Many people have said to me “Spray booth filters need changing all the time”. You could call your spray booth supplier and ask them to solve the problem. To me it sounds like the spray booth is doing its job. The objective of the spray booth is to remove solvent gasses and airborne particulates from the spray area. In an ideal world we would have 100% transfer efficiency. That means there would be no airborne solvent gasses, apart from those evaporating from the coated surface during cure and all the particulates emitted from the spay gun would land on the work-piece. Unfortunately, we don’t live in an ideal world and there is an “overspray”. We can’t eliminate overspray, but we can take measures to dramatically reduce it.

When coatings are spray applied you will always experience coating losses. The term that compares the amount of coating applied to the work-piece compared to overspray losses is called “transfer efficiency”. There are many factors that affect the transfer efficiency such as: –

  • The coating characteristics (viscosity & surface tension)
  • The choice of applicator (spray gun) to match with material characteristics
  • Spray gun settings (fluid flow rates & air atomising pressures)
  • Additional equipment technologies such as electrostatics
  • Spray equipment operator techniques

Spray application transfer efficiency can be as bad as 15% and can be as good as 75%. I would advise all companies who spray apply coatings on a large scale to calculate their transfer efficiency. With the high cost of coatings low transfer efficiencies can prove very expensive. This means the original subject of “Spray booth filters need changing all the time” is only a symptom of a much deeper financial loss.

If you are concerned about overspray losses and you are constantly changing your spray booth filters contact