in Vol. 2 - August Issue - Year 2001
Lead Times reduced with automated Glass Bead Peener
USF Vacu Blast International is part of the global USF Surface Preparation Group and is a well established specialist in the design and manufacture of controlled shot peening and precision abrasive equipment for the aerospace industry.
Precision engineering specialist, Weston EU, based at Foulridge, near Colne in Lancashire, has recently installed a USF Vacu-Blast 'Ventus(r) 150 AXT' automated glass bead peening machine specifically for the controlled processing of aeroengine compressor blade aerofoils for fatigue life enhancement. This operation was previously subcontracted.
As a result of activities within its lean manufacturing programme, Weston EU - a leading manufacturer of precision components and assemblies for the aerospace, power generation, automotive and telecommunications industries, amongst others - has been able to significantly reduce lead times on these particular parts. After only a few months of operation, lead times have been cut from 17 weeks to 6.5 weeks, with an ultimate target period of just one week. Whilst producing a future state value stream map, Weston identified that the installation of a glass bead peen machine was necessary to create product flow.
500'000 Airfoils per Working Year
The new machine has a production capacity of around 500,000 aerofoils per working year. The parts processed are in titanium, nickel based alloys and steel, can measure between 15mm and 200mm in length and are retained in special polyurethane location and masking tools on a variable speed turntable, which swings in and out of the enclosure to facilitate loading and unloading. The polyurethane tools are tailored to accept different part sizes, depending on production requirements.
Intensities from Almen 7N - 11N
Processing takes place in a 1500mm x 1400mm x 1000mm high enclosure, with peening carried out by an array of eight suction-fed blast guns attached to a reciprocating roof-mounted manipulator. The guns are fitted to universally adjustable mounts to allow accurate positioning during initial machine set-up.
The machine uses glass beads within the 100µm to 800µm size range and peening intensity varies between Almen 7N and 11N, according to the particular component and specification. Peening parameters are governed by a PLC based programmable control unit to ensure process repeatability.
High Level of Cleanliness
Special features of the machine include automatic media recovery, air washing and recycling of reusable media (degraded material is directed to a dust collection bin); automatic air-purging for component cleaning after peening; and high-efficiency filtration to ensure that air exhausted from the dust collection unit is maintained at a high level of cleanliness in line with COSHH requirements.
The Ventus AXT 150 peener is one of a range of USF Vacu-Blast 'Ventus' surface treatment and abrasive blasting machines, which is claimed to be the widest and most versatile range of its kind available and embraces over 230 manual, semi-automatic and automatic variants, with processing enclosures up to 2m x 2m x 2m and capable of using all types of blast media.
Roger Brickwood or Chris Brooks
USF Vacu-Blast International
Slough, Berkshire, SL1 4DJ, UK