You can just paste the quote here and save everyone's time.

jdelgadoc (Automotive)
(OP)
24 Jan 19 23:28
Greetings,

I've been looking on the internet for information about surface energy of injection moulded plastics, specifically Polycarbonate, I want to know if this surface energy changes over time and how can I measure or prove this. I'm in charge of a Coating Process of Poylcarbonate pieces, so I want to have information on why the plastic parts have a defect similar to orange peel after being painted while they were 2 days in storage after moulding process, and I think the surface energy of the plastic and the humidity it can get in storage are the responsibles for my scrap parts.

Your description is unclear. Were the parts molded, stored, and painted, or molded, painted, and stored?

But, yes, surface tension can change with time after molding, or after surface treatment. Surface treatment should be done just prior to painting most plastics. Surface treatment is really an essential part of any painting process. I can be as simple as wiping the surface. But most plastics should be flame or plasma treated.

Paint issues are often surface prep and physical condition issues.

TTFN (ta ta for now)
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