We provide new experimental results on studies of composites with glass-coated ferromagnetic microwires aligned with the requirements of carbon composites. This work focuses on the free space microwave measurements of composites made from carbon fibers and ferromagnetic microwires inclusion focusing on the electromagnetic properties. We prepared several glass-coated microwires and selected Co-based microwires with optimum soft magnetic properties and high magnetoimpedance effect for composite fabrication. We observed that by using a low-frequency modulating ac magnetic field parallelly oriented to the ferromagnetic microwires allows us to distinguish the microwave signals originated from the ferromagnetic microwires inclusions from the response generated by the carbon fibers. The location of carbon fibers near magnetic microwires has a critical effect on the response signals (parameters S amplitude) obtained from such composites.

One of the main advantages of fiber-reinforced polymer (FRP) composites is the ability to reduce their weight while they exhibit exceptional properties such as high strength, stiffness, and resistance to corrosion, and reduction in their lifetime maintenance when they are compared to the metallic components. These features led fiber-reinforced polymer composites to have applications in the mechanical, construction, aerospace, automotive, medical, marine, and other manufacturing industries. However, the use of this type of material is not possible in all of these applications since, in certain sectors, the fire resistance property that the material must present is one of the key factors. For this reason, a thermosetting resin composed of ultraviolet (UV)-curable acrylic monomers has been used as a matrix, where transparent aluminum trihydrate (ATH) flame-retardant fillers were incorporated for manufacturing flame-retarded UV-curable composites. The composite parts were produced by using glass fiber-reinforced UV-curable prepregs. An exhaustive study of different types of ATH-based flame-retardant additives and the possible cooperation between them to improve the fire properties of the UV-curable composite was carried out. Additionally, the most suitable additive percentage to meet the railway sector requirements was also evaluated, as well as the evolution in the viscosity of the matrix and its processing capacity during the manufacture of the prepregs at 60 °C. The compatibility between the fillers and the matrix was assessed using a dielectric analysis (DEA). The fire properties of both the matrix and the final composite were established.

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.

Fiberglass reinforced polymeric composites are ideal for various applications due to their mechanical properties and lightweight. However, nowadays many fiberglass reinforced composite manufacturing processes are manual, which makes it complicated for them to meet industrial requirements regarding the quality and reliability of the manufactured parts, limiting their applications. The development of automatic and digital processes lead to the reduction of manual labour and, as a consequence, the cost and variability of the process. Nevertheless, the industrial implementation of these automatic processes requires them to be economically affordable, flexible and simple. Therefore, the research work carried out has focused on the development of an automatic fiberglass composite manufacturing process able to produce composites with mechanical properties comparable to those obtained in conventional manufacturing processes. For this purpose, a two-stage manufacturing line has been developed: (i) the automatic manufacture of fiberglass and ultraviolet (UV) resin prepregs, and (ii) the compaction and curing of these prepregs. The process has been validated by measuring the physical and mechanical properties of the manufactured composites and comparing them to those obtained with hand lay-up and infusion processes. Key Words: Automatic process, fiberglass, prepregs, UV curing, energy efficiency, productive efficiency.

This work presents recent advances in the optimization of an automated process for manufacturing glass fiber composites, based on the production of UV-cured prepregs. The aim of this development is to facilitate the production of glass fiber parts with a polyester matrix, ensuring a repeatable and controllable process. Moreover, this innovative technology enhances process efficiency and improves the quality of the final product. This work focuses on monitoring the manufacturing process using specific sensors, such as laser measurement devices and thermocouples, with the aim of ontrolling key process parameters, including the impregnation temperature and the thickness of the resin layer deposited on the dry fabric. Continuous monitoring, enabled by the integration of a data acquisition and analysis platform, makes it possible to improve both the quality and efficiency of the process. It also facilitates the development of models for implementing adaptive controls, issuing reprocessing instructions, and validating product quality in real time. Within this framework, temperature at various stages of the process and the resin content in the prepreg have been monitored and analyzed, establishing their correlation with machine parameters that govern the impregnation process. Resin content was measured using a newly patented device (EP 23382517.3), and the results were compared with fiber content measurements obtained through weight difference analysis. In this project, the UV-curing prepreg manufacturing process was successfully monitored, enabling real-time visualization and analysis of key process parameters. This revealed a clear correlation between these parameters and the resin content, laying the foundation for future full machine automation. This technology can be applied to UV-curable resins, including acrylic thermoplastics, bio-based, flame-retardant, or dual-cureon. UV and thermal resins, as well as to all types of glass fibers, thereby broadening its applicability across various composite manufacturing processes. • Keywords: Process automation, fiberglass prepregs, ultraviolet (UV) curing, composite materials, process monitoring, sensors in composite manufacturing, adaptive control, quality optimization, resin content in prepregs.