Analysis of the development status of gravure printing inks at home and abroad
1 With the continuous improvement of domestic people's living standards, packaging and printing have developed by leaps and bounds in recent years. The introduction of printing equipment, the improvement of plate making equipment, and the improvement of printing ink have brought people's refinement of printed matter packaging bags, and raised people's awareness of environmental protection. As an ink, its basic function is to give people the information they need through certain equipment
1) classification of inks
in order to meet the needs of various printing methods and printing purposes, there are many kinds of inks with different physical and chemical properties and great differences in performance. Clear classification is the premise of using inks well
① classified by drying method. When the printing ink is transferred from the printing plate to the surface of the substrate, the ink will change from liquid to solid film, which is the drying of the ink. The drying of the ink has both physical and chemical effects
a. oxidation polymerization dry ink. The resin in the ink reacts with oxygen in the air to solidify the resin and form a glue like structure and dry
b. penetration drying ink. The ink penetrates into porous materials such as paper and dries
c. volatile dry ink. This kind of ink contains a large number of volatile solvents. After printing on the surface of the substrate, the solvent volatilizes to the atmosphere, and the remaining resin and pigment in the ink form a solid film and adhere to the surface of the substrate
d. radiation drying ink. Radiation drying is a drying method in which the ink depends on the energy of the radiation line, so that the separate plug-in control board of the ink connecting material will produce a strong induction electromotive force to produce polymerization and change from liquid to solid. It is mainly that some substances in the ink absorb energy to produce free radicals, which cause the unsaturated double bond reaction in the ink resin to crosslink and cure
e. other dry inks. There are many other drying methods, including wet solidification drying, condensation drying, precipitation drying, two-component reaction drying, gelation drying, etc
② classification by printing method
a. lithographic printing ink
b. relief printing ink
c. flexographic printing ink
d. gravure printing ink
e. hole printing ink
③ gravure printing ink classification. The inks used for gravure printing are mainly classified according to their uses, including publishing inks, packaging inks and industrial inks
the ink used in composite flexible packaging materials basically belongs to the category of packaging and printing ink, which is our most concerned variety
2) composition of ink
printing ink is a paste colloid formed by evenly dispersing and mixing materials such as pigments, connecting materials and fillers. The pigment endows the printing with rich and colorful colors. The connecting material is used as the carrier of the pigment, and also as an adhesive to surround the pigment on the surface of the substrate. The filler endows the ink with appropriate properties, so that the ink can meet the printing suitability of various printing processes. The liquid components in the ink are called binders, solid pigments and various additives
gravure printing ink is roughly composed of 5% - 15% pigment, 20% - 40% binder resin, 0% - 60% solvent and 0% - 5% additives
2. Current situation of ink at home and abroad
1) domestic gravure ink
at present, domestic surface printing ink is divided into ink for general flexible packaging (such as shopping bags, maternal and infant health products) (the ink is mainly based on benzene soluble polyamide resin PA), ink for cigarette packaging (mainly based on nitrocellulose resin NC) and paper box ink (water-based ink), and more than 70% of the composite ink is BOPP special ink based on chlorinated polypropylene (CLPP), %Of them are polyurethane (PU) inks, and some are PVB alcohol soluble inks. Due to price and other factors, different materials and different packages use up to several 10 tons of ink. To the printing factory, there are many kinds of ink, many inventories, and delivery is also very easy to delay
2) foreign gravure inks
Japan, Europe and the United States have different packaging requirements, so the ink system is also very different. A small number of advertising newspapers and periodicals in Japan are rotary flexographic printing. Most sanitary products are gravure printing (the ink gradually changes from benzene containing to benzene free (aliphatic hydrocarbon solvent) system, cigarette bags are also gravure based, composite packaging bags are benzene soluble polyurethane (to benzene free) system, CLPP system has basically disappeared. In the field of composite packaging, general-purpose inks account for a large proportion. In Europe and the United States, in addition to composite packaging bags, others are mainly flexographic, (water-based or alcohol soluble) even the composite packaging is mainly alcohol soluble HC + Pu, so this scheme is very common in European and American color paste + resin liquid
Quliang 3) the development of domestic gravure inks is becoming more and more strict with the trend of environmental protection and energy problems
in recent years, the consumption of domestic inks has been increasing at a rate of%, much higher than low-grade inks. It can be predicted that in the near future, people's requirements for ink quality will exceed the price. At the same time, while constantly introducing printing equipment, people will also try to use foreign management models to manage their own workshops, and gradually integrate with developed regions
it can be predicted that with the development of universal ink or color paste + resin liquid system, the production of ink will also take a further step in the direction of large-scale production. The final mode will be: on the one hand, mass production in the workshop; on the other hand, all-weather technical services of ink residents in the printing plant
how to achieve the goal still needs a long process. It is not realistic to take one step to the final state. At present, there are already some large printing plants doing this work, and we are also cooperating. It is foreseeable that there will be a satisfactory harvest in the near future
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