Shear properties of a glass-fibre/vinylester composite cured with high intensity ultraviolet light for use in automated manufacturing processes

This work presents preliminary results on the potential for rapid curing of a glass-fibre/vinylester composite with high-intensity ultraviolet (UV) light. Two 10-ply laminates were manufactured by hand lay-up with a resin formulated with a photo-initiator (Derakane 411-350 vinylester and Ciba Specialty Chemicals Irgacure 819 photo initiator). For the first laminate, all 10 plies were laid-up at once, then cured in approximately 4 minutes using a high intensity 200 Watt mercury short arc UV light. For the second laminate, each ply was laid and then exposed for less than 1 second to the same UV light. Testing of the resin-sensitive interlaminar shear strength showed no difference in properties between the two laminates. Furthermore, the shear strength was comparable to the properties of laminates cured via traditional heat curing methods with a typical 24-hour room temperature cure followed by a thermal post-cure. The study shows that a ply-by-ply approach to lay-up and partial cure, which is the likely procedure for automated ply-by-ply placement process, such as automated fibre placement, does not affect laminate performance.