Easy lid technology status and market prospects

Canned food nutrition, safety, convenience, should be the most convenient food. However, as tinplate cans have been fully covered for decades, glass cans have been victorious in Soviet-style vials. Consumers have spread "delicious cans and difficult mouth opening." This is a "hard-core" issue. Consumers eat very inconvenient, but also seriously affected the development of canned food industry. Canning industry is now actively promoted, tin cans with easy to pull lid, glass jar with unscrewed lid. Ten years ago, a large number of easy-to-use lid is a pomegranate canned food, tin is the end of tin cans, easy to pull lid with aluminum alloy, also comes with a small plastic spoon, food is very convenient, consumers are very satisfied with the annual sale of rice pudding now The amount of about 30 million tons.

But not all canned varieties can be modeled on the rice pudding can be used aluminum lid. A few years ago, Guangdong, a canned food factory production of tomato juice cans, tinned canned rice pudding cans using tinplate cans, lid aluminum alloy lid, the contents of 0.5% salt (Nacl), the calculation of chlorine content of 303mg / kg, storage for several months, the lid at the rivets and scribe lines appear leaky tank was forced to stop production.

Tin cans at the end of the tinplate, such as the lid with aluminum alloy, canned food, the formation of micro-cells, the occurrence of bimetallic reaction, aluminum anode, tin cathode, cathode area than the anode area, the local deep anode Pitting until perforation. Taiwan literature reported that a few years ago Taiwan's popular coconut juice drink cans, using aluminum easy-lid, tin can body bottom tinplate, the contents of chloride ion concentration of 440 ~ 1492mg / kg, PH = 4.4 ~ 4.6, mainly apple acid. The initial canning, corrosion components (malic acid, chloride ions) penetrate the coating film, the electrochemical reaction. At this point the coating is the cathode, the coating film exposed by the membrane damage at the tin, iron as the anode, until a considerable area of tin, iron exposed, and aluminum easy to pull due to the coating at the exposed aluminum in series with the formation of micro-cells, Bimetallic reaction. At this point, aluminum corrosion dissolution for the anode, coupled with the presence of chloride ions in the content to promote the accelerated development of corrosion reaction, resulting in aluminum alloy easy to pull rivets, crossed at the piercing.

Reported that some high-acid foods, chloride ions over 100mg / kg, including meat and poultry aquatic vegetables canned (due to adding salt that is sodium chloride) cans tin bottom tinplate, lid should not be made of aluminum alloy, tin should be easy to pull Cover, in order to avoid bimetallic electrochemical reaction and perforation.

China's tinplate easy to pull the lid of major manufacturers are Zhejiang Changhong system covered Ltd., Yiwu City, easy to open the cover Industrial Company, as well as Shantou City Shantou Zhang Hardware Technology Factory and some are in the new factory. It is estimated that about 1.2 billion tinplate cans will be produced this year, of which about 100 million are exported, providing about 1.1 billion or so canned domestic canned products, and roughly 440,000 tons of canned food will be matched.

China is expected to produce more than 3 million tons of canned food this year, except for the use of glass jars in part. Therefore, the future prospect of tinplate is very wide.

Canned tin industry in the world can easily see the situation is also rising trend. According to the information, there are more than 60% of canned foods in Europe with easy-open cans and only 25% in the United States. Heing produced about 400,000 tons of canned canned foods in 1985 and recently reported compbell.s ( Campbell soup canning company) production of soup cans have been used in the lid.

At present, the quality of the tinplate easy-lid manufacturing of major domestic enterprises has been greatly improved and improved over the previous years, but there are still some technical problems. Easy to pull the quality of the basic requirements, it should be sealed and easily opened. I ran into the tin lid easily used to use the vise to help, all can be opened, and sometimes rivets fall, can only still use the can opener. Shaped lid easy to pull away more difficult. Now two factories producing tinplate easy to cover most of the equipment imported brand-name products, there should be no problem. I think the main thing is the thickness, hardness and mold problems of using tinplate. Therefore, enterprises should also organize technical forces, carefully study and adopt effective measures to continuously improve quality and play the advantages and proper functions of easy-lifting lid.