Comparison of strength characteristics of polylactic acid test pieces with low interior fill percentage formed by a 3D-printer

2019 ◽  
Vol 2019.68 (0) ◽  
pp. 608
Author(s):  
Asahi YONEZAWA ◽  
Miho SUZUKI ◽  
Kohei TAKEDA ◽  
Kohei TAKEDA
Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2125
Author(s):  
José María Rosales ◽  
Cristina Cejudo ◽  
Lidia Verano ◽  
Lourdes Casas ◽  
Casimiro Mantell ◽  
...  

Polylactic Acid (PLA) filaments impregnated with ethanolic mango leaves extract (MLE) with pharmacological properties were obtained by supercritical impregnation. The effects of pressure, temperature and amount of extract on the response variables, i.e., swelling, extract loading and bioactivity of the PLA filaments, were determined. The analysis of the filaments biocapacities revealed that impregnated PLA filaments showed 11.07% antidenaturant capacity and 88.13% antioxidant activity, which after a 9-day incubation shifted to 30.10% and 9.90%, respectively. Subsequently, the same tests were conducted on printed samples. Before their incubation, the printed samples showed 79.09% antioxidant activity and no antidenaturant capacity was detected. However, after their incubation, the antioxidant activity went down to only 2.50%, while the antidenaturant capacity raised up to 23.50%. The persistence of the bioactive properties after printing opens the possibility of using the functionalized PLA filaments as the feed for a three-dimensional (3D) printer.


2019 ◽  
Vol 821 ◽  
pp. 167-173 ◽  
Author(s):  
Muammel M. Hanon ◽  
Róbert Marczis ◽  
László Zsidai

In this paper, the mechanical properties of Polyethylene terephthalate-glycol (PETG) tensile test specimens have been investigated. The test pieces were prepared using fused deposition modelling (FDM) 3D printing technology. Three print settings were examined which are: raster direction angles, print orientations, and infill percentage and patterns in order to evaluate the anisotropy of objects when employing FDM print method. The variations in stress-strain curves, tensile strength values and elongation at break among the tested samples were studied and compared. Illustration for the broken specimens after the tensile test was accomplished to know how the test pieces printed with various parameters were fractured. A comparison with some previous results regarding the elongation at break has been carried out.


2014 ◽  
Vol 631 ◽  
pp. 160-165
Author(s):  
Ryoki Karashima ◽  
Takeshi Yabutsuka ◽  
Takeshi Yao

We precipitated Apatite Nucleus (AN) by raising pH of SBF. We mixed various concentration of AN in polylactic acid (PLA) and pressed by uniaxial press and cold isostatic press. We investigated the effect of AN concentration on bioactivity. We fabricated composite of PLA and AN configurating the shape by using 3D printer. The composite showed high bioactivity.


2021 ◽  
Vol 902 ◽  
pp. 101-106
Author(s):  
Khompee Limpadapun ◽  
Jenjira Sukmanee

This study investigated characteristics of moisture desorption for polylactic acid (PLA) filaments. The filaments tend to absorb moisture from humid air, led to moisten filaments. The absorption of even small amounts of moisture by filaments during storage and/or 3D printing, degraded the quality of final parts, and therefore, caused manufacturing problems. In this work, the filaments were subjected to humid conditions to achieve various moisture concentrations (0.75, 1.3 and 1.87 wt.%). Warm air-drying processes are used to reduce the moisture for different times (1, 2, 3, 4, 5 and 6 hours) and temperature (40, 50 and 60 °C). It was founded that the moisture from the polylactic acid (PLA) filaments can be discovered the moisture by use 60 degree of temperature in 5 hours warm air-drying process.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7560-7572
Author(s):  
Qianqian Zhu ◽  
Qian Yao ◽  
Jun Liu ◽  
Jianzhong Sun ◽  
Qianqian Wang

The application of Fused Filament Fabrication (FFF) 3D printing for offices, educational institutions, and small prototyping businesses has recently attracted increased attention. Thermal-fused filaments could emit potentially hazardous atmospheric particulate matter (PM) and volatile organic compounds (VOCs). This study evaluated the particle and VOCs emission characteristics of an FFF 3D printer with lignocellulose/polylactic acid (PLA) filament to reduce emissions. The PM2.5, PM0.2-10, and VOCs emission behaviors of the FFF 3D printer with a lignocellulose/PLA filament were investigated in a test chamber under different printing conditions. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was applied to analyze the formation of VOCs from lignocellulose/PLA filaments. Analysis indicated that particle formation dominated the heating process, whereas VOCs were mainly released during the printing process. The results further showed that printing at higher relative humidity and high filament feeding temperatures triggered higher VOCs emissions. In addition, high humidity facilitated particle agglomeration and reduced PM concentration. Printing at higher filament feeding temperatures also resulted in high particle emissions. Finally, Py-GC/MS analysis determined the decomposition products of the lignocellulose/PLA filament corresponding to the main ingredients of VOCs.


Inventions ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 21 ◽  
Author(s):  
Miho Suzuki ◽  
Asahi Yonezawa ◽  
Kohei Takeda ◽  
Akira Yamada

A fused filament fabrication (FFF) 3D printer is a simple device capable of manufacturing three-dimensional structures in a series of easy steps. Commercial-level FFF 3D printers have spread rapidly in many fields in recent years. Poly(lactic acid) (PLA) is a biodegradable thermoplastic polymer used as a typical printing medium for FFF 3D printers. The FFF printer constructs an object with melted polymer extruded from a tiny scanning nozzle. The mechanical properties of FFF 3D structures printed with different scan patterns can therefore vary in accordance with the directions from which forces act upon them. The nozzle scan pattern also influences the deterioration of the mechanical properties of the structures in accordance with the degradation caused by the hydrolysis of PLA. In this study we conducted tensile tests to evaluate the strength characteristics of 3D printed test pieces formed from PLA using four different scan patterns: parallel, vertical, parallel-and-vertical, and cross-hatched at opposing diagonal angles to the tensile direction. We also formed test pieces by an injection molding method using the same material, for further comparison. We evaluated the deterioration of the test pieces after immersing them in saline for certain periods. After the test pieces formed by different nozzle scan patterns were immersed, they exhibited differences in the rates by which their maximum tensile stresses deteriorated and their masses increased through water uptake. The influences of the scan patterns could be classified into two types: the unidirectional scan pattern influence and bidirectional scan pattern influence. The data obtained in this research will be applied to structural design when the FFF 3D printer is employed for the fabrication of structures with PLA filament.


2020 ◽  
Vol 16 (2) ◽  
pp. 24-33
Author(s):  
Haneen Mahdi Jaber ◽  
Muhammed Abdul -Sattar ◽  
Nabel Kadhim Abd al-Sahib

Prosthetic is an artificial tool that replaces a member of the human frame that is  absent because of ailment, damage, or distortion. The current research activities in Iraq draw interest to the upper limb discipline because of the growth in the number  of amputees. Thus, it becomes necessary to increase researches in this subject to help in reducing the struggling patients.  This paper describes the design and development of a prosthesis for people able and wear them from persons who have amputation in the hands. This design is composed of a hand with five fingers moving by means of a gearbox ism mechanism. The design of this artificial hand has 5 degrees of freedom. This artificial hand works based on the principle of  under actuated system. The used motor is 6V Polulu high-power carbon brush micro metal gearmotor with gear ratio equal to 50:1. The motor was chosen due to its compactness and cheapness. The hand manufacturing process was done using  a 3D printer and using polylactic acid material. Numbers of experiments were accomplished using the designed hand for gripping objects. Initially, the electromyography signal (EMG) was recorded when the muscle contracted in one second, two seconds, three seconds. The synthetic hand was able to produce a range of gestures and grasping for objects.


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