Investigation of variable bead widths in FFF process

Gharehpapagh, Bahar
Dölen, Melik
Yaman, Ulaş
Fused filament fabrication technology provides the opportunity to produce complex objects with sophisticated interior features. Here, extruding variable bead widths for desktop 3D printers is presented in order to improve resolution and to decrease the build time. In the proposed method, the cross-section is continuously varied according to the geometric features associated with the layers. That is, thinner beads can be utilized to print features with higher accuracy such as the outer surfaces, edges/corners, and features with finer details. Larger beads could be employed to cover interior regions where the accuracy is not an important concern. In this paper, a comprehensive review on nozzles with variable bead widths is given. Then, new orientation-controlled extruder designs with rectangular orifice, which focuses on controlling the filament flow inside the nozzle to determine variable bead widths at the output of the nozzle, will be introduced. Numerical- and experimental analysis will be conducted to show comparatively the performance of the presented design. The repeatability of this process is also evaluated for nominal bead widths. The studies show that there is a good agreement between numerical and experimental results. The paper will be concluded with key points on the advantages of these proposed nozzle design.


Characterization of novel materials for fused filament fabrication
AL-DUAIS, ABDULLAH ABDULRAHMAN NAJI; Özerinç, Sezer; Kazanç Özerinç, Feyza; Department of Mechanical Engineering (2021-6-24)
Fused filament fabrication (FFF) is a polymer additive manufacturing technology that is suitable for a wide range of applications due to its low cost and ease of use. This thesis investigated two types of novel materials for FFF use. First, a foaming PLA filament is considered and the mechanical properties of 3D printed specimens using this filament is characterized. The results show that the strength, modulus and density of the foaming PLA can be tuned over a wide range of values by varying FFF process par...
Numerical and Experimental Investigation into LWIR Transmission Performance of Complementary Silicon Subwavelength Antireflection Grating (SWARG) Structures
Cetin, Ramazan; Akın, Tayfun (Springer Science and Business Media LLC, 2019-03-18)
This paper presents a detailed comparison between the long wave infrared (LWIR) transmission performances of binary, silicon based, structurally complementary pillar and groove type antireflective gratings that can be used for wafer level vacuum packaging (WLVP) of uncooled microbolometer detectors. Both pillar and groove type gratings are designed with various topological configurations changing in various period sizes (Delta) from 1.0 mu m to 2.0 mu m, various heights/depths (h) from 0.8 mu m to 1.8 mu m,...
Development of electrochemical etch-stop techniques for integrated MEMS sensors
Yaşınok, Gözde Ceren; Akın, Tayfun; Department of Electrical and Electronics Engineering (2006)
This thesis presents the development of electrochemical etch-stop techniques (ECES) to achieve high precision 3-dimensional integrated MEMS sensors with wet anisotropic etching by applying proper voltages to various regions in silicon. The anisotropic etchant is selected as tetra methyl ammonium hydroxide, TMAH, considering its high silicon etch rate, selectivity towards SiO2, and CMOS compatibility, especially during front-side etching of the chip/wafer. A number of parameters affecting the etching are inv...
Investigation of structural and electronic properties of ZnCdTe ternary alloy nanostructures
Kurban, Mustafa; Erkoç, Şakir; Department of Physics (2016)
Nanostructures, including II-VI compound semiconductors, have attracted enormous attention in a wide range of applications of nanotechnology due to the unusual mechanical, electrical and thermal properties under varying size, geometry, temperature and pressure when compared to corresponding bulk materials. However, these properties are not directly measurable by experiments because of the methods or the availability of the experimental tools, so theoretical models and computations play an important role in ...
Effect of annealing on the mechanical properties of pla parts produced by fused filament fabrication
Aydın, Sencer; Özerinç, Sezer; Department of Micro and Nanotechnology (2021-9-01)
Additive manufacturing has become a disruptive technology for the production of load bearing components in a wide range of applications. Fused filament fabrication (FFF) is among the most effective and economical techniques for the printing of polymeric parts. There are numerous thermoplastic materials suitable for FFF. Among these, Polylactic acid (PLA) is a renewable, sustainable and cost-effective alternative. For better utilization of PLA parts produced by FFF, there is a need to understand the structur...
Citation Formats
B. Gharehpapagh, M. Dölen, and U. Yaman, “Investigation of variable bead widths in FFF process,” 2019, vol. 38, Accessed: 00, 2020. [Online]. Available: