Replacement of steel parts with high-performance thermoset composites will lead to significant weight reduction and strength increase of components that can benefit both the automotive and construction markets. However, lack of automation in processing composites increases not only cost but high-volume production, thereby limiting their widespread use. Flexibility in design and the ability to use various material combinations make pultrusion technology ideal for the fabrication of cross-sectional composite parts. However, the remarkable issues that reduce competitiveness of the pultruded profiles are the time required for polymerisation of the resin inside the die, which results in a low-speed process, as well as the additional steps that are needed when coating is used to improve the surface of the profile. The EU-funded project COALINE (Development of an innovative manufacturing process for the in-line coating of pultruded composites) was initiated to resolve these issues. Researchers developed a methodology for in-line coating of pultruded parts that reduces the polymerisation time with novel microwave heating and specially formulated thermoset resin systems. The innovative process significantly reduces the necessary steps and volatile organic compound and small particle emissions to obtain high-quality coated parts through integration of the forming, coating and finishing processes in one step. Therefore, it can produce lower-cost thermoset composite materials suitable for replacing traditional structural metallic parts, thereby reducing weight, in vehicles for example. Furthermore, the reduction of the time needed when producing the coated profiles allows high output and continuous production. In particular, an innovative control system facilitates adhesion of the coating to the composite by controlled curing in each stage of the process. Fast-curing primers – also incorporated in-line – facilitate the posterior adhesion of adhesives with on-demand debonding properties in order to join the composites and other metallic parts, and also improve the recycling and maintenance of pultruded structures. COALINE’s newly developed process is faster, cheaper and more environmentally sustainable compared to the traditional pultrusion process. The project represents a step forward to increase vehicle performance by decreasing its weight thanks to the use of low-cost, high-performance composites.
Pultrusion, vehicles, manufacturing, coating, composites, COALINE