Influence of Rheological and Thermal Properties of Polymers During Melt Spinning on Bicomponent Fiber Morphology

2016 ◽  
Vol 25 (8) ◽  
pp. 3296-3302 ◽  
Author(s):  
Esma Ayad ◽  
Aurélie Cayla ◽  
François Rault ◽  
Anne Gonthier ◽  
Thierry LeBlan ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Melt Spinning ◽  
Fiber Morphology ◽  
Bicomponent Fiber

Improvement of Morphology, Structure, and Thermal Properties of Electrospun PVA/RSF Fiber Mats by SiO2

2012 ◽  
Vol 184-185 ◽  
pp. 1017-1020 ◽  
Author(s):  
Yan Hua Liu ◽  
Li Xing Dai
Keyword(s):  
Thermal Properties ◽  
Silicon Dioxide ◽  
Solution Viscosity ◽  
Electrospun Fibers ◽  
Fiber Morphology ◽  
Fiber Mats ◽  
Hydrogen Bonding Interactions ◽  
Regenerated Silk Fibroin ◽  
Solution Conductivity ◽  
Scanning Electron

Poly(viny1 alcohol) (PVA)/regenerated silk fibroin (RSF)/silicon dioxide (SiO2) fiber mats were prepared by electrospinning of composite solutions. Fiber morphology was observed under a scanning electron microscope and effects addition of SiO2 was evaluated. Results showed that the obtained fibers exhibited a smooth outer surface, and the continuity was improved because of the different solution conductivity, solution viscosity and compatibility of PVA and RSF by the addition of 1.0 wt. % SiO2. It was found that both Si-O-C linkage and hydrogen bonding interactions were existed among SiO2, PVA, and RSF by FTIR spectroscopy. The addition of SiO2 also resulted in the decrease of crystallinity and increase of thermal properties of electrospun fibers, which were suggested as a result of enhanced compatibility and physical properties of PVA and RSF composite.

Thermal Properties and Crystallization Behavior of Co67Fe4Cr7Si8B14 Amorphous Alloy

2010 ◽  
Vol 297-301 ◽  
pp. 330-337
Author(s):  
M. Haddad-Sabzevar ◽  
S. Sahebian ◽  
Z. Jamili ◽  
S.A. Hasheminejad
Keyword(s):  
Thermal Properties ◽  
Melt Spinning ◽  
Crystallization Behavior ◽  
Heating Rates ◽  
Transformation Mechanism ◽  
Avrami Model ◽  
Avrami Analysis ◽  
Thermal Analyzer ◽  
Spinning Process ◽  
Higher Temperature

In order to investigate the crystallization behavior of the Co67Fe4Cr7Si8B14 amorphous metallic alloy, ribbons of this alloy were prepared by planar flow melt spinning process (PFMS). Differential scanning calorimetery (DSC) and differential thermal analyzer (DTA) were used to analyze the thermal properties and crystallization behavior of the samples at three heating rates of 10, 20 and 30º C/min. The experimental data were fitted to the Avrami model to determine the crystallization behavior. The results showed that the crystallization exotherm became wider and shifted toward a higher temperature range as the heating rate increased. The Avrami analysis also showed that n is about 1, which is related to the same transformation mechanism at different heating rates. The Kissinger method was used to determine the activation energy for the first crystallization peaks. The measured value is approximately 332.67 kJ/g.

scholarly journals A New Three-Dimensional Mobile Magnetic Melt Spinning Device

2021 ◽  
Author(s):  
Kai Zhang ◽  
Wu Zhao ◽  
Qingjie Liu ◽  
Miao Yu
Keyword(s):  
Electric Field ◽  
High Voltage ◽  
Melt Spinning ◽  
Three Dimensional ◽  
Fiber Surface ◽  
Electrospinning Process ◽  
Superior Performance ◽  
Fiber Morphology ◽  
High Voltage Power Supply ◽  
Melt Electrospinning

Abstract The size and morphology of nanofibers directly determine their application scope and performance, while regular patterned fibers further demonstrate their superior performance in the field of sensors and biomaterials. Melt electrospinning enables controlled deposition of fibers and is currently one of the most important means of preparing patterned fibers. However, due to the existence of high-voltage electric field, melt electrospinning has safety problems such as partial discharge and electric field breakdown, coupled with the charge rejection on the fiber surface, which seriously affects the positioning deposition of fibers and makes it difficult to obtain regular patterned fibers, greatly limiting the application areas and application effects of patterned fibers. Therefore, the improvement and innovation of the spinning process is particularly urgent. Based on material-field model and contradiction matrix of TRIZ theory, the problems of melt electrospinning device are systematically analyzed. The technical conflicts are solved by the inventive principles. A three-dimensional mobile magnetic melt spinning device model is constructed, a magnetic spinning test prototype is developed, and the prototype performance and influencing factors are studied by fiber morphology. The results show the following: (1) Replacing electrostatic fields with permanent magnetic fields can fundamentally avoid safety hazards such as electric field breakdown. (2) The magnetic field force on the molten polymer fluid can generate enough stretching force to overcome the surface tension and form fibers. (3) The fibers are deposited without a whipping instability phase similar to the electrospinning process, allowing easy preparation of regular patterned fibers. (4) The planar motion of the collector creates additional stretching effect on the fibers, which can further reduce the fiber diameter. (5) In magnetic spinning, no external high-voltage power supply is required, enabling the portability of the device. The results of this paper can provide a new method for preparing nanofibers with patterned morphology.

scholarly journals Antistatic Fibers for High-Visibility Workwear: Challenges of Melt-Spinning Industrial Fibers

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2645
Author(s):  
Rudolf Hufenus ◽  
Ali Gooneie ◽  
Tutu Sebastian ◽  
Pietro Simonetti ◽  
Andreas Geiger ◽  
...  
Keyword(s):  
Melt Spinning ◽  
Specific Resistance ◽  
Minor Element ◽  
Working Environment ◽  
Electrically Conducting ◽  
Conducting Materials ◽  
Melt Spin ◽  
Dark Color ◽  
A Minor ◽  
Bicomponent Fiber

Safety workwear often requires antistatic protection to prevent the build-up of static electricity and sparks, which can be extremely dangerous in a working environment. In order to make synthetic antistatic fibers, electrically conducting materials such as carbon black are added to the fiber-forming polymer. This leads to unwanted dark colors in the respective melt-spun fibers. To attenuate the undesired dark color, we looked into various possibilities including the embedding of the conductive element inside a dull side-by-side bicomponent fiber. The bicomponent approach, with an antistatic compound as a minor element, also helped in preventing the severe loss of tenacity often caused by a high additive loading. We could melt-spin a bicomponent fiber with a specific resistance as low as 0.1 Ωm and apply it in a fabric that fulfills the requirements regarding the antistatic properties, luminance and flame retardancy of safety workwear.

Thermal conductivity of biomimetic leaf composite

2017 ◽  
Vol 52 (13) ◽  
pp. 1737-1746 ◽  
Author(s):  
G Liu ◽  
R Ghosh ◽  
D Mousanezhad ◽  
A Vaziri ◽  
H Nayeb-Hashemi
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Composite Structures ◽  
Volume Fraction ◽  
Cell Structure ◽  
Matrix Material ◽  
Mechanical And Thermal Properties ◽  
Ceramic Fibers ◽  
Fiber Morphology ◽  
Fiber Volume

The venous morphology of a typical plant leaf affects its mechanical and thermal properties. Such a material could be considered as a fiber reinforced composite structure where the veins and the rest of the leaf are considered as two materials having highly contrast mechanical and thermal properties. The variegated venations found in nature is idealized into three principal fibers—the central mid-fiber corresponding to the mid-rib, straight parallel secondary fibers attached to the mid-fiber representing the secondary veins, and then another set of parallel fibers emanating from the secondary fibers mimicking the tertiary veins of a typical leaf. This paper addresses the in-plane thermal conductivity of such a composite by considering such a venous fiber morphology embedded in a matrix material. We have considered two cases, fibers having either higher or lower conductivity respect to the matrix. The tertiary fibers do not interconnect the secondary fibers in our present study. We carry out finite element based computational investigation of the thermal conductivity of these composites under uniaxial thermal gradients and study the effect of different fiber architectures. To this end, we use two broad types of architectures both having similar central main fiber but differing in either having only secondary fibers or additional tertiary fibers. The fiber and matrix volume fractions are kept constant and a comparative parametric study is carried out by varying the inclination of the secondary fibers. We find the heat conductivity in the direction of the main fiber (Y direction) increases significantly as the fiber angle of the secondary increases. Furthermore, for composite with metal fibers, the conductivity in the Y direction is further enhanced when composite is manufactured by having secondary fibers forming a closed cell structure. However, for composite with ceramic fibers, the conductivity of the composite in the Y direction is little affected by having secondary fibers closed. An opposite behavior is observed when considering conductivity of the composite in the X direction. The conductivity of the composite in the X direction is reduced with increase in the angle of the secondary fibers. Higher conductivity in the X direction is achieved for composite with no closed cells for composites with metal fibers. The results also indicate that for composites with the constant fiber volume fraction, morphology of tertiary fibers may not significantly alter material conductivities. In conclusion, introducing a leaf-mimicking topology in fiber architecture can provide significant additional degrees of tunability in design of these composite structures.

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