emit light. Light penetrates through. The nanopigment has a small particle size, weak light scattering, a small spectral absorption area, and a light reflectance of less than 1%, so the appearance of the color is significantly deeper than the submicron pigment. The application of nano-pigments is quite extensive. The real life examples include ink-jet inks, coatings, inks, and photo-electric displays. In the manufacturing process of products, the addition of 3% to 5% of nanopigment to the ink can improve the ink. Shading rate, saturation, anti-rotation, water resistance and other issues. In addition, in ordinary and color laser printers, the thickness of the toner particles is an important factor that determines the quality of the output, and it is also a key to whether the resolution of the printer can be further improved. Therefore, using nanomaterials to make carbon powder for laser printing, especially color laser printing, can greatly improve the quality of the output. In addition, in the current color ink-jet printing, due to the ink problem, not only the print quality is affected, but also the nozzle clogging and other failures occur from time to time. However, once the nano-material ink is developed, it is believed that these problems can be well solved. In addition, color laser printing and color inkjet printing are the major printing devices for future digital printing and on-demand printing. Nanotechnology will play an important role in this field. In electrostatic copying, magnetic nanopowders are used instead of non-magnetic toners, which are widely used today, and it is possible to save the use of ferromagnetic particles as carriers in non-magnetic toners, and to make a single-component copying developer, which can be saved. Raw materials and improve copy quality.

2. Nano UV Varnish

Paper packaging products, surface gloss processing technology is gradually developing to the direction of UV curing UV coating, nano-UV polishing oil to color corrugated box with wear resistance, scratch resistance, moisture, high gloss and other properties. Nano-UV varnish is mainly composed of nano-oligomer (such as epoxy-acrylic acid, etc.), reactive diluent, photoinitiator and other additives. There are many methods for UV coating, which can be used for coating and printing machines, roller coating or printing.

3. Nano processing media

The application of nanotechnology has spawned new packaging material plates. When a special surface treatment is performed, two kinds of two-dimensional surfaces with different properties can be formed on the medium in a staggered manner, and the surface area of ​​each of the surfaces and the interface of the two-phase structure are nanometer sizes. When a piece of material has the same hydrophilicity and lipophilicity in the nanometer size, it will have an ultra-hydrophilic and super-lipophilic interface. Recently, the photosensitive resin plate recently introduced by Medtech has been exposed by short ultraviolet light and the surface of the plate is smoother than the normal solid plate. Ideal for corrugated box printing. After nanotechnology processing, the wear resistance, stretch tension, print resistance, toughness, and plate storage life have been greatly improved. Laser engraving machines and rubber plates are low in cost compared with resins, and their efficiency is also increased exponentially. It can be expected that when the ever-improving nano-high technology is widely used in corrugated box printing, the resolution of corrugated boxes will be higher and the effect will be better.

(author/Lin Qishui)

China Packaging News