Moisture Sorption and Degradation of Polymer Filaments Used in 3D Printing

Abstract

Experimental research of the moisture sorption process of 12 typical filaments used for FFF was performed in atmospheres with a relative humidity from 16 to 97% at room temperature. Materials with high moisture sorption capacity were revealed. Fick’s diffusion model was applied to all tested materials, and a set of sorption parameters was found. The solution of Fick’s second equation for the two-dimensional cylinder was obtained in series form. Moisture sorption isotherms were obtained and classified. Moisture diffusivity dependence on relative humidity was evaluated. The diffusion coefficient was independent of the relative humidity of the atmosphere for six materials. It essentially decreased for four materials and grew for the other two. Swelling strain changed linearly with the moisture content of the materials and reached up to 0.5% for some of them. The degree of degradation of the elastic modulus and the strength of the filaments due to moisture absorption were estimated. All tested materials were classified as having a low (changes ca. 2–4% or less), moderate (5–9%), or high sensitivity to water (more than 10%) by their reduction in mechanical properties. This reduction in stiffness and strength with absorbed moisture should be considered for responsible applications.

Environmental Durability of Bio-Based and Synthetic Thermoplastic Composites in Large-Format Additive Manufacturing

“…The moisture content of CF/ABS specimens increased and approached saturation levels at the end of the testing period. Aniskevich et al [ 45 ] reported similar moisture uptake behavior in 3D-printed ABS polymers.…”

The Tensile, Thermal and Flame-Retardant Properties of Polyetherimide and Polyetherketoneketone Processed via Fused Filament Fabrication

“…Moreover, the degradation of tensile properties due to moisture absorption was studied for twelve different filaments, including PEI and PEKK [3]. According to the results obtained, both materials were classified as having a moderate (5-9%) sensitivity to water by their reduction in mechanical properties, while the maximal moisture sorption capacity and swelling coefficient of PEI were almost twice as high as for PEKK.…”

“…Additive manufacturing has gained widespread adoption across various sectors due to several compelling motivations, such as design flexibility, reduced material waste, rapid prototyping, customization, supply chain simplification, tooling and assembly reduction, and environmental benefits [1][2][3]. These advantages drive the use of additive manufacturing across various industries, e.g., aerospace, automotive, healthcare, defence, and military, promising improved efficiency, reduced costs, and innovative product development [4,5].…”

Fabrication and Characterisation of Sustainable 3D-Printed Parts Using Post-Consumer PLA Plastic and Virgin PLA Blends

“…PLA plastic is known to be susceptible to moisture absorption, which can result in hydrolytic degradation during the filament extrusion process. This degradation may cause the breakdown of polymeric chains and decrease the material elongation [77][78][79]. However, the same moisture content acts as a plasticiser, making the material softer and more ductile [79].…”