Annual Review
December 2014
STATIC ELECTRICITY & THE FINISHING INDUSTRY Anyone who works in the Finishing Industry will be aware of the huge problems caused by dust and other airborne contaminants. If left unchecked, the costs in time and materials alone can run into the thousands. Typically this problem stems from an electric field and static charge build up, which causes dust, or other contaminants, to be attracted to the product. If a contaminant ends up being included in the coating, or other decoration, it often results in a blemish which can mean the rejection of the product. Static and Dust on Metal Parts Static and dust attraction is normally associated with plastics and non-conductive materials, but there are exceptions. The best-known of these is probably in the automotive sector. The bare chassis of a car is grounded metal and so incapable of holding much charge, but there is still an electrostatic dust attraction. The reason for this is that the static charge is in the airborne dust particles. These charged dust particles are attracted to the chassis because it is conductive and grounded. Some years ago an engineer at the Ford plant in Dagenham calculated that it probably cost over ÂŁ1000 whenever a Fiesta was found to have a painting blemish due to statically attracted dust. This included taking the chassis off-line, tacking off the blemish by hand, putting it back on-line and repainting it. The answer to this problem for most automotive plants is to install an ionised air gate immediately before the spray booths. This blows ionised air at high speed around the profile of the vehicle. The ionised air kills the static charge on the dust, allowing the speed of the air to remove it. This type of system can be operated with blown or compressed air. For large applications the greater purchase cost of a blown air system will be paid back quickly (typically within 6 months) due to its much lower running costs. Fraser Anti-Static have successfully installed ionised airgates such as the one shown opposite on car, coach and truck plants worldwide.
Gravity fallen dust is inevitable in many factories. Removing this dust from metal products isn’t always straightforward. If you use an ordinary compressed air blow-off gun, it could make the problem worse – the fast moving air can create a static charge when it impacts with the product. This may blow off the dust, but the now statically charged dust, is just floating around waiting to be re-attracted to the product. The solution is to use an ionised airgun which will remove dust without causing a static charge.
If you would like to discuss a Static Control Solution, call Fraser Anti-Static today on (UK) T: 01398 331 114 mention Engineering update and receive a discount on your first order. www.fraser-antistatic.co.uk The only choice for Quality Static Control Solutions |55