Improvement of flexural strength and compressive strength by heat treatment of PLA filament for 3D-printing

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940025 ◽  
Author(s):  
Jeong-Hyo Hong ◽  
Tianyu Yu ◽  
Zixuan Chen ◽  
Soo-Jeong Park ◽  
Yun-Hae Kim

Poly-lactic Acid (PLA) is an environmentally friendly material with better stability in heat shrinkage than Acrylonitrile Butadiene Styrene (ABS), such as warping in 3D printing. This study focused on the enhancement of the mechanical properties of PLA filament for 3D printers through different heat treatment temperature and heat exposure time of PLA samples. The results showed that the highest flexural strength was recorded in the PLA sample that went through heat treatment at [Formula: see text] and heat exposure time of 300 s. And it tended to decrease with temperature and time after this point. But it has higher flexural strength than neat PLA. The compressive strength showed the highest compressive strength through heat treatment at [Formula: see text] for 600 s. Because compressive strength has no threshold limit temperature in experimental temperature, compressive strength showed a tendency to increase with increasing heat exposure time and high temperature at same condition. This result showed that the heat treatment process affects the flexural strength and compressive strength and can be improved upon using appropriate heat treatment conditions.

2007 ◽  
Vol 124-126 ◽  
pp. 1031-1034
Author(s):  
Bong Soo Jin ◽  
Bok Ki Min ◽  
Chil Hoon Doh

To find out suitable Si surface treatment and heat treatment conditions, acid treatment of Si wafer was done for lithium polysilicate electrolyte coating on Si wafer. In case of HCl treatment, the wet angle of a sample is 30o, which is the smallest wet angle of other acid in this experiment. Acid treatment time is 10 min, which is no more change of wet angle. Lithium polysilicate electrolyte was synthesized by hydrolysis and condensation of lithium silicate solution using perchloric acid. Thermal analysis of lithium polysilicate electrolyte shows the weight loss of ~23 % between 400 and 500 , which is due to the decomposition of LiClO4. The XRD patterns of the obtained lithium polysilicate electrolyte also show the decrement of LiClO4 peak at 400 . The optimum heat treatment temperature is below 400 , which is the suitable answer for lithium polysilicate electrolyte.


2010 ◽  
Vol 69 ◽  
pp. 69-74 ◽  
Author(s):  
Ömer Arıöz ◽  
Kadir Kilinç ◽  
Mustafa Tuncan ◽  
Ahmet Tuncan ◽  
Taner Kavas

Geopolymer is a new class of three-dimensionally networked amorphous to semi-crystalline alumino-silicate materials, and first developed by Professor Joseph Davidovits in 1978. Geopolymers can be synthesized by mixing alumino–silicate reactive materials such as kaolin, metakaolin or pozzolans in strong alkaline solutions such as NaOH and KOH and then cured at room temperature. Heat treatment applied at higher temperatures may give better results. Depending on the mixture, the optimum temperature and duration vary 40-100 °C and 2-72 hours, respectively. The properties of geopolymeric paste depend on type of source material (fly ash, metakaolin, kaolin), type of activator (sodium silicate-sodium hydroxide, sodium silicate-potassium hydroxide), amount of activator, heat treatment temperature, and heat treatment duration. In this experimental investigation, geopolymeric bricks were produced by using F-type fly ash, sodium silicate, and sodium hydroxide solution. The bricks were treated at various temperatures for different hours. The compressive strength and density of F-type fly ash based geopolymeric bricks were determined at the ages of 7, 28 and 90 days. Test results have revealed that the compressive strength values of F-type fly ash based geobricks ranged between 5 and 60 MPa. It has been found that the effect of heat treatment temperature and heat treatment duration on the density of F-type fly ash based geobricks was not significant. It should be noted that the spherical particle size increased as the heat treatment temperature increased in the microstructure of F-type fly ash based geobricks treated in oven at the temperature of 60 °C for 24 hours.


2019 ◽  
Vol 13 (4) ◽  
pp. 343-348
Author(s):  
Adam Gnatowski ◽  
Rafał Gołębski ◽  
Piotr Sikora

A comparative analysis of the thermomechanical properties of semicrystalline and amorphous polymeric materials was carried out. Samples were produced by using a 3D printing technology on the SIGNAL printer - ATMAT. The following polymeric materials were used to make the samples: TPU-thermoplastic polyurethane elastomer, ABScopolymer acrylonitrile-butadiene-styrene, Nosewood, PET-ethylene terephthalate, PLA-poly (lactic acid). The research included a thermal analysis of the dynamic properties (DMTA) of manufactured materials.


Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3789
Author(s):  
Svetlana A. Kulikova ◽  
Sergey S. Danilov ◽  
Kseniya Yu. Belova ◽  
Anastasiya A. Rodionova ◽  
Sergey E. Vinokurov

The key task in the solidification of high-level waste (HLW) into a magnesium potassium phosphate (MPP) compound is the immobilization of mobile cesium isotopes, the activity of which provides the main contribution to the total HLW activity. In addition, the obtained compound containing heat-generating radionuclides can be significantly heated, which increases the necessity of its thermal stability. The current work is aimed at assessing the impact of various methodological approaches to HLW solidification on the thermal stability of the MPP compound, which is evaluated by the mechanical strength of the compound and its resistance to cesium leaching. High-salt surrogate HLW solution (S-HLW) used in the investigation was prepared for solidification by adding sorbents of various types binding at least 93% of 137Cs: ferrocyanide K-Ni (FKN), natural zeolite (NZ), synthetic zeolite Na-mordenite (MOR), and silicotungstic acid (STA). Prepared S-HLW was solidified into the MPP compound. Wollastonite (W) and NZ as fillers were added to the compound composition in the case of using FKN and STA, respectively. It was found that heat treatment up to 450 °C of the compound containing FKN and W (MPP-FKN-W) almost did not affect its compressive strength (about 12–19 МPa), and it led to a decrease of high compressive strength (40–50 MPa) of the compounds containing NZ, MOR, and STA (MPP-NZ, MPP-MOR, and MPP-STA-NZ, respectively) by an average of 2–3 times. It was shown that the differential leaching rate of 137Cs on the 28th day from MPP-FKN-W after heating to 250 °C was 5.3 × 10−6 g/(cm2∙day), however, at a higher temperature, it increased by 20 and more times. The differential leaching rate of 137Cs from MPP-NZ, MPP-MOR, and MPP-STA-NZ had values of (2.9–11) × 10−5 g/(cm2∙day), while the dependence on the heat treatment temperature of the compound was negligible.


2017 ◽  
Vol 263 ◽  
pp. 137-141
Author(s):  
Su Jun Guan ◽  
Liang Hao ◽  
Hiroyuki Yoshida ◽  
Hiroshi Asanuma ◽  
Fu Sheng Pan ◽  
...  

Photocatalyst coatings on alumina (Al2O3) balls had been successfully fabricated by mechanical coating technique, with titanium carbide (TiC) powder and subsequent heat treatment in carbon powder. The effect of heat treatment conditions in carbon powder on the formed compounds, surface morphology and photocatalytic activity of photocatalyst coatings was investigated. XRD results show that the formed compounds change with increasing the heat treatment temperature in carbon powder, and rutile TiO2 on the surface of TiC coatings at 1073 K and 1173 K. The generated oxygen vacancies confirmed by XPS measurement, are in favor of narrowing band gap to enhance the visible-light photocatalytic activity of photocatalyst coatings. The photocatalytic activity of photocatalyst coatings has been effectively enhanced, and the samples fabricated at 1073 K and 1173 K for 2 h show higher activity. The fabrication strategy provides us a facile preparation procedure of visible-light responsive photocatalyst coatings.


2010 ◽  
Vol 168-170 ◽  
pp. 1712-1716
Author(s):  
Zhuo Hao Xiao ◽  
Ming Hua Luo

The LAS glass containing P2O5has been prepared by conventional molten quenching method. The influence of heat treatment conditions on crystallization behavior, including phase transformation and microstructure, and thermal expansion coefficient (TEC) of Li2O–Al2O3–SiO2(LAS) glass-ceramics were investigated. DSC, XRD, SEM and TEC were used to detect the microstructure and properties of glass-ceramics under the different heat-treatment conditions. The results show the virgilite crystalline separated firstly from the matrix glass when heat treatment temperature was 850 °C. As the heat treatment temperature increased from 850 °C to 1050 °C, virgilite and β-spodumene were identified as main crystal phases. The TEC of glass-ceramics ranges from 0.5×10-6 °C-1to 2.8×10-6 °C-1, which is much lower than that of matrix glass.


Holzforschung ◽  
2001 ◽  
Vol 55 (6) ◽  
pp. 601-605 ◽  
Author(s):  
K. Mitsui ◽  
H. Takada ◽  
M. Sugiyama ◽  
R. Hasegawa

Summary The effect of heat treatment on changing the color of light-irradiated wood was investigated. The change in the lightness, ∆L*, of light-irradiated wood with heat treatment was much greater than that of unirradiated wood. The chroma coordinates, ∆a*, of irradiated wood increased with treatment temperature and time. ∆b* decreased after showing a sharp increase with a short period of heat treatment. It is thought that the changes are related to a change in the chemical composition which was accelerated by heat. With low temperature treatment, the color of irradiated wood changed remarkably with high relative humidity. Little change in color was observed with low relative humidity. Therefore, heat and the presence of water accelerated the change in the color of irradiated wood. This treatment is available as a new coloring method.


2011 ◽  
Vol 332-334 ◽  
pp. 912-915
Author(s):  
Dan Zhang ◽  
Lei Xu ◽  
Rui Wang ◽  
Li Feng Xu

Various heat treatment conditions with temperature scans of 300-700 °C, and annealing time scans of 1-4 hours were adopted in the annealing of Ti-49.5at.%-Ni shape memory alloy ultra thin wires. The mechanical hysteretic curves and the crystal morphology were obtained by the tensile-recovery testing and scan electric microscopes (SEM). The result shows that the shape memory effect of Ni-Ti alloy first decline after rising with the heat treatment temperature increases. Alloy with heat treatment effect in 500°C, presents the best. Time is not a significant factor for heat treatment.


2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Xiaomeng Hao ◽  
Qiuyi Wang ◽  
Yihua Wang ◽  
Xin Han ◽  
Chenglong Yuan ◽  
...  

AbstractBamboo is now widely used in construction, papermaking, textile, furniture and other fields because of its renewable, fast-growing, high-strength, high-yield and easy processing. However, compared with wood, bamboo and bamboo products are more vulnerable to damage by fungi and pests. An effective and eco-friendly method is urgently needed to improve their physical and chemical properties, decay resistance and anti-mildew properties, and hydrophobic properties. Here, bamboo was heated with methyl silicone oil. The effect of different temperatures (140 °C–200 °C) and different times (2 h–6 h) on the properties of bamboo was studied systematically, including chemical composition, physical and mechanical properties, surface wettability, decay resistance and anti-mildew property. No starch granules were observed inside the parenchymal cell lumen of bamboo specimen heat treated at 200 °C for 6 h. And with the increase of heat treatment temperature and time, the content of cellulose and hemicellulose decreases gradually while relative content of lignin increases due to its better thermal stability. Accordingly, the surface wettability decreases due to the changes of the surface functional groups and micro-morphologies. Under the condition of oil heat treatment at 160 °C for 2 h, the compressive strength parallel to grain of bamboo samples reach the maximum of 109.52 MPa. With further increase of heating temperature, the corresponding compressive strength decreases. The resulted bending strength and MOE both display similar changing trend. However, the optimal parameter is at 180 °C for 2 h, with the highest bending strength and MOE values of 142.42 MPa and 12,373.00 MPa, respectively. Finally, the decay resistance and anti-mildew property are dramatically enhanced with increased heat treatment temperature and time. All the corresponding changing mechanisms are investigated in depth and in detail. Our results provide comprehensive process parameters and micro-mechanism for the performance of oil heat treatment of bamboo, which can be used to guide the actual production.


2021 ◽  
Vol 899 ◽  
pp. 413-419
Author(s):  
Marina M. Murzakanova ◽  
Rustam M. Mamkhegov ◽  
Vladimir Z. Aloev

The effect of heat treatment on the structural changes and properties of the synthesized PPS samples was studied. The optimum temperature and the exposure time of the heat treatment of PPS were established, which allow to increase thermal stability, improve rheological and mechanical characteristics.


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