Environmental protection is the eternal theme of maintaining human living environment. With the increasing awareness of environmental protection, green printing is an inevitable trend in the development of printing industry. The development and application of environmentally friendly printing materials can effectively promote the development of green printing. This article has carried out targeted and specific analysis from paper, ink, plate and printing methods.

1, environmentally friendly paper

1) Vacuum aluminum paper

The raw and auxiliary materials used in vacuum aluminum paper production are odorless and non-toxic, and meet the US FDA standards: its printing performance and machinability are very good, and it can be applied to gravure, letterpress, offset, flexo, screen printing, and can also be pressed. Grain, die-cutting, and even embossing: it is degradable, recyclable, easy to handle and recycle, meets environmental requirements, and is an essential packaging material for export products.

2) Light paper

Lightweight paper is made of non-chlorinated imported wood pulp. It only needs to be beaten during production. It does not need to be steamed, so there will be no waste gas discharge. The paper has a high bulk and surface strength, which can achieve a lower weight to achieve higher thickness requirements. If you use light paper printing, it will be much lighter than ordinary offset paper, which not only reduces the transportation cost but also facilitates the convenience of the reader.

Now many companies are committed to research on environmentally friendly paper. Longmeng Environmental Protection Paper developed by Hong Kong Longmeng Environmental Paper Group Co., Ltd. is made of 80% inorganic mineral powder and other non-toxic additives. The manufacturing process does not use wood pulp at all. And water resources make the paper industry completely environmentally friendly. Longmeng environmental protection paper has many advantages such as super water resistance and mildew proof, anti-mite and rapid degradation.

2, environmentally friendly ink

Ink is currently the largest source of pollution in the printing industry, with an annual global ink production of 3 million tons. The global emissions of organic volatiles (VOC) caused by inks have reached several hundred thousand tons per year. These organic volatiles can form a more serious greenhouse effect than carbon dioxide, and will form oxides and photochemical smog under the sunlight, which will seriously pollute the atmosphere and affect people's health. In addition, food, toys and other packaging and printing of ordinary inks, such as heavy metals, harmful to the human body will directly harm the health of the consumer. At present, the main environmentally friendly inks are as follows:

1) Water-based ink

The biggest difference between water-based inks and solvent-based inks is that the solvent used is water instead of organic solvents, which greatly reduces VOC emissions and does not affect human health. It is not easy to burn, its ink is stable, its color is bright, it does not corrode the plate, it is easy to operate, the price is cheap, the adhesion after printing is good, the water resistance is strong, and the drying is rapid, so it is especially suitable for packaging printed matter such as food, beverage, medicine, etc. Recognized environmentally friendly printing materials are also the only inks currently approved by the American Food and Drug Association.

2) UV curing ink

Ultraviolet curing (UV) ink refers to an ink that cures ink by using ultraviolet light of different wavelengths and energy under ultraviolet irradiation. The ultraviolet spectroscopy energy is used to polymerize the monomers in the ink vehicle into a polymer, so the color film of the UV ink has good mechanical and chemical properties. At present, UV ink has become a more mature ink technology with less pollutant emissions. In addition to solvent-free, UV inks are not easy to paste, clear dots, bright and bright ink, excellent chemical resistance, and low consumption.

3) Soy ink

Soybean ink is a mixture of edible soybean oil (or other dry or semi-dry vegetable oils) and pigments, resins, waxes and the like. This ink does not contain volatile organic compounds that are polluting the atmosphere, is odorless and non-toxic, and is gradually replacing mineral oil inks centered on condensed rotary offset color inks. Affected by the protection of the environment, its popularity and promotion is very fast, taking the lead in Europe, followed by Japan and South Korea, 90% of newspapers in the United States have begun to use soy ink.

Some companies use linseed oil instead of soybean oil. Flaxseed oil is also a natural raw material, but it is a dry oil, which is faster than soybean oil, and the printing performance is smooth and stable, and the effect is better than soybean oil.

4) Waterborne UV ink

The water-based UV ink is made by adding a certain amount of water and 5% environmentally friendly solvent to the UV ink, combined with a special water-based resin. This allows the ink to retain the advantages of fast curing of UV ink, energy saving, small footprint, environmental protection, etc., and achieves printing requirements after the ink is solidified, the water is volatilized, and the ink layer is thinned. This ink is a new direction in the field of UV ink research.

5) Alcohol soluble ink

Alcohol-soluble ink is ethanol (alcohol) as the main solvent, non-toxic, safe, environmentally friendly and hygienic. It is an ideal substitute for traditional plastic inks. In South Korea and Singapore, alcohol-soluble inks have replaced toluene inks. The CL gravure alcohol-soluble composite plastic film ink is jointly developed by Hunan Jingxin Technology Co., Ltd. and Yep (Hong Kong) Ink Co., Ltd. It is an environmentally friendly product made of alcohol-soluble nitrocellulose resin and other high-grade resins. Mainly used for chocolate food, cold snacks and ordinary fast food packaging. This ink not only promotes environmental protection, but also enhances the international competitiveness of China's packaging industry. Alcohol-soluble ink, which mainly plays a role in flexo printing, is also a kind of ink with little pollution, and is mainly used in food, medicine, beverage, tobacco and alcohol, and packaging and printing of daily necessities in contact with human body.

3, environmentally friendly printing ink cleaning agent

CS-Y13 printing ink cleaning agent is made of surfactant, emulsifier, penetrant, rubber anti-aging agent and other additives. It has the characteristics of non-toxic, odorless, non-flammable, safe to store, low in price, strong in washing and deinking. The ink cleaning agent meets the professional standard of Q/CS013-2002, and is the only product of its kind that has obtained the China Green Environmental Label certification. This kind of ink cleaning agent is non-flammable after emulsification, is harmless to the human body, meets the requirements of safety, environmental protection and energy saving, and is a new generation of printing ink cleaning agent.

4, environmental protection plate

1) Green Star Edition

Agfa's flush-free version---Green Star version reduces waste liquid by 93% compared with the traditional CTP process, and reduces waste liquid by 96% compared with traditional film making. Since the market has been more than two years, the world has 1000 It is used by many printers. This version does not require any chemical syrup, only the plate protection glue, the waste liquid produced does not contain any toxic substances, and can be directly discharged.

2) Free handling of CTP plates

The unprocessed plate material means that the plate material can be printed on the machine after exposure and imaging on the direct plate making equipment without any subsequent processing steps. In terms of plate-making methods, the process-free plates are divided into two categories: process-free plates for DI (on-board direct imaging) presses and plates for exposure imaging on CTP platesetters. The process-free CTP plate improves production efficiency, eliminates the need for chemical development, reduces the amount of energy consumed during exposure, reduces the overall plate making cost, shortens the plate making process cycle, and the advantages of today's increasingly emphasis on environmental protection --- It is more obvious to the environment without pollution.

5, environmental printing method

At present, most of the flexographic printing uses environmentally friendly inks such as water-based, alcohol-soluble, and UV, so there is no residual content of the solvent, and a trace amount of alcohol does not affect human health. The unique structure and printing principle of flexographic printing meets the requirements of green packaging printing without any doubt, so it is an ideal and recognized green printing method.