Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
INFLUENCE OF ANNEALING ON PLA MECHANICAL AND THERMAL RESISTANCE
Submission Author:
Lucas Melo Queiroz Barbosa , MG , Brazil
Co-Authors:
Felipe dos Anjos Rodrigues Campos, Lucas Melo Queiroz Barbosa, Kauã Ferreira de Almeida, Pedro Henrique Veiga Oliveira, Gabriel Candido Andrzejewski , Paulo Filho, Álisson Rocha Machado
Presenter: Lucas Melo Queiroz Barbosa
doi://10.26678/ABCM.COBEM2023.COB2023-0503
Abstract
Fused Filament Fabrication (FFF) is a widely used additive manufacturing process. It involves extruding a polymer filament through a heated nozzle, which moves in three axes and deposits the material in layers on a flat bed. As the plastic cools and solidifies in each layer, it receives some thermal energy from subsequent depositions. Understanding the thermoplastic properties, particularly the glass transition temperature (when molecules become more mobile and adherent) and the crystallization temperature (when molecules organize into crystals, providing more strength and less ductility), is essential for this process. The objective of this work was to evaluate the impact of annealing on specimens, allowing the materials to crystallize and also improve layer contact and adhesion. Tensile and flexural tests were conducted according to ASTM D638 and ASTM D6272 standards to verify changes in mechanical properties, while heat deflection temperature (ASTM D648) tests and geometric deviation measurement evaluated the thermal resistance and warping, respectively. The methodology involved a complete factorial experimental design with 2 levels and 3 factors (2³), for each of the tests. A universal testing machine was used for both tensile and flexural tests while the heat deflection tests were conducted in an Arduino automatically controlled electric oven to ensure a steady temperature increase rate of 2 °C per minute. Results have shown small changes in the material resistance due to printing, and little dimensional changes aswell, with greater effects from printing parameters, which could happen due to sensibility of the material to humidity, since it is contrary to what expected. However, the thermal resistance of the polymer improved greatly, showing an interesting feature of the annealing process for PLA and its wide range of uses in the industry and consumer end applications within additive manufacturing.
Keywords
Additive Manufacture, annealing, crystallinity, Impact Resistance
