Advantages of water-based inks in the printing of plastic products

Plastic water-based ink is composed of water-based resin, additives, pigments, water and other raw materials. When selecting materials, all need to meet the requirements of environmental protection. In the production process, pure water is used instead of organic solvents. Water-based ink is non-flammable, non-explosive, odorless and non-toxic. It is the world's most environmentally friendly printing ink.

Water-based ink environmental advantages

Plastic water-based inks use water as a solvent, and there is no organic solvent (VOC) volatilization and no odor during the printing process. There is no pollution or damage to the environment or to the printing operator's body. Water-based ink products will not burn themselves, and will not cause fire due to static electricity and short-circuit of wires, etc. Water-based inks will be used for printing, and the printed products will not have any residual solvent. It meets the environmental protection requirements for food packaging and other packaging in any countries and regions in the world. .

Advantages of water-based inks in printing costs

With water-based ink printing, first it does not need to be diluted with any organic solvent, only with clear water. The printing industry often says "how much solvent can be added", such as adding 30% to 50% of the solvent in the ink, and mistakenly believe that the more solvent the better, the lower the cost. In actuality, the added 30%-50% of the solvent is added during the entire printing process, which is due to the volatilization of the solvent causing the viscosity of the ink to change. The quicker the printing speed is, the faster the volatility of the formulated diluent is, and the more times the solvent is added, which means that the printing cost is constantly increased. Therefore, it is not until the 10KG ink is added with 5 KG solvent that printing starts. According to industry standards, inks have high color concentrations and low viscosity (except for screens, etc.). This relates to the raw materials selected by the ink manufacturer, such as the molecular weight of the resin, the formulation, and the production process. The amount of solvent added in the printing process is different from the closed printing room, and the rest will be changed due to factors such as temperature, wind force, etc. The addition of thinner to the ink is only to reduce the viscosity of the ink, making it suitable for printing, such as excessive When added, the color density of the ink will be reduced, and the amount of the binder will be reduced at the same time so that no good product can be printed. Therefore, water-based inks only add pure water, and they are added at one time (prepress). In the printing process, it will not cause the color change due to the change of viscosity, and it will not be like the ink, due to the waste generated when the diluent is added during the printing process, which greatly improves the pass rate of the printing product and saves The cost of the solvent reduces the appearance of waste, which is one of the cost advantages of waterborne inks.

At present, the printing industry purchases ink. Some companies only look at the surface price and do not consider other aspects. Such as white ink, look at the surface of the unit price is cheaper, but in the printing need to use 40μ deep or more plates to print, and some even use 60μ deep plate, this is mainly because the use of 35μ or less plate printing, India The coverage of the product is not enough, whiteness is not enough, so you can only make a fuss on the printing plate, the printing plate must be thick and the ink layer is thick, the printing speed is slow, this will not only increase the output, but also double the cost, such as The printing area of ​​KG ink is greatly reduced. To calculate the printing area, the cost of 18 yuan/Kg white ink plus thinner due to its small printing area will be doubled, and the deep printing will only be suitable for printing. The theory of weight delivery companies.

The use of water-based ink printing is better than the first hardware, such as good drying equipment, shallow version and so on. Water-based inks are printed using a shallow version, which avoids the phenomenon of water ripples, improves the printing speed, and more importantly, increases the printing area. For example, white ink uses a 25 μ deep printing plate, and the printing area can reach 180-200 square meters. The use of ink printing needs 40μ or more printing plates, the printing area is only about 100 square meters. A medium-sized printing company, such as using 10 tons of ink each month, to complete the same amount of printing, using water-based ink to print only 5.5-6.5 tons can be used. For example, compared with the mid-range composite ink, the average price of 5 primary colors is 25 yuan/KG, and the monthly 10 tons of ink is 250,000 yuan, plus 30% of the supporting solvent, the average price is 8 yuan/KG, or 3 tons. The solvent is 24,000 yuan, which is equivalent to using 274,000 yuan of material to complete the printing volume, and the same amount of printing using water-based ink printing, only 6 tons, the average price of water-based ink is 30 yuan / KG, that is, with 180,000 Yuan's materials have the same amount of printing. The printing company can save 1 million yuan in materials in one year. This is the amount of ink that people often say. From the above comparison, it is not difficult to see that the amount of ink consumption is crucial. . Comprehensive calculation of finished products can enable enterprises to create greater economic benefits.

The production of water-based ink is different from that of ink, so its sales method is also different. The ink is sold as finished ink. If the color saturation of the ink is not enough, only the deep version can be used to adapt. This is not only time-consuming but also increases the consumption of ink. In addition to the sales of water-based inks, in addition to finished inks, printing companies can also purchase colorants from water-based ink manufacturers. At the same time, water-based ink factories provide resin suppliers and post-process processes, implementing their own ink distribution methods. The cost of the finished ink can be greatly reduced, and the type of the printing ink can be adjusted at any time according to the printing order. For example, after the printing and compounding, the remaining water-based ink can be adjusted to the printing ink, and the gravure printing can also be adjusted to the flexographic printing. , printing paper and so on. The implementation of a multi-purpose ink, reducing the amount of ink inventory, reducing the occupation of funds, this model with its flexibility and low cost in foreign countries, a considerable number of enterprises in China have adopted this approach, with this method of ink prices About 20% lower than the purchase cost of ink, according to the calculation of ink consumption, only use 150,000 yuan of water-based printing ink will be able to complete the print volume of 274,000 yuan of ink.

Other characteristics of water-based inks, such as printing speed, gloss, abrasion resistance, etc., were published in the 05 (flexible packaging magazine) and are not stated here.

The use of water-based ink should have the conditions and precautions

Before using water-based inks, you must understand the characteristics of water-based inks. However, due to traditional practices and conservative ideas, some soft package companies have not yet been able to grasp the printing technology of water-based ink. In fact, in the printing process, so-called water-based ink printing technology is consistent with the printing technology of ordinary ink. But why are some soft pack companies still unable to print qualified products? This is mainly due to the failure to grasp the characteristics of water-based inks reflected on the press.

First of all, the printing machine should have good drying equipment, so that the surface temperature of the substrate that is blown onto the substrate can reach 60°C-80°C, and the strong wind power. Because the drying equipment is different for each type of printer, the location of the sensors is also different. If the length of the oven is not enough and the film is moving, the temperature in the first half of the oven cannot reach the temperature indicated by the temperature meter. That is, the temperature indicated by the temperature meter does not equal the drying temperature of the surface of the sheet, which is related to the wind force. There is a lot to do. So, the same drying temperature of 80 degrees, different plants will appear different printing speeds. There is also the outlet position of the oven, which cannot be blown down to avoid plugging.

Shallow version. Why use a water-based ink with a shallow version. This is mainly to increase the printing speed and avoid water ripples. The shallower the plate, the thinner the ink layer on the substrate. In this way, the higher the color density of the aqueous ink is required, the thinner the ink layer is, the faster the printing speed can be.

According to the water-based ink required for the daily printing volume, it is best to use a large bucket for uniform dilution (adding fresh water). The viscosity of the water-based ink is kept constant, and only new ink is added during the printing process, so that color aberration and waste products can be avoided. Each printing company can dilute according to printing experience, printing speed, and the depth of the printing plate. The lighter the printing plate is, the lower the viscosity of the ink is, and the faster the printing speed can be. On the contrary, the deeper the printing plate, the higher the viscosity of the ink, the slower the printing speed, and the argument that any printing viscosity should be, if it is out of the actual situation of the printing company. That is unfounded and unscientific.

After the water-based ink is poured in the ink tank, it is necessary to rotate the printing plate for 2-3 minutes. The purpose is to stir and moisten the plate. Do not put down the blade at this time. Some printing companies still have traction film pulled down, and the plate stops spinning for too long. Because the water-based ink is different from the ink, the ink plate is rotated and then the plate can be re-dissolved to eliminate the phenomenon of plug printing. However, water-based inks do not dissolve, and if the plate is plugged, it will need to be re-washed, which will affect work efficiency.

During the printing process, the effect of stopping the machine can be lifted and the printing plate can be continuously rotated to shorten the stopping time of the printing plate as much as possible. Resting halfway, the scraper can be lifted to keep the plate in rotation.

After printing, water-based ink should be poured back into the barrel, sealed, and left for later use. Clean the plate with water, and move faster. If the water-based ink is not yet dry, it can be completely cleaned with clean water. If there are plugs available soap powder boiling water cleaning, you can also use solvent cleaning, all the washing water and hand-washing water, it is best to set up several pools to sediment filtration, so as not to contaminate groundwater sources.