Response of fiber diameter to a continuously changing draw ratio in a laser drawing process

2015 ◽  
Vol 86 (10) ◽  
pp. 1074-1083 ◽  
Author(s):  
Munekazu Matoba ◽  
Yutaka Ohkoshi ◽  
Kyoung Hou Kim ◽  
Toshifumi Ikaga
Keyword(s):  
Draw Ratio ◽  
Fiber Diameter ◽  
Drawing Process

The Effect of Drawing Process on the Properties of Split-Film PTFE Fiber

2012 ◽  
Vol 602-604 ◽  
pp. 1946-1950 ◽  
Author(s):  
Xin Min Hao ◽  
Yuan Yang ◽  
Bin Xiang Huang ◽  
Lei Huang ◽  
Guo Jun Zhang
Keyword(s):  
Mechanical Properties ◽  
Draw Ratio ◽  
Breaking Strength ◽  
Three Dimensional ◽  
Drawing Process ◽  
Heat Setting ◽  
Elongation At Break ◽  
Ptfe Membrane ◽  
Hot Drawing ◽  
Temperature Controlled

From PTFE baseband prepared by three-dimensional drawing, after the processing of different temperature and time. And then by twisting, hot drawing and heat setting, the PTFE filament was prepared in appropriate tension conditions. The surface morphology of the resulting filaments was observed by SEM, the result shows that the uniformity of the PTFE membrane has been improved by using three-dimensional drawing process, hot drawing processes had a great effect upon the breaking strength and elongation at break of PTFE fibers. In order to keep ensure reasonable mechanical properties, the draw ratio in the range of 20 to 50 times to adjust the temperature controlled at 150°C to 300 °C.

A study of ethylene vinyl alcohol copolymer fiber for the drawing process

2016 ◽  
Vol 87 (9) ◽  
pp. 1081-1095
Author(s):  
Syang-Peng Rwei ◽  
Zhi-Feng Jue ◽  
Whe-Yi Chiang ◽  
Yu-Hua Chen ◽  
Jui-Hsiang Chen
Keyword(s):  
Stress Relaxation ◽  
Initial Stress ◽  
Vinyl Alcohol ◽  
Draw Ratio ◽  
Drawing Process ◽  
Ethylene Vinyl Alcohol ◽  
Drawing Temperature ◽  
Drawing Stress ◽  
Initial Modulus ◽  
Ethylene Content

This study investigates the effect of the drawing process of ethylene vinyl alcohol (EVOH) fibers on their physical properties. Three different ethylene contents, namely EV-32, EV-38 and EV-44, were used where the ethylene content has the order of EV-44 > EV-38 > EV-32. The result indicates that at the same drawing temperature and draw ratio, the online drawing stress of the fiber with high ethylene content is higher than that with low ethylene content. Moreover, the drawn EVOH fiber, at the drawing temperature of 80℃ and the draw ratio of 2.0, exhibits an optimal mechanical property. As the draw ratio increases, the online drawing stress, birefringence and initial modulus increase. Notably, unlike typical polymeric fibers, the glass transition temperature ( Tg) of the drawn EVOH fibers decreases with the draw ratio due to more water being absorbed by thinner fibers within the same number of samples. The draw ratio was found to have little effect on the melting temperature ( Tm). At the same draw ratio, the online drawing stress, birefringence, stress and initial modulus of the fiber EV-44, which has the highest ethylene content, is higher than those of EV-32 and EV-38. The creep strain of the drawn fibers EV-32 and EV-38 linearly increase with the drawing time when the applied stress maintains constant at 150 MPa, while an insignificant increase is observed for EV-44, suggesting that EV-44 is difficult to deform and has higher size stability. In the stress relaxation test, the elongation increases with the initial stress. At the same elongation percentage, the initial stress of the drawn fibers has the following trend: EV-44 > EV-38 > EV-32 and the stress relaxation time (τ) has the following trend: EV-44 > EV-38 > EV-32, indicating again that EV-44 is relatively difficult to deform during drawing. Finally, EV-44 fiber performed the best in the hot water resistance test.

scholarly journals COMPARISON OF CONVENTIONAL DRAWING, INVERTED DRAWING AND WARM FORMING PROCESSES FOR DEEP DRAWING OF ALUMINIUM CUPS

2014 ◽  
pp. 279-282
Author(s):  
RAJAGANAPATHY C ◽  
THIVAKAR K. G ◽  
SARAVANAKUMARN SARAVANAKUMARN
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Draw Ratio ◽  
Warm Forming ◽  
Process Time ◽  
Drawing Process ◽  
Forming Process ◽  
Die Set ◽  
Cup Drawing

Cup drawing is one of the important operations in sheet metal forming. Manufacturing of the aluminium base cup involves several stages such as blanking, first drawing, second drawing, taper formation and trimming. This increases the process time. An attempt has therefore, been made to develop a comprehensive, rigorous, yet easily-workable method of analysis for designing a die set to combine the intermediate stages of drawing process. Conventional drawing, inverted drawing and warm forming processes are experimented for yielding successful drawing in single setup. Die sets are separately designed for above said processes. The die sets, thus designed is simulated using DEFORM-F2 to analyze the successful Drawability of the die sets. From the simulations conducted, the die set designed for warm forming process yields greater Limiting Draw Ratio (LDR). Using warm forming process, the LDR of 2.0 was achieved which is much higher when compared with the conventional drawing.

Study on structures and properties of ultra-hot drawing UHMWPE fibers fabricated via dry spinning method

2018 ◽  
Vol 38 (9) ◽  
pp. 863-870 ◽  
Author(s):  
Xinwei Wang ◽  
Han Zheng ◽  
Yongfei Sun
Keyword(s):  
Molecular Weight ◽  
Draw Ratio ◽  
Average Molecular Weight ◽  
Raw Material ◽  
Drawing Process ◽  
Scanning Calorimetry ◽  
Fracture Force ◽  
Dry Spinning ◽  
Hot Drawing ◽  
Uhmwpe Fibers

Abstract High tensile strength ultra high molecular weight polyethylene (UHMWPE) fibers were prepared via the dry spinning method. Raw material was UHMWPE resin with 6 million viscosity-average molecular weight (Mv). Changes of morphology, mechanical properties, thermal properties and crystallization process of the fibers in the ultra-hot drawing process were studied by scanning electron microscopy (SEM), tensile tester, differential scanning calorimetry (DSC), and wide-angle X-ray diffraction (WAXD). Results show that there was a maximum value of fracture force at a draw ratio of 40 and excessive draw ratio destroyed crystal structures in fibers and led to a decrease in the fracture force value. A shoulder peak appeared in DSC curves of ultra-drawing samples and its peak value maintained at 154°C in different samples. In addition, three peaks can be observed in all WAXD patterns of drawing samples. The mechanism of microstructural changes during the hot drawing process was elucidated.

A Statistical Analysis of the Influence of Multi-Stage Hot-Drawing on the Overall Orientation of Biodegradable Aliphatic-Aromatic Co-Polyester Fibers

2013 ◽  
Vol 8 (1) ◽  
pp. 155892501300800 ◽  
Author(s):  
Basel Younes ◽  
Alex Fotheringham ◽  
Hassan M. El-Dessouky ◽  
Ghassan Haddad
Keyword(s):  
Draw Ratio ◽  
Fractional Factorial ◽  
Regression Equations ◽  
Drawing Process ◽  
Plate Temperature ◽  
Drawing Temperature ◽  
Multi Stage ◽  
Relaxation Temperature ◽  
Hot Drawing ◽  
Temperature Relaxation

Biodegradable as-spun linear aliphatic-aromatic co-polyester (AAC) fibers were processed under a fractional factorial design as a function of hot-drawing conditions using appropriate experimental and statistical methodology. The multi-stage hot-drawing process and overall orientation of the biodegradable AAC fibers were characterized and statistically analyzed. The results obtained showed that the most effective and significant parameters influencing fiber overall orientation are the draw ratio and the drawing temperature. Birefringence is affected positively by draw ratio and plate temperature, and negatively by drawing temperature, the interaction between drawing stage and relaxation temperature, relaxation temperature and the interaction between draw ratio and spin finish. From results and analysis, a combination of factor levels was designed for controlling the birefringence of the material studied using the regression equations obtained. A new forecasting statistical model has been suggested for optimizing the drawing process effect. Such optimized (AAC) fibers could be used in agricultural, horticultural and other textile applications.

scholarly journals Response of Fiber Diameter with the Continuously Changing of Draw Ratio

2014 ◽  
Vol 70 (8) ◽  
pp. 167-173 ◽  
Author(s):  
Munekazu Matoba ◽  
Akiyoshi Ito ◽  
Toshifumi Ikaga ◽  
Yutaka Ohkoshi
Keyword(s):  
Draw Ratio ◽  
Fiber Diameter

An in situ small-angle X-ray scattering study of the structural effects of temperature and draw ratio of the hot-drawing process on ultra-high molecular weight polyethylene fibers

RSC Advances ◽  
2016 ◽  
Vol 6 (56) ◽  
pp. 51125-51134 ◽  
Author(s):  
Minfang An ◽  
Haojun Xu ◽  
You Lv ◽  
Qun Gu ◽  
Feng Tian ◽  
...  
Keyword(s):  
Small Angle ◽  
Draw Ratio ◽  
Drawing Process ◽  
Structural Effects ◽  
X Ray ◽  
X Ray Scattering ◽  
Hot Drawing ◽  
Scattering Study ◽  
Effects Of Temperature

An in situ small-angle X-ray scattering study of the structural effects of temperature and draw ratio of the hot-drawing process on UHMWPE gel fibers was performed with equipment simulating the hot-drawing process on an industrial production line.

Quantitative Diameter Measurements of Chromatin and TMV Fibers in the Freeze-Dried State

1988 ◽  
Vol 46 ◽  
pp. 170-171
Author(s):  
B. D. Athey ◽  
A. L. Stout ◽  
M. F. Smith ◽  
J. P. Langmore
Keyword(s):  
Reliable Method ◽  
Fiber Diameter ◽  
Quantitative Agreement ◽  
One Dimension ◽  
Fiber Axis ◽  
Two Dimensional ◽  
Fiber Density ◽  
Variable Diameter ◽  
Freeze Dried ◽  
Expected Values

Although there is general agreement that Inactive chromosome fibers consist of helically packed nucleosomes, the pattern of packing is still undetermined. Only one of the proposed models, the crossed-linker model, predicts a variable diameter dependent on the length of DNA between nucleosomes. Measurements of the fiber diameter of negatively-stained and frozen- hydrated- chromatin from Thyone sperm (87bp linker) and Necturus erythrocytes (48bp linker) have been previously reported from this laboratory. We now introduce a more reliable method of measuring the diameters of electron images of fibrous objects. The procedure uses a modified version of the computer program TOTAL, which takes a two-dimensional projection of the fiber density (represented by the micrograph itself) and projects it down the fiber axis onto one dimension. We illustrate this method using high contrast, in-focus STEM images of TMV and chromatin from Thyone and Necturus. The measured diameters are in quantitative agreement with the expected values for the crossed-linker model for chromatin structure

Effect of Glycosaminoglycans on Thrombin- and Atroxin-Induced Fibrin Assembly and Structure

1989 ◽  
Vol 62 (04) ◽  
pp. 1057-1061 ◽  
Author(s):  
Marcus E Carr ◽  
Patrick L Powers
Keyword(s):  
Chondroitin Sulfate ◽  
Fiber Diameter ◽  
Lag Phase ◽  
Low Molecular Weight ◽  
Fibrin Gels ◽  
Fiber Size ◽  
Induced Changes ◽  
The Impact ◽  
Fiber Radius ◽  
Turbidity Increase

SummaryThis study was performed to quantitate the impact of several glycosaminoglycans (GAG) on fibrin assembly and structure. Gel formation was monitored as the increase in optical density at 633 nm subsequent to thrombin (2 NIH u/ml) or atroxin (0.10 mg/ml) addition to solutions of buffered fibrinogen (1 mg/ml) or plasma. Gel absorbance was measured as a function of wavelength (400 to 800 nm) and gel fiber diameter and mass/length ratio (μ) were calculated. Chondroitin sulfate A (CSA)shortened the lag phase, enhanced the maximal rate of turbidity increase, and increased the final gel turbidity of fibrin gels formed by thrombin or atroxin. CSA (16 mg/ml) increased fiber μ from 1.3 to 3.1 × 1013 dalton/cm and fiber radius from 6.0 to 8.6 × 10-6 cm in thrombin-induced gels. μ increased from 0.7 to 2.7 × 1013 dalton/cm and fiber radius from 4 to 7.8 × 10-6 cm for atroxin-induced gels. Above 16 mg/ml, CSA caused fibrinogen precipitation in purified solutions but not in plasma. CSA inhibited thrombin-induced plasma clotting of plasma but effects in atroxin-mediated plasma gels paralleled those seen in purified solutions. Chondroitin sulfate B (CSB)-induced changes in fibrin were similar but slightly less dramatic than those seen with CSA. μ increased from 0.9 to 2.0 × 1013 dalton/cm for thrombin-induced fibrin gels and from 0.8 to 2.3 × 1013 dalton/cm for atroxininduced gels. Low molecular weight heparin (Mr = 5100) slowed fibrin assembly and reduced fiber size by 50% in thrombininduced gels. Changes in μ of atroxin-induced gels were much less pronounced (<20%). This study documents pronounced GAGinduced changes in fibrin structure which vary with GAG species and may mediate significant physiologic functions.

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