A photo-activated adhesive-based work-holding system has been introduced to the UK and Europe by newly appointed sole agent NCMT Ltd, Thames Ditton.

Called Blue Photon, it was developed at The Pennsylvania State University, to fixture difficult-to-hold parts for tight-tolerance machining and inspection.

The process involves applying an adhesive that is cured by ultraviolet light via fibre optic cables. The adhesive can subsequently be melted and the machined workpiece removed by immersion in hot water or by application of another heat source, which optimally should be at 80°C.

Alternatively, the adhesive contact points can be sheared to free the workpiece by rotating the gripper pins in the fixture plate with a spanner. Moreover, no witness mark is visible where the glue was applied.

Use of the technique has grown rapidly in the USA’s aerospace industry and is now spreading to other industries, such is its ability to hold components securely with an average shear resistance of 136kg; it also gives cutters excellent all-round access for machining on five sides.

Unlike magnetic clamping systems, it can be used to secure not only ferrous metals but also non-ferrous metallic parts, as well as ceramics, composites and delicate materials.

One current application of Blue Photon is the clamping of gamma titanium aluminide, which is being used to produce low-pressure turbine blades for the latest generation of high-efficiency jet engines.

The alloy, which is brittle and difficult to handle, halves the weight of aero components compared with Ti64, providing big savings on fuel consumption.

Other advantages of the clamping process are an absence of workpiece distortion, good damping properties (to suppress chatter), reduced fixture costs when holding complex parts, and the elimination of locating lugs on castings.

More information can be found at the Web site (www.ncmt.co.uk/pioneers-in-machining-technology/products/bluephoton).