scholarly journals A Comprehensive Investigation on 3D Printing of Polyamide 11 and Thermoplastic Polyurethane via Multi Jet Fusion

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2139
Author(s):  
Wei Shian Tey ◽  
Chao Cai ◽  
Kun Zhou

Multi Jet Fusion (MJF) is a recently developed polymeric powder bed fusion (PBF) additive manufacturing technique that has received considerable attention in the industrial and scientific community due to its ability to fabricate functional and complex polymeric parts efficiently. In this work, a systematic characterization of the physicochemical properties of MJF-certified polyamide 11 (PA11) and thermoplastic polyurethane (TPU) powder was conducted. The mechanical performance and print quality of the specimens printed using both powders were then evaluated. Both PA11 and TPU powders showed irregular morphology with sharp features and had broad particle size distribution, but such features did not impair their printability significantly. According to the DSC scans, the PA11 specimen exhibited two endothermic peaks, while the TPU specimen exhibited a broad endothermic peak (116–150 °C). The PA11 specimens possessed the highest tensile strength in the Z orientation, as opposed to the TPU specimens which possessed the lowest tensile strength along the same orientation. The flexural properties of the PA11 and TPU specimens displayed a similar anisotropy where the flexural strength was highest in the Z orientation and lowest in the X orientation. The porosity values of both the PA11 and the TPU specimens were observed to be the lowest in the Z orientation and highest in the X orientation, which was the opposite of the trend observed for the flexural strength of the specimens. The PA11 specimen possessed a low coefficient of friction (COF) of 0.13 and wear rate of 8.68 × 10−5 mm3/Nm as compared to the TPU specimen, which had a COF of 0.55 and wear rate of 0.012 mm3/Nm. The PA11 specimens generally had lower roughness values on their surfaces (Ra < 25 μm), while the TPU specimens had much rougher surfaces (Ra > 40 μm). This investigation aims to uncover and explain phenomena that are unique to the MJF process of PA11 and TPU while also serving as a benchmark against similar polymeric parts printed using other PBF processes.

2017 ◽  
Vol 26 (5) ◽  
pp. 096369351702600 ◽  
Author(s):  
Wenjing Xia ◽  
Nianqing Zhu ◽  
Zhongbin Ni ◽  
Mingqing Chen

Biodegradable composites from poly (butylene succinate-co-butylene adipate) (PBSA) and Taihu Lake (Wuxi, China) blue algae were prepared by melt blending. The property and structure of biocomposites were investigated. By adding extra amount of water to blue algae, the formulated blue algae acted as a plastic in the composites during blending, and exhibited a reinforcing effect on the PBSA matrix. With increasing blue algae content, the thermal stability of the composites decreased; the tensile strength at break and elongation at break of the composites reduced, but the Young's modulus of the composites increased. However, the composite with 30% blue algae loading still exhibited good mechanical performance (tensile strength at break of 21.3 MPa, elongation at break of 180%). The fabrication of value-added PBSA/algae composites appeared as an effective approach to reduce the secondary environmental pollution of Taihu blue algae.


2021 ◽  
Author(s):  
Balaji Ayyanar Chninnappan ◽  
K. Marimuthu ◽  
C. Bharathiraj ◽  
B. Gayathri ◽  
S. K. Pradep Mohan

Abstract Samanea saman (SS) flower particulates were filled in Polylactic acid (PLA) composites were fabricated with different 0, 10, and 20 wt. % through the injection molding process. The elemental composition and morphology of SS PLA composites were studied through FESEM and Energy Dispersive X-ray analysis. Thermal stability of the SS PLA composites specimens was carried out through Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimeter (DSC). Crystal orientations studied through X-Ray Diffraction (XRD) showed the presence of the orthorhombic SS particulates. The properties of the composites were investigated such as tensile strength, compressive strength, flexural strength, and Shore D Hardness. It was found that 20 wt. % of SS filled PLA composites has a superior tensile strength of 43.76 MPa, the compression strength of 37.94 MPa, the flexural strength of 72.47 MPa, and Shore D Hardness of 80.1 SHN than pure PLA. SS particulates-filled PLA composites would be used for low-strength applications.


2011 ◽  
Vol 71-78 ◽  
pp. 1154-1157 ◽  
Author(s):  
Zhi Fei Liao ◽  
Guo Lin Song ◽  
Feng Shi ◽  
Zhan Song Yin ◽  
You Yang ◽  
...  

The PLA/Rice straw fiber composites with various content ratios were prepared by using an internal mixer and a flatten press. The thermal properties, interface effect and mechanical performance of as-prepared PLA/Rice straw fiber composites were studied by mechanical performance measurement, TG, DSC and SEM technique. It was found that increasing the content of rice straw fiber leads to the decrease of the melting temperature while the improvement of the crystallinity of these composites. Introducing the rice straw fibers into PLA matrix does not result in any enhancement of mechanical property. However, the tensile strength of the composite increases as the content of rice straw fiber increases from 10% to 30%. The interface effect between fibers and PLA was obviously observed by SEM photo. It was thought such an issue could be improved by the addition of appropriate coupling agents into the composites.


2006 ◽  
Vol 315-316 ◽  
pp. 661-665
Author(s):  
C.Y. Yao ◽  
Wei Peng ◽  
Tao Gao

In recent work, a creative idea has been proposed by applying the rapid prototyping technology to develop a new diamond-coated blade based on ultraviolet-cured resin bond. The new technology features many advantages such as fast processing speed, low environmental pollution, and low energy consuming. This paper makes an investigation on the adherence and abrasion mechanisms of such diamond blades. The experimental plan is well designed for selection of an optimal prescription of the mixture to achieve good mechanical performance and a manufacturing process is proposed to produce ultraviolet-cured resin bonded diamond coated blades. Practical experiments are carried to test the blade performance and to compare with different tools in incising artificial crystal. Furthermore, this paper also observes how the tensile strength and elastic modulus of ultraviolet-cured resin affect the crevasse and quality of machined edge surfaces.


2014 ◽  
Vol 644-650 ◽  
pp. 4760-4762 ◽  
Author(s):  
Bao Feng Xu ◽  
Sheng Lai ◽  
Zhi Dan Lin ◽  
Jiang Ming Chen ◽  
Jun Lin

Graphene nanoplatelets (GNP) and thermoplastic polyurethane (TPU) have been often used as filler and matrix, respectively, to produce composites. In this work, TPU/GNP composites were prepared via a melt blending method. The mechanical properties and frictional properties of TPU/GNP composites were investigated. Because the GNP is very expensive, we investigated to use graphite as the filler, to use PP-g-MAH as the compatibilizer and examined the characteristics of the prepared composites. Frictional properties and mechanical properties of GNP/TPU composites remarkably improve when adding PP-g-MAH as the compatibilizer. Tensile strength of composite containing 10wt % of GNP and 10wt% PP-g-MAH was measured as 25.5MPa. When the graphite was used to replace for GNP, the frictional properties of composites decreased, but the mechanical properties improved.


2015 ◽  
Vol 12 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Abhishek Suvarna ◽  
Akash Katagi ◽  
Jackson Pasanna ◽  
Sunil Kumar ◽  
Basavaraju Bennehalli ◽  
...  

The present investigation focuses on the fabrication and mechanical characterization of alkali treated natural abaca fiber reinforced urea formaldehyde composites. The composites were prepared by means of compression moulding, and then the effects of fiber loading on mechanical properties such as tensile strength, flexural strength and impact strength were investigated. The composite with 40 wt% abaca fibers gave excellent tensile strength and flexural strength showing that it has the most superior bonding and adhesion of all the composites. In particular, the highest value, 10.02 kJ/m2 of charpy impact strength is observed in the composite with 50 wt% abaca fiber. This work revealed the potential of using abaca fibers in fiberboard.


2021 ◽  
Vol 886 ◽  
pp. 241-255
Author(s):  
Youssef Maaloufa ◽  
Soumia Mounir ◽  
Khabbazi Abdelhamid ◽  
Khalid El Harrouni

The objective of our work is to study the influence of nature and the shape of the insulating materials on the mechanical performance of composites based on plaster. The study aims to increase the thermal performance of the building envelope and the same time maintains sufficient mechanical properties of the composites studied. Plaster was combined with two additives (alpha fiber and granular cork). A physical and mechanical characterization of the composites plaster-fiber alpha and plaster-cork was carried on. Authors obtained an important gain in term of lightness 27 % concerning the composite plaster-fiber alpha, however for the composite plaster-cork, the value is 34 %. Concerning the mechanical properties, authors found a decrease in flexural strength of 60 % for the plaster-cork, and an increase of 33 % for the plaster-alpha fiber. For the compressive strength, a reduce of 87 % for the plaster-alpha fiber and 80% for the plaster-cork was observed. Those finding are justified by the scanning microscopic electron tests which show the distribution of the two insulators and adhesion within the plaster matrix.


2012 ◽  
Vol 587 ◽  
pp. 67-76
Author(s):  
Jabbar Abbas Jabir Al Khafaji ◽  
Najah Mahdi Lateef Al Maimuri ◽  
Abdul Hadi Meteab Hassan Al Sa'adi

A study of a mechanical performance(Compressive strength, flexural strength, and splitting tensile strength)of self-compacting (SCC) and conventional (NCC)concretemixes and some physical properties of the mixes made of Portland cement under the effect of acidic solution attackare made. Trichloroacetic and Salicycilic acids are selected and used in this study. It is found that the reduction percentage in compressive strength is about 6% and 3% under the effect of Trichloroacetic acidic solution whereas itisabout 8% under the effect the salicycilic acidic solution attackfor both SCC and NCC mixes after 62 days of treatment for bothSCC and NCC mixes respectively. The reduction percentage in flexural strengthisabout 27% and 37% under the effect of the Trichloroacetic acidic solution attack whereas itis about 59% and 79% under the effect the salicycilic acidic solution attackfor both SCC and NCC mixes respectivelyafter 62 days of treatment. The reduction percentage in splitting tensile strength is about 60% and 63% under the effect the Trichloroacetic acidic solution attack whereas it is 70% and 88% under the effect of the salicycilic acidic solution attack% for both SCC and NCC mixes after 62 days of treatment. At the age 90 days, the SCC and NCC mixes have a reductionpercentage in the cubes weight of 3% and 4% whereas there is an increasing in volume of 0.3% and 0.4% respectively under the effect of salicyclic acid solution attack.It is observed that SCC mixes offer more resistant and less deterioration against acidic solutions attack.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Matthias Michael Lexow ◽  
Dietmar Drummer

Selective laser sintering (SLS) is a process based on the principle of a locally confined energy input by a laser into a powder bed, producing highly complex parts without the use of moulds or any other tools. In order to ensure good results for the processing behaviour of a new material, the powder must perform well during the phase of feeding the material into the process chamber which majorly influences the quality of the spread of the powder into the part bed and thus the mechanical performance of the final parts. In the present study, the principle of modification of fine powders with flow agents is applied aiming to enable the use of powders for SLS which are otherwise unsuitable due to poor flowability. In addition, the influence of antistatic agent on the powder flow and processing behaviour is discussed. The additives are found to strongly improve the flow behaviour at already very small contents and thus allow for processing of the composite material. The development of determining factors shares insight into the mechanisms of dry particle coating and its implementation into a growing market of material development.


2015 ◽  
Vol 1119 ◽  
pp. 677-682
Author(s):  
Alessandra Dal Cin ◽  
Lorenzo Massaria ◽  
Enzo Siviero

The aim of this study is to evaluate the influence of SFRC repairs of different thicknesses on the mechanical performance of RC slabs, especially with respect to the crack pattern and level of cracking load. To understand the influence of SFRC, in terms of performance and variation of cracking load after repairing, a comparison with a reinforced concrete slab without fiber reinforcement was made. The study shows also the mechanical characterization of SFRC through conventional testing, to evaluate compressive strength, fracture energy, tensile strength and toughness. Concerning the application of SFRC on the concrete slab surface, the bond was improved by removing a small amount of superficial material. Finally, the experimental results on cracks distribution, displacements and level of cracking load are shown.


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