Estudio de efecto en propiedades mecánicas por el uso de solventes para suavizar superficies de impresiones 3D tipo FDM.
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Date
2024
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
En este trabajo, se aplica un método de post-procesado químico a piezas de ácido poliláctico (PLA) impreso, para ello se fabrican probetas en la impresora 3D Ultimaker 2+ siguiendo las dimensiones presentadas en la norma ASTM 638 probeta tipo V, con las fibras orientadas a ±45° y una densidad de relleno de 100% y se exponen al vapor de dos solventes, Cloroformo y Diclorometano durante tiempos de 5, 10, 15, 30, 45, 60 y 120 minutos a temperatura ambiente (20°C). Luego de realizar el tratamiento se mide la rugosidad para ver el efecto suavizante según el solvente y el tiempo de exposición, posteriormente se hace un análisis Raman para estudiar si existe cambio químico en la estructura del polímero Para obtener las propiedades mecánicas de resistencia a la tracción, deformación y módulo elástico se realizaron ensayos de tracción cuyos resultados obtenidos se utilizaron como parámetros para ver el efecto del comportamiento de manera estática como también prolongado en el tiempo del PLA por medio de la realización de ensayos de relajación de esfuerzos y ensayos de fluencia. Como resultados se obtuvo una disminución de la rugosidad de las piezas de hasta un 79% para el caso del cloroformo una vez transcurrido 30 minutos y un 57% al usar diclorometano con un tiempo de exposición de 10 minutos, también una disminución de las propiedades mecánicas luego de aplicar el post-procesado químico, desde los 15 minutos el módulo elástico al igual que la resistencia a la tracción van disminuyendo considerablemente llegando a un 80% y 70% menos respectivamente al usar diclorometano y una disminución de un 88% y 77% al exponer las muestras al cloroformo en comparación a la probeta sin tratamiento, en cambio la deformación iba aumentando, volviéndose un material más dúctil.
In this work, a chemical post-processing method is applied to printed polylactic acid (PLA) parts, for this probes are manufactured on the Ultimaker 2+ 3D printer following the dimensions presented in the ASTM 638 type V probe standard, with the fibers oriented at ±45° and a filling density of 100% and are exposed to the vapor of two solvents, Chloroform and Dichloromethane for times of 5, 10, 15, 30, 45, 60 and 120 minutes at room temperature (20°C ). After carrying out the treatment, the roughness is measured to see the softening effect depending on the solvent and the exposure time, subsequently a Raman analysis is performed to study if there is a chemical change in the structure of the polymer. To obtain the mechanical properties of tensile strength, deformation and elastic modulus, tensile tests were carried out, the results of which were used as parameters to see the effect of the behavior of PLA statically as well as prolonged over time by carrying out stress relaxation tests and creep tests. As results, a decrease in the roughness of the pieces of up to 79% was obtained in the case of chloroform after 30 minutes and 57% when using dichloromethane with an exposure time of 10 minutes, also a decrease in mechanical properties. After applying the chemical post-processing, from 15 minutes onwards the elastic modulus as well as the tensile strength decrease substantially, reaching 80% and 70% less respectively when using dichloromethane and a decrease of 88% and 77% when exposing the samples to chloroform compared to the untreated probe, however, the deformation increased, becoming a more ductile material.
In this work, a chemical post-processing method is applied to printed polylactic acid (PLA) parts, for this probes are manufactured on the Ultimaker 2+ 3D printer following the dimensions presented in the ASTM 638 type V probe standard, with the fibers oriented at ±45° and a filling density of 100% and are exposed to the vapor of two solvents, Chloroform and Dichloromethane for times of 5, 10, 15, 30, 45, 60 and 120 minutes at room temperature (20°C ). After carrying out the treatment, the roughness is measured to see the softening effect depending on the solvent and the exposure time, subsequently a Raman analysis is performed to study if there is a chemical change in the structure of the polymer. To obtain the mechanical properties of tensile strength, deformation and elastic modulus, tensile tests were carried out, the results of which were used as parameters to see the effect of the behavior of PLA statically as well as prolonged over time by carrying out stress relaxation tests and creep tests. As results, a decrease in the roughness of the pieces of up to 79% was obtained in the case of chloroform after 30 minutes and 57% when using dichloromethane with an exposure time of 10 minutes, also a decrease in mechanical properties. After applying the chemical post-processing, from 15 minutes onwards the elastic modulus as well as the tensile strength decrease substantially, reaching 80% and 70% less respectively when using dichloromethane and a decrease of 88% and 77% when exposing the samples to chloroform compared to the untreated probe, however, the deformation increased, becoming a more ductile material.
Description
Tesis presentada para optar al título profesional de Ingeniera Civil Mecánica
Keywords
Solventes, Impresión tridimensional, Innovaciones tecnológicas