scholarly journals Mechanical Properties of Additively Manufactured Thermoplastic Polyurethane (TPU) Material Affected by Various Processing Parameters

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3010
Author(s):  
Tao Xu ◽  
Wei Shen ◽  
Xiaoshan Lin ◽  
Yi Min Xie
Keyword(s):  
Mechanical Properties ◽  
Medical Devices ◽  
Thermoplastic Polyurethane ◽  
Critical Factor ◽  
Processing Parameters ◽  
Aerospace Engineering ◽  
Post Processing ◽  
Build Orientation ◽  
Good Biocompatibility ◽  
Material Tests

Thermoplastic polyurethane (TPU) is a polymer material that has high ductility, good biocompatibility and excellent abrasion resistance. These properties open a pathway to manufacturing functional TPU parts for applications in various fields such as aerospace engineering, medical devices and sports equipment. This study aims to investigate the mechanical properties of additively manufactured TPU material affected by three different processing parameters, including build orientation, mix ratio of the new and reused powders and post-processing. A series of material tests are conducted on TPU dumb-bell specimens. It is found that the mix ratio of the new powder is the most critical factor in improving the mechanical properties of the printed TPU parts. Compared to reused powder, new powder has better particle quality and thermal properties. Besides, build orientation is also a very important factor. TPU parts printed in flat and on-edge orientations show better tensile strength and deformability than those printed in upright orientation. In addition, post-processing is found to significantly enhance the deformability of TPU parts.

scholarly journals Preparation of Thermoplastic Polyurethane (TPU) Perforated Membrane via CO2 Foaming and Its Particle Separation Performance

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 847 ◽  
Author(s):  
Chengbiao Ge ◽  
Wentao Zhai ◽  
Chul B. Park
Keyword(s):  
Mechanical Properties ◽  
Thermoplastic Polyurethane ◽  
Saturation Pressure ◽  
Base Material ◽  
Processing Parameters ◽  
Porous Membrane ◽  
Channel Structure ◽  
Separation Performance ◽  
Membrane Thickness ◽  
Operating Pressure

The way in which a perforated structure is formed has attracted much interest in the porous membrane research community. This novel structure gives materials an excellent antifouling property as well as a low operating pressure and other benefits. Unfortunately, the current membrane fabrication methods usually involve multi-step processes and the use of organic solvents or additives. Our study is the first to offer a way to prepare perforated membrane by using a physical foaming technique with CO2 as the blowing agent. We selected thermoplastic polyurethane (TPU) as the base material because it is a biocompatible elastomer with excellent tensility, high abrasion resistance, and good elastic resilience. Various processing parameters, which included the saturation pressure, the foaming temperature, and the membrane thickness, were applied to adjust the TPU membrane’s perforated morphology. We proposed a possible formation mechanism of the perforated membrane. The as-prepared TPU membrane had good mechanical properties with a tensile strength of about 5 MPa and an elongation at break above 100%. Such mechanical properties make this novel membrane usable as a self-standing filter device. In addition, its straight-through channel structure can separate particles and meet different separation requirements.

scholarly journals Preparation of Thermoplastic Polyurethane (TPU) Perforated Membrane via CO2 foaming and Its Particle Separation Performance

2019 ◽  
Author(s):  
Chengbiao Ge ◽  
Wentao Zhai ◽  
Chul B. Park
Keyword(s):  
Mechanical Properties ◽  
Thermoplastic Polyurethane ◽  
Saturation Pressure ◽  
Base Material ◽  
Processing Parameters ◽  
Porous Membrane ◽  
Channel Structure ◽  
Separation Performance ◽  
Membrane Thickness ◽  
Operating Pressure

The way in which a perforated structure is formed has attracted much interest in the porous membrane research community. This novel structure gives materials an excellent antifouling property as well as a low operating pressure and other benefits. Unfortunately, the current membrane fabrication methods usually involve multi-step processes and the use of organic solvents or additives. Our study is the first to offer a way to prepare perforated membrane by using a physical foaming technique with CO2 as the blowing agent. We selected thermoplastic polyurethane (TPU) as the base material because it is a biocompatible elastomer with excellent tensility, high abrasion resistance, and good elastic resilience. Various processing parameters, which included the saturation pressure, the foaming temperature, and the membrane thickness, were applied to adjust the TPU membrane’s perforated morphology. We proposed a possible formation mechanism of the perforated membrane. The as-prepared TPU membrane had good mechanical properties with a tensile strength of about 5 MPa and an elongation at break above 100%. Such mechanical properties make this novel membrane usable as a self-standing filter device. In addition, its straight-through channel structure can separate particles and meet different separation requirements.

Preparation and selective laser sintering of bamboo flour/copolyester composite and post-processing

2015 ◽  
Vol 30 (8) ◽  
pp. 1045-1055 ◽  
Author(s):  
Dejin Zhao ◽  
Yanling Guo ◽  
Kaiyi Jiang ◽  
Hui Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Selective Laser Sintering ◽  
Single Layer ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Post Processing ◽  
New Type ◽  
Bamboo Flour

A new type of biocomposite, bamboo flour/copolyester (BFCP) composite for selective laser sintering (SLS™) was studied in this article. The bamboo flour was made from the bamboo residual of the bamboo production collected from a chopsticks factory. The BFCP composites of three mixture ratios (20/80, 25/75, and 30/70 (wt/wt)) were processed by SLS™. The proper processing parameters were determined by single-layer sintering methods. The mechanical properties of test specimens made from BFCP composites of three mixture ratios have been investigated. The results demonstrated that the mechanical properties of the specimens made by BFCP composite of 20/80 (wt/wt) were the best among those of the three mixture ratios and the average tensile strength, flexural strength, and impact strength of the specimens made from BFCP composite of 20/80 (wt/wt) were up to 4.14 MPa, 11.02 MPa, and 0.84 kJ m−2, respectively. The mechanical properties of specimens are extremely improved through infiltrating epoxy resin.

scholarly journals Fabrication of Poly(ε-caprolactone) Scaffolds Reinforced with Cellulose Nanofibers, with and without the Addition of Hydroxyapatite Nanoparticles

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Pedro Morouço ◽  
Sara Biscaia ◽  
Tânia Viana ◽  
Margarida Franco ◽  
Cândida Malça ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Reliability ◽  
Cellulose Nanofibers ◽  
Processing Parameters ◽  
Cell Cultivation ◽  
Hydroxyapatite Nanoparticles ◽  
Biodegradable Scaffolds ◽  
Good Biocompatibility ◽  
3D Composite ◽  
Mechanical Performances

Biomaterial properties and controlled architecture of scaffolds are essential features to provide an adequate biological and mechanical support for tissue regeneration, mimicking the ingrowth tissues. In this study, a bioextrusion system was used to produce 3D biodegradable scaffolds with controlled architecture, comprising three types of constructs: (i) poly(ε-caprolactone) (PCL) matrix as reference; (ii) PCL-based matrix reinforced with cellulose nanofibers (CNF); and (iii) PCL-based matrix reinforced with CNF and hydroxyapatite nanoparticles (HANP). The effect of the addition and/or combination of CNF and HANP into the polymeric matrix of PCL was investigated, with the effects of the biomaterial composition on the constructs (morphological, thermal, and mechanical performances) being analysed. Scaffolds were produced using a single lay-down pattern of 0/90°, with the same processing parameters among all constructs being assured. The performed morphological analyses showed a satisfactory distribution of CNF within the polymer matrix and high reliability was obtained among the produced scaffolds. Significant effects on surface wettability and thermal properties were observed, among scaffolds. Regarding the mechanical properties, higher scaffold stiffness in the reinforced scaffolds was obtained. Results from the cytotoxicity assay suggest that all the composite scaffolds presented good biocompatibility. The results of this first study on cellulose and hydroxyapatite reinforced constructs with controlled architecture clearly demonstrate the potential of these 3D composite constructs for cell cultivation with enhanced mechanical properties.

Microstructural and Mechanical Properties of Selective Laser Melted Al 4047

2015 ◽  
Vol 752-753 ◽  
pp. 485-490 ◽  
Author(s):  
Shafaqat Siddique ◽  
Eric Wycisk ◽  
Gerrit Frieling ◽  
Claus Emmelmann ◽  
Frank Walther
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Processing Parameters ◽  
Complex Geometries ◽  
Optimal Parameters ◽  
Post Processing ◽  
Laser Melting ◽  
Process Cost

Selective laser melting (SLM) has been recognized as a pertinent process for manufacturing of complex geometries. Al 4047 has been manufactured in this study with different processing parameters of the SLM process to obtain the optimal parameters suitable for required applications, as well as to determine the effect of these parameters and post-processing heat treatment on mechanical properties. A unique Al-Si eutectic microstructure is obtained with Al dendrites growing in the scanning direction. Mechanical properties of the SLM manufactured Al 4047 are at par with those of conventionally manufactured alloy. These properties can be varied by changing the SLM process parameters which can help controlling the process cost depending upon required mechanical properties.

scholarly journals Selective laser sintering and post-processing of sisal fiber/ poly-(ether sulfone) composite powder

BioResources ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 1338-1353
Author(s):  
Jian Li ◽  
Aboubaker I. B. Idriss ◽  
Yanling Guo ◽  
Yangwei Wang ◽  
Zhiqiang Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Composite Powder ◽  
Selective Laser Sintering ◽  
Testing Machine ◽  
Single Layer ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Sisal Fiber ◽  
Post Processing

Selective Laser Sintering (SLS) technology can be utilized to recycle residues from forestry and agriculture, thereby alleviating shortages of materials and reducing energy consumption by producing wood-plastic pieces for industrial application. The mechanical strength of wood-plastic SLS parts is low, which restricts the application of this technology. In this study, a novel type of sisal fiber/poly-(ether sulfone) (PES) composite was prepared using a polymer mixing method in order to improve the mechanical properties of SLS parts. Single-layer sintering method was adopted to determine the proper processing parameters. The mechanical properties of the parts with different ingredient ratios and different particle sizes of sisal fiber before and after post-processing were tested using a universal testing machine. The morphology was examined using scanning electron microscopy (SEM). Results showed that the mechanical properties of the printed parts were relatively enhanced; when the mixing ratio of composite powder was 10/90 wt/wt. In addition, the part fabricated by powder of particles size less than 0.105 mm (0.125 mm ≥ PS < 0.105mm) had the best mechanical strength. Moreover, the post-wax treatment significantly improved the strength of the parts, and the surfaces became smoother.

Surface Modification and its Influence on the Microstructure and Creep Resistance of Nickel Based Superalloy René 77 / Modyfikacja Powierzchniowa Oraz Jej Wpływ Na Mikrostrukture I Wytrzymałosc Na Pełzanie Odlewów Z Nadstopu Niklu Ren´E 77

2013 ◽  
Vol 58 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Zielinska ◽  
J. Sieniawski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Surface Modification ◽  
Turbine Blades ◽  
Processing Parameters ◽  
Grain Structure ◽  
Creep Tests ◽  
Cobalt Aluminate ◽  
Nickel Based Superalloy ◽  
Average Grain Size

Superalloy René 77 is very wide used for turbine blades, turbine disks of aircraft engines which work up to 1050°C. These elements are generally produced by the investment casting method. Turbine blades produced by conventional precision casting methods have coarse and inhomogeneous grain structure. Such a material often does not fulfil basic requirements, which concern mechanical properties for the stuff used in aeronautical engineering. The incorporation of controlled grain size improved mechanical properties. This control of grain size in the casting operation was accomplished by the control of processing parameters such as casting temperature, mould preheating temperature, and the use of grain nucleates in the face of the mould. For nickel and cobalt based superalloys, it was found that cobalt aluminate (CoAl2O4) has the best nucleating effect. The objective of this work was to determine the influence of the inoculant’s content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties at high temperature of nickel based superalloy René 77. For this purpose, the ceramic moulds were made with different concentration of cobalt aluminate in the primary slurry was from 0 to 10% mass. in zirconium flour. Stepped and cylindrical samples were casted for microstructure and mechanical examinations. The average grain size of the matrix ( phase), was determined on the stepped samples. The influence of surface modification on the grain size of up to section thickness was considered. The microstructure investigations with the use of light microscopy and scanning electron microscopy (SEM) enable to examine the influence of the surface modification on the morphology of ’ phase and carbides precipitations. Verification of the influence of CoAl2O4 on the mechanical properties of castings were investigated on the basis of results obtained form creep tests.

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