Aluminum is a resource-rich white light metal, and the world's aluminum production is second only to steel. Its application in the packaging industry occupies the first place in non-ferrous metals. As packaging material, aluminum generally uses aluminum plates, aluminum blocks, aluminum foil, and aluminum-coated films. Aluminum plates are usually used as can-making materials or lid-making materials; aluminum blocks are used to make extruded and thinned cans; aluminum foil is generally used for moisture-proof inner packaging or composite materials and flexible packaging. The packaging plates are all rust-proof aluminum alloys. Manganese and magnesium mainly play a role in improving the strength of the material and improving the processing performance. Copper can also increase the strength of the material, and it will also reduce the corrosion resistance and processing performance. When copper and magnesium are added in the same day, the heat treatment effect becomes better, but the corrosion resistance and workability will decrease; the addition of silicon is mainly to reduce the melting point of aluminum, improve strength and melt fluidity, and reduce the coefficient of thermal expansion. Aluminum foil is a flexible metal thin material made of industrial pure aluminum plate with a thickness of 0.4mm to 4.7mm (more 0.5mm is used) after repeated cold rolling and thinning. 1. Characteristics of aluminum materials Compared with other packaging materials, aluminum materials have the following advantages: (1) The density of aluminum is very small, 2.7g / cm3, which is only 35% of steel. This makes the container easy to achieve light weight. The surface of aluminum can naturally produce a dense layer of aluminum oxide film. This colorless film can prevent further oxidation. But aluminum materials also have some shortcomings, mainly: (1) Aluminum production consumes much more energy than tinplate and TFS, so the price is expensive. At present, some of the shortcomings of aluminum can be compensated by compounding with other materials. For example, the compound of aluminum foil and paper or plastic can increase its rigidity and tensile strength; to overcome the shortcomings of low rigidity of thin-walled aluminum cans, a small amount of liquid nitrogen can be filled before closing the container, and the internal pressure generated by the vaporization of liquid nitrogen can be increased The rigidity and pressure resistance of the container; the aluminum foil coated with nitrocellulose and modified polyolefin not only improves the chemical properties of the aluminum foil, maintains a good printing appearance, but also provides heat-to-seal properties. Second, the application of aluminum materials in packaging 1. Aluminum anti-theft bottle cap At present, most of the packaging of liquor, wine, medicinal wine and beverages in China is still dominated by glass bottles. About 50% of the wine bottle caps are made of aluminum anti-theft caps. The national anti-theft caps will grow at a rate of 10% per year. It is expected that By 2010, the amount of anti-theft caps will reach 15 billion, requiring about 60,000 tons of aluminum strip. There are nearly 200 aluminum cap production plants in China, with an annual design capacity of about 9 billion pieces, of which 30 production lines have been introduced, with a production capacity of more than 5 billion pieces, which can produce nearly one hundred types of caps. Aluminum bottle caps are mostly processed on production lines with a relatively high degree of automation, so the strength, elongation and dimensional deviation of the materials are very strict, otherwise it will cause cracks or creases during deep drawing processing. In order to ensure that the bottle cap is easy to print after molding, the surface of the bottle cap material is required to be flat, without rolling marks, scratches and stains. The alloy materials generally used are 8001-HI4, 3003-H16, etc. Material specifications are generally 0.20 ~ 43.23mm thick, allowable tolerance ± 0.1%, width 449mm ~ 796mm. The production of aluminum bottle cap material can be made by hot-rolled billet or continuous casting and rolling billet, which are made by cold rolling. Production practice shows that the hot rolled billet is better than the cast rolled billet in the use effect of the anti-theft cover. 2. Aluminum-plastic blister packaging At present, it is more and more common for health foods and pharmaceutical tablets and capsules to be packed in blister packs. Aluminum-plastic blister is also called blister pack, or PTP (Press Through Packaging) for short. The aluminum foil used in blister packaging is a sealing material densely attached to a rigid plastic PVC sheet, so it is also called a lid material. Almost all products in modern packaging that require opaque or high-barrier composite materials use aluminum foil as the barrier layer. This is because aluminum foil has a highly dense metal crystal structure that can completely block any gas, so it is widely used. It is expected that the packaging used for pharmaceutical blister materials will account for about 60% to 70% of the packaging of tablets and capsules for future medicines, and is one of the most promising pharmaceutical packaging materials at present. [next] However, the current quality of pharmaceutical aluminum foil in China is far from the imported aluminum foil. Judging from the actual situation reflected by several domestic manufacturers of PTP pharmaceutical packaging, there are mainly two problems. (1) The number of medicinal aluminum foil pinholes is far from the requirements. The pinhole of aluminum foil is a defect of penetrating performance, which affects the barrier performance of aluminum foil, especially for pharmaceutical packaging. It is easy to penetrate oxygen, water vapor, and light to reduce the efficacy of drugs. The national standard for medicinal aluminum foil requires that the diameter of the pinhole is not more than 0.3mm, and the diameter of 0.1mm to 0.3mm cannot be more than 1 / m2. At present, domestic aluminum foil rarely meets this standard. (2) The thickness of the medicinal aluminum foil is uneven and the tensile strength is low. Due to the uneven thickness of the aluminum foil, it is easy to cause the coating amount of the adhesive to reach the standard coating amount range during the mechanical coating process of the PTP aluminum foil, which further affects the thermal strength of the aluminum foil and the polyvinyl chloride hard sheet. Due to uneven thickness and low tensile strength, foil breakage occurs after tension is applied during unwinding and rewinding in actual processing, which is not conducive to normal production. These problems require attention from raw material manufacturers. 3. Aluminum beverage can Currently. The development of aluminum beverage cans has three major characteristics, namely easy-open lids, special cans, and self-heating / self-cooling beverage cans. For a long time, although metal packaging such as aluminum beverage cans has been challenged by tinned plates and PET materials, due to its light weight and recyclable advantages, it is still one of the main beverage packaging forms and has not only been developed steadily. And it is also constantly developing and innovating. Recently, Coins Packaging has successfully developed EPOL (Easy Opening Cap). The can lid is made of polymer-coated steel ring and anti-corrosion aluminum foil heat. It can be used in existing filling equipment. The aluminum foil lid can be opened safely and is more suitable for the elderly and children. Due to the competition of PET bottles, the demand for aluminum beverage cans on the Japanese market has gradually decreased in recent years, but with the development of new aluminum bottle cans, the demand for aluminum cans has begun to rise again. At present, companies such as Takeuchi Stamping Industry, Yamato Can Co., Ltd. and Mitsubishi Materials have entered the field of aluminum bottle can production, and aluminum bottle can lids developed by Chaiqi Factory have also been put on the market. In order to complement each other's strengths, Japan's Yamato Can Company focused on the advantages and disadvantages of two beverage packaging containers, PET bottles and aluminum cans, and took the lead to avoid weaknesses. It was the first in the world to successfully develop a new container for beverage packaging that can give metal cans a new density "New bottle-shaped metal cans (new bottle cans). The new bottle can is a new packaging container developed beyond the existing two-piece can and three-piece can structural framework. It not only applies the current three-piece metal can compound technology, curling and capping technology, but also applies Two-piece can deep-drawing forming technology is used to make the can body, and then the existing can contents and the processing technology with screw cap are used to realize the use of metal aluminum material, forming a bottle with a shape of 28mm in diameter New type metal bottle packaging container. The new container combines the advantages of metal cans and PET bottles, while overcoming the inherent shortcomings of both. Taking into account environmental issues, the single bottle aluminum alloy material is used for the new bottle cans. On the surface of the material, that is, the inner and outer surfaces of the can body are compounded with PET film material; the inner surface of the bottom cover is also compounded with PET The film is coated with PET on the outer surface; the bottle cap is coated with low-density PET, and the outer surface is coated with printing. In this way, the inner surface of the new bottle can can avoid contact with the contents, without using the various coatings traditionally used in metal cans. After the successful trial production of the new bottle, it has been exhibited at the Australian Can Industry Exhibition in 2000 and won the grand prize awarded by the exhibition in the name of a Japanese company. This technology is also noticeable internationally, and the demand for aluminum-PET composite tanks may be further expanded in the future. According to a survey by the Japan Aluminum Can Recycling Association, since these four companies entered the field of aluminum bottle can production, the sales volume of aluminum bottle cans reached 1.5 billion irrigation in 2002, which was 2.5 times the previous year and increased on this basis in 2003. About 20%. The beverage packaging market is one of the largest markets in the metal packaging market. In order to improve the brand effect, in addition to the silver-white characteristics of aluminum, the shape of aluminum cans is also increasingly important, so manufacturers of metal forming equipment are also discussing aluminum can forming and embossing technologies. Because aluminum is easier to form and reach the required shape, researchers are exploring aluminum can reel expansion forming, spin forming and flow forming technologies, which will be first used in beer cans in the near future. The use of aluminum can packaging for beverages such as beer and soda has increased the use of aluminum products, while other industries are also considering the use of aluminum can products. According to information provided by U.S. Industrial Information Resources, more than a year ago, Japan ’s largest aluminum can manufacturer, Yamato Aluminum Can Company, began producing aluminum cans for beer and tea companies. The other two Japanese aluminum can manufacturers are expected to double their output in the next 2 to 3 years. Aluminum cans are favored by the beverage industry because of their light weight and easy recycling. Recently, aluminum cans have continued to spread to other industries and have a tendency to replace glass bottles and metal bottles. 3. Conclusion Experts believe that the new market share of aluminum materials will also make new progress with the promotion of so-called active packaging. Due to the application of new technologies for the development of aluminum products, the demand for aluminum materials will be further expanded in the future. Frying Pan,Skillet Pan,Non Stick Pan,Carbon Steel Pan Jiangmen Junerte Stainless Steel Kitchenware Co.,Ltd , https://www.jetkitchenware.com
(2) Aluminum is non-toxic and tasteless, meeting the hygienic standards of packaged food.
(3) The aluminum surface has high gloss, easy to color, and good printing effect.
(4) The opening performance of the easy-open cover made of aluminum is better than that of tinplate.
(5) Aluminum has excellent light and heat reflection performance and conduction performance, which can improve the effects of heat sterilization and low temperature treatment of food cans.
(6) The mechanical properties of aluminum can be maintained at a low temperature, which is especially suitable for the packaging of frozen food.
(7) The composite film made of aluminum foil is completely airtight and opaque, which can effectively protect the food inside. Aluminum foil can also increase the strength of the aluminum-plastic composite film.
(8) Waste materials can be recycled and reused, which can not only save energy consumption but also prevent the pollution caused by wastes, and meet the requirements of environmental protection.
(2) Aluminum is a non-magnetic material, so the original equipment that uses magnetic to absorb raw materials must be modified.
(3) Aluminum materials have poor corrosion resistance and should not be used to contain acidic, alkaline and salty foods.
(4) Aluminum is softer and has lower strength than tinplate. It is prone to deformation and surface scratches due to collision during manufacturing and transportation.
(5) Aluminum welding is difficult, so it can only be manufactured by stamping or bonding.