Problems faced by the hottest development of green

2022-10-04
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Problems faced by the development of green printing

the industrial development speed in the world today is amazing, and the industrial pollution produced is also shocking. Toxic industrial wastewater, waste gas, solid waste and so on are gradually devouring our homes. At the same time, more and more people also begin to care about our living environment and begin to realize the importance of environmental protection for sustainable development. Today, environmental protection has been deeply rooted in the hearts of the people. At present, printing enterprises all over the world are advocating environmental protection, and have stepped up the research and development of green materials and pollution-free printing methods. Among them, the most outstanding is ecoprint in the United States. They not only develop environmentally friendly paper, cooperate with ink manufacturers, improve ink production lines, remove ingredients harmful to the environment from childhood, and use pollution-free fountain solution substitutes... Even the energy is pollution-free wind power generation. Summarizing the production experience in recent years, combined with the current technical status, we can strive to reduce the environmental pollution caused by printing from the following aspects

choose environmental friendly ink

ink is essential in the printing industry and is used in a large amount, but it is also the most serious harm to human health and the environment and other parts that may be very important for special rigidity and wear resistance. The first is volatile organic compounds VOC. The volatilization of ink solvent will cause serious greenhouse effect, form photochemical smoke, and damage the human nervous system; The second is the heavy metal elements such as pliers, chromium and mercury in the ink and pigment. If the Shantou ink containing these heavy metals is used for food packaging or the printing of articles in close contact with the human body, the consequences will be unimaginable. In order to reduce the damage of ink to the environment, it is necessary to use new pollution-free ink

UV curable ink

UV curable ink refers to the use of ultraviolet radiation with different wavelengths to turn the ink from liquid to solid, and film-forming and drying. Because this ink does not contain any volatile solvents, it has no VOC or other harmful substances emissions, and the pollution is almost zero. It is a real environmental friendly ink. It also has the advantages of good gloss, bright colors, fast drying speed and so on. It is an ideal Shantou ink. At present, UV ink technology has been relatively mature, but when using it, we should pay attention to prevent UV damage to operators and avoid the generation of ozone. These problems can be solved by equipping the operators with UV protective overalls and rubber gloves and constantly blowing around the UV lamp

water based ink

this ink uses water and ethanol as solvents, with extremely low VOC emissions, little environmental pollution, and no harm to human health. It is the only ink approved by the American food and drug association among all printing inks at present. In the United States, 95% of flexo prints are printed with water-based inks. In addition, it also has the characteristics of not easy to burn, bright colors, non-corrosive plates, good adhesion, strong water resistance and so on. It should be noted that water-based ink is generally alkaline. Therefore, the wastewater from cleaning ink tank, ink roller and printing plate should be added to acidic substances before being discharged, otherwise it will cause water pollution

aqueous UV ink

because the diluent of UV ink currently used is toxic and irritating to the skin, it is necessary to improve this diluent. Aqueous UV ink was born under this background. It uses ethanol and water as diluents. This kind of ink has the good environmental protection characteristics of the above two inks

new environmentally friendly inks

such as vegetable oil inks, soybean oil is currently the most used. The standard of American Soybean Oil Association stipulates that the soybean oil content of sheet fed offset printing ink is more than 20%, and the soybean oil content of rotary offset printing ink is more than 7%. Osaka printing ink company of Japan has also recently launched a new environmental friendly ink, which is a sheet fed offset ink. It is 100% vegetable oil ink with soybean oil as the main body, which meets the environmental protection requirements

R & D and use of

pollution-free film and developer

at present, not all enterprises have the ability to adopt CTP and digital components made of viggs Victrex Paek, which have higher production efficiency and proofing process. Laser imagesetters are also everywhere, and the use of silver salt containing film has become an inevitable problem. When fixing, the waste water contains silver ions, which will cause damage to the environment. The harm of developer can not be ignored. The developer is usually hydroquinone and other drugs harmful to human body. Long term contact will cause hair loss, skin redness, and serious eye diseases

now there is a dry film imaging technology. Using a special film can solve the above problems. It has no exposure and development process of traditional film, and it can image without any chemical substances, so it is called "green film"

using CTP and digital proofing

computer direct plate making technology, the graphic information after Rip is directly output to the printing plate through the computer, which removes the film as the intermediate link, reduces the steps of film output, development, fixing and plate printing in plate making, greatly reduces the discharge of waste liquid containing silver, hydroquinone and other harmful to human body and the environment, and also reduces the harm of ultraviolet light to human body and air pollution, It brings good news to environmental protection

the digital proofing technology corresponding to CTP is phasing out the traditional proofing technology for film printing. Digital proofing and CTP technology together announced the advent of the digital printing era, but also announced that the film that has been used for many years and has hidden dangers of environmental pollution is about to withdraw from the printing market. Heavy metals and toxic developers that do great harm to human body and the environment will no longer be used. This technology undoubtedly greatly accelerates the pace of printing towards environmental protection

however, CTP and digital proofing technology are not perfect. At present, CTP has not been produced in large scale, so the price is relatively high and the use cost is large. Only a few large enterprises are willing to buy it, while many other small and medium-sized enterprises still use the traditional plate making method with low cost. The same is true for digital proofing. Not only is the machine expensive, but also the proofing cost is about twice that of the traditional one. These factors have restricted the development of environmental friendly printing technology

vigorously promote flexographic printing

flexographic printing has developed rapidly in Europe and the United States and other developed countries because of its good printing quality, a wide range of substrate materials, low investment, high efficiency, good environmental performance and other advantages. An important reason why flexographic printing takes the lead in the field of packaging is that it uses water-based ink and does not contain toxic organic substances, which is just in line with the green development trend of modern packaging and printing. The biggest feature of water-based ink is that it significantly reduces VOC emissions, thereby reducing air pollution and improving the working environment of the printing workshop. Because of its environmental protection characteristics, it is especially suitable for the packaging and printing of food, beverages, drugs and other items

UV ink without solvent can also be used for flexo printing, so there is no solvent emission and no environmental pollution. In short, due to the use of environmentally friendly green materials, flexographic printing is expanding its scope of application, and is even more dominant in the field of packaging and printing. Therefore, in order to achieve green printing, we must vigorously promote flexographic printing

try anhydrous offset printing and alcohol free printing

anhydrous offset printing uses ink repellent silicone resin coated plates. Removing the coating in the image and text part can absorb ink and realize image and text transfer, so there is no need for fountain solution to achieve ink and water balance. The fountain solution contains volatile isopropanol and other toxic organic substances, which will affect the function of kidney and lung, and even cause dermatitis or nervous system damage if inhaled by the human body for a long time. Generally, the inks used for waterless offset printing are soybean oil inks and aromatic free inks, which do not produce VOC, so they will not have an impact on human body and the environment. Therefore, removing the fountain solution and using non solvent inks can be said to be a major contribution of waterless offset printing to environmental protection

in addition to removing the fountain solution in the production process, we can also find its substitute to reduce the harm of IPA to workers' health and the environment. Alcohol free printing just meets 2) UPS discontinuous power supply responding to the equipment; Requirements. This substitute mainly comes from one or two chemicals of ethylene glycol and ether plus other additives, which has good environmental protection performance. Of course, the use of substitutes will also bring some new problems, such as the new fountain solution volatilizes too slowly, which is not conducive to the cooling of the machine, and substitutes are not as effective as alcohol in disinfecting the fountain system

develop the digital printing market

because digital printing is directly from computer to print, there is no need for film and printing plate, which saves many intermediate steps of traditional printing and avoids the use of toxic chemicals such as developer. Digital printing adopts new imaging technology, which can largely avoid a series of problems caused by the volatilization of organic solvents in the process of image and text transfer in traditional printing. The main imaging principles of digital printing are as follows:

electrostatic photography

its basic principle is to use the laser scanning method to form an electrostatic latent image on the photoconductor, then use the Coulomb force between the charged toner and the electrostatic latent image to realize the visualization of the latent image, and finally transfer the toner to the substrate. Because electrostatic photography uses toner, there is no volatile organic compounds in the whole printing process. It is a pollution-free imaging technology

inkjet printing

spray the ink from the fine nozzle to the substrate at a certain speed, and finally realize the reproduction of the ink image through the interaction between the ink and the substrate. According to the way of inkjet, it can be divided into continuous inkjet and on-demand inkjet

magnetic recording imaging

this technology relies on the magnetic material to form the latent image under the action of the external magnetic field, and then uses the interaction between the magnetic toner and the magnetic force of the latent image to complete the visualization of the latent image, and finally transfers the magnetic toner to the substrate to complete the printing

electrocoagulation imaging

the ink condenses through the electrochemical reaction, so that the ink is fixed on the surface of the imaging drum to form an image. The ink that does not react in the non graphic part is still liquid and can be scraped off. Finally, the ink fixed on the surface of the drum and inspected by s (3) 400 tungsten filament scanning electron microscope for the number, size and dispersion of 'phases in the alloy under different heat treatment systems can be transferred to the substrate through the action of pressure

eliminate the film covering and plastic coating process

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