Third, the ecologicalization of packaging materials
1) Due to the rapid increase in the consumption of plastic packaging materials, the “white pollution†caused by the increasing serious, must take appropriate measures for thorough governance, the way to solve is the ecologicalization of plastic packaging: 1) Degradable plastic packaging materials since the development of biodegradable plastics Because photodegradable plastics decompose into water, carbon dioxide, plastic powder, or low molecular weight oligomers, it will become a new source of pollution. In general, starch-destructive decomposition is slow, and decomposed fragments remain contaminated. Microbial degradation of plastic is more desirable, but the price is higher.
2) Recyclable plastic packaging material Polyethylene naphthalate (PEN) is more heat-resistant than PET and can withstand the sterilization conditions required for low-acid foods 牗116°C, 63min ç‰, especially for gas barrier and UV protection Better performance, longer shelf life, can replace glass bottles, and therefore has a wide range of application prospects for packaging of beer, beverages, cosmetics, food, etc., and is a package that can be reused.
3) Foamed packaging materials In accordance with the Montreal International Convention, CFC foaming agents are banned. Foamed plastics production is moving towards a "zero ODP" and "low GWP" low-pollution process. The current development of high melt strength polypropylene (HMSPP) and polypropylene homopolymers can produce foamed polypropylene with fine micropores and uniform distribution. Due to the low density, 20% of raw materials can be saved compared to polypropylene sheets with the same properties. The same environmental load is also reduced. In order to reduce the environmental load, bubbly cushioning material substitutes have also been developed, such as blister plastic films, paper liners, pulp molded products, and paper-plastic composite bag inflatable cushions.
4) The reduction of thin-wall containers and pouch containers is an important direction for the ecologicalization of packaging materials. The use of membranes instead of bottles, monolayer membranes instead of multilayer membranes, bottles, and cans have been reduced to achieve reductions. Mainly through changes in consumer attitudes, eco-design, improve the quality of packaging, materials, high-strength light quality and other measures to achieve.
(2) Edible packaging is mainly used for food and medicine packaging, using starch, protein, plant fiber and other natural materials as raw materials. The packaging is harmless to the human body, edible and has a certain strength. For example, ice cream cups, drug capsules, and the like have been used. At present, there are starch casings, starch dishes, and the like that have been developed in research and are being expanded in application.
(3) The development of natural biological resources using natural biological resources to develop packaging materials has the characteristics of low environmental load and abundant resources. Making full use of bamboo, sawdust, hemp, cotton fabrics, wicker, reeds, crop straws, rice straw, wheat straw and other raw materials, expanding the variety of packaging, and increasing the technical content have become one of the directions of ecological packaging. For a long time, people have accepted baskets, bottles and other packaging, but due to the diversification of packaging materials, natural bio-materials packaging production technology has stagnated, and there is a gradual trend of shrinkage. In recent years, due to the improvement of public environmental awareness, natural bio-packaging materials have received more attention from people. For example, domestically developed polystyrene foam meal box substitutes using crop straws and rice straw as raw materials, and disposable leaf bowls made from heat-set, bleached, and sterilized leaves are favored by foreign importers.
(4) Paper packaging has many advantages, and it occupies the top place in packaging materials. In the main four kinds of packaging in China, paper packaging accounts for more than 50%. However, per capita forest resources in China are poor, and non-wood pulp and papermaking should be actively developed. Reeds, bagasse, cotton stalks, wheat straw, bamboo, and other wood-based papermaking should be used to expand the accelerated plantation, and the branch materials, waste materials, and processing materials should be fully utilized. , to expand the source of raw materials. Through the development of new pulp enhancers and improved corrugated board structure, the paper strength is increased and the board thickness is reduced to achieve the purpose of reduction.
Fourth, recycling of packaging materials
(1) The industrial waste in a recycling factory is more recyclable than the waste generated after use. The source of the waste is clearly identified. The variety and quantity of the waste can be easily grasped, and impurities are rarely mixed. Therefore, the most effective recycling method can be achieved." Closed system "recovery.
(2) Recovery of waste after packaging 1) Recovery of glass packaging containers Recycling and recycling beer bottles is a successful example of waste recycling. There are mainly reasonable recycling mechanisms, and consumers have formed a good sense. The recovery rate of beer bottles in Japan can reach 95% or more. China began to implement new international standards in 1999, and the recycling period for beer bottles is 2 years. Glass bottles that cannot be reused can be used as glass raw materials instead of silica sand, limestone, and soda ash.
2) Recycled paper packaging paper packaging used a larger amount of cardboard, China's old corrugated paper has a stable recovery mechanism, basically can be recycled, but overall still lags behind developed countries. 80% of Japanese packaging paperboard uses old pulp. The recycling of paperboard, general paper bags, and packaging paper can be treated by ordinary recycled paper, but it must be softened and dispersed to remove iron, glue and other foreign materials through filtration and centrifugation. Different from the new paste, the surfactant is used to emulsify and remove the printing ink.
3) Plastic Packaging Recycling
1 Implementation of Reusable Containers The reuse of large plastic containers for industrial liquid raw materials or liquid products has been adopted. Beverage containers and other liquid product containers with large turnover volume can be reused by manufacturing standard bottles, realizing container enlargement, marking, functionalization, developing sterilization and washing technologies, and establishing an effective recycling mechanism. At present, PET bottles can be reused more than 20 times and PC bottles can be used more than 100 times. The United States develops concentrated cleaning products and recharging technologies, and the recharge rate can reach 40%.
2 The characteristics of the marked plastic packaging are many varieties and similar appearance, which brings difficulties for recycling. Marking can facilitate classification, simplify the process and reduce costs. 3 Recycling technology of plastic packaging materials With the maturity of the recycling mechanism and technological progress, the cost will decrease and the proportion of material recovery will increase. The chemical recovery is limited to individual varieties. PS, PMMA pyrolysis recovery monomer, PET, nylon hydrolysis recovery monomer, is currently mainly achieved economic rationality. It is an ideal method to dispose of plastic packaging material by pyrolysis of oil and gas, which can handle mixed plastic waste. However, the price of recovered oil and gas is still higher than the price of crude oil. It is economically more favorable than pyrolysis to be used as a blast furnace reductant and heat source. In order to promote the recycling of packaging waste, some countries have established social systems to share the recycling economy.
4) Recycling of metal packaging In China, packaging bottles, steel drums, aluminum drums and aluminum cans are basically recovered because of their high residual value. The main barrels are mainly reused, and the cans are generally melted to make other low-value aluminum products. Considering aluminum's good reproducibility, saving resources, energy, and reducing environmental load, the aluminum recycling level should be further improved. Whether it is the United States with a large aluminum production or Japan with a lack of resources, great importance is attached to aluminum recycling. Seventy percent of aluminum cans in the United States are remelted and rolled from cans and recycled old cans. In 1998, the aluminum cans had a recovery rate of 63%.
(3) Recycling of foreign packaging materials Europe first promulgated the “Regulations on Packaging Management†in Germany, and in 1991 it established a “Dual Waste Disposal System†by manufacturers and merchants, which has achieved significant results and the consumption of packaging materials within 5 years. The volume was reduced by 12%; in 1998, Germany changed the “Regulations on Packaging Management†to “Avoiding and Recycling of Packaging Wasteâ€. The experience of Germany’s operations has attracted widespread attention around the world. The European Community Packaging Guidelines were introduced in 1994 and came into force in 1996. Japan enacted the Container Packaging Recycling Act in 1995. In 1997, it implemented the recycling of iron and aluminum cans, glass bottles, beverage cartons, and PET bottles. In 2000, it was expanded to all containers. The Dutch SVM organization consists of 200 packaging companies, including packaging materials production, sales, beverage canning and recycling and other departments. In 1993, 28 packaging production and sales companies in the United Kingdom formed the producer responsibility industry group. The establishment of these organizations improved the packaging material recovery system.
