Examination of Layer Thicknesses of a Model Produced by Fused Filament Extrusion

Abstract

Nowadays additive manufacturing continues to gain more and more space in industrial technology. In particular, FDM (fused deposition modelling) machines have become easily available to the public. Quality of parts is impacted by several factors. In this study we investigate layer thicknesses of a prototype manufactured from PLA, and we pay special attention to the thickness of sequentially deposited layers.

The Social Composition of Medical Students at the Erzsébet University Between 1930 and 1945

“…60 He played an important role in setting up and equipping the Dental Clinic. 61 He was dismissed in 1946, and until his death he was the chief dentist of the Hungarian State Railways Hospital. 62 After his graduation in 1937, Dezső worked at the Clinic of Surgery, then between 1947 and 1982 at the Paediatric Clinic as the head of the Department of Otorhinolaryngology.…”

An Overview of Military Confrontations between of the Assyrian Army against the Medes in the 7th centuries BCE

“…Again, the main condition of success was cooperation between different troop types as the missile troops were always accompanying those designed for hand-to-hand combat. 31 Seventh century Assyrian infantry wore at least helmets but armours were very frequent. Most common were lamellar corselets but the discs covering crucial area of central rib cage were also frequent.…”

Additively manufactured respirators: quantifying particle transmission and identifying system-level challenges for improving filtration efficiency

“…One concern about the efficacy of using AM to produce respirators is the intrinsic porosity in FFF- and PBF-produced parts, which can affect filtration efficiency, accuracy, and reliability of the printed respirators. In FFF processes, porosity can result from adjacent layers not fully fusing [ 12 , 13 ], gaps left from changing direction and stopping/starting melt extrusion, and/or gaps left from adjacent extruded paths failing to fuse together [ 14 , 15 ]. Such inherent, process-induced defects have been shown to cause up to 32% porosity in FFF parts, with 200–800 μm diameter pores [ 16 ], which could render them ineffective in protecting against 0.3 μm virus particles.…”

“…Another anticipated challenge in the use of AM to directly fabricate PPE through shared digital designs is the inherent variability between AM machines, materials, and build parameters [ 21 ], which can affect the mechanical properties of the printed materials and the accuracy of the printed geometries. In FFF, processing parameters such as layer thickness [ 12 ], layer orientation [ 22 ], raster width and spacing [ 23 ], and filament feed rate [ 14 ] influence porosity, part quality, and performance. Prior round robin studies have shown variation between parts/tolerances despite parts being made on similar FFF systems [ [24] , [25] , [26] ].…”