Production of LLDPE and Sisal Composites via 3D Printing

Abstract

3D printing is a processing technique that presents an interesting possibility for obtaining various materials, with advantages such as lower cost and design adaptation. Various materials are used for printing, including polymers. However, some difficulties can be faced due to the characteristics of the processed materials, such as their mechanical propertie (tensile strength and strain at maximum load). In this context, composite materials formed by linear low-density polyethylene (LLDPE) and sisal fibers in natura and chemically treated with sodium hydroxide solutions were obtained via extrusion (initially on a twin-screw printer to obtain the masterbatch, a single-screw printer to manufacture the filaments and a 3D printer to obtain the test specimens) with the aim of developing new materials and contributing to aspects related to LLDPE processing in the context of additive manufacturing. The specimens were mechanically evaluated through tensile testing, revealing that the control formulation exhibited greater tension at maximum force than the composites, as well as greater strain at maximum load. Comparing the materials with fiber addition without treatment and with treatment with sodium hydroxide at different content, it was observed that the treatment did not lead to significant differences in the evaluated mechanical properties. Thus, although the processing was successful, resulting in intact specimens, fiber treatments under the evaluated conditions were not sufficient to obtain improved mechanical properties.