I want to say something about thermoplastic material when you meet thickness problem, actually thermoplastic materials are good for parts with a thin wall. The value we often use is from 1.5 mm to 4 mm. though it could be as thin as 0.6 – 0.9mm, or even 0.25 mm at time.
Each injection molding engineer should be familiar with this material. and injection mold designers as well
it is often used in injection molding, also there are many kinds of molding method