Title: Enhancing Structural Performance of Upcycled Fiber-Reinforced Thermoplastic Composites Through Additively Manufactured Continuous Fiber Reinforced Preforms

Authors: Garam Kim, Eduardo Barocio, Sungjun Choi, Martin Eichenhofer, Jordan Kalman, R. Byron Pipes

DOI: 10.33599/nasampe/c.23.0063

Abstract: The rapid growth in the adoption of lightweight composite materials is also creating a growing demand for recycling methods that could retain some of the structural characteristics of composites. Thermoplastic composites are preferred over thermoset composites when it comes to recycling. Mechanical recycling, which involves shredding composite parts at the end-of-life (EOL) and reforming it into different parts, is a widely discussed recycling process for thermoplastic composites. However, this process involves significant attrition of fibers which results in a reduction in the mechanical and transport properties that depend on the fiber length. Consequently, this method of recycling composites significantly devalues the structural characteristics of the composite. In an effort to enhance the structural characteristics of recycled composites, this paper demonstrates a process that incorporates additively manufactured continuous fiber preforms in a geometry that is compression molded with recycled composite. The continuous fiber preform is designed to serve as the primary structural reinforcement whereas the recycled material serves as a secondary reinforcement in the composite part. This upcycling approach was demonstrated for an aircraft overhead pin bracket geometry. Continuous fiber preforms were manufactured with 60% by volume of carbon fiber-reinforced Poly Ether Ketone Ketone (PEKK) using the 9T Labs continuous fiber Red Series® Build Module. The preforms were designed using Additive Fusion Technology (AFT) to account for reshaping during the molding process and ensure the continuous fiber is located where required. Two types of recycled composite material were used to make the pin bracket: shredded carbon fiber PEKK laminate and shredded EOL additively manufactured carbon fiber reinforced PEKK. The performance of the pin bracket was evaluated by the load at the onset of failure and the ultimate load under tensile loading of the bracket. The results demonstrated the potential of this upcycling method to enhance the structural characteristics of recycled composite materials and compensate for the loss of structural characteristics associated with fiber attrition.

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Conference: CAMX 2023

Publication Date: 2023/10/30

SKU: TP23-0000000063

Pages: 17

Price: $34.00