• Skrifvars, Mikael
• Säämänen, Arto

Abstract

In the recent years the awareness of the problems causedby the styrene emission during the processing ofunsaturated polyester resins has enlarged. The spray-upapplication of gel coats is especially problematic and itproduces high styrene emission rates. The emission ofstyrene has been reduced through material changes, workpractice controls and add-on controls. However, theinfluence of the spray-up process factors on the styreneemission has not been studied before. The aim of thisstudy was to examine possibilities to reduce the styreneemission by optimization of the spray-up process factors.The following factors were studied under controlledlaboratory conditions: orifice size and angle of thespray gun tip, spraying pressure, distance between spraygun and mold as well as the shape of the mold. Theinfluence of the rolling pattern during the laminationwas also studied. Several significant factors were found:High pressure and long spraying distance increased boththe unit styrene emission and the emission rate. Theorifice size had two effects; a large orifice decreasedthe amount of styrene emitted per sprayed amount of resinbut increased the emission rate of styrene. The shape ofthe mold did not affect the styrene emission. The styreneemission is greater if the entire mold area is rolled. Toachieve lower emission is it necessary to roll an area assmall as possible, this is especially important if alarge mold is laminated. The results showed that emissionof styrene can be reduced significantly by a optimalselection of the spray gun settings and the way ofworking. Optimal settings also increased the transferefficiency resulting in decreased material loss.

Topics

• impedance spectroscopy
• resin