Resins for Spray Up
The most common resin system used for the spray-up process is general purpose or DCDP polyester, isophthalic polyesters and vinyl ester resins. The spray up technique can be said to be an extension of the hand lay-up method. In this technique, a spray gun is used to spray pressurized resin and reinforcement which is in the form of chopped fibers. Orson provides wide range of resins for spray up application.
Generally, glass roving is used as a reinforcement which passes through spray gun where it is chopped with a chopper gun. Matrix material and reinforcement may be sprayed simultaneously or separately one after one.
Spray release gel is applied on to the mold surface to facilitate the easy removal of component from the mold. A roller is rolled over the sprayed material to remove air trapped into the lay-ups. After spraying fiber and resin to required thickness, curing of the product is done either at room temperature or at elevated temperature.
After curing, mold is opened and the developed composite part is taken out and further processed further. The time of curing depends on type of polymer used for composite processing.