Dalau, a specialist supplier and machinist of plastics, has installed a sixth 5-axis machining centre as part of a £1m spend in new machine tools at its Clacton-on-Sea factory.
The new Hermle C 250 machining centre has been modified to accept vacuum workholding fixtures and was supplied by the German manufacturer's UK sales and service agent, Geo Kingsbury, which also carried out the customisation.
The Hermle installation is part of a £1 million spend on machine tools at the Clacton factory within the past year to cope with a steep increase in demand for Dalau's machined components across numerous industries. They include automotive and medical as well as the semiconductor sector, particularly in the US and Germany. The expansion has seen the number of 5-axis machining centres increase to six, the appointment of two extra programmers and a move to double-shift operation.
Production manager Ben Bonds explains that there is no machining centres of this size specifically for milling and drilling plastics as the market would not be large enough to make such a machine commercially viable. So Dalau has to rely on production centres designed for cutting metal, which for processing plastics tend to be unnecessarily large for a given working volume. They are also far too powerful; in the 5-axis shop at Clacton, the load drawn by the spindle motors never exceeds 5 per cent.
The new C 250 is currently devoted to finish-machining a family of PTFE pump bodies that have been roughed on another of the 5-axis machines. Four or five operations are required to complete the machining operations in total cycle times of between three and four hours. An air conditioned environment held at 21°C ensures that tolerances down to ± 0.05 mm can be held easily, despite the tendency for plastics to distort during machining.
The four-part assemblies into which these components go are delivered to a US customer specialising in manufacturing equipment for the semiconductor industry. Indeed, four-fifths of the shop's output is exported to long-standing customers in the US, where Dalau has had a sales subsidiary since 1990 in New Hampshire.