China's food container packaging materials should be ecologically developed

Since the 1980s, the economic development of our country has been advancing by leaps and bounds, and all walks of life have achieved great results that attract worldwide attention. The living standards of the people have been greatly improved, and the dietary conditions and lifestyle have also been greatly changed. In particular, changes in rural dietary conditions and dietary patterns. People are pursuing a fast, simple, and comfortable lifestyle. Some people have changed their lifestyle from making breakfast to instant noodles, bread, ham, bag milk, etc. Various foods, gifts, and fruits and vegetables have also been changed from paper, bamboo, and wood packaging. For exquisite plastic packaging materials. Every household produces plastic garbage every day, so plastic waste generated from life is an important factor causing “white pollution”. At present, the city's "white pollution" has received the attention of the government and relevant departments and has been initially resolved. However, 80% of China’s population is in rural areas, and the environmental pollution caused by plastic living garbage is increasing day by day. The pollution consequences have not aroused the general public’s understanding. China’s large population accounts for one-sixth of the global population. It is the common responsibility of the entire people and even humanity to manage plastic pollution, to protect the earth, and to create a beautiful living environment for our own survival and future generations.
At present, the government has not yet had the ability to handle rural plastic waste. This requires governments at all levels to increase their management and publicity efforts. If we want to fundamentally solve this pollution problem, we must research and produce and use those biodegradable plastic packaging materials. This is a major issue that needs urgent solution. At present, domestic and foreign countries have developed and produced a variety of biodegradable plastic packaging materials instead of plastic packaging materials, and have been actively promoted and applied.

1 Degradable plastic film material

1.1 Water-soluble plastic packaging film

The main raw materials of this product are polyvinyl alcohol (PVA) and starch, all components (including additives) are all C"H"O compounds and are non-toxic, and only physical dissolution occurs between the components during the filming process. , to improve its physical properties, mechanical properties, process performance and water solubility. Water-soluble film products belong to green packaging materials [1]. As for the degradation mechanism, PVA has the degradability characteristics of water and bio-industry. It dissolves first in water to form a glue solution and penetrates into the soil to increase soil stickiness, air permeability and water retention. Sex, especially suitable for sand soil transformation, the PVA in the soil can be decomposed by bacterial strains isolated from the soil, and ultimately can be degraded into CO2 and H2O.

1.2 Plastic film made of potato and whey This product is a kind of biodegradable plastic film made of potato and whey, which is produced by using enzymes to convert whey formed during cheese making and disused potatoes into The glucose syrup is then fermented with bacteria into a liquid containing lactic acid. The cheese in the liquid is separated by electrodialysis and heated to evaporate the water, leaving behind the polylactic acid molecules that can be made into films and coatings. The plastic film thus produced can be made into a fresh-keeping bag and replaces the packaging material coated with polyethylene and waterproof wax. The greatest advantage of this product is that it can be decomposed into lactic acid which is harmless to the environment.

2 Degradable foam material

2.1 Degradable foam plastics Degradable plastics can be divided into synthetic photodegradation according to the degradation mechanism, photodegradation with photosensitizers, and multifunctional plastics with various plastics. For synthetic photodegradable plastics, polyhydroxybutyrate (PHB) and polyhydroxylase lipid (PHV) are mainly studied at present. The degradation principle is that the polymer absorbs ultraviolet light and initiates photoinitiation, so that the chain energy is weakened and long chain is split. Lower molecular weight fragments. The physical properties are degraded, and the lower molecular weight fragments are further oxidized in the air, resulting in radical chain scission and further degradation into CO2 and water.

2.2 Add photosensitizers Photodegradable plastics Add a small amount of photosensitizer in the plastic processing process, due to the photo-initiating effect of photosensitizer and photochemical reaction to generate free radical initiators, it can accelerate the process of polymer photodegradation, photodegradable plastic only Can be degraded under solar irradiation conditions.

2.3 Biodegradable plastics are mostly incompletely biodegradable with starch and polyolefin plastics. The degradation mechanism of such plastics is that starch granules are first attacked and consumed by fungi and bacteria, thereby weakening the strength of the plastics. At the same time, after the plastics are in contact with certain salts existing in the soil, peroxides are formed by self-oxidation and promote plastics. The polymer chains in the polymer break, they promote each other and complement each other. The bacteria consumes starch, which increases the plastic surface and facilitates auto-oxidative degradation. As time passes, the polymer chain gradually breaks and shortens, causing the plastic strength to decrease until the molecular weight of the polymer is finally reduced to the extent that it can be metabolized by microorganisms.

2.4 Fully biodegradable plastics The raw materials are mainly natural polymer materials such as starch, honey and biodegradable synthetic polymers or water-soluble polymer materials as the main raw material, and the degradation mechanism is in the normal outdoor natural conditions, natural UV rays, oxygen, and microorganisms act on the product, breaking the main chain of the polymer, causing a drastic decrease in molecular weight. The starch entangled in the polyolefin molecules is decomposed at the same time. The product is broken at the touch, and the remaining substances can be accepted by the environment in insects and microorganisms. Continuing to return to nature.

3 Foaming Plant Fiber Buffer Packaging Materials

Foaming plant fibers are made from plant fibers (waste newspapers, cardboard boxes and other plant fiber materials, etc.) and starch addition aids. At present, research on the production and mechanism of foamed plant fiber cushioning packaging materials are being conducted at home and abroad. Samples made in the laboratory have shown that the development of this product has great market potential [3]. The process methods adopted for the plant fiber foamed products are mainly concentrated on the non-added chemical foaming agent, that is, the foaming agent is not required to generate foaming, and the raw material is foamed by water vapor to form a granular foaming pulping. The product is more environmentally friendly than chemical foaming with additives.

4 Traditional Ecological Packaging Materials

4.1 Paper packaging materials Paper used as food packaging materials is the most economical, suitable printing, suitable for promotion, popular, environmental protection and pollution-free traditional packaging materials. In history, the majority of people used grass paper and paper ropes as various food packaging materials. China's papermaking resources are very rich, and the production process is simple. Most foods, fruits and vegetables can use paper products as packaging materials. According to experts’ prediction, China’s current consumption of paper and paperboard packaging is about 50 million tons, of which the largest amount is corrugated cardboard and honeycomb paperboard. China can consume 15 million tons of corrugated paper annually. Corrugated paper is a kind of buffer packaging material that people used earlier. It has good processing performance, low cost, wide application temperature range, and it is not only conducive to environmental protection, but also can be recycled. China's accession to the World Trade Organization has a greater demand for paper product packaging, and some developed countries have stricter environmental food packaging requirements. Researching the use of paper products as food packaging will give companies a golden opportunity for development.

4.2 Wood and Bamboo Packaging Materials Bamboo and bamboo packaging materials are used in food packaging. Our country has a history of thousands of years. Foods such as noodles and pickled foods are woven into sticks using sticks and bamboo sticks, and then they are leak proof inside and outside the tins. Made of materials, especially all kinds of fear of squeezing foods need more bamboo and bamboo packaging, all kinds of fruits and vegetables still use bamboo or twigs woven into boxes. Bamboo and wood are rich in packaging materials, low in price, easy to recycle or reuse, and non-pollution. For example, the Great Wall dry red wine is packaged in wooden boxes. The wooden packaging box is noble and beautiful, and improves the grade and popularity of the wine, especially As a gift, a wooden box is a gift for relatives and friends, which is very popular among consumers. Research and development of bamboo and wood materials for food packaging, how to make more food use its bamboo and wood packaging, how to make traditional bamboo and wood packaging mechanized production, which is the responsibility and obligation of packaging design researchers. At present, the degree of mechanization is relatively high, and the development of bamboo and wood packaging flow operations, especially the use of synthetic or compressed wood, is more highly mechanized and is more conducive to mechanized production.