Back to basics produces economic thin-wall sections

A fresh approach in design and construction has resulted in the creation of a lighter and cleaner low-energy plant

Having identified a market for high quality thin-walled aluminium extrusions, down to a unit weight of 0.05kg/m, SECO Aluminium needed a 450ton press that could sustain high performance for very precise extrusions, in small batch sizes, with rapid low-cost tool changes.

To achieve the high accuracy required, a direct extrusion press was converted to indirect operation, thus combining the best virtues of both. With a much stronger structural frame and improved alignment control from the single main cylinder of a direct press, this redesign also gives much more overall rigidity.

A new die oven was designed, together with a quick-release die assembly, which, with a fixed front die ring, facilitates frequent die changes, typically within 2min.

As the plant would need to handle extrusion sizes from capillary to pen casings, planTRUSION was commissioned to create a miniature handling system, bespoke built from custom plant components with the standard pitch reduced from 1000mm to 500mm. To keep costs under control aluminium beams required for the belt system were extruded in-house on a neighbouring machine.

The first stage of the handling system was a special hot-cut saw and lead-out table, with a short run-out and adjustment to accommodate any sag in the fine extrusions.

Existing designs were again employed for the belt systems, with the pitch reduced from 1000mm to 500mm. These integrate with the driven roller system, to feed a 150mm packet of extrusions to the stretcher and then return to collect successive packages without a gap.

An innovative submarine stretcher system includes an unmanned swinging tailstock that automatically `pops up’ between the feed belts, together with a fully indexed headstock for fine adjustment of tension.

After the stretcher the packets are bundled up to 500mm wide before being fed, by the saw conveyor to the 550mm capacity final cut saw which incorporates a gauge stop.

Modern PLCs control the complete plant, using multiplexed signals and two bus wires.

SECO Aluminium Tel: 01376 515141