One of the important ingredients in beer is hops, which imparts a special bitter taste to the beer. The ingredients in the hops are light-sensitive and can decompose under the influence of ultraviolet light in the sun, creating an unpleasant "sunshine smell". Colored glass bottles can To some extent, reducing this reaction to occur. Add tin foil at the bottleneck, in this weak link can reduce the transmission of ultraviolet light, reduce "sunshine smell" hygiene, prevent and reduce corrosion is also one of its role, of course, there is beauty , exquisite, this is also very important, or is the most important goal, so that beer feels very good grade, some brands of beer, such as Budweiser tin foil anti-counterfeiting features, there is a red color temperature-sensitive Budweiser Signs, when the beer with the rapid development of the packaging industry, most breweries in the use of beer bottle label aluminum foil (referred to as beer standard), now used products 80112O, 0.0115mm foil. The following describes the technical process, product mechanical properties, pinholes, and user technical requirements for the production of aluminum foil for beer targets from cast-rolled blanks. At the same time, the development trend of aluminum foil for beer targets is also predicted. 2.2 Process Control Points for Cold Rolling and Foil Rolling Processes 2.2.1 Cold Rolling and Foil Rolling The standard aluminum foil for beer has higher requirements on the shape and surface quality. It is necessary to select a new grinding work roll for the aluminum foil rolling of the finished product pass. The condition of the work roll and the guide roll should be good. In each pass, the appropriate plate shape curve should be set or selected to ensure the flatness of the aluminum foil. The thinner beer standard aluminum foil can only be used for sealing after being colored and printed. Therefore, the surface quality of the aluminum foil is required to be high. The surface of the aluminum foil is not allowed to have oil spots, obvious impressions, and other defects. After the beer mark is printed, it is necessary to mark the surface of the aluminum foil evenly. This is a unique technical requirement of the beer mark. Therefore, the requirements for the pinhole degree of the aluminum foil are very strict, and almost no pinhole defects appear on the aluminum foil. If there are many original pinholes in aluminum foil and the small holes marked by the finished beer mark itself, the surface of the aluminum foil will become a “sieveâ€, and other properties of the aluminum foil will also deteriorate, which will seriously affect the labeling speed of the brewery. However, at present, beer labels supplied with cast-roll stocks in China can achieve smaller aluminum foil pinholes, and in this respect, they can basically meet the requirements of users.
1, the main technical indicators of beer standard aluminum foil 1.1 Beer standard aluminum foil chemical composition In China, whether it is used hot rolled blanks or the use of cast billet production of beer standard aluminum foil, the chemical composition is 8011 alloy, the main alloy See Table 1 for composition. However, in the production, the range of actual control components of different manufacturers is not the same. For example, North China Aluminum Corporation adopts alloys with low component control range to produce beer standard aluminum foil. The control range of its chemical composition mainly considers the tensile strength of products. Technical indicators such as elongation rate and pinhole degree of aluminum foil should meet the requirements of users.
1.2 Mechanical properties The thickness of the aluminum foil used in beer is 0.0115mm. The mechanical properties of the aluminum foil are generally tensile specimens in the form of strips, ie tensile specimens with a parallel section width of 15mm, a length of 170mm and a gauge length of 100mm. 80112O, 0.0115mm Beer standard aluminum foil tensile strength is generally between 80 ~ 90N/mm2, elongation of 2% to 2.5%. In addition, different users have additional requirements such as burst strength. These technical indicators are generally inspected by a liquor label printing factory, and the aluminum foil supplier does not independently perform inspections through process assurance.
1.3 Requirements of Pinholes and Surface Quality of Aluminum Foil The thinner beer standard aluminum foil can be used for sealing after being colored and printed. Therefore, the surface quality of the aluminum foil is required to be high. The surface of the aluminum foil is free from defects such as oil spots and obvious impressions. After the beer mark is printed, it is necessary to mark the surface of the aluminum foil evenly. This is a unique technical requirement of the beer mark. Therefore, the requirements for the pinhole degree of the aluminum foil are very strict, and almost no pinhole defects appear on the aluminum foil. If there are many original pinholes in aluminum foil and the small holes marked by the finished beer mark itself, the surface of the aluminum foil will become a “sieveâ€, and other properties of the aluminum foil will also deteriorate, which will seriously affect the labeling speed of the brewery. However, at present, beer labels supplied with cast-roll stocks in China can achieve smaller aluminum foil pinholes, and in this respect, they can basically meet the requirements of users.
2. The control points of the production process of aluminum foil for beer standard The following is a review of the process control points for the production of beer standard aluminum foil from casting and rolling stocks. The process flow is: cast smelting → composition adjustment → static furnace refining → online degassing → adding grain fine Chemicals → Filtration → Casting → Cold Rolling → Heat Treatment in Intermediate Thickness → Aluminum Foil Rolling → Dual Rolling → Finished Product Slicing → Finished Product Heat Treatment → Inspection Package.
2.1 Process control points of the casting and rolling process In the production process of casting and rolling, the control of the melt quality of aluminum is relatively strict. Except for the normal adjustment of components and thorough slag removal, the melt poured into the holding furnace (remaining furnace) must be refined. Refining time depends on the weight of the charge, generally should be more than 15min, refining medium N2 or N2 + CCl4; before casting, on-line refining, so that into the casting zone of the aluminum melt hydrogen content as much as possible.
In order to control the grain size of the cast slab, a grain refiner should be added before the melt enters the filter box. The commonly used Al2Ti2B wire with a diameter of 9.5 to 10 mm is slightly different depending on the width of the slab and the casting speed. If a 7.5 mm x 1200 mm cast slab is produced at a casting speed of 1.0 m/min, the addition speed of Al2Ti2B wire is generally 200-250 mm/min.
2.2.2 Heat Treatment of Intermediate Thickness and Finished Product Thickness When domestically produced aluminum foil is used for the production of beer standard aluminum foils, the annealing is generally performed in the middle of the cold rolling process. The annealing temperature is higher (usually above 500°C). For uniform annealing, different manufacturers choose to perform intermediate annealing at different thicknesses, for example at 2.0 mm or 0.8 mm thickness. Homogenizing annealing can improve the rolling properties of the blank and increase the elongation of the aluminum foil. The factors considered in the annealing of finished aluminum foil are to eliminate the rolling oil on the surface of the aluminum foil and ensure the mechanical properties of the finished product. Generally, low temperature and long time heat preservation is used to remove oil, such as (180-230)°C (20-30)h, degreasing. The effect can reach Class A water brushing performance as stipulated in the GB3198 standard; considering the mechanical properties to meet the technical standards, it is generally kept at 300°C for 20 to 30 hours for annealing.
With the increasingly fierce competition in the Chinese beer industry, the competition for beer products has shifted from the competition of quality and price to brand-centric, quality, label and packaging as the three major support points of the comprehensive competition. Among them, the label as an important method of distinguishing products and consumers to buy an important factor, has been highly valued by manufacturers, "do wine is to do the label."
However, for some time, the beer label has not received the attention of the majority of colleagues, but with the rapid development of beer packaging, the label of beer bottles is also changing, and now most of the breweries use aluminum foil. Use industry terminology to call it a beer mark. A good beer mark can not only create a good visual impact, but also gain market recognition. It is a beautiful and practical brand endorsement for beer packaging.
Now domestic beer commercial products are 80112O, 0.0115mm foil. Here, the author reviewed the technical process, product mechanical properties, pinholes, and user's technical requirements for the production of aluminum foils for beer targets from cast-rolled blanks. At the same time, the author also predicted the development trend of aluminum foils for beer targets.
First of all, the main technical indicators of the aluminum foil for beer use should be considered from the chemical composition, mechanical properties, and pinhole and surface requirements of aluminum foil.
In China, no matter whether it is a hot-rolled billet or a beer-marked aluminum foil produced by casting and rolling, the chemical composition is 8011 alloy. The main components of the alloy are shown in Table 1. However, in the production, the range of actual control components of different manufacturers is not the same. For example, North China Aluminum Corporation adopts alloys with low component control range to produce beer standard aluminum foil. The control range of its chemical composition mainly considers the tensile strength of products. Technical indicators such as elongation rate and pinhole degree of aluminum foil should meet the requirements of users.
The thickness of the aluminum foil used for beer is 0.0115mm, and tensile test specimens are generally used for testing the mechanical properties. These are tensile specimens with a parallel section width of 15mm, a length of 170mm, and a gauge length of 100mm. According to the user's use, 80112O, 0.0115 The tensile strength of mm beer standard aluminum foil is generally between 80 and 90 N/mm2, and the elongation is between 2% and 2.5%.
In addition, different users have additional requirements such as burst strength. These technical indicators are generally inspected by a liquor label printing factory, and the aluminum foil supplier does not independently perform inspections through process assurance.
Secondly, the main points of control of the production process of aluminum foil for beer are described. The process control points and process flow for the production of beer standard aluminum foil from cast billet are: cast smelting → composition adjustment → static furnace refining → on-line degassing → adding grain refiner → filtration → cast rolling → cold rolling → heat treatment in intermediate thickness → Aluminum foil rolling → double rolling → finished product slitting → finished heat treatment → inspection packaging.
Casting and rolling process control points are mainly in the casting process, the aluminum melt quality control is relatively strict, in addition to the normal adjustment of the composition, complete slag, pour into the holding furnace (static oven) melt to be carried out Refining, refining time depends on the weight of the charge, generally should be more than 15min, refining medium N2 or N2 + CCl4; before casting, on-line refining, so that into the casting zone of the aluminum melt hydrogen content as much as possible. In order to control the grain size of the cast-rolled slab, a grain refiner should be added before the melt enters the filter box. The commonly used Al2Ti2B wire with a diameter of 9.5 to 10 mm is slightly different depending on the width of the slab and the casting speed. If a 7.5 mm x 1200 mm cast slab is produced at a casting speed of 1.0 m/min, the addition speed of Al2Ti2B wire is generally 200-250 mm/min.
The process control points of the cold-rolling and foil-rolling processes are elaborated from the following aspects: The aluminum foil used for beer standard has high requirements for the shape and surface quality. It is necessary to select a new grinding work roll for the aluminum foil rolling of the finished product pass, the work roll The condition of the guide roller is good, and the appropriate plate shape curve is set or selected in each pass to ensure that the aluminum foil plate shape is flat.
Heat treatment at intermediate thickness and finished product thickness. In China, when using cast-rolled blanks to produce beer-marked aluminum foil, an annealing is usually performed in the middle of the cold-rolling. Since the annealing temperature is higher (generally above 500°C), it is called uniform annealing, and different manufacturers choose different The thickness is intermediately annealed, for example at 2.0 mm or 0.8 mm thick. Homogenizing annealing can improve the rolling properties of the blank and increase the elongation of the aluminum foil. The factors considered in the annealing of finished aluminum foil are to eliminate the rolling oil on the surface of the aluminum foil and ensure the mechanical properties of the finished product. Generally, low temperature and long time heat preservation is used to remove oil, such as (180-230)°C (20-30)h, degreasing. The effect can reach Class A water brushing performance as stipulated in the GB3198 standard; considering the mechanical properties to meet the technical standards, it is generally kept at 300°C for 20 to 30 hours for annealing.
Finally, the development trend of beer standard aluminum foil is described. Beer labels are moving towards thinning, alloying, and high-performance trends. The goal of domestic aluminum foil manufacturers to conduct process research is also roughly in this direction.
Beer thinning trend with aluminum foil. Currently, the general thickness of aluminum foil for beer is 0.0115mm, and some foreign-funded enterprises in China have proposed to reduce its thickness to the target of 0.0112, 0.015, and 0.01mm, and the requirements on material properties will not change. At present, North China Aluminum Co., Ltd. has produced a beer standard aluminum foil with a thickness of 0.0112mm or less by adjusting the 8011 alloy composition and annealing process; North China Aluminum has also conducted research on the alloying of aluminum foil for beer standardization. The 8××× alloy can batch produce beer standard foil with a thickness of 0.0105mm.
Alloying and high-performance trends in aluminum foil for beer marks. With the thinning of the aluminum foil for beer, it is obvious that the performance of 8011 alloy and the pinhole degree are difficult to fully meet the requirements of users. The original alloy composition must be adjusted or a new alloy must be prepared to maximize the thinning of the aluminum foil. Guarantee the performance indicators. The North China Aluminum Company currently develops an 8××× alloy O-state beer standard aluminum foil with a thickness reduced to 0.0105mm, and the strength can reach 85-95N/mm2, and the elongation (standard gauge length 100mm) can reach 2.5%-3.0. %, more than 95% of products have no pinholes, and product quality has been recognized by users in Guangzhou, Wenzhou, and Suzhou.