First, the development of packaging materials

Initial stage of packaging materials, can be traced back to before recorded history of mankind, when the packaging material taken from nature. After the artificial production of packaging materials such as paper, glass, metal, etc. to provide better packaging materials, packaging, varieties up more gradually, and was widely accepted.

Packaging really rise from the 1950s invention of synthetic materials - plastics began. Plastic is light, durable, barrier, easy to shape, the shape of diverse, less resource and energy consumption, etc., to replace a large number of natural resources processing of packaging materials to promote the emergence of new packaging machinery. It can be said of modern packaging, with the development of the plastics industry to develop. The sixties by the China Plastics Industry thermoplastic thermosetting plastic products to the transition period. Seventy to eighty years later developed a composite packaging materials such as aluminum-plastic composite materials, paper-plastic composite materials, plastic and plastic composite materials, etc., can replace metal, glass, paper, packaging materials,
reusable bag to improve the barrier properties of packaging , structural, and printing, making the packaging more convenient and more secure. Especially in recent years, PET, BOPP, nylon film, metallized film production, a strong impetus to the development of plastic packaging materials. Now the development of new technologies to promote the emergence of various new packaging.

Materials, industrial packaging materials gradually occupy an important position. According to incomplete statistics, the world's annual sales of packaging materials, about 500 billion U.S. dollars, employing more than 500 million, accounting for 1.5% of GDP to 2.3%.

However, packaging and short service life and high volume (such as the United States, municipal solid waste generated each year 1.5 million tons, of which 1 / 3 is packaging waste. Japanese city of about 50 million tons of solid waste annually, of which packaging waste is 21 million tons) and difficult to focus on the urban environment and the human body causing serious harm. Plastic film caused by the low recovery rate of white pollution when burned emit ozone-depleting chemicals, destruction of ecological balance of the environmental problems caused widespread concern in society.

Eco-packaging began in 1987, the United Nations Commission on Environment and Development "Our Common Future" document, it refers to the ecological environment and harmful to human health, energy, recycling and materials recycling,
nonwoven bag the packaging can promote sustainable development. Not just the pursuit of ecological materials excellent performance, but also requires the manufacture of materials, use, recycling waste until the entire life cycle must be coordinated with the coexistence with the environment and comfort. From the 1990s to now, eco-packaging materials with great development.

Second, the study of ecological packaging

1 plastic packaging eco-

Plastic packaging has many advantages in terms of packaging materials occupy an important position. While plastic packaging waste in a large proportion, about 40%. Its biggest drawback is not easy to degrade, causing pollution. Currently researchers on the development of new plastic packaging, primarily chemical degradation of biodegradable plastics and plastics.

(1) bio-degradable plastics ideal biological solution is a plastic with excellent performance, environmental microorganisms can be discarded after the complete decomposition of the polymer material. Paper is biodegradable materials, and usually non-biodegradable synthetic plastic polymer material. Biodegradable plastic is both paper and biodegradable plastic synthesis of new high performance polymer materials. Biodegradable polymer (macromolecular) materials, the degradation mechanism has been confirmed: mainly by bacteria or enzymes to break down high molecular weight molecules into small molecular weight fragments, and then further broken down by bacteria into carbon dioxide and water and other substances. Can be divided into three categories:

Polyester produced by microorganisms. Is a microbial fermentation-based molecules, it is the use of microbial enzymes to produce easy-biodegradable nature of hydrolytic depolymerization of polyester materials, synthetic polymers and then
recycle PET reusable bag break down the absorption of these compounds contain micro-organisms and microbial polysaccharides such as polyester. Microbial polyester to reduce manufacturing costs, the ongoing use of synthetic biodegradable plastics plant research. United States, Japan has used genetic engineering techniques, so that some plants grow directly out of its branches biodegradable polyesters, such as the United States, Michigan State University research group of microbial polyester biosynthesis genes into the plant system, has successfully developed the polyester can be synthesized.

From plants of the natural polymer (starch, cellulose, etc.). Starch synthesis and abroad to carry out this study of biodegradable plastics is very hot. United States of Havana. Lan Bate pharmaceutical companies through the operation of plant genes, partial control of the macromolecular chains of starch branching degree, thus creating an inexpensive starch biodegradable plastics. The company has been promoting the application of medicinal starch capsules and success. On this basis, they also use starch and biodegradable polymer mixture developed a thermoplastic biodegradable plastics, and to "NOVON" a commercial for the brand.

Synthetic polymer. The use of chemical synthesis of biodegradable plastics, such as polycaprolactone (PCL), 1975 years began to be used, but very limited use, it is said into the soil can be degraded after 12 months of 95%. PCL and starch blends, PCL and PHBV blends, PCL, and nylon 6 blends have been developed, and the protein, urea and other polysaccharide-based biodegradable polyester is manufactured, and are biodegradable plastics .

(2) chemical degradation of plastic water-soluble plastic packaging film as a novel green packaging materials in Europe, America, Japan and other countries has been widely used for packaging of various products, such as pesticides, fertilizers, pigments, dyes, detergents, water treatment agents, mineral additives, detergents, concrete additives, photographic chemicals and chemical reagents
recycling bag and other horticultural care. Its main features are: complete degradation, degradation of the final product is CO2 and H2O, can solve the problem of packaging waste disposal; safe and convenient to use, avoid direct contact with users of packaging, can be harmful for the packaging of goods; good mechanical properties, and can heat sealing, heat sealing strength is higher; with security features, high-quality products to extend the life cycle.

The main raw materials of water-soluble packaging film is a low degree of polyvinyl alcohol solution, the use of polyvinyl alcohol film forming, water-soluble and biodegradable, adding various additives such as surfactants, plasticizers, anti-sticking agent . The degradation mechanism, the two kinds of polyvinyl alcohol with water and bio-degradation characteristics of the formation of the first water-soluble glue into the soil, increase soil group argillic, permeability and water retention, especially for sand transformation. Of PVA in the soil can be isolated from soil bacteria - a single cell (Pseudomonas) strain decomposition. At least two bacterial symbiotic system composed of biodegradable polyvinyl alcohol: a bacterial activity of bacteria is polyvinyl alcohol, and the other is to produce
rpet bag material required PVA active bacteria strains. Alcohols catalyzed oxidation of polyvinyl alcohol, and then cut off the oxidized enzyme hydrolysis of PVA main chain, and further degradation will eventually degrade to CO2 and H2O.

Water-soluble packaging films have better characteristics and environmental features, extensive attention has therefore been developed, there is a very good prospect. Such as Japan, the United States, France has a large volume sales of such products, such as the United States, W. T. P Company and C. C. I. P, France's GREENSOL synthetic chemical companies and Japanese companies, their customers
recycle PET bag are also some well-known large companies, such as Bayet (Bayer), Henkel (Henkel), Shell (Shell), Agr. Eva (Aige Fu) and other large companies have started using water-soluble film packaging their products. China Zhuzhou Institute of Technology and Guangdong Zhaoqing Franshion packaging materials Packaging Corporation of China Science and Technology in support of joint research and development of water-soluble film and production equipment has passed the provincial appraisal, has been put into production, to market its products are .

Other ecological study of plastic packaging

a. development of lightweight, thin film, high-quality plastic. To reduce the amount of plastic packaging waste, countries actively promote the film, and improve its quality. The development of Japan's trade surplus tough thin PET film, thickness of 0.5 microns, precision electronic components used in the packaging. Finland developed an OPA / PE compound film, the thickness was reduced by 1 / 3, while other properties are not affected.

b. Develop re-use of recyclable plastic. Plastic packaging materials if they can re-use, can greatly reduce raw material consumption and environmental pollution. For example, the use of PET bottles, PET bottles made by the crushing blow again after a new bottle, in physics, chemistry, mechanical properties virtually unchanged. Glycol polyethylene naphthalate (PEN) to better heat resistance than PET, low-acid foods can withstand the conditions required for sterilization, UV resistance and better gas, can replace the glass, can be reused, there are wide range of applications.

c. development of new foam. As the foam lunch boxes and cushioning materials less packaging material, a huge amount, people study the new foam. There are now more ideal dichloromethane foam PS, PP, PET, used in food and electronics packaging. US-developed and efficient CFC-free polyurethane foam can INSTAPACK material with very little foam, you can repeat the molding use, easy to handle. The current development of high melt strength polypropylene (HMSPP), and polypropylene homopolymer polypropylene to produce a foam, can be compared with the performance of polypropylene sheet to save 20% of the raw materials, but also reduces the environmental load.

(2) natural bio-packaging material

Use of natural resources development, packaging materials, bio-load low with the environment, abundant resources and so on. Full use of bamboo, wood, hemp, cotton fabrics, wicker, reed, straw, rice straw and wheat straw chitin and other materials to expand the variety of packaging and improve the technical content has become one of the direction of eco-packaging.

For example, processed into straw board straw, energy saving, thermal insulation, heat insulation, sound insulation and other functions, good ventilation, high impact strength, and is waterproof and shock resistance significantly higher than traditional materials; In addition, straw board used as packaging materials, The unit mass is the same size cardboard material 1 / 10, has obvious advantages; domestic development of the rice straw as raw material to the end of meal substitutes for polystyrene foam; Po leaves after heat qualitative, bleaching, sterilization can create disposable packaging, attention by foreign importers.

In addition to straw, the country also use other straw as raw material to develop a special cardboard disposable tableware. It uses chemical additives to improve the quality of straw application optimization techniques to ensure the manufacture of tableware straw close to the board the required physical properties of wood pulp, has conducted a surface suitable for food packaging, processing, so that the finished product has a water resistant , no leakage, non-hierarchical, anti-oil and sealing functions. And can be recycled writing paper production.

Chitin is also a very good natural raw materials. Worldwide each year hundreds of chitin biosynthesis million tons, second only to the natural production of cellulose, is the second largest biopolymer on earth resources. Preparation of chitin processing with packaging materials, good air permeability, water resistance or moisture. As the raw material from natural, non-toxic, tasteless, heat to meet food, health, medicine and
recycle bag other packaging materials industry hygiene requirements. The material also has good chemical stability, light resistance, chemical resistance, resistance to oil resistance, organic solvent resistance, cold resistance, etc., its stability is better than paper.

3 edible packaging materials

The packaging harmless, edible and has a certain strength, mainly used in food and pharmaceutical packaging, the use of starch, protein, plant fiber, chitin and other natural substances as raw materials.

Corn protein packaging film: under natural conditions can be easily broken down into organic matter for heavy oil, containing high saturated fat and strong, and fast food packaging industry, deep-fried potato food, moon cake production and other food companies. Corn protein is mainly used for packaging films and other snack food packaging with inner oil. The film is a corn protein synthesis paper and packaging materials, will not be fat infiltration. The packaging material prospects. Many large companies are optimistic about this new environmentally friendly materials. Coca-Cola Company in Salt Lake City Winter Olympics used 500,000 disposable cups, all made of corn plastic. This cup is only 40 days in the open air environment disappeared. Leading Japanese electronics manufacturer Sony has been two years of plastic made from corn paper packaging MD disc. New packaging and packaging in the past as beautiful, but does not have a "durable" adverse effect. Chemical giant DuPont products have joined the development team to corn plastics, the company's research also received $ 19 million the U.S. Department of Energy's financial support.

Soy protein edible film packaging: versatile, suitable for all kinds of instant foods. Mainly soybean meal remaining after extraction of material production, a vast source of raw materials. Especially in the north area is rich in soy-rich raw materials. Because the system is the use of soybean meal after taking residues, the price is very cheap. Both the resistance of the oxygen into the packaging film, but also to maintain moisture, but also to ensure flavor. This edible packaging film applications in the food production industry in a very wide, most candy, cakes can be used, with preservation of function due to the packaging and raw materials, and therefore has an excellent industrial prospects.

Chitosan edible packaging film: This edible packaging, food packaging waste and to solve the conflict between environmental protection, used in candy, preserved fruit, fresh cake, moon cake fresh and so on. The packaging film shellfish extract using chitosan as the main raw material, the combination of chitosan and lauric acid to produce uniform edible films, packaging films and packaging with the peeled fruit and fruit pieces, there are very Good Preservation. The packaging material used by the shell chitosan was crushed shellfish processing products. As from natural, environmental pollution, the human body after consumption of the efficacy of micronutrient supplementation, can be described as a new type of environmentally friendly food packaging. The downside is the limited source of raw materials.

Edible composite packaging film: the different proportions of protein, fatty acids and starch synthesis together to produce different physical properties of edible films. The product can be adjusted according to food packaging film soft, hardness, form different types of inner packaging in the food industry should have a huge market.

4 new paper packaging

(1) paper packaging film studies. To develop high-performance alternative to paper packaging films commonly used in plastic food packaging film is very promising. The moisture-proof cellophane for example can be used in food processing, cosmetics packaging. Germany's Fraunhofer Institute where Seoul has recently developed application of the polymer thickness of only a few microns of high-strength paper membrane, with a tear-resistant, moisture-proof, easy sealing, can blow molding, biological decomposition rate and so on.

(2) honeycomb sandwich board. Is an intermediate for natural honeycomb paper core, upper and lower sides of the cardboard bonded with a light, strong, just, stable four major advantages, there are very good cushioning properties and mechanical strength, suitable for packing fragile items such as glass, precious equipment and precision instruments.

Third, the development of eco-packaging research

Eco-packaging materials are not only manufacturers of packaging materials in the production of a revolution, but also by the world's attention, so the eco-packaging research from the development, design, production, use, and disposal process of the whole consideration.

Nano-plastic has excellent physical and mechanical properties, high strength, heat resistance, good gloss and transparency, high barrier, excellent processing performance, is eco-friendly materials, can be used for food, chemical materials, toxic substances packing.

Institute of Chemistry / Molecular Science Center, State Key Laboratory of Engineering Plastics has successfully developed a polyamide (PA6 and PA66), polyester (PET and PBT), polyethylene, polystyrene, epoxy resin and a series of nano-plastic, and to achieve
non woven bag china some of the industrial production of nano-plastic. Nanocomposites in food packaging market has great potential. Plastics such as polyamide 6 nm (nc-PA6) film made with the slices can be prepared by extrusion blow molding and heat-shrinkable casing film, biaxially oriented film composite membrane, compared with normal PA6 has better barrier properties , mechanical properties and transparency.

A use of nanotechnology CO2 efficient catalytic synthesis of biodegradable plastic, from the Guangzhou Institute of Chemistry, Chinese Academy of Sciences developed. CO2 and propylene oxide with the polymerization of the biodegradable plastic, and can replace the market of fast food containers widely used, both to solve the environmental problems caused by CO2, but also arising from the use of plastic packaging to avoid the "white pollution . "

Gene technology is one of the direction of research, the use of advanced directional design of artificial gene splicing technology that allows plants to grow in accordance with the design requirements of people of various shapes, all colors of the container (even those pre-designed container can grow by a variety of patterns and designs), such as a variety of milk, juice, vinegar, packaging, packaging of disposable tableware may be cut from a genetically re-grow directly on the corn plant, the future of the bottle may be from a technology created through genetic modification directly on the harvested pepper plants.