When Good Parts Coat Bad: Stripping Reject Components to Salvage Profits
On average, the overall coating industry runs about mid-single digits for rejects due to coating defects. Of course, the more stringent your quality requirements, the higher the coating defect rates will be. Coating lines that must produce "Class A" finishes can hit about a 10 percent defect rate on average, while general industrial finishes for function and good aesthetics can run at 2 percent to 3 percent. Substrate materials and part geometries also can greatly influence reject rates.
The first goal is not to produce coating defects. There are a number of standard practices that should always be evaluated when working toward higher product quality and reduced reject rates. These include proper pre-cleaning and pretreatment of work, proper application equipment maintenance and settings, quality coating materials, and rack cleanliness to promote good part grounding. On high production lines, even fractional percentage yield improvements can translate to many thousands of additional good parts. All of these factors work in concert to produce good finishes of predictable and reproducible quality and to minimize coating defects.