Packaging printing ink and environmental protection

In recent years, due to the rapid rise and development of industries such as foods, beverages, cigarettes, pharmaceuticals, health products, cosmetics, hardware, household appliances, clothing, and toys, especially with the expansion of foreign trade, the market's demand for packaging and printing products is increasing day by day; According to statistics, the annual demand of the US printing market in 2003 was as high as 162.4 billion U.S. dollars, while nearly 21,000 packaging and printing enterprises in China had a total output value of only 75 billion yuan in 2002.

According to preliminary surveys, there are nearly 670 cities in the country that have different types of printing presses. The inks they use are mainly divided into organic solvent inks, water-soluble inks, high-solid inks, and benzene-free inks. The organic solvent type ink uses toluene, xylene, acetone, butanol, ethyl acetate and other low-boiling point volatile organic compounds as the solvent, so it is widely used due to its high printing speed, good print quality, and low cost. In the process of use, due to the volatilization of organic solvents, a large amount of toxic and harmful organic waste gas will be generated, which will cause serious local pollution. If the human body is exposed for a long time, it will bring serious damage to the nervous system and hematopoietic function.

Most of the existing domestic or imported printing machinery are not equipped with corresponding purification devices when they leave the factory. If no corresponding purification device is installed, there will be a large amount of toxic and harmful exhaust gases (such as “triphenyl”) in the production process. Acetone, etc.) are directly discharged into the atmosphere, which seriously pollutes the atmospheric environment of the city and will cause harm to the urban environment and human survival that cannot be ignored. For example, in July last year when the national six-party ministries and commissions launched a nationwide clean-up and rectification of the environmental protection market, a color printing company in the Huli Industrial Zone of Xiamen City, Fujian Province, produced organic waste without the need for any environmentally friendly purification facilities. The public was dizzy and vomiting. The local environmental protection department has now ordered them to stop production for rectification.

According to the “State of the Environment Bulletin” published by the State Environmental Protection Administration, the proportion of population living in China’s air quality standards only accounts for 26.3% of the total population in the city. The air pollution in large and very large cities is obviously heavier than that in small and medium-sized cities. The urban air environment will be further deteriorated, and a number of comprehensive standards for air pollutants, such as the Integrated Emission Standard for Air Pollutants (GB16297-1996), have been formulated for this purpose in various countries and regions. There are clear regulations; at the same time, environmental protection facilities that require new construction or expansion projects must strictly implement “three simultaneous” approvals (ie, simultaneous design, simultaneous construction, and simultaneous production use), and the national unified certification system will also be established and fully started. When applying for environmental management system ISO14000), quality management system ISO9000, occupational health management system (OHSMS) and other quality management system certifications, the discharge of environmental protection standards will become one of the most important conditions.

In order to comply with national and local laws and regulations, to ensure the sustainable development of the company itself, and to improve the working environment of the surrounding areas and employees, some printing companies have invested (some even invested heavily) equipped with corresponding printing presses for the company's printing presses. Purification facilities, but for a variety of reasons caused by the majority of companies still unable to meet emission standards or were included in the deadline for rectification, causing losses to the company to varying degrees, the main reasons for the following aspects:

(1) Due to the relatively late start of China's environmental protection industry, the control technology is relatively backward, and the relevant pollutants are not targeted, so that the purification effect cannot be achieved;
(2) The treatment process or equipment is too complex, resulting in high equipment operating costs;
(3) The equipment has hidden safety hazards, and improper control may cause safety accidents;

Concave failure rate is high, operation is unstable, maintenance is troublesome, so that environmental protection equipment can not function properly.
Due to the lack of understanding of environmental protection and purification equipment by manufacturers, coupled with the above-mentioned various reasons, some enterprises are skeptical about investing in the construction of environmental protection and purification equipment, and fear that the above problems will be caught in a dilemma.
With the development of the environmental protection industry in recent years, there are many kinds of organic pollutants and different physical properties. At present, China's organic waste gas treatment often uses the following methods:

1.Condensation recovery method: The organic waste gas is directly introduced into the condenser and adsorbed, absorbed, resolved, and separated, and valuable organic matter can be recovered. This method is applicable to the conditions with high concentration of organic waste gas, low temperature, and small air volume, and requires auxiliary refrigeration. Equipment, mainly used in the pharmaceutical, chemical industry, printing companies are less used.

2. Absorption method: generally adopts physical absorption, that is to say, the exhaust gas is introduced into the absorption solution to be purified; after the absorption solution is saturated, it is heated, analyzed and condensed and recovered; this method is applicable to the atmospheric quantity, low temperature, low concentration exhaust gas, but needs to be equipped Heating analysis recovery device, large equipment, high investment.

3. Direct combustion method: The combustion of auxiliary fuel such as fuel gas or fuel oil is used to heat the mixed gas to decompose harmful substances into harmless substances under high temperature. This method is simple in process and low in investment. It is suitable for exhaust gas with high concentration and small air volume. , but the requirements for safety technology and operation are more bureaucratic.

4. Catalytic combustion method: The exhaust gas is heated by catalytic combustion to convert into harmless and odorless carbon dioxide and water; this method has low ignition temperature, energy saving, high purification rate, convenient operation, small area, and large investment in equipment. At high temperature or high concentration of organic waste gas.

5. Adsorption:

(l) Direct adsorption method: The organic waste gas is adsorbed on activated carbon, and the purification rate can reach more than 95%. The equipment is simple and the investment is small. However, the activated carbon is frequently replaced, and the working procedures such as loading and unloading, transportation and replacement are increased, resulting in increased operating costs.
(2) Adsorption-recovery method: Adsorption of organic waste gas using fiber activated carbon, followed by superheated steam backflushing near the saturation to perform desorption regeneration; this method requires the provision of the necessary amount of steam.
(3) New Adsorption-Catalytic Combustion Method: This method combines the advantages of the adsorption method and the catalytic combustion method. It is adsorbed by a new type of adsorbent material (honeycomb activated charcoal) and introduced into the hot air after desaturation to perform desorption and analysis. After desorption, Exhaust gas leads to catalytic flameless combustion of the combustion bed, thoroughly purifies it, and the hot gas is recycled in the system, which greatly reduces energy consumption. This method has the characteristics of stable and reliable operation, low investment, low operating cost, convenient maintenance, etc. It is applicable to the treatment of large amounts of wind and low concentrations of exhaust gas. It is a mature and practical method for domestic treatment of organic exhaust gas.

With the increasing awareness of environmental protection in the entire society, environmental protection departments at all levels have stepped up efforts to monitor and penalize environmental protection in all walks of life.

The printing industry has always been one of the most active industrial fields in China's technological transformation. The elimination of old equipment, the constant upgrading and introduction of high-tech and equipment have formed some new features and development trends in the industry, and how to solve the problems of development and environmental protection, It has always been an important issue for all people in the industry to maintain the sustainable development of the company.

Reprinted from: China Coating Network