Can shaping with a smoother finish

A can body expanding machine that enables smoother shapes to be achieved has been developed for the canmaking industry by Cantec, the Soudronic subsidiary.

The Cantec spread expander has already been used successfully by Ardagh for the manufacture of shaped cans for premium infant formula products.

Of the processes for shaping cans that are available to canmakers, which include blow molding or high-pressure forming, Cantec prefers mechanical forming because the tooling is more simple, the process is fast and uses less energy, despite limitations on the range of shapes and the expansion rate.

This is normally a two-step process, the first of which uses die-shaping to form both ends of the body to the final diameter with a pre-flange to stabilise the edge. In the second process, a spread expanding station controls the segmented expanding tool – a special design without linear guides – to create the final shape

To create a shaped can with fewer witness marks, the spread expander can operate in double action mode, in which the tooling first expands to shape with the marks, then relaxes, and rotates half a pitch to reform the marks.

The Cantec spread expander is offered as a stand-alone machine or in combination with spin flanging and double seaming. Three diameter ranges are offered – 52-73mm, 73-99mm and 99-153mm – with speeds of 500 to 250cpm.

More information from Cantec GmbH & Co KG, Helenenstrasse 149, D-45143 Essen, Germany. Tel: 49 203 633-0. Website: