Huddersfield-based PTG Heavy Industries Ltd (www.ptgheavyindustries.com) has won an order worth $1.5 million to supply two of its Crawford Swift Powerstir friction stir welders to Andritz Sundwig GmbH.

Based in Hemer, Germany, the latter is a leading specialist in the design and development of specialist turn-key systems for the production of hot- and cold-rolled strip made from stainless steel, coated metals, non-ferrous metals and special materials. The Crawford Swift friction stir welders will be used in two aluminium-foil processing lines that Andritz Sundwig is currently developing for joining aluminium foil strips up to 2m wide and from 0.4 to 6mm thick.

Traditionally, the ends of aluminium foil strips are joined by ‘stitching’ them together to provide a continuous roll for production purposes. However, stitching can create rough joints that sometimes damage elements of the processing line. By contrast, friction stir welding uses frictional heat combined with precisely controlled forging pressure to produce high-integrity, full-penetration welded joints that are smooth and virtually defect-free.