The application of the hottest PVDC in the packagi

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Application of PVDC in chilled meat packaging (Part 2)

high barrier packaging materials

at present, the three high barrier materials recognized in the world are PVDC, ev-oh and pan. The three materials are copolymers, and the barrier property to oxygen, ev-oh is better than PVDC, PVDC is better than pan; For the barrier property of water vapor, ev-oh is better than PVDC, and PVDC is better than pan. However, under high humidity conditions, ev-oh is very easy to absorb moisture due to the -oh group in its molecular structure, and the barrier property will be significantly reduced. At the same time, with the increase of environmental humidity, the barrier property of Pan materials also decreased significantly. PVDC is a kind of packaging material with the best comprehensive barrier performance in the world

pvdc is the English abbreviation of polyvinylidene chloride, which is a polymer compound formed by the polymerization of vinylidene chloride monomer (hereinafter referred to as VDC). In the late 1930s, Dow Chemical Company of the United States began to carry out extensive research on the copolymerization and processing of VDC and VC. In 1947, it realized industrial production with the trade mark saran. Japan began research in 1948 and put into industrial production in 1954. Asahi Kasei and Wu Yu have successively carried out the production and research of PVDC. In the 1980s, Dow Chemical Company of the United States launched vdc-ma series. Since the 1990s, some powerful multinational companies in the West have increased the development and application of vinylidene chloride and other copolymers, such as the copolymerization of vinylidene chloride with methyl acrylate, methacrylic acid, acrylonitrile, etc., so that the production and development of vinylidene chloride resin has entered a new stage. At present, the main manufacturers of PVDC resin in the world are Dow Chemical Company in the United States, Wuyu Chemical Co., Ltd. in Japan, Asahi Chemical Co., Ltd., Solvay in Belgium, etc

pvdc is an excellent food packaging material, especially resistant to high temperature cooking and good barrier to oxygen, steam and various odors, which is unmatched by other plastics. At the beginning, it was mainly processed into film, which was used in the packaging of weapons and ammunition during World War II. It was gradually transferred to food packaging in the late 1950s and early 1960s, and then gradually applied to drug packaging and other fields. With the acceleration of modern packaging technology and the pace of modern people's life, the popularity of microwave ovens and refrigerators, and the consumption of fresh-keeping film increased sharply, making the application of PVDC more popular. EVOH, a new high barrier material appeared in the 1980s, once threatened the development of PVDC because of its recyclable performance and its unique environmental protection effect. However, its barrier property against humidity decreased significantly. It must be protected from humidity to achieve a high oxygen barrier effect, which greatly limits its scope of application

pvdc is the only large-scale industrialized plastic in the world that can withstand high temperature cooking and has high barrier properties. The film made with it has been widely used in China, and the biggest use is as sausage casing. These applications fully show the performance and unparalleled advantages of PVDC materials. However, PVDC is also a plastic that is difficult to synthesize and process due to sudden heat cooling. Only a few large companies in the world have these synthesis and processing technologies, so the output is small, the price is expensive, and the scope of promotion and application is narrow. Jinan new era Gold Testing Instrument Co., Ltd. all over the world tells you that the annual output in the testing process is only more than 100000 tons. However, due to its unique performance, it occupies an important position in the plastic packaging material industry, especially in the food packaging industry. Using it as an intermediate layer to manufacture multilayer composite materials is the frontier of technological progress and technological innovation in the plastic packaging industry at present

China began the research work on the practical application of PVDC resin in the early 1980s. First, the birth of ham sausage introduced PVDC film into China. Then, represented by Luoyang Chundu, it broke the blockade of the United States and Japan on this technology, introduced the processing technology and equipment of PVDC film, and created China's PVDC film processing industry. In the late 1990s, a group of packaging materials researchers represented by Mr. Shude, a famous PVDC film processing expert in China and senior engineering teacher of Luoyang Chundu, tried to apply PVDC plastics to other packaging fields and achieved success

pvdc is used for packaging chilled meat

PVDC plastic is used for packaging chilled meat. It is not a simple PVDC film, but a multi-layer coextrusion film with PVDC as the barrier layer. Vinylidene chloride, methyl acrylate, methacrylic acid, acrylonitrile copolymer are selected as the barrier layer, which is made by coextrusion with other wear-resistant materials, heat sealing materials, etc. This film has extremely high oxygen barrier, with oxygen transmittance of <50 ml/m2, ATM, 24h, 23 ℃, 65% RH, and extremely high water vapor barrier, with water vapor transmittance of <5g/m2, ATM, 24h, 23 ℃, 90% RH. At present, the more common structures in the world are pe/tie/pvdc/tie/pe and pe/tie/pa/tie/pvdc/tie/pe five layer and seven layer structures. The multi-layer co extruded high barrier film used in modified atmosphere packaging technology is mainly cast and blown, which does not have shrinkage, and the thickness is generally 90 ~ 150 μ m. With high transparency and puncture resistance, it can inhibit microbial reproduction by changing the gas environment inside the package. Vacuum shrinkable packaging is mainly made by multi-layer coextrusion double bubble film blowing. PVDC is used as the barrier layer. After coextrusion with other special materials by double bubble method and off-line treatment, the shrinkage rate of the product is about 35 ~ 45%. Using the heat shrinkability of the shrinkable film, it is close to the surface of meat products to prevent moisture seepage, and the thickness is generally 50 ~ 90 μ m。 The PVDC coextrusion films with these structures have been produced and researched by enterprises such as Luoyang Chundu, Hebei Qinhuangdao and Xingtai in China since the late 1990s, but they have not been localized so far. A small number of Chinese enterprises are using high barrier packaging materials, which are completely dependent on imports

by using PVDC coextrusion film to pack chilled meat, the fresh-keeping period of meat can be extended, the sales field of meat processing enterprises can be expanded, and the long-distance markets at home and abroad can be covered. For export-oriented enterprises, the storage period of meat products in long-distance transportation can be greatly improved, and the quality of meat products can be guaranteed. According to the survey, at present, less than 1% of the chilled meat production and processing enterprises use high barrier plastic packaging materials, which are only used in the export packaging of beef and mutton

conclusion: with the gradual maturity of the domestic chilled meat market, hot fresh meat and frozen meat will gradually withdraw from the mainstream of raw meat consumption, and chilled meat will "enter the homes of ordinary people" at an unprecedented rate of development. For domestic raw meat processing enterprises, new requirements have also been put forward in terms of packaging. We are glad to see that some domestic raw meat export-oriented enterprises and packaging production enterprises have keenly captured this information and have begun to use and produce this new high barrier packaging material. Grassland Xingfa, Changchun Haoyue, Baoquanling, Hua'an cattle industry, etc. Qinhuangdao jiaruite Plastic Technology Co., Ltd., Zhengzhou Baolan Packaging Technology Co., Ltd. and other enterprises committed to the development and research of new packaging products in China are stepping up the development of this packaging material. In October 2005, Qinhuangdao jiaruite Plastic Technology Co., Ltd. took the lead in launching PVDC multilayer coextrusion shrink film in China, and has been fully introduced to the market

with the development of science and technology and the continuous demand of the market, the demand for high barrier packaging materials in the packaging of raw and fresh meat will become greater and greater. More and more packaging scientists and technicians will be involved in the development and research. China's chilled meat packaging will have a more brilliant tomorrow. Of course, any kind of fresh-keeping technology has certain disadvantages. The adoption of scientific new packaging technology and packaging materials can not completely solve all the problems of chilled meat in production, circulation and storage. Chilled meat production enterprises can really keep fresh only by comprehensively utilizing various fresh-keeping measures and improving the hygienic conditions of processing.

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