Metallic aluminum has many properties that make it useful in a wide range of applications. It is lightweight, strong, nonmagnetic, and nontoxic. It conducts heat and electricity and reflects heat and light. It is strong but easily workable, and it retains its strength under extreme cold without becoming brittle. The surface of aluminum quickly oxidizes to form an invisible barrier to corrosion. Furthermore, aluminum tube can easily and economically be recycled into new products.
The article contains following；
1,How to choose the raw material
2,The first step is compare a rough form
3,Third step is to trim the tube to the specified length on both the top and bottom ends
4,Fourth step is the spray application of an internal lining
1,How to choose the raw material?
Aluminum compounds occur in all types of clay, but the ore that is most useful for producing pure aluminum is bauxite. Bauxite consists of 45-60% aluminum oxide, along with various impurities such as sand, iron, and other metals. Although some bauxite deposits are hard rock, most consist of relatively soft dirt that is easily dug from open-pit mines. Australia produces more than one-third of the world's supply of bauxite. It takes about 4 lb (2 kg) of bauxite to produce 1 lb (0.5 kg) of aluminum metal.
Caustic soda (sodium hydroxide) is used to dissolve the aluminum compounds found in the bauxite, separating them from the impurities. Depending on the composition of the bauxite ore, relatively small amounts of other chemicals may be used in the extraction.
of aluminum. Starch, lime, and sodium sulphide are some examples.
Cryolite, a chemical compound composed of sodium, aluminum, and fluorine, is used as the electrolyte (current-conducting medium) in the smelting operation. Naturally occurring cryolite was once mined in Greenland, but the compound is now produced synthetically for use in the production of aluminum. Aluminum fluoride is added to lower the melting point of the electrolyte solution.
The other major ingredient used in the smelting operation is carbon. Carbon electrodes transmit the electric current through the electrolyte. During the smelting operation, some of the carbon is consumed as it combines with oxygen to form carbon dioxide. In fact, about half a pound (0.2 kg) of carbon is used for every pound (2.2 kg) of aluminum produced. Some of the carbon used in aluminum smelting is a byproduct of oil refining; additional carbon is obtained from coal.
Because aluminum smelting involves passing an electric current through a molten electrolyte, it requires large amounts of electrical energy. On average, production of 2 lb (1 kg) of aluminum requires 15 kilowatt-hours (kWh) of energy. The cost of electricity represents about one-third of the cost of smelting aluminum.
2,The first step is compare a rough form
The manufacture of aluminum tubes starts with what is called an aluminum slug or blank. It is fed into a set of tools in the die which then extrude it. This extrusion press then roughly forms a completed tube form.
3,Third step is to trim the tube to the specified length on both the top and bottom ends
The next step is to trim the tube to the specified length on both the top and bottom ends. At this point, the tube is threaded which enables us to screw on the cap. During extrusion, aluminum becomes work hardened so during the next step, it is passed through a process which makes the metal malleable. This is done at about 460 degrees centigrade.
4,Fourth step is the spray application of an internal lining
The next step, which is used primarily in the pharmaceutical industry, is the spray application of an internal lining. This acts as barrier protection for metal sensitive products between the exposed aluminum and the pharmaceutical, or other product, to be packaged.
If the tube is not internally coated, it will bypass the internal lining step and go to the next step which is the coater rolling of a base coat onto the tube. This coat prepares the tube for the application of offset printing. The base coat is then cured and brought back to a printing machine which puts on the customer’s specified colors and copy. You can see all these tubes detailed for the different customers who require different types of decoration.
Tubes for some products require a fold sealant that acts as a barrier to prevent product seepage from the fold end of the tube. The final step in the production of aluminum tubes is the capping operation. And, again, customers generally dictate the types of styles and caps that they like. Primarily, four different materials — polypropylene, and high, medium, and low density polyethylene — are used as cap material.
The tubes are then checked, packed in boxes, inspected and loaded either into cartons or on skids for final shipment to the customer.
