Glass Polyester Composites Pressing Mixing Plant Glass Polyester Composites (GPO) Variety of Glass Rovings, Chopped strands is combined with Polyester Resins to produce GPO.Different Resins are chosen and varieties of additives are added to produce different grades. “Lamtuf has developed unique process for producing void free GPO sheets” Laminates meets following Standards NEMA LI–1–2001IEC 60893-3-5 DIN 7735 IS: 10192 – 1982 Get a Technical Data Sheet