Green Packaging: An Inevitable Choice for Chinese Enterprises (I)

Green packaging material

Broadly speaking, green packaging materials are packaging materials that are harmless to human health, have good protection for the ecological environment, and are recyclable during production, manufacture, use, and recycling.

1. Repeated and recycled packaging materials

Repeated use of packaging, such as beer, drinks, soy sauce, vinegar and other glass bottles can be used repeatedly. Sweden and other countries implement repeated reuse of polyester beverage bottles and PC milk bottles for more than 20 times.

Recycling packaging, such as polyester bottles, can be recycled after physical and chemical methods. The physical method refers to direct and thorough purification and smashing without any residual contaminants. The treated plastics are then directly used to produce recycled packaging containers. The chemical method means that the recovered PET bottle is crushed and washed, and then the depolymerization agent such as methanol water, ethylene glycol, or diethylene glycol is used to depolymerize all the PET into monomers or partially depolymerize into oligomers under the action of a basic catalyst. The monomers or oligomers are then re-polymerized into recycled PET resin packaging material.

The repeated use and regeneration of packaging materials only prolongs the service life of plastics and other polymer materials as packaging materials. After reaching the end of its service life, it still faces the problems of waste disposal and environmental pollution.

2. Edible packaging materials

The development of edible packaging materials is the best way to solve the contradiction between food packaging waste and environmental protection. The goal pursued in the development of edible packaging is to produce a packaging film that does not affect the flavor of the packaged food, which can be consumed. For example, glutinous rice paper used for candy packaging and corn baking packaging cups for packaging ice cream are well known.

The pullulan resin that has been put into industrial production in the 1970s is an odorless, amorphous, amorphous white powder, and is a non-ionic, non-reducing, stable polysaccharide. Because it is easily dissolved in water, it can be used as a viscous, neutral, and non-liquoring non-gelling aqueous solution. Its 5% to 10% O% water solution can be made into a film with a thickness of 0.01 mm by drying or hot pressing. This film is transparent, colorless, odorless, non-toxic, has toughness, high oil resistance, and can be eaten. Can do food packaging. Its gloss, strength, and folding resistance are better than films made from high-chain starch.

There is also an edible cling film, which has been developed into a multi-component edible film made of a variety of biological macromolecules (proteins and polysaccharides) and lipids having various functional properties. Such composite membranes mainly form a stable emulsion by interacting with different molecules, and then they are dried to volatilize the solvent to form a porous, transparent or translucent film of a three-dimensional network structure. The porous network structure enables the membrane to have The obvious waterproofness and certain selectable breathability, therefore, has a broad application prospect in the food industry, especially in the preservation of fresh fruits and vegetables.

3. Degradable packaging materials

Degradable packaging material refers to a plastic whose chemical structure changes at a specific time and in a specific environment. Degradable plastics not only have the functions and characteristics of traditional plastics, but also can be split and degraded in the natural environment through the action of ultraviolet light in the sunlight or the action of microorganisms in the soil and water after the service life is completed, and finally renewed in a non-toxic form. Enter the ecological environment and return to nature.

Biodegradable plastics are generally classified into synthetic photodegradable plastics, photodegradable plastics and biodegradable plastics added with photosensitizers, and multi-functional degradable plastics combined with various degradable plastics. According to the degradation environmental conditions, degradable plastics can be divided into photodegradable plastics, biodegradable plastics (fully biodegradable plastics and partially biodegradable plastics), chemically degradable plastics (oxidative degradable plastics and water degradable plastics), and the above three kinds of degradation. Plastic composite degradable plastic.

Among synthetic photodegradable plastics, polyhydroxybutyrate (PHB) and polyhydroxyvalerate (PHV) are the most widely produced, and their properties are similar to those of polyethylene and polypropylene, and the price is about 10 times that of polyethylene. The principle of its degradation is that the polymer absorbs ultraviolet light to initiate the photoinitiation, so that the bond energy is weakened, long chains are split into lower molecular weight fragments, and physical properties are degraded. The lower molecular weight fragments are further oxidized in the air, generating radical chain scission and further degrading to carbon dioxide and water.

In the plastic processing process, adding a small amount of photosensitizer can make general plastics become photodegradable plastics. This method is simpler than the copolymerization synthesis method and the cost is lower. Photodegradable plastics are mainly used as beverage bottles, shopping bags, garbage bags, and plastic films in foreign countries. Domestic research and development of photodegradable plastics are mainly used for plastic film. In recent years, photodegradable plastics have been developed for use in disposable snack boxes. Because photodegradable plastics can only be degraded under solar irradiation conditions, they are greatly constrained by geographical environment and climatic conditions. To achieve accurate time control, it is difficult to degrade and the buried part cannot be degraded. Therefore, large-scale application is subject to certain restrictions. limit.

Polymers based on petroleum as raw materials are difficult to be decomposed by ordinary microorganisms under natural conditions. Polymers and natural polymers synthesized from genes that are prone to hydrolysis have high biodegradability. Researches in our country are based on the incomplete biodegradable plastics that are blended with starch and polyolefin plastics. The degradation principle of such plastics is that starch granules are first eroded by fungi and bacteria and consumed, thereby weakening the strength of the plastics. At the same time, the starch granules are subjected to autoxidation and contact with some salts existing in the soil to form peroxides, which promote the polymer in the plastics. The molecular chain breaks, they promote each other, complement each other, the bacteria consumes the starch, causes the plastic surface area to increase to be advantageous to the auto-oxidation degradation. As time goes by, the polymer chain gradually breaks and shortens, so that the plastic strength decreases until the molecular weight of the polymer is reduced to the extent that it can be metabolized by microorganisms.

4. Paper packaging material

The raw materials of paper are mainly natural plant fibers, which will quickly rot in nature, will not pollute the environment, and can also be recycled for papermaking. Pulp molded products not only have the advantages of light weight, low cost, shock resistance, etc., but also have the characteristics of good air permeability, which are conducive to the preservation of fresh foods. In the international commodity circulation, they are widely used in egg products, fruits, glass products, etc. Fragile, easy to break, 1, white squeezed items on the packaging.

In the new century, environmental protection has become a problem that involves the survival and development of every company and individual. With the continuous emergence of new environmentally friendly materials and technologies, green packaging has gradually become a realistic choice. Establishing environmental awareness, keeping up with the trend of international green packaging, and developing green packaging are the inevitable choices for Chinese companies to embrace economic globalization.

First, the current situation and misunderstanding of China's packaging

Most of the packaging is a one-off consumer goods, short life cycle, waste discharge. With the rapid development of China's economy, the increase in the number of commodities and the variety of products, the corresponding packaging design has also been significantly improved. Relevant information shows that China's packaging industry currently has more than 25,000 companies, and its annual production value has increased from 7.2 billion yuan in 1980 to 220 billion yuan in 2000, which is increasing by nearly 20% every year. However, the development of the packaging industry also consumes at the same time. A lot of resources.

At the same time, there is a misunderstanding on the basic concept of packaging design in our country. We believe that product packaging design is only an important means to evoke consumers' desire to purchase, promote sales of goods, and obtain economic benefits. Under the influence of this concept, a large number of packaging designs that only focus on the immediate economic benefits emerged. If the product packaging size, volume is too much, unnecessary multi-level cumbersome packaging, in order to make the goods have a sense of high-end, high-cost printing, in order to reduce the packaging cost, the use of packaging materials that are not easy to recycle and processing are also everywhere. In addition, the industrialization level of China's packaging industry is still low, the use of packaging products and recycling and processing systems are not perfect, and management tools are scarce, resulting in a large number of packaging waste. According to statistics, at present, there are more than 100 million tons of wastes from the packaging industry in the world and 15 million tons in China. The annual amount of packaging waste accounts for about one-third of the city's fixed waste in terms of weight, and accounts for 1/2 of its volume, and the amount of emissions is increasing at a rate of 10% per year, thus making the packaging waste pollute the environment. The problem has become increasingly prominent, causing the world’s public and environmental protection community to attach great importance.

In 1987, the UN Environmental Protection Agency held its first meeting on the protection of the ozone layer in Montreal, Canada. Representatives of 56 countries and regions signed the protocol and for the first time set forth clear requirements and directions for the coordinated development of the packaging industry and the environment. Some countries have successively promulgated relevant laws and regulations regarding packaging and packaging waste. The environmental protection circles of the United States and other countries have put forward three opinions on reducing the quality of packaging wastes. First, they should minimize or use less packaging; second, they should try to recycle packaging. The third is that all those that cannot be recycled can be biodegradable and do not endanger the public environment. For this reason, Germany, France, the United States, the European Community and other countries have successively formulated strict packaging waste restriction laws. There are also more and more environmental protection clauses in the national trade agreements. Green packaging has become a barrier for western developed countries to hinder the entry of developing country goods into the international market, forming a "green trade barrier." If there is no green label product, some developed countries will refuse to import, and may not offer preferential prices and tariffs. After China's accession to the WTO, although China will have an all-round multilateral trade environment, if packaging fails to keep up, it will restrict the development of foreign trade exports and make it more difficult for China's products to reach the international market. Therefore, it is imperative to promote "green packaging" in our country.