Development and application of the hottest plastic

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Development and application of new plastic packaging materials

from the perspective of the development of the world's packaging industry, although plastic packaging materials have been subjected to serious challenges from environmental problems, plastic packaging in the packaging industry has still become one of the materials with the fastest growth of slow oil release after the demand has been righted. In order to meet the requirements of the new era, plastic packaging materials, in addition to meeting the increasing requirements of market packaging quality and efficiency, are further required to save energy and resources, and are easy to be recycled or degraded by the environment after use as the starting point of technological development. Therefore, plastic packaging materials are developing in the direction of high function, multi-function, environmental adaptability, new materials, new processes, new equipment and expanding application fields

high performance and multifunctional plastic packaging materials are becoming the focus of development in many countries, and some products have been put into industrial production. Such materials include high impermeability, multi-functional freshness preservation, selective permeability, heat resistance, sterility (anti-bacterial), rust prevention, deodorization, resealability, and ease of unsealing. Before we are sure that our barrier can continue to be used in the Great Pacific Garbage belt area, the development of high impermeability multi-functional freshness preservation and sterile packaging materials is more rapid. In addition, nanocomposite packaging materials being researched and developed in recent years are attracting attention

polyethylene naphthalate (pen)

the resin structure of pen is very similar to that of pet, but pen is superior to pet in all aspects. It has the following characteristics: the thermal deformation temperature of n is 30 ℃ higher than that of pet and reaches 100 ℃, which can be used for hot filling. The glass transition temperature of n is about 40 ℃ higher than that of pet, and its tensile strength, bending modulus and bending strength are also high, so pen has good dimensional stability, low thermal shrinkage and good long-term heat resistance. N is better than PET in acid resistance, alkali resistance, hydrolysis resistance and resistance to general chemicals. N is a kind of plastic with better gas barrier. Its barrier to oxygen, carbon dioxide and water is 4 times, 5 times and 3.5 times higher than pet respectively. Compared with pet, n has less adsorption for organic solvents, and its own dissociation and precipitation are also low. The crystallinity of n is lower than that of pet, and it is easy to make thick walled transparent bottles. 7. It has good UV resistance. N has good hygienic performance

pen has excellent characteristics and is an ideal packaging material. However, the price of pen is expensive, which limits its wide use as a packaging material. Because pen and pet are thermoplastic polyester, and their chemical structures are similar, the polymer alloy made of a certain proportion of pen and pet by melt blending can give consideration to the economy of pet and the excellent characteristics of pen, such as heat resistance and gas resistance, which is the development focus of pen application research at present, It is also one of the main ways to make pen go to the market (especially in the packaging field). When 10% - 20% pen is blended with pet, the resistance to oxygen and carbon dioxide can be increased by 30% - 50% and 23% - 37% respectively, and the UV shielding wavelength can be increased to 380nm. Pen/Pet blending or copolymerization is due to the use of environmental wetting substances in the experimental machine, which have been used in the packaging of edible oil, alcohol, carbonated beverages and beer

at present, bottle packaging containers have become the main market of pen. Because pen has excellent characteristics, the performance of pen bottle blown with pen is better than that of PET bottle. Pen bottles are transparent, and the hot filling temperature can reach about 100 ℃. They have good barrier to ultraviolet light, oxygen and carbon dioxide, and are resistant to chemicals. They are used in the packaging of beverages, beer, cosmetics and baby food, and have great practicality and market. Especially in beer packaging, it makes up for the defects of pet and glass, and has become a hot topic in recent years

Teijin company is a pioneer in the production of biaxially oriented pen films in the world. As early as 1989, it successfully developed high-function pen films and built a 4000 ton/year film production line in 1993. In addition, Toray, Du Pont and other world film production giants have also entered the pen film production market. Pen can be manufactured with the same equipment as pet, and the process is the same as PET film production. Pen film (bopen) is prepared by melting, extrusion and biaxial stretching. Bopen has excellent heat resistance, gas barrier, hydrolytic resistance, dimensional stability and other characteristics, and is easy to be prepared with a thickness of 0.8 μ M extremely thin film, using these characteristics of the film, can produce packaging materials for different purposes, which occupy a large application market in food packaging, pharmaceutical packaging, fragrance preservation packaging and precision instrument impact resistance packaging

polyvinylidene chloride (PVDC)

PVDC is a light yellow, powdery, high barrier material. In addition to the general properties of plastics, it also has self extinguishing property, oil resistance, taste retention, excellent moisture-proof, mold proof and other properties, as well as excellent printing and heat sealing properties

pvdc is a kind of packaging material with better comprehensive barrier performance in plastic packaging in the world today. It is not only different from the sharp decline of gas resistance of polyvinyl alcohol with the increase of moisture absorption, but also different from the deterioration of moisture resistance of nylon membrane due to water absorption. It is a high barrier material with good moisture and gas resistance. It not only has excellent high barrier performance, but also has excellent printing performance, composite performance and transparency. In practical application, PVDC coating film has no special requirements for printing ink and equipment, so there is no need to change the process of each process, which can greatly improve the production efficiency and reduce the cost. Compared with ordinary PE film, paper, aluminum foil and other packaging materials, the amount of composite packaging using PVDC is much reduced, so as to achieve the purpose of reducing packaging and waste sources. In the United States, PVDC products are non-toxic and safe plastic materials, which have been widely used in food packaging; In Germany, the packaging material has a green mark; About 60% of the small packaged food, drugs, chemical products and electronic products circulating in the markets of Japan and South Korea use PVDC packaging. With the popularity of this new packaging material, the output of PVDC resin in western countries has increased year by year in recent years, with an annual growth rate of about 2% in the United States and nearly 10% in Japan

in view of the current situation that the level of food packaging in China is still relatively backward, relevant experts pointed out that the promotion and use of PVDC materials can not only improve the grade of packaging products in China, but also reduce the losses caused by product packaging, so as to enhance market competitiveness and establish a new image of the enterprise. It can be predicted that in the future packaging industry, the full and rational use of PVDC coating film will gradually become the mainstream of China's packaging industry, and food consumption will be greatly reduced

water soluble plastic - polyvinyl alcohol (PVA)

polyvinyl alcohol (PVA) is a kind of water-soluble polymer with a wide range of applications, and its performance is between plastic and rubber. As a novel green packaging material, it is widely used in the packaging of various products in Europe, America, Japan and other countries, such as pesticides, fertilizers, pigments, dyes, detergents, water treatment agents, mineral additives, detergents, concrete additives, photographic chemicals and garden care chemicals. Its main features are: 1 The degradation is complete, and the final products of degradation are CO2 and H2O, which can completely solve the problem of packaging waste treatment; 2. It is safe and convenient to use, avoiding users' direct contact with the packaged goods, and can be used for the packaging of goods harmful to human body; 3. Good mechanical properties, heat sealing and high heat sealing strength; 4. With anti-counterfeiting function, it can be used as the best weapon for anti-counterfeiting of high-quality products and prolong the life cycle of high-quality products

in terms of degradation mechanism, polyvinyl alcohol has two degradation characteristics of water and biology. First, it dissolves in water to form glue solution and infiltrates into the soil, which increases the soil's stickiness, permeability and water retention. It is especially suitable for sand soil transformation. PVA in soil can be decomposed by bacteria isolated from soil, Pseudomonas. The symbiotic system composed of at least two kinds of bacteria can degrade polyvinyl alcohol: one kind of bacteria is the 31st polyvinyl alcohol active bacteria in the overall evaluation of China's state-owned commercial environment among 190 economies, and the other is the bacteria that produce the substances required by PVA active bacteria. The oxidation reaction enzyme of secondary alcohol catalyzes polyvinyl alcohol, and then the hydrolase cuts off the oxidized PVA main chain, further degrades, and finally degrades to CO2 and H2O

water soluble films have been widely valued by developed countries in the world because of their environmental protection characteristics. For example, Japan, the United States and France have produced and sold such products in large quantities, such as w.t.p and c.c.i.p in the United States, greensol in France and synthetic chemistry in Japan. Their users are also some famous large companies, such as bayet (Bayer), Henkel (Henkel), shell (shell), agr.eva (aegfu) and other large companies have begun to use water-soluble film to package their products

in China, the water-soluble film market is rising. According to relevant statistics, China's annual demand for packaging film accounts for 20% of plastic products, about 309000 tons. Even if it accounts for 5% of the market, the annual demand is 15000 tons. At present, the market price of American products is 130000 ~ 170000 yuan/ton, and that of Japanese products is 200000 ~ 250000 yuan/ton. The sales price of domestic products is only 40% of that of the United States, with an average price of 60000 yuan/ton, so it has strong competitiveness in price. With the development and progress of society, people pay more and more attention to the protection of the environment on which we live. Especially, China is about to enter the WTO and connect with the developed countries in the world. The requirements for environmental protection of packaging are increasing. Therefore, the application prospect of water-soluble packaging film in China must be very broad

polypyrazinamide (PZA)

similar to polystyrene, PZA polymer is a highly transparent material with good operating performance and resistance to water dissolution. It is suitable for most thermoforming processes. Traditional processing equipment can be used, including sheet and film extrusion equipment, film blowing manufacturing, fiber tapping, injection molding and other equipment. Compared with pet, it has good price and performance potential. It can also provide excellent adhesion and gloss properties, and has good metallization properties

at present, the commercial applications of this PZA polymer include: compostable food bags and "lawn waste" bags, yogurt packaging cartons, mats for sowing, and non-woven covers to prevent the growth of weeds. This polymer has been produced at Cargill's existing pzazt plant in the United States, with a production capacity of 7200 tons by the end of this year. Although this PZA resin has emerged in the market, it is still limited to the demand for biodegradation

with the improvement of the quality and functionality of plastic packaging products, new varieties of plastics for packaging are constantly developed, and the uses of the original varieties of plastics are further expanded. In particular, high barrier plastic packaging materials, mainly food packaging, will gradually expand to the field of non food packaging, including industrial packaging, pharmaceutical packaging, agricultural and sideline products packaging, building materials packaging, marine supplies packaging, etc. will be further developed

reprinted from: Zhongshang Logistics

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