Influence of the Fibre Content, Exposure Time, and Compaction Pressure on the Mechanical Properties of Ultraviolet-Cured Composites

Abstract

A new process for the impregnation, consolidation, and curing of glass-fibre-reinforced polyester composites was developed to reduce manufacturing costs and secure end properties that compete with other traditional materials. This new process, based on the ultraviolet (UV) curing of prepregs, could be a viable alternative to infusion and other processes. In this paper, we showed that glass fibre composites 3 mm thick could be easily formed using suitable photoinitiating systems. We achieved improved mechanical properties through the application of favourable parameters to traditional manufacturing processes such as hand lay-up and infusion. The prepreg polymerization was monitored by dielectric analysis (DEA), and we evaluated the relationship between the UV radiation exposure time and curing degree. Both the exposure time and compaction pressure affected the fibre content of composites and interlaminar shear strength. Experimental results showed that compaction pressures higher than 4 bar are necessary to increase the mechanical properties of the UV-cured composites. Finally, the properties of the composites manufactured by this new process were compared to the properties of composites manufactured using traditional processes such as hand lay-up and infusion.

On the Influence of Flame-Retardant Additives on UV-Curable Thermosetting Glass Fiber-Reinforced Composites

“…The manufactured UV composites were produced according to the previous publication [ 8 ] based on glass-fiber-reinforced acrylic polyester. The acrylic resin that was used was a UV-curable resin composed of two polyester oligomers (TES21100 and VTC50) and an acrylic monomer (VTC5), and these were supplied by IVM Chemicals, Parona, Italy.…”

“…The compositions of the prepared formulations depending on the content of the flame-retardant filler are detailed in Table 2 . An unfilled formulation (Formulation_0) was prepared as a control sample according to a previous publication [ 8 ].…”

“…The prepregs manufacturing process was based on a previous publication [ 8 ], which consists of the impregnation of the fibers with UV-curable formulation, which was followed by a pre-curing process. Figure 1 a shows the impregnation process, which was carried out using hand rollers.…”