Safety Spectacles: Moulded Polycarbonate with a Hard Coat

Industrial safety spectacles are injection-moulded from tough, transparent polycarbonate, often as a single front piece with the lenses, hinged to moulded temple arms; one design meeting the ANSI Z87.1 impact standard uses a lens 0.080 inch thick. Polycarbonate scratches easily, so the lenses get a thin, clear, abrasion-resistant coat of about 3–5 micrometres. Hard coats are applied by dipping or spinning after moulding: acrylate coats are cured by UV, siloxane coats by heat. Frames may be moulded in nylon.