In recent years, packaging has occupied an important position in the industry. According to incomplete statistics, the annual sales of packaging materials in the world is about 50 billion U.S. dollars, employing more than 5 million people, accounting for 1.5 to 2.3% of the GNP. The packaging industry in developed countries is the ninth or tenth largest industry in China. Since China's reform and opening up, the packaging industry has achieved rapid development. However, due to the constraints of technology, capital, and management, research and implementation of the organic integration of packaging materials and the environment and the recycling of ecological recycling are still at a relatively low level.
First, the contradiction between packaging and the environment
Because packaging materials have a short service life, a large amount of use, they are difficult to be degraded after being discarded, and the solid waste volume is large and difficult to concentrate, causing serious damage to the urban environment and the human body, it is the earliest product that has attracted public attention. In the United States, 150 million tons of municipal waste is produced each year, of which 1/3 is packaging waste. The annual volume of municipal solid waste in the European Community is 100 million tons, of which more than 80 million tons of packaging waste. Japan has about 50 million tons of municipal solid waste per year, including 21 million tons of packaging waste. According to statistics, 70% of the packaging products produced in China each year are discarded after use. According to the packaging production volume in 2000, there are 15 million tons of packaging waste, and the average per capita is 12Kg.
The research on packaging in terms of environmental protection should not only focus on the final destination of the packaging, but should also focus on the impact of various processes throughout the entire lifecycle of the packaging on the ecological environment. The impact of the life cycle of the packaging on the ecological environment involves almost every aspect of the atmosphere, water, soil, oceans, and forests. The influence of packaging materials such as paper, plastics, glass and metal on the environment is obvious to all, and the pollution caused by packaging also has its own particularities. In a commercialized society, as long as there are human activities, the packaging is accompanied by the distribution of goods. Various areas, so a wide range of pollution; disposable packaging accounted for a large proportion, short life cycle, large amount of waste; population is relatively concentrated in the coast and cities, causing tremendous pressure on the city's ecological environment, packaging waste in urban waste The volume of objects has reached 30% to 40%. At present, there are already 2/3 cities in China that are surrounded by garbage.
In 2000, the output of China's plastic products reached 16 million tons, and the packaging plastics accounted for 26%, reaching more than 4 million tons. In some big cities, the proportion of plastic waste in China has reached and exceeded the level of developed countries, and the number of composite products has increased. Plastic products are difficult to degrade and difficult to recycle.
With the development of economy, changes in consumer attitudes, and the increasing consumption of packaging materials, “white pollution†has emerged and becomes more and more serious. White pollution mainly refers to the pollution caused by the abandoned plastic packaging used in the environment. The production capacity of plastic lunch boxes in China has exceeded 7 billion, and disposable plastic bags have become necessities of life. In the 1970s, developed countries had problems with "white pollution" and began to study countermeasures. In 1997, the State Environmental Protection Administration proposed the prevention and control countermeasures of “pioneering education as the guide, strengthening management as the core, recycling as a means, and product substitution as supplementâ€. The hazards caused by “white pollution†include: flying on railroads, highways, inland rivers and sea lanes, tourist attractions, city streets, ground water, ground, air, and trees, which seriously damage ecological landscapes; plastic packaging products are difficult to degrade, The degradation cycle in nature is about 200 to 400 years. It destroys the structure in the soil, and the dissolution aids contaminate the soil and groundwater; it enters rivers, lakes, and sea waterways, affects navigation, deteriorates water quality, and affects the normal operation of hydropower stations; Or the accidental eating of marine animals can cause illness until death. With regard to the contradiction between plastic packaging and the environment, research should mainly be conducted from the following aspects:
1. At present, compared with traditional packaging materials, plastic packaging has low environmental load, excellent performance, and economy, so the social demand for plastic packaging will continue to grow, but it can be considered as little as possible.
2. Plastic packaging, especially disposable plastic packaging materials whose hard-to-degrade and toxic components, such as heavy-metal pigments and plasticizers, are indisputable if they do not properly deal with the damage to the ecological environment after use. Manage, recycle, and develop new plastic packaging materials that harmonize with the environment.
3. Most of the current plastic packaging materials are thermoplastic plastics, which can be recycled and recycled, and there are already relatively mature recycling technologies. Therefore, comprehensive measures should be adopted to increase the recycling ratio of recycled plastic packaging materials and increase economic efficiency. The pressure on the environment.
4. Any new plastic packaging material and non-plastic packaging material replacing the currently used packaging materials must pass environmental protection research to prevent attention to only the end of the pollution, to prevent the replacement of another pollution form or place with a pollution form or place.
Second, the environmental protection design of packaging
The environmental protection design of packaging should fully consider the impact of packaging's entire life cycle process on resources, energy, and ecological environment. Packaging materials have different functions depending on their applications. In order to satisfy different functions at the same time, multiple types of composite materials are often used, and multiple material combinations undoubtedly make recycling difficult. Therefore, it is required to consider the balance and unity of functional and environmental adaptability in the design. The environmental protection design of packaging materials should consider reducing the environmental load of the material life cycle, mainly including the following requirements.
1, consider harmful. Need to consider the harmful effects of water, oil and solvent soluble substances, such as foam polystyrene bowl containers, polycarbonate food containers, polycarbonate bottles are included in the environmental hormone suspect packaging; PVC food packaging bag free single Whether SCCP is lower than the standard requirement (below 0.5μg/g); whether the used excipients contain poisonous or harmful metals such as lead, mercury, cadmium, hexavalent chromium, etc.; whether the packaging materials are recycled and treated for the emission of harmful substances.
2, save resources. The following requirements should be considered when designing.
(1) Packing design should avoid stacking bed frames and excessive packaging;
(2) The recycled packaging should use long-lived materials.
(3) In the ease of use, the weight ratio of the contents to the packaging material is maximized;
(4) Try to use low-density packaging materials;
(5) Use high-performance materials to reduce material consumption.
3, save energy. Try to choose materials with low total energy consumption in the material life cycle. Considering the balance between environmental load and volume and strength of packaging materials, most materials are based on the environmental weight per unit weight. The characteristic of page packaging materials is to comprehensively consider the environmental load factors of unit volume and unit rigidity (requirements of structural materials). Therefore, a large container can be selected as a light-weight polyester bottle, and a container that is small and requires strength can be selected from steel. Because of the low strength of the paper, it is not suitable for large-scale containers. Glass and aluminum have high energy consumption, but they can be recycled and are suitable depending on the recovery rate and recycling efficiency.
4, the functional package. The design of packaging materials must meet the requirements of physical and chemical properties of the contents, and have effective protection functions. For example, vegetables and fruits require materials that have air permeability and moisture permeability. Frozen foods require materials that have toughness at low temperatures, and easily oxidized food packaging materials require gas barriers. Sex. The loss of functionality caused by the loss of functionality of the contents is undoubtedly the largest consumption of packaging and content resources and energy. In addition, we must ensure the strength of packaging materials and the sealability of the packaging to prevent the phenomenon of “running, leaking, and floating†in the packaging process, transportation process, storage process, and use process, and cause environmental pollution.
5. The recycling of packaging waste. Environmental design of packaging should consider the recycling of packaging waste, including the following aspects.
(1) Packing materials should be selected to suit the existing recycling and recycling systems, or materials that may be established in the future for recycling and recycling systems, which can increase the recovery rate and reduce the recycling costs. Try to use materials that are currently mature in recycling technology. The use of easily identifiable materials or materials with identification marks facilitates separate recycling.
(2) Adopting a volume-reducing design, it can be folded after use, and it is easy to apply force to press blocks. Composite material packaging materials are easy to separate, and the shape design is suitable for transport volume reduction.
(3) Transparent or brown glass is used for the glass container. Try not to use stained glass.
(4) Plastic packaging should be made of plastic materials that can be degraded and compostable after use.
(5) Try to use packaging materials and designs that can be reused after simple handling (such as washing). Reusable packaging should choose easy-to-clean packaging materials.
(6) Try to use reusable packaging containers such as glass and some plastic containers.
(7) Try to choose materials that are not subject to secondary pollution during incineration or degradation of the packaging waste, composting, and landfill disposal.
(8) Try to use recycled materials or waste materials as packaging materials.
(9) In the case of meeting functional requirements, try to choose a single material packaging design.
(10) When incineration is required, materials with little or no residue should be selected, such as aluminum foil composites. Select a material with low heat of combustion because it will shorten the life of the furnace.
Third, the use of environmentally friendly packaging materials
1, plastic packaging materials
Plastic packaging material has light weight, good transparency, good processing performance, good corrosion resistance, good mechanical properties, high barrier property, easy multi-component and multi-function, low price, low resource and energy consumption, There are many advantages such as small environmental load. Modern packaging is developed with the development of the plastics industry. However, due to the rapid increase in consumption, causing serious white pollution, people have come to realize that they must take corresponding measures to conduct thorough governance and adopt environmentally friendly packaging. The solution is the environmental protection of plastic packaging, including the following measures.
(1) Degradable plastic packaging materials. With the implementation of ISO14000, biodegradable plastic packaging materials have received further attention. Since the development of biodegradable plastics, since photodegradable plastics have been decomposed into water, carbon dioxide, plastic powders or low molecular weight oligomers, it will become a new source of pollution. In general, the decomposition of starch will be slowed down and the decomposed fragments will still be contaminated. Microbial degradable plastics Better, but higher prices. Degradable plastic packaging materials are suitable for specific applications and disposable packaging materials. The production of biodegradable plastic packaging materials has increased quite rapidly, but the proportion of the entire plastics is still quite low. In recent years, the industrialization of the whole degradable plastic has developed rapidly. The German industrial standard DIN54900 specifies that the conversion rate of 60% within 180 days is a fully degradable plastic. The aliphatic diol, aromatic dicarboxylic acid polymer and polylactic acid can meet the standards.
(2) Recyclable plastic packaging materials. Polyethylene naphthalate (PEN) is more heat-resistant than PET and can withstand the sterilization conditions required for low-acid foods (116°C, 63 minutes), while PET is only resistant to 70°C, especially for gas barrier UV protection. Better, longer shelf life, can replace glass bottles, and therefore have a wide range of applications in beer, beverages, cosmetics, food and other packaging, and think that it can be reused packaging.
(3) Foam packaging materials. Expanded Polystyrene (EPS) has formed a situation where everyone calls out because of the proliferation of disposable lunch boxes. However, it still occupies a considerable position in the packaging materials. Due to the use of less materials, 95% to 98% of air is the environmental load. Low, also the most manageable in plastics. EPS is an excellent thermal insulation, cold preservation and buffer packaging material, in place of wooden boxes in various forms, used in home appliances, electronic equipment, packaging buffers and fish boxes. According to the "Montreal International Convention," the ban on CFC foaming agents, foam plastic production is moving toward "zero ODP" and "low GWP" low-pollution processes. The current development of high melt strength polypropylene (HMSPP) and polypropylene homopolymers can produce foamed polypropylene with fine micropores and even distribution. Due to its low density, it can save 20% of the same performance polypropylene sheet. The same environmental load is also reduced. In order to reduce the environmental load, foam packaging cushioning material substitutes have also been developed, such as bubble plastic film, pulp molded products, and paper-plastic composite bag inflatable cushions.
(4) thin-walled containers, pouches. Reduction is an important direction for the environmental protection of packaging materials. To replace the bottle with a film instead of a multilayer film with a single film,