Hot Powder Bed Compaction: A Rapid Fabrication Approach for Thermoplastic Composite Components

Abstract

Traditionally thermoplastic composite prepreg fabrication methods often rely on molds or costly tooling, limiting the agility and efficiency of the fabrication process. A compelling need for a high-performance thermoplastic composite prepreg fabrication approach that eliminates the dependence on molds, simplifies the fabrication process and accelerates prototyping, enabling rapid iterations in product development. The proposed hot powder bed compaction (HPBC) technique eliminates the need for specialized molds and still provides fully consolidated components. The HPBC process involved a three-step sequence comprising powder densification, heating, and consolidation stages. These stages help effectively control time–temperature-pressure parameters to achieve good fusion between the prepreg sheets. This paper showcased the HPBC process on a hinge bracket made from glass fiber-reinforced nylon prepreg sheets to illustrate its performance. Experimental mechanical characterization was carried out on treated HPBC coupons and compared with the molding process. Notably, the experimental flexural test results indicated a flexural modulus of 13.79 GPa and flexural strength of 295 MPa for HPBC-treated specimens, placing them in a comparable range with molded components. Microscopy analysis revealed the complete fusion interface of the prepreg sheets, and DSC analysis shows increases in crystalline fraction from 31.5 % to 44.1 % in PA6. Hence, the HPBC process presents a versatile and effective approach for fabricating high-performance, complex-shaped, void-free, components using thermoplastic composite prepreg.