Articles
Progress in Additive Manufacturing (23639520)
Extrusion-based additive manufacturing of thermosets and short fiber-reinforced thermoset composites is a challenging task and remains, despite recent advances, unable to fully leverage the entire design freedom offered by state-of-the-art technology due to low viscosity and solidification way of ink. This study introduces an enhanced direct ink writing (DIW) technique for effectively printing thermoset resins and corresponding short glass fiber-reinforced composites, achieved without adding any rheological modifiers and using ultraviolet (UV) curing. The proposed method utilizes time-dependent rheological control to enhance the ink's properties, offering a cost-effective and experimentally simplified approach. Experimental results suggest that the raster angle had no substantial effect on the mechanical properties, or in other words, the printed specimens behave like an isotropic material. To achieve maximum tensile properties, the ink parameters, such as fiber weight fraction, mixing time, and mixing speed, were optimized using the Taguchi design of experiment. The results showed a strong correlation between predicted and observed values, confirming the efficacy of the approach. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.
Additive manufacturing (AM) technology of thermoset polymer composites has great potential to address the disadvantages of widely used thermoplastic resins in terms of processing, cost, modification of compound formulation, dimensional stability, and stress crack resistance. Whilst there are other AM processes for thermoset polymer composites, the two most common techniques; VAT photopolymerization and extrusion-based methods are discussed. This chapter deals with the basics of these two technologies and attempts to describe the limitations and advantages of each. In particular, the key features and challenges regarding both techniques are presented. Furthermore, common materials available for thermosetting AM systems are described in combination with the 3D printing of fiber-reinforced polymer composites. A description of the important parameters that enhance the performance of printed parts is provided. © 2024 Elsevier Inc. All rights are reserved including those for text and data mining AI training and similar technologies.
Ansaripour, A.,
Heidari-rarani, M.,
Mahshid, R.,
Bodaghi, M. International Journal of Advanced Manufacturing Technology (02683768)132(3-4)pp. 1827-1842
A simple and inactive structure is able to transform into a complex and active one via four-dimensional (4D) printing. Controlling bending deformation, activation time, and temperature is crucial in 4D printing. This study aimed to comprehensively evaluate and analyze the effect of different process parameters on the bending deformation of polylactic acid (PLA) shape-morphing produced by material extrusion additive manufacturing. These parameters included layup, layer thickness, printing speed, nozzle temperature, nozzle diameter, and bed temperature. Since the bending deformation is significantly affected by the specimen wall, this study has focused, for the first time, on the simultaneous influence of process parameters and presence of a wall on the deformation. Furthermore, the study examined the influence of printing parameters on activation time and activation temperature. The results indicated that increasing the pre-strain stored in the parts led to a decrease in activation time and activation temperature. Subsequently, the Taguchi design of experiment method was used to optimize the most influential parameters on the bending deformation. The difference between the optimal predicted and the experimental deformations was less than 2%. Layer thickness, layup, nozzle temperature, and printing speed were recognized as the most effective parameters for controlling deformation, respectively. © The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature 2024.
