scholarly journals Effective Formation of Well-Defined Polymeric Microfibers and Nanofibers with Exceptional Uniformity by Simple Mechanical Needle Spinning

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 980 ◽  
Author(s):  
Hoik Lee ◽  
Yuma Inoue ◽  
Myungwoong Kim ◽  
Xuehong Ren ◽  
Ick Kim
Keyword(s):  
Polymer Concentration ◽  
Processing Parameters ◽  
Mechanical Force ◽  
Processing Parameter ◽  
Needle Size ◽  
Precise Control ◽  
Spinning Process ◽  
Facile Fabrication ◽  
Further Development ◽  
Highly Uniform

The fabrication of nanofibers with a mechanical force has attracted increasing attention owing to its facile and easy fabrication. Herein, we demonstrate a novel and facile fabrication technique with the mechanical force, needle spinning, which utilizes a needle tip to draw a polymer solution to form fibrous structures. We studied the effect of the processing parameters to the nanofiber structure, namely, the pulling away speed, pulling away distances, needle size, and polymer concentration, which were systemically controlled. As the needle spinning provides an effective route to adjust those parameters, highly uniform nanofibers can be achieved. There are clear tendencies in the diameter; it was increased as the polymer concentration and needle size were increased, and was decreased as the pulling away distance and pulling away speed were increased. Needle spinning with a precise control of the processing parameter enables us to readily fabricate well-defined nanofibers, with controlled dimensions in diameter and length; plus, single nanofibers also can be easily formed. Those features cannot be realized in common spinning process such as electrospinning. Therefore, this technique will lead to further development of the use of mechanical force for nanofiber fabrication and will expand the range of nanofibers applications.

Influence of Polyacrilonitrile (PAN) Concentration on the Mechanical and Physical Properties of Electrospun Fibres

2011 ◽  
Vol 471-472 ◽  
pp. 43-48
Author(s):  
Siti Saniah Ab. Karim ◽  
Abu Bakar Sulong ◽  
Che Husna Azhari ◽  
Ng Min Hwei ◽  
Mohd Reusmaazran Yusof
Keyword(s):  
Melt Spinning ◽  
Polymer Concentration ◽  
High Specific Surface Area ◽  
Polymer Fiber ◽  
Polymer Fibre ◽  
Surface Area Ratio ◽  
Needle Size ◽  
Collector Plate ◽  
Spinning Process ◽  
Nano Size

Electrospinning is direct process to produce polymer fibre with high specific surface area ratio. Apart from polymer fibre producing; electrospinning also can produce a continuous nano size of polymer fibre, which the benefit of this process is the fibre can be produced straight away with lower cost than conventional melt spinning process. Recently, successful attempts have been made to produce polymer fibre by adjusting the parameters of electrospinning such as the collector distance, needle size, polymer concentration voltage applied. From this study, the electrospun fibre was distributed randomly on collector plate surface. The diameter of the fibre produced increase as the polymer concentration was increased. The fibre distribution does not affected by the differ polymer concentrations electrospun, but there were polymer beads formed at the low polymer concentration in solvents. The fiber elongation value is the highest by polymer fiber of 9 wt % while the highest strength is by polymer fiber of 7 wt %. The polymer fibre with low concentration consequently showed the brittle characteristic.

scholarly journals Comparative Studies of Electrospinning and Solution Blow Spinning Processes for the Production of Nanofibrous Poly(L-Lactic Acid) Materials for Biomedical Engineering

2014 ◽  
Vol 16 (2) ◽  
pp. 43-50 ◽  
Author(s):  
Michal Wojasiński ◽  
Maciej Pilarek ◽  
Tomasz Ciach
Keyword(s):  
Lactic Acid ◽  
Biomedical Engineering ◽  
Fiber Diameter ◽  
Polymer Concentration ◽  
Average Diameter ◽  
Solution Concentration ◽  
Processing Parameters ◽  
Average Fiber Diameter ◽  
Processing Parameter ◽  
Solution Blow Spinning

Abstract Comparative statistical analysis of the infiuence of processing parameters, for electrospinning (ES) and solution blow spinning (SBS) processes, on nanofibrous poly(L-lactic acid) (PLLA) material morphology and average fiber diameter was conducted in order to identify the key processing parameter for tailoring the product properties. Further, a comparative preliminary biocompatibility evaluation was performed. Based on Design of Experiment (DOE) principles, analysis of standard effects of voltage, air pressure, solution feed rate and concentration, on nanofibers average diameter was performed with the Pareto’s charts and the best fitted surface charts. Nanofibers were analyzed by scanning electron microscopy (SEM). The preliminary biocompatibility comparative tests were performed based on SEM microphotographs of CP5 cells cultured on materials derived from ES and SBS. Polymer solution concentration was identified as the key parameter infiuencing morphology and dimensions of nanofibrous mat produced from both techniques. In both cases, when polymer concentration increases the average fiber diameter increase. The preliminary biocompatibility test suggests that nanofibers produced by ES as well as SBS are suitable as the biomedical engineering scaffold material.

Integration of multivariate control charts and decision tree classifier to determine the faults of the quality characteristic(s) of a melt spinning machine used in polypropylene as-spun fiber manufacturing Part I: The application of the Taguchi method and principal component analysis in the processing parameter optimization of the melt spinning process

2021 ◽  
pp. 004051752098861
Author(s):  
Chung-Feng Jeffrey Kuo ◽  
Chang-Chiun Huang ◽  
Cheng-Han Yang
Keyword(s):  
Principal Component Analysis ◽  
Rotational Speed ◽  
Melt Spinning ◽  
Principal Component ◽  
Processing Parameters ◽  
Gear Pump ◽  
Processing Parameter ◽  
Spinning Process ◽  
Spun Fiber ◽  
Head Temperature

Melt spinning is the most extensively used method of fabricating polymeric fibers in the textile industry. This series of studies aimed to construct an automatic abnormality diagnosis system for polypropylene (PP) as-spun fiber produced by the melt spinning process. Part I of this study aimed to construct the processing parameter optimization for the PP as-spun fiber produced by the melt spinning machine. The product quality resulting from the processing parameters of the melt spinning process included six control factors: extruder temperature, gear pump temperature, die-head temperature, rotational speed of extruder, rotational speed of gear pump, and take-up speed. The quality characteristics included fiber fineness, breaking strength, breaking elongation, and modulus of resilience. The quality data were derived from the experiments, the design of which were based on the orthogonal array of the Taguchi method in order to calculate the signal-to-noise ratio, analysis of variance, and confidence interval. Principal component analysis was then applied to eliminate the multi-correlation of the output responses and transform the correlated responses into principal components, to obtain multi-quality optimum processing parameters. These optimum parameters, including the extruder temperature (180°C), gear pump temperature (220°C), die-head temperature (240°C), the rotational speed of the extruder (7.5 rpm), the rotational speed of the gear pump (15 rpm), and take-up speed (700 rpm) would later be used to build a prediction of an abnormality diagnosis system for identification of fault processing parameters in a melt spinning machine in Part II of this study.

scholarly journals Warpage Optimisation Using Recycled Polycar-bonates (PC) on Front Panel Housing

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1416
Author(s):  
Nur Aisyah Miza Ahmad Tamizi ◽  
Shayfull Zamree Abd Rahim ◽  
Abdellah El-hadj Abdellah ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Marcin Nabiałek ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Processing Parameters ◽  
Front Panel ◽  
Processing Parameter ◽  
Mechanical Recycling ◽  
Great Opportunity ◽  
Average Value ◽  
Optimal Processing ◽  
Materials Used ◽  
Optimisation Methods

Many studies have been done using recycled waste materials to minimise environmental problems. It is a great opportunity to explore mechanical recycling and the use of recycled and virgin blend as a material to produce new products with minimum defects. In this study, appropriate processing parameters were considered to mould the front panel housing part using R0% (virgin), R30% (30% virgin: 70% recycled), R40% (40% virgin: 60% recycled) and R50% (50% virgin: 50% recycled) of Polycarbonate (PC). The manufacturing ability and quality during preliminary stage can be predicted through simulation analysis using Autodesk Moldflow Insight 2012 software. The recommended processing parameters and values of warpage in x and y directions can also be obtained using this software. No value of warpage was obtained from simulation studies for x direction on the front panel housing. Therefore, this study only focused on reducing the warpage in the y direction. Response Surface Methodology (RSM) and Genetic Algorithm (GA) optimisation methods were used to find the optimal processing parameters. As the results, the optimal ratio of recycled PC material was found to be R30%, followed by R40% and R50% materials using RSM and GA methods as compared to the average value of warpage on the moulded part using R0%. The most influential processing parameter that contributed to warpage defect was packing pressure for all materials used in this study.

scholarly journals Optimisation of Shrinkage and Strength on Thick Plate Part Using Recycled LDPE Materials

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1795
Author(s):  
Norshahira Roslan ◽  
Shayfull Zamree Abd Rahim ◽  
Abdellah El-hadj Abdellah ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Katarzyna Błoch ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Thick Plate ◽  
Processing Parameters ◽  
Processing Parameter ◽  
Plastic Injection Moulding ◽  
Optimal Setting ◽  
Quality Of Products ◽  
Validation Tests ◽  
Plastic Injection

Achieving good quality of products from plastic injection moulding processes is very challenging, since the process comprises many affecting parameters. Common defects such as warpage are hard to avoid, and the defective parts will eventually go to waste, leading to unnecessary costs to the manufacturer. The use of recycled material from postindustrial waste has been studied by a few researchers. However, the application of an optimisation method by which to optimise processing parameters to mould parts using recycled materials remains lacking. In this study, Response Surface Methodology (RSM) and Particle Swarm Optimisation (PSO) methods were conducted on thick plate parts moulded using virgin and recycled low-density polyethylene (LDPE) materials (100:0, 70:30, 60:40 and 50:50; virgin to recycle material ratios) to find the optimal input parameters for each of the material ratios. Shrinkage in the x and y directions increased in correlation with the recycled ratio, compared to virgin material. Meanwhile, the tensile strength of the thick plate part continued to decrease when the recycled ratio increased. R30 (70:30) had the optimum shrinkage in the x direction with respect to R0 (100:0) material where the shrinkage increased by 24.49% (RSM) and 33.20% (PSO). On the other hand, the shrinkage in the y direction for R30 material increased by 4.48% (RSM) and decreased by 2.67% (PSO), while the tensile strength of R30 (70:30) material decreased by 0.51% (RSM) and 2.68% (PSO) as compared to R0 (100:0) material. Validation tests indicated that the optimal setting of processing parameter suggested by PSO and RSM for R0 (100:0), R30 (70:30), R40 (60:40) and R50 (50:50) was less than 10%.

scholarly journals Nanostructured Strontium-Doped Calcium Phosphate Cements: A Multifactorial Design

2021 ◽  
Vol 11 (5) ◽  
pp. 2075
Author(s):  
Massimiliano Dapporto ◽  
Davide Gardini ◽  
Anna Tampieri ◽  
Simone Sprio
Keyword(s):  
Calcium Phosphate ◽  
Setting Time ◽  
Processing Parameters ◽  
High Energy ◽  
Powder Particle Size ◽  
Extrusion Force ◽  
Precise Control ◽  
Calcium Phosphate Cements ◽  
Shear Mixing ◽  
Mixing Techniques

Calcium phosphate cements (CPCs) have been extensively studied in last decades as nanostructured biomaterials for the regeneration of bone defects, both for dental and orthopedic applications. However, the precise control of their handling properties (setting time, viscosity, and injectability) still represents a remarkable challenge because a complicated adjustment of multiple correlated processing parameters is requested, including powder particle size and the chemical composition of solid and liquid components. This study proposes, for the first time, a multifactorial investigation about the effects of powder and liquid variation on the final performance of Sr-doped apatitic CPCs, based on the Design of Experiment approach. In addition, the effects of two mixing techniques, hand spatula (low-energy) and planetary shear mixing (high-energy), on viscosity and extrusion force were compared. This work aims to shed light on the various steps involved in the processing of CPCs, thus enabling a more precise and tailored design of the device, based on the clinical need.

Dissimilar Friction Stir Lap Welding of AA2198 and AA7075 Sheets: Forces, Microstructure and Mechanical Properties

2021 ◽  
Author(s):  
Antonello Astarita ◽  
Fausto Tucci ◽  
Alessia Teresa Silvestri ◽  
Michele Perrella ◽  
Luca Boccarusso ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Welding Process ◽  
Processing Parameters ◽  
Processing Parameter ◽  
Friction Stir Lap Welding ◽  
Friction Stir ◽  
Lap Shear ◽  
Microstructure And Mechanical Properties ◽  
Lap Welding ◽  
Factorial Design Of Experiments

Abstract This paper deals with the dissimilar friction stir lap welding of AA2198 and AA7075 sheets. The influence of processing parameters, namely welding speed and tool rotational speed on joint features, microstructure, and mechanical properties were investigated implementing a full factorial design of experiments. During the welding process, axial and transversal forces were continuously measured using a dedicated sensed fixture aiming at the correlation of this processing parameter with the quality of the achieved joints. The reported outcomes showed a very narrow processing window in which it was possible to avoid the formation of defects while the formation of an hook was observed for all the joints welded. The influence of the weld bead morphology on the lap shear strength was elucidated proving that the strength is ruled by the hook morphology. A correlation between the process parameters and the forces arising was also attempted. The final microstructure of the joints was studied and explained and also compared with the microhardness results.

scholarly journals An Innovative Approach of Parameter Loading Path Design for Grain Refinement and Its Application in Ni80A Superalloy

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6703
Author(s):  
Guo-Zheng Quan ◽  
Yan-Ze Yu ◽  
Xue Sheng ◽  
Kun Yang ◽  
Wei Xiong
Keyword(s):  
Strain Rate ◽  
Grain Refinement ◽  
Deformation Mechanism ◽  
Processing Parameters ◽  
Loading Path ◽  
Processing Parameter ◽  
Compression Process ◽  
Innovative Method ◽  
Path Design ◽  
Loading Path Design

In order to obtain the desired mechanical properties of products, an innovative method of loading parameter designs for acquiring the desired grain refinement is proposed, and it has been applied in the compression process of Ni80A superalloy. The deformation mechanism maps derived from processing maps based on the Dynamic Materials Model (DMM) theory were constructed, since the critical indicator values corresponding to dynamic recrystallization (DRX) and dynamic recovery (DRV) mechanisms were determined. The processing-parameter domains with DRX mechanisms were separated from the deformation mechanism map, while such domains were chaotic and difficult to apply in innovative parameter loading path design. The speed-loading path derived from strain rate-loading path in a compression process was pursued. The grain refinement domains are discretized into a finite series of sub-domains with clear processing parameters, and the optimal strain rate of each sub-domain is determined by step-by-step finite element simulation. A 3D response surface of the innovative optimal loading path of strain rate was fitted by interpolating methods. Finally, the isothermal compression experiments for Ni80A superalloy were conducted, and the microstructure observations indicated that the desired grain refinement was achieved. This innovative method of parameter loading path design contributes to the microstructure adjustment of the alloys with DRX mechanism.

Microstructure Analysis of Melt-Spun Al3Ti Intermetallics by XRD and EXAFS

1996 ◽  
Vol 460 ◽  
Author(s):  
Jinmin Chen ◽  
W. E. Frazier ◽  
E. V. Barrera
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Melt Spinning ◽  
Composition Range ◽  
Processing Parameters ◽  
Wheel Speed ◽  
Annealing Temperatures ◽  
Melt Spun ◽  
Temperature Heat ◽  
Spinning Process

ABSTRACTIn an effort to expand the composition range over which Al3Ti is stable, various amounts of niobium were substituted for titanium and processed by melt-spinning. Several samples were annealed both at 600°C and 1000°C for 24 hours. The effects of processing parameters such as wheel speed, the amount of niobium, and annealing temperatures on the structure were investigated by XRD and EXAFS. XRD showed that for all the samples the only structure present was DO22-The DO22 structure was stable even after the high temperature heat treatments. By means of EXAFS, niobium atoms were observed to occupy titanium sites in the DO22 structure. Furthermore, in the unannealed samples, increasing wheel speed of the melt spinning process or the niobium concentration tended to distort the crystal structure. It was observed that Ti EXAFS had different results from the Nb EXAFS beyond their occupying similar sites, which suggested there may exist some composition zones, i.e. rich Nb zone or rich Ti zones, although the structures present were still DO22. The samples were found to experience different distortions as a function of annealing temperatures.

Melted Zone Characteristics of Laser Welded Titanium Alloy (Ti-6Al-4V) under Different Process Parameters

2013 ◽  
Vol 315 ◽  
pp. 304-308 ◽  
Author(s):  
Nur Jannah Md Ngajib ◽  
Magdelyne A.A. Liman ◽  
Zazuli Mohid ◽  
Md Saidin Wahab
Keyword(s):  
Titanium Alloys ◽  
High Strength ◽  
Medical Application ◽  
Processing Parameters ◽  
Laser Source ◽  
Processing Parameter ◽  
Machine Material ◽  
Melted Zone ◽  
Selective Area ◽  
Processed Material

Being widely used in aircrafts structure and aircraft turbine parts, chemical processing equipment and marine hardware, titanium alloys are well known of their high strength and corrosion resistant even though this material is categorized as hard to machine material and reactive to hydrogen and oxygen in elevated temperature. And joining titanium alloys in fabricating parts used in aerospace and medical application requires excellent temperature distribution control to minimize the heat effect. Due to this, laser welding is one of the best methods for the selective area heat induction capability and high accuracy. However, proper processing parameter need to be determined based on the characteristics of the laser source and processed material. Hence, this study is carried out to clarify the performance of a medium range powered laser by comparing and analyzing the welding beads characteristics changes occurred under different processing parameters. Welding beads were analyzed visually from two directions to obtain overall view of molten zones.

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