One of the busiest paintshops in the world has to not only keep pace with extraordinary demand, but also to constantly upgrade its facilities to be greener and leaner
For a man with possibly the biggest job in automotive paintshop, Liu Dong seems very relaxed when we meet in his comfortable airy office at the FAW-VW Changchun plant. At a nearby hotel, two of the world’s largest paint equipment providers are presenting their proposals to VW paintshop managers, to win a contract to re-fit Dong’s No 1 paintshop but he dismisses the gravity of this: “It is just a re-fit, to bring the old number one paintshop up to better efficiency and more modern environmental standards, my team can take care of the bidding and the contract, no problem.”
The size of his remit at Volkswagen might seem at odds with his calm demeanour, Dong has a challenging task; to continue painting up to 2500 vehicles a day at FAW Volkswagen’s giant Changchun plant in Jilin Province while upgrading the paintshops to meet new quality, cost and environmental standards. He is also responsible for paintshop planning and implementation at the new Chengdu plant, some four hours flight time away, in Sichuan Province.
APS was allowed a free run of the main plant’s No. 2 paintshop. Building work on this facility started in 2004 and start of production was in 2005. About 1000 people work three shifts in No. 2, with 100 of those employed in maintenance. Indeed, maintenance is a major preoccupation for Liu Dong; with such a throughput of bodies and the high quality standards demanded by Chinese VW and Audi buyers, cleanliness and smooth running of the lines is vital.
Bodies come in to the e-coat area and are mounted on an Eisenmann VarioShuttle system for PT and ED; 27 VarioShuttles are used in pre-treatment (PT) and 17 in electrodeposition (ED). Dong tells me that sheer volume of work requires him to keep one complete spare VarioShuttle ‘arm’ as a clean ‘float’ part – one arm is always clean and ready to be exchanged for a ‘dirty’ one, on a daily basis.
Indeed maintenance requires one production-free day every two weeks, when the shuttle system is fully cleaned and serviced; regular cleaning (after each ‘round’ of e-coating) is done by dipping the shuttle in a tank of a BASF-sourced mild acid cleaner. E-coat media is filtered through Hayward filters (now part of Eaton Corporation) and PT chemicals are sourced from Chemetall.
On the new Bora model, the company has moved to a sealing solution that has been seen in Europe for some time; a very carefully controlled amount of a Henkel sealer is run into the roof ‘ditch’ – the join between the roof panel and the body side – using a Fanuc robot and a Graco pump system.
This application was designed and built by a Swiss supplier, EFTEC. The Bora body then goes under an infrared heat lamp station to cure the sealer before other seam sealers and underbody coatings are cured in the next oven stage. The Bora bodies are identified by a Siemens RFID tag and sensor system and so are stopped under the infrared lamp station. Underbody coating is fully automated in three stations, with two robots each, using four vision system cameras in each station. There are some places on the bodies that the robots cannot reach and in a last station, seam sealer is applied manually by brush.
Insulation for sound deadening and anti-drumming is magnetic for vertical panels and is cured in the usual way, in the sealer oven stage.
All bodies are hand spot sanded and any dust is manually blown off with compressed air and wipers before underbonnet and door shuts are primed manually; exterior primer is applied by Fanuc robot. Cabin interiors are not primed; this is to save cost and Volkswagen feels the quality of e-coat is now so good that interior priming is unnecessary.
Topcoat is batched into seven to eight car colour runs and the door shuts and interiors, pillars and underbonnet are sprayed manually before robots paint the first coat electrostatically and the second coat with air feed for metallics. Measurement of paint thickness and quality is manual and carried out with three different devices; BYK Gardner colour spectrophotometers for colour checking and its wave-scan meters for orange peel and DOI measurement, and Hynix meters for paint thickness.