Aluminum cold extrusion is a common process in the manufacture of pressure containers as well as special fire extinguishers, cylinders, gas and water bottles and symmetrical parts starting from a billet. The billet is obtained by cutting an aluminum bar.
Once properly lubricated it is inserted into the die, consisting of a matrix and a punch. The punch goes down into the matrix and, by pressure only, the aluminum is extruded in reverse on the punch. This operation is performed at controlled speeds and forces, generating heat that is dissipated by the special water cooling circuit of die. Galdabini hydraulic press is based on a vertical 4-column type SEV/630-A of 6.300 kN for the aluminum cylinder cold extrusion and a 1,000 kN C-frame press type SE/100 to taper the upper end.
The overall cycle time is about 9 seconds for 4 parts, 2,500 pieces/hour for a press that will work h24 for 330 days a year. In total more than 12 million pieces per year of extruded CO2 bottles.