Pollution and environmental protection countermeas

2022-09-23
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Pollution of packaging and printing and environmental protection countermeasures

1 the relationship between packaging and printing and life

today's society has developed to the extent that all commodities need packaging and all packaging needs printing. Printing is the most important decoration and processing means of product packaging, and packaging without printing is almost unimaginable. Printing plays a role in transmitting information and promoting products. At the same time, for some commodities, printing also plays an important role in anti-counterfeiting. Today's packaging and printing is developing towards more exquisite and improving the added value of goods

2 the impact of printing on the environment

in all links of the printing process, such as hezushun, huweiping, tanyiguo, School of mechanical and electrical engineering, Kunming University of science and technology, improper processing of the process will produce environmental pollution problems, which will have adverse effects on human body and the environment, mainly in:

first, air pollution. Organic compounds (VOC) emitted by solvent ink in the drying process, isopropanol in alcohol wetting solution, hot melt adhesive used for wireless binding, volatile gas of glazing paint, etc. all pollute the air and are harmful to human health

second, water pollution. Inorganic substances such as corrosive liquid and electroplating waste liquid containing heavy metals used in the process of plate making, ink cleaning and discharge liquids such as offset printing, gravure printing, flexo printing and silk screen printing, and organic substances contained in the developing and fixing waste liquid of photographic film and printing plate are all one of the reasons for water pollution, as well as soil pollution

third, noise pollution. Printing machines, air compressors and various molding machines will produce varying degrees of noise. In addition, the noise generated by binding equipment is also very large

fourth, the pollution of waste pages and printing waste generated in the printing process. Pollution caused by discarded containers containing ink, glue and polish, waste products generated during printing or trial printing, and environmental pollution caused by discarded printing materials

3 green design in the printing process

pollution in the printing process is mainly produced in the factory, so green design in printing needs to be controlled and improved in the following links:

1) prepress design and graphic processing

now there is a trend, especially in gifts and health products. In order to improve the sales price of goods, some enterprises, Often make an issue of packaging materials and printing: packaging and printing should be as gorgeous as possible, using the best materials, the most processes, multiple anti-counterfeiting, polishing, laminating, and bronzing. This has led to the prevalence of over printing and over packaging. On the one hand, it is a waste of limited resources and energy; on the other hand, it also aggravates the impact on the environment; on the other hand, it also increases the cost of packaging and ultimately increases the burden on consumers

this requires designers to take more responsibility for the environment. In the decoration design and creativity, they should try to use the color, texture and gloss of the printing material itself to avoid full version. Therefore, when purchasing a pressure testing machine, they should first understand the scope of application of the instrument, the design of printing, and avoid excessive printing: under the condition of meeting the decoration requirements, they should try to reduce the use of bronzing, laminating and other processes, as well as packaging materials, Reduce the difficulty of recycling printed materials after they are discarded

2) imaging plate making

computer direct plate making technology directly outputs the graphic information after rip to the printing plate through electric CTP, 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, p-diphenol and other harmful to the human environment, and also reduces the damage of ultraviolet light to human body and air pollution, It brings good news to environmental protection

3) printing

what has the greatest impact on the environment in the printing stage is the solvent. Precautions for using high and low temperature universal material testing machine: type, especially benzene solvent ink. First of all, the organic solvents in ink cause serious harm to human health. Ink solvent will damage the subcutaneous fat of human body, and long-term contact with some containers will make the skin dry and rough. If it penetrates into the skin or blood vessels, it will endanger people's hematopoietic function with the blood circulation. Solvent gas is sucked into the trachea, bronchus, lungs and transmitted to other organs through blood vessels and lymphatic vessels, which may cause chronic poisoning of the body

the current solution is to use non benzene solvent inks, water-based inks, UV inks, or solvent recovery devices

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

4 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 and good environmental performance. Flexographic printing adopts water-based ink, which does not contain toxic organic substances, 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, the application scope of flexographic printing is expanding

promote anhydrous offset printing and alcohol free printing. Anhydrous offset printing uses a printing plate coated with ink repellent silicone resin. Removing the coating on the image and text part can absorb ink and realize the transfer of image and text. Therefore, there is no need for fountain solution to achieve water ink balance. The fountain solution contains volatile isopropanol and other toxic organic substances. Once inhaled by the human body for a long time, it will affect the function of the kidney and lung, and even cause dermatitis or damage to the nervous system. In the actual production process, we generally carry out the control system of color difference from the following six aspects. Generally, the inks used for waterless offset printing are soybean oil inks and aromatic free inks. They do not produce VOC, so they will not have an impact on human body and the environment

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 this requirement. This substitute mainly comes from one or two chemicals of ethylene glycol and ether plus other additives, which has good environmental protection performance

5. Post press processing

promote the use of UV varnish. Because UV varnish contains almost no solvents, and the emission of organic volatiles is very small, it reduces air pollution, improves the working environment, and reduces the risk of fire

try to use less lamination processing. First of all, it will cause white pollution like the plastic products we usually use. The film covered on the surface of printed matter is as difficult to degrade as other plastic products, and benzene is involved in processing, which is harmful to human health. In addition, the coated paper can not be recycled, which wastes natural resources

reprinted from: fine chemicals in the 21st century

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