Advanced hybrid composites: Integrating carbon fiber tape into glass fiber thermoplastics via automated tape placement overmolding

Long fiber thermoplastic (LFT) composites have gained significant attention in various industries due to their desirable properties, including ease of processing, recyclability, superior strength, and corrosion resistance. Glass fiber (GF) is commonly used as a reinforcing material in LFT composites, given its low cost and excellent mechanical properties. However, there are challenges associated with the existing manufacturing processes, such as fiber attrition and limitations in achieving anisotropic properties. In this study, the overmolding of glass fiber-reinforced polyphenylene sulfide long fiber thermoplastic (G-LFT) and unidirectional continuous carbon fiber/polyphenylene sulfide tape (CF-Tape) using an Automated Tape Placement (ATP) robotic system has been investigated. The aim is to explore the potential of ATP for improving the mechanical properties of LFT composites. The results reveal that the overmolding process using CF-Tape on G-LFT leads to significant enhancements in mechanical performance. A 129% increase in tensile strength and a 192% improvement in flexural strength were observed compared to the G-LFT baseline. The bond strength at the interface was evaluated through flatwise tensile testing, which resulted in partial failure within the CF-Tape and a measured bond strength of 7.52 MPa ± 0.34. Thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) were conducted to analyze the thermal behavior of the parts. The crystallinity was measured using DSC data, and a value of 33.4% was obtained. Low-velocity impact testing has been conducted to understand the dynamic behavior of G-LFT and G-LFT/CF-Tape. The impact energy absorbed was found to be similar in both cases. A numerical model was used to reduce the number of experiments. It was found that the flexural strength would improved by 60% by adding five layers of CF-Tape. In summary, this research contributes to expanding the knowledge of overmolding techniques and highlights the potential of ATP-based overmolding for for enhancing the localized strength and easily applied to intricate geometries.