INFLUENCE OF SURFACE SEALING AND RELEASE AGENTS ON SURFACE CHARACTERISTICS OF ADDITIVELY MANUFACTURED FIBER-REINFORCED THERMOPLASTIC COMPOSITE TOOLS

Fiber-reinforced composite additive manufacturing is a promising technology for producing composite tooling due to its ability to facilitate rapid tool fabrication, design flexibility, and reductions in material waste and labor. However, the Surface finish quality of the additively manufactured tool surfaces post-machining remains a concern. The heterogeneous nature of fiber reinforcement and polymer matrix, which are intermixed on the surface, may negatively impact surface finish quality, potentially affecting surface roughness, friction, and the required demolding force. Typical practices involve applying surface treatment agents, to improve surface finish quality. However, there is limited quantitative data about specific effects of each agent. In this study, the influence of surface treatment agents; primers, sealers, and release, on the surface characteristics of composite tools was investigated. Test specimens were additively manufactured using polyethersulfone (PESU) reinforced with 25 % carbon fiber by wt%. Surface properties required for tooling applications—such as hardness, wear resistance, surface roughness, and friction—were evaluated before and after the application of surface treatment agents. Scanning electron microscopy (SEM) and analysis further confirmed that the treated surfaces exhibited improved morphology and purity, supporting the suitability of these surface agents for composite tooling applications.