1 The relationship between packaging and printing and life Today's society has grown to the point where all goods need to be packaged and all packages need to be printed. Printing is the most important means of packaging and processing of product packaging. Unprinted packaging 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 anti-counterfeiting role. Today's packaging and printing are moving toward more exquisite and higher value-added products.
2 Impact of Printing on the Environment
During various aspects of the printing process, such as Kunming University of Science and Technology, He Zushun, Hu Weiping, Tan Yiguo, the improper handling of the process, it will cause environmental pollution problems, which will have an adverse impact on the human body and the environment, mainly in:
The first is air pollution. The organic compounds (VOC) discharged from the solvent ink during the drying process, the isopropyl alcohol in the alcohol wetting solution, the hot melt adhesive used in the wireless glue binding, and the volatile gas in the coating coating are all contaminated with air and harmful to human health.
The second is water pollution. Inorganic substances such as etching liquids and electroplating waste liquids containing heavy metals used during the plate making process, ink cleaning liquids such as offset printing, gravure printing, flexo printing, silk screen printing, and organic substances contained in the developing and fixing washing waste liquids of photographic film and printing plates. It is one of the causes of water pollution, and it also causes soil pollution.
The third is noise pollution. Printing machines, air compressors, and various molding machines all generate noise of varying degrees. In addition, the noise produced by the binding equipment is also great.
The fourth is the waste pages generated during the printing process and the pollution of printed materials. Pollution caused by discarding containers filled with ink, glue, and varnish, waste generated from printing or testing, and contamination of discarded printed matter.
3 Green Design in Printing Process
The pollution in the printing process is mainly generated in the factory, so the green design in printing needs to be controlled and improved in the following steps:
1) Prepress design and graphic processing
Now there is a trend, especially in gifts and health products. In order to increase the sales price of goods, some companies often make a fuss about packaging materials and printing: packaging and printing should be colorful, with the best materials, and most Process, multiple security, glazing, laminating, bronzing, and one less, which led to the over-printing and excessive packaging of the prevalence. One is a waste of limited resources and energy, while the other also adds to the impact on the environment. It also increases the cost of packaging and ultimately increases the burden on consumers.
This requires the designer to take more responsibility for the environment. In the design and creativity of the interior design, the color, texture, and gloss of the printing material itself should be used as much as possible to avoid the design of the full-page printing and to avoid over-printing: in the case of satisfying the decoration requirements. Minimize the use of hot stamping, laminating, etc., and reduce packaging materials as much as possible to reduce the difficulty of recycling after discarding the printed matter.
2) Imaging Plate Making
The computer-to-plate technology directly outputs the graphic information after RIP to the printing plate through the electric CTP, removing the film as an intermediate link, reducing the steps of film output, developing, fixing and printing in the plate making, and greatly reducing the silver content. Emissions of waste liquids, such as hydroquinone, which are harmful to the human body's environment and environment, have also reduced the harm of ultraviolet light to the human body and air pollution, and have brought good news to environmental protection.
3) Printing
The most environmental impact in the printing stage is the solvent type, especially the benzene solvent type ink. First, the organic solvents in the ink pose a serious hazard to human health. Ink solvents can damage the subcutaneous fat in the human body. Exposure to certain containers for a prolonged period can cause the skin to become chapped and rough. If it penetrates into the skin or penetrates blood vessels, it can endanger the hematopoietic function of the person with blood circulation. Solvent gas is sucked into the airway, bronchus, lungs, and through blood vessels and lymphatic vessels to other organs, which may cause chronic poisoning.
The current solution is to use non-benzene solvent inks or water-based inks, uV inks, or solvent recovery devices.
Since digital printing is directly from computer to print, film and plates are not needed, eliminating many intermediate steps of traditional printing and avoiding the use of toxic chemicals such as developer. Digital printing adopts a new imaging technology, which can largely avoid a series of problems brought about by the volatilization of organic solvents in the transfer process of traditional graphics.
4 promotion of flexographic printing
Flexo printing has developed rapidly in developed countries such as Europe and America due to its good printing quality, wide range of substrates, low investment, high efficiency, and good environmental performance. Flexo printing uses water-based inks and does not contain toxic organics, which is exactly in line with the green development trend of modern packaging printing. The biggest feature of water-based inks is the significant reduction of VOC emissions, which reduces air pollution and improves the printing shop's working environment. Due to its environmental characteristics, it is particularly suitable for the packaging and printing of food, beverages, and pharmaceuticals.
Flexo can also use solvent-free uV inks, so there is no solvent emissions and no environmental pollution. In short, the application range of flexographic printing is continuously expanding due to the adoption of environmentally friendly green materials.
Promotion of waterless and non-alcoholic printing Waterless offset printing Using ink-repellent silicone resin coated printing plates, removing the coating in the graphic part can absorb the ink and realize the graphic transfer, so no fountain solution is needed. Achieve ink and water balance. The fountain solution contains volatile organic compounds such as isopropanol, which, once inhaled by the human body, can affect the functions of the kidneys and lungs, and even cause dermatitis or damage to the nervous system. The commonly used inks for waterless offset printing are soybean oil inks and aromatic-free inks, which have no VOCs and therefore do not affect the human body and the environment.
In addition to removing the fountain solution from the production process, we can also look for alternatives to reduce the risk of IPA to workers' health and the environment. Alcohol-free printing just meets this requirement. This substitute is mainly composed of one or two chemicals of ethylene glycol and ether plus other additives and has good environmental performance.
5. Postpress
Promote the use of UV Varnish. Since UV Varnish is almost solvent-free, organic volatiles emissions are minimal, thus reducing air pollution, improving the working environment, and reducing the risk of fire.
Minimize the use of laminating processing. First of all, it will cause white pollution like the plastic products we usually use. The thin film covering the surface of the printed material is as difficult to degrade as other plastic products. In addition, benzene is involved in the processing and it is harmful to the human body. In addition, the coated paper cannot be recycled and it wastes natural resources.
Source: Guangzhou Packaging & Printing E-commerce Network