Lift-off at Westland with one-off dust extraction system
13th January 2000

For machining foam cores for helicopter blade spars, Westland Helicopters has installed a 5-axis high speed CNC router by Rye Machinery. Extraction for very high volumes of foam dust has been provided by J.B. Thorne of Leicester. The high density foam cores are a key component of Westland's high-technology blades and tail rotors, which are finished with a combination of complex carbon and glass-based materials.

The Rye machine is installed in the dynamic composite components production shop at Westland. During the machining process substantial volumes of foam dust are generated. This is extracted by a one-off "push-pull" system specified by Westland via the purpose built booth and extraction system from Thorne.

It is based on an Autoflo 142 reverse jet extraction unit which collects foam dust in polythene bags for manual removal and replacement. To ensure maximum dust removal efficiency, low-level grilles "push" cleaned air from the top of the extraction unit back into the machining area where it is sucked through into the Autoflo once again.

The Autoflo AFT/AFC series has been designed to use either tubular or cartridge filters in the same casing, a feature Thorne believes to be a 'first'. Because of its modular design, the new Autoflo offers much greater flexibility of size than existing units, while the cleaning system has been redesigned to make more effective use of compressed air.

By incorporating major modifications to the conventional system, the cleaning process drastically reduces the risk of overloading the cleaned filter, thus improving the life of the filter media. The high-efficiency filter elements are continuously cleaned by downblasted compressed air in 60-second cycles. Waste dust may be collected in bags as at Westland, or in a sealed hopper.

Thorne's Autoflo continuous automatic dust extraction equipment for all dust problems. In addition, it designs systems of all sizes, for external and internal use, from complete turnkey installations to individual units. It also supplies hoods, ducting, and a range of special work benches and laminar flow booths.

All Thorne systems meet current COSHH requirements, on which the company is qualified to give up-to-date advice. Thorne also carries out mandatory testing on installations when this service is required.