Computer simulation and CAD has saved Durr more than £6m in its development of a paint shop for the new Rover 75 at the car manufacturer’s Oxford plant, according to Paul Anderson, Durr’s sales and marketing director.
Speaking at last month’s unveiling of the paint shop at Rover’s Oxford plant, Durr said: `Simulation was one of the most important tools the project team used. The virtual-reality display was particularly helpful to judge what the working environment inside the plant would be like.’
Packages such as AutoSimulations’s AutoMod were used to design the paint shop ergonomically to optimise factors such as working height and orientation of car bodies.
Process equipment such as manual spray guns have been designed to be readily at hand and automatically charged with the right colour paint.
The paint shop employs around 450 people – about the same as its predecessor. But its output of 60 units per hour is 50% higher than the previous shop’s, with the Rover 75 accounting for around 35 units.
The painting process runs over 13 stages. The first, phosphating, provides corrosion resistance and a surface for the first coat of paint, after which the body is dipped in an electrically charged bath for further corrosion resistance.
It is then rinsed to improve its surface, and heat-sealed in an oven.
In the next stage the body is cleaned using revolving ostrich feathers mounted on rollers. Each feather fibre has a hooked tip which can carry dust away to be vacuumed up.
A spray primer coat is then applied using electrostatic machines. This provides an anti-chip finish while enhancing the depth and durability of the final colour coat.
The `wet-on-wet’ waterborne basecoat is applied next, using electrostatic high-voltage atomisers which have an 85% transfer efficiency, compared with 70% at the old paint shop and 35% for manual spraying.
The second basecoat is blasted with air spray guns to achieve consistent coating and improve the look of metallic paint, while interior surfaces are sprayed manually.
After being dried in an infra-red oven at around 85-90 degrees C, a clear lacquer is applied to exterior surfaces, the body is rinsed in white spirit and is finally passed through to trim and final assembly.
The paint shop is already contributing to a boost in quality at the Oxford site. Its rating on BMW’s internal quality scale has improved to 0.77, compared with 1.8 for the old paint shop. Rover aims to hit a 0.4 rating by December 2000.
`This has been a very successful project,’ Anderson said. `We came in on the £80m budget and hit every deadline.
`We’ve hit quality levels quickly; now we must reduce operating costs.’