Q: We are struggling to compete with other players in the market, though we are operating at the same application system conditions: the same type of powder coating gun, the same voltage level, the same flow, the same line speed. The resin ratio in the formula is 60-70%, and we use a special anti-stat additive.
The problem is our powder coating only gives the product a thickness of 30-40 micrometers, while the powder of the rival company can produce products with a thickness of 60-70 micrometers. What’s the problem with our product?
A: I think I understand your problem. Here are some things I would investigate.
Particle size is the single most important property when it comes to transfer efficiency. Questions: what is your median (D50) particle size? More important, what is the percent below 10 microns and above 100 microns? How do you measure particle size distribution? How do you control it? You should target a median particle size of 35-40 microns. In addition, you should target <1.0% by volume particles greater than 100 microns.
What is the specific gravity of your powder? Is it similar to the competitive product? Is it higher? Higher specific gravity can reduce transfer efficiency by lowering particles due to gravity (falling to the booth floor).
How well does your customer maintain their application system? Do they have good grounding (earth) on the hangers and hooks? Are the spray guns well-maintained? How often do they provide maintenance for their equipment? You may be experiencing poor application performance due to poor maintenance on the spray guns, reclaim, and spray booth.
By the way, I’m not a big fan of adding electrostatic additives to powders. I think that it’s a band-aid approach and should be tried after all else fails.