There are three aluminium can production lines at Rexam Beverage Can’s UK plant in Milton Keynes, with each line catering for different sizes of cans, including 44cl, 50cl and 56.8cl. The company recently reviewed its manufacturing practices and has since invested in screw jack systems to streamline operations in the can washing area.
Hitherto, the washing facility was altered manually for each different can size. The changeover was a labour intensive task, taking six people, an average of four hours to turnaround one production line.
Converting the line meant men with spanners climbing the machine framework, running nuts up or down large diameter threaded studs and once positioned, locking them off with a second nut - a time consuming and costly activity in terms of lost production. Since the upgrade, this activity has been successfully cut to just one individual working for 20 minutes. A major part of this transformation is down to the addition of screw jack systems from Power Jacks.
The cans travel through a six-stage process via a conveyor. Stages 1 and 2 are wash tanks, which contain a solution of Hydrofluoric acid, which etches the can surface to provide a key for the print process. The remaining stages in tanks 3 to 6 finish the process by washing and finally blow drying the cans.
The fully automated system for height adjustment of tanks 3 to 6 uses 28 Power Jacks screw jacks, each rated at 10kN load capacity. Model TE2500 inverted translating screw jacks were selected for this task from standard E-Series Metric Machine Screw Jacks, though some degree of customisation was necessary.
Stainless steel components were specified because of the mildly corrosive application environment.
Indeed, the scope of supply extended beyond the screw jacks, to include bevel gearboxes, drive shafts and couplings to ensure consistent, repeatable and synchronised movement over the length and span of the washer line.
“The improvement was dramatic”, recalls Jim Brownrigg, the conversion manager at the plant. “Needless to say, five hours and 40 minutes is a massive saving in any production environment. This success is thanks to some clear thinking from the Rexam plant engineers, their system integrator and the Power Jacks Group engineers.”