Aluminium in the Packaging Industry » Production · Use · Recycling « MARKETS for ALUMINUM PACKAGING 3
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Aluminium in the Packaging Industry » Production · Use · Recycling « MARKETS FOR ALUMINUM PACKAGING 3 Contents Markets for aluminum packaging 3 12 Of some 74,000 people employed in the German aluminium count for 24 per cent. Eleven per cent goes into flexible tubes industry, about 15,000 work in the packaging sector. In 2016 and aerosol cans and five per cent is used for capsules and Markets for aluminum Applications in the the sector had a turnover of 2.3 billion euros, representing screw closures. packaging packaging industry around 16 per cent of the total turnover of the industry. This is equivalent to some 414,000 tonnes. Thus about eleven per The production of primary aluminium is not covered by this cent of the total production of the aluminium industry is used brochure. However, a brief description will first be given 4–5 13 in the packaging sector, making it the third largest market of the production of recycled aluminium and rolling ingots Recycling Rigid aluminium packaging for aluminium products in Germany. (continuous casting) and the rolling process. Beverage cans · Food cans · Aerosol Some 60 per cent of the aluminium used for packaging is The manufacture of different types of aluminium packaging cans · Bottles · Small tubes and small 6 –7 processed to foil or thin strip. Food and beverage cans ac- and their fields of application will then be described. tins · Closures The casting process Continuous or direct chill casting 18 –19 8 – 9 Semi-rigid aluminium Bauwesen packaging Aluminium products The rolling process in Germany in % Collapsible tubes · Capsules Maschinenbau Hot, cold or foil rolling Trays and containers Transport sector (48) Verpackung 10 20 – 21 Building and construction (13) Mechanical engineering (7) Eisen- und Stahlindustrie Surface treatment and foil Flexible packaging with Packaging (11) conversion Elektrotechnik aluminium foil Iron and steel industry (6) Degreasing · pickling · protective lac- Electrical engineering (7) quering · lamination · coating · printing Haushaltswaren Houshold goods, office supplies (4) embossing Other markets (4) Sonstiges 11 Material properties Aluminium packaging in Germany in % Verpackungen mit Aluminiumfolie Packaging aluminium foil (60) Nahrungsmittel- und Getränkedosen Food and beverage cans (24) Capsules and closures (5) Tubes and aerosol cans (11) Kapseln und Schraubverschlüsse Tuben und Aerosoldosen The pyrolysis process RECYCLING 5 recycles aluminum. LIFE SPAN 12 years + Recycling Loop Aluminum from short-lived applications can be recycled into long-life products. ALU © DAVR – Deutsche Aluminium Verpackung Recycling GmbH POOL LIFE SPAN 0,5 years + LIFE SPAN up to 50 years + Recycling Aluminium has a high intrinsic material value. This has meant vending machines do not accept such packaging. This conglomeration of materials using so-called eddy-current that recycling aluminium has always been worthwhile eco- means there is no mixing with other aluminium scrap. separators. The fraction comprising aluminium or alumini- nomically, especially since it can be remelted time and again Beverage cans made of tinplate that are collected via the um-laminate packaging is then baled and transported to the without any loss in quality. That is why one refers to alumin- same scheme are separated from the aluminium beverage recycling plant for processing. The bales supplied weigh up ium as a permanent material which, unlike other materials, cans using magnets. This avoids the need for elaborate to a tonne and are decompacted using special equipment. can be recycled an unlimited number of times thanks to its sorting and processing. Producing a beverage can weighing A shredder reduces the size to 10 –15 centimetres. The next © DAVR – Deutsche Aluminium Verpackung Recycling GmbH inherent physical properties. The recycled material comes approximately 15 grams results in 120 g of CO2 less be- stage is a large storage bunker, from where it is transported from every field of application and is fed into the aluminium ing emitted than would be the case with production of the via conveyor belts or metering screw conveyors to the so- pool together with primary aluminium, to then be used for aluminium via electrolysis. The smelters recover high-grade called pyrolysis oven. high-grade products. In Germany, it has been possible in aluminium from the can scrap and this is used to produce recent years to recover ever-greater amounts of aluminium, new products, including new beverage cans. Pyrolysis is a process in which organic substances, such also from packaging, thanks to the combination of the deposit as paint, labels, films or residual contents, that are adher- system (beverage cans), the household collection of packaging The recycling of aluminium packaging or packaging con- ing to the aluminium packaging are separated from the via the so-called dual system and appropriate investment in taining aluminium that is not subjected to a deposit and is aluminium in a so-called pyrolysis drum in the absence of modern collection, sorting and recycling technologies. obtained via a collection system is a process that begins with oxygen. Energy is released in the form of heat during the the user. The consumer collects the packaging at home or low-temperature carbonisation and this heats the drum Since the introduction of the deposit on beverage cans in at work in the yellow bins or sacks of the dual system. Such in a continuous process. The temperature in the drum 2003, the recycling of aluminium beverage cans has been packaging includes, for example, pet-food cans, chocolate reaches 450 – 500 ° C. The residence time is 30 – 60 minutes. optimised continually. Today, about 96 per cent of the cans foil, trays, tubes, aerosol cans and single-portion packs for Aluminium packaging maintains its shape after pyrolysis, used are collected and recycled thanks to this system. coffee. The yellow bins and sacks are then collected by a and can be melted down to aluminium or processed. Redemption is via reverse vending machines located in local waste-disposal company on behalf of the dual system, supermarkets or beverage stores or manually at kiosks or loaded onto trucks and compacted. The recyclable material The collection and recycling of aluminium packaging has filling stations. The beverage cans are usually compacted in is subsequently transported to a transshipment point from undergone a remarkable development in Germany. The the machines and supplied by the trade to the smelter. This where the compacted material is distributed to one of about recycling rate was 57 per cent in 1995 but only ten years material stream is defined by the alloy used to produce the 40 sorting plants throughout Germany. At the sorting plant, later 76 per cent of aluminium packaging was already be- beverage can because the deposit scheme does not apply all of the material is separated into the groups of recycla- ing recycled. The recycling rate has continually increased to other forms of aluminium packaging; therefore reverse bles. Non-magnetic aluminium is separated out from the since then and is now about 90 per cent. In modern sorting plants the collected material is split up into different material groups. THE CASTING PROCESS 7 The casting process (continuous casting) Various shapes of rolling ingot can be cast in computer con- The vertical continuous casting process described here is the trolled continuous casting plants, in which the casting process preferred method of producing ingots worldwide. In addition, is performed completely automatically. there are horizontal continuous casting plants in which the strands are allowed to grow in a horizontal direction. In the The casting device comprises a water-cooled mould with a various types of strip casting process, molten aluminium is base that can be lowered. The molten aluminium is poured cast between two water-cooled steel strips, rotating steel slowly into the mould and solidifies on the walls and base; it moulds or rolls and, depending on the process used, strip thus forms a beaker whose contents are still molten. While 6 – 30 mm thick solidifies at a low flow rate. The strip is sub- molten metal is continuously poured into the mould at the top, sequently rolled directly. the base is lowered uniformly at such a rate that the level of the molten metal in the mould remains constant. This leads Casting wheels (so-called rotary Rigamonti casting wheels) to the formation of a strand or ingot, which is sprayed with are used to cast strip for slug production, for example for aer- water from all sides to cool it completely. osol cans and tubes. The wheels have a recess that is covered by a steel strip, whose width and depth corresponds to the Solidification proceeds from the bottom to the top into the dimensions of the strip. Molten metal at 750 ° C is guided to innermost parts of the ingot. In this way, an ingot is produced the inlet pouring gate of the casting wheel. The casting wheel that is fine-grained, compact and free from pores over its and the steel strip are water-cooled. Thus, when the alumin- whole cross-section. Only the surface solidified by water ium leaves the casting wheel its surface is already solidified cooling is irregular and thus has to be post-worked: both and can be removed without any support at a temperature ends of the ingot are sawn off to remove irregularities arising of 500 ° C. The cast strip is hot rolled further, cooled to about from the casting process and the cast skin is removed on all 50 ° C in a water bath, cold rolled to make it smooth and to sides by milling. achieve the desired thickness, and then coiled. Continuous / strip casting Melting Casting Filtering Ingot Sawing / Casting milling © TRIMET Aluminium SE 8 THE ROLLING PROCESS THE ROLLING PROCESS 9 The rolling process The rolling process includes hot and cold rolling. The prod- up rolls ensure that the high pressure does not cause the Hot rolling ucts are plate (thickness >6 mm), strip (0.021 – 6 mm) and foil smaller diameter working rolls to bow out.