Volume 8, Issue 4 (July 1980)
Application of Accelerated Weathering Test to Glass-Fiber Reinforced Polyester Sheets of Improved Surface Durability
An accelerated weathering test has been applied to three types of commercial glass-fiber reinforced polyester (GRP), the durability of which has been improved by the application of various surface finishes. The nature and rate of induced surface degradation were monitored throughout the exposure period by scanning electron microscopy and, where possible, compared with those produced by horizontal outdoor exposure at Ottawa, Canada. Acrylic-lacquer-coated GRP underwent six types of surface damage leading to exposure and surface microcracking of the GRP substrate. The first three types of damage produced by artificial weathering were similar to those induced so far after six years of outdoor weathering, resulting in an acceleration factor of 6. Gel-coated GRP sustained surface microcracking as for outdoor exposure with an acceleration factor of 9. Poly(vinyl fluoride)-laminated (PVF) GRP underwent five types of damage, resulting in delamination of PVF and surface microcracking of the unprotected GRP resin. The first two types of damage have been verified to date after six years of outdoor exposure and were accelerated by a factor of 5.