Color flexo carton printing ink experience

For a long time, many of China's goods in the international consumer market image is "low price, quality, poor packaging", many traders importEd Chinese goods through improved packaging in secondary sales. And some European countries D in order to prevent a large number of Chinese goods into, playing "packaging card."
to take a positive attitude towards such rules of the game, domestic packaging products should talk about quality, grade, environmental protection, and gradually move towards

. Corrugated cartons as one of the most commonly used packaging of ordinary consumer goods, environmentally friendly flexo printing will become the mainstream of domestic carton manufacturing industry, and flexo printing of the printing of the printing, color flexo printing cartons will certainly promote the development of ink.
cartons color green
why do ordinary corrugated cartons need to pursue color? First, the needs of the market, consumers increasingly prefer high-quality printed packaging. High-quality printed packaging makes consumers feel a sense of pleasure when shopping, a sense of awareness and trust in goods.
, the design of corrugated cartons is changing, and designers are demanding that packaging show more of the product's content and beautify the product. Now more and more corrugated carton design has used high-quality patterns, through the perfect embodiment of the pattern layer to better represent the design of ideas and content. Promote the corporate culture, so that goods to consumers have affinity, can stimulate consumers' desire to buy.
third, through the design of high-quality patterns to improve the positioning of goods in the market. High-quality pattern printing indirectly reflected in high-quality products, which is a kind of paving for the positioning of the products, and can make the product's internal packaging, outer packaging and transport packaging organic unity, strengthen the awareness of the product market.
, the coloring of corrugated cartons helps to improve the anti-counterfeiting function of product packaging. Through professional design company design, professional plate-making company to produce plates and high-level carton printing manufacturers to work together to produce high-quality color corrugated cartons, to be counterfeiters through scanning cartons to obtain plate-making data, and then by small corrugated carton manufacturers to print counterfeit possibilities are very small. Domestic fraud is still rampant, causing huge losses to many enterprises. Most enterprises in the small packaging of products to make a big article to prevent counterfeit and inferior products. However, most of the small packaging is offset or graved printing, for technical reasons to be counterfeited the opportunity. If the printing of outer packaging cartons also take technical measures, it is bound to increase the difficulty of counterfeiting.
the advantages of soft printing first of all in the green environment, the use of water-based ink printing on the working environment and substation without any pollution, absolutely beneficial to field operators and end-consumers. Carton industry has introduced and developed a large number of high-net line flexo printing machine, mainly Bost, Matian, TCY, South China Sea Oriental, Jingshan light machine and other brand models, carton net printing easily more than 50 lines, exquisite direct offset printing.
and carton packaging to logistics and transportation function-based, commodity display function with consumers at least one meter distance, flexible printing can completely replace offset printing to meet carton color. In addition, because flexo printing is generally directly printed on molded cardboard, corrugated combined strength of the same ration paper is better than offset printing, bringing a lot of room for price reduction to the cost of cartons.
the development of flexible ink
flexible ink printing regardless of the use of white paper or cardboard paper as paper, color effect can be reflected. With the ever-changing soft printing technology, ink products to high-quality ink-based, and constantly develop a higher scientific and technological content of UV/EB curing flexible ink, improve ink and cardboard ink diffusion, so that soft printing products ink thicker, more saturated, layered, aesthetic leap on paper. With the continuous development of flexible printing machines, the packaging printing industry will promote the demand for water-based inks and a variety of new flexible inks more urgent, demand will be further increased.
currently has all kinds of carton flexo printing machine nearly a thousand units, mainly using water-based ink printing, annual consumption of more than 50,000 tons, accounting for 25% of the total ink consumption. Ink is suitable for carton printing for two reasons: First, because corrugated cardboard is a loose cross fabric of fiber, strong water absorption, water-like ink transferred to the surface of cardboard easy to penetrate drying, do not need to set drying device;
Water-based inks
Water-based inks are made from a combination of water-based polymer resins and emulsions, organic pigments, water solvents and related additives by a physical and chemical process, free of volatile organic solvents and some toxic and harmful substances in solvent-based inks. The main difference between it and solvent-based ink is that the solvent used is not organic solvent but water, that is, the connecting material is composed of resin and water, its environmental protection is more suitable for food, beverages, pharmaceuticals and other health requirements of strict products. The composition of water-like ink configuration is as follows:
color material is ink coloring material, multi-choice color spectrum complete, high color concentration, easy to achieve a higher cover of organic pigments, such as magenta ink, yellow ink, blue ink, etc. are generally used organic pigments;
water-soluble or water-dispersed resin is the connection material of ink, is an important factor affecting the quality of ink, viscosity, adhesion, gloss, drying and other printing suitability depends on the resin composition. There are many kinds of water-based ink connection materials, which can be selected according to different occasions and functions. At present, the domestic ink company's research and development of inks focus on the research of connecting materials, including polyethylene alcohol, hydroxyethyl cellulose and polyethylene pyridoxine and other water-soluble link, soluble resin saline soluble link and often referred to as latex acrylic, ethylene or butyl polymer diffusion link.
from the formulation point of view, the ability of domestic ink oil packaging slurry is poor, can only reach 50%, the ability of imported resin packaging slurry reached 80%. Domestic ink because of the thick particle size, easy to damage the printing mesh roller, imported ink particle size is finer, with the mesh roller between the formation of a good affinity, will not scratch the surface of the printing material and affect the printing effect.
water-based inks are mainly water, which can be used with a very small amount of alcohols, such as ethanol, isopropyl alcohol or polypropanol. The addition of alcohols can help improve the stability of the ink, speed up the drying speed, reduce the surface Γ hub the  thanslugs? The additives of water-type inks include amine stabilizers, de-foaming agents and slow-drying agents, which regulate PH values, eliminate bubbles and adjust curing drying time. Color and ink is an important raw material for ink manufacturing, we are in the domestic distribution of ink are imported color paste and ink.
choose water-resistant inks, attention should be paid to the viscosity, concentration, fineness, drying speed, wear resistance, water resistance and stability of the inks.
viscosity
viscosity is the size of ink cohesion and the most important control index in ink applications. Ink sticky through the low, will cause light color, network expansion volume, high-gloss point deformation, uneven ink transmission and other drawbacks;
temperature on ink viscosity The temperature has a great effect on ink viscosity.
of the workshop temperature on printing quality can be seen in Table 5, the relative humidity is better at 60% to 85%.
the most sensitive when the temperature difference is high in winter and summer. When the temperature is high, the water evaporates quickly, the drying is fast, in the operation, we should pay attention to extend the drying time or improve the machine speed, when the temperature is low, the water evaporation is slow, the ink is also slow, in the operation, can improve the ink drying speed or add drying device. When used in winter, because the ink is easy to freeze below 0 degrees C, if the ink freezes, it can be placed in a room with high temperature, let it dissolve naturally, stirred well, can continue to use.
in actual production, when using a printing press with an ink scraper, ink transmission is not as stable when the temperature is too low as when the temperature is slightly higher. An increase in ink temperature reduces viscosity, resulting in a lower print density and a thinner ink layer. To maintain consistent print quality, it is necessary to maintain ink viscosity consistency. The printer must attach great importance to the influence of ink temperature, and the temperature of ink should be stabilized in the printing shop before printing. This measure is very important, otherwise the ink density in the printing process will have a more obvious change.
effect of touch denaturation on ink viscosity
touch denaturation refers to the increase of fluidity under the external force stirring, gradually decreasing fluidity after stopping stirring, and restoring the performance of the original condition. Ink placement time after a long time, some of the poor stability of ink easy to precipitate, layering. There is also the phenomenon of false thickness. At this time, can be fully stirred, after a certain period of time after stirring, the above problems naturally disappear. When using fresh ink, be sure to stir well in advance, and then make dilution adjustment. Or expect to a certain amount of ink on the machine, the degree of viscosity decline, because the machine contains water and ink tentacles can improve the flow of ink. When printing is normal, also regularly stir ink bucket, especially ink with high white pulp content.
The pH value of the ink
the effect of the PH value on the viscosity of the ink
the pH value of another indicator to be controlled in the ink application, the normal range is 8.5 to 9.5, when the printing performance of the water-based ink is the best, the print quality is the most stable. As ammonia continues to evaporate during printing, operators also add new inks and additives to the ink from time to time, so the pH value of the ink can change at any time. Using a standard PH meter, the pH value of the ink can be easily measured.
When the PH value is higher than 9.5, the alkalinity is too strong, the viscosity of the water-based ink is reduced, the drying speed is slower, the water resistance is poor, easy to paste, and when the PH value is less than 8.5 that is, the alkaline is too weak, the viscosity of the water-based ink will increase, the ink is easy to dry, blocked to the plate and mesh roller, causing the surface dirty, and produce air bubbles. The effect of PH value on water-based ink printing suitability is mainly reflected in the viscosity stability and dryness of ink and dot clarity. As the pH value increases, the viscosity of the ink decreases and the drying speed slows down.
Application Experience
Water-based inks often encounter some problems in the cardboard printing process, the reason analysis and solution can be referred to as follows:
. The adjustment of printing pressure is critical, it includes the pressure between the plate and the insemination and the pressure between the mesh roller and plate. If the ink sticks too high, the ink drys too fast, the solution is to adjust the pressure, dilute the ink, add slow drying agent.
. Ink dry on the plate, printing edge fuzzy words, may be the hot wind blowing to the plate, paper fiber mixed into the ink led to electrostation reaction, the elimination method is to dilute the ink and gradually speed up, the ink system cover, or replace the ink, install the electrostation device.
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. Ink on the plate accumulation or network pile, the reasons include too much ink, printing pressure is too large, ink drying too fast or ink is too weak, the solution is to replace the mesh roller, adjust the pressure, add slow drying agent or use high-color strong ink.
. The reasons for poor printing adhesion are ink drying temperature is too low, ink and material affinity, material surface due value is too low need corona treatment, etc. , the solution is to measure surface pressure, improve drying temperature, change ink varieties or hair-printing material surface.