Control on molecular weight reduction of poly(ε-caprolactone) during melt spinning — A way to produce high strength biodegradable fibers

2013 ◽  
Vol 33 (7) ◽  
pp. 4213-4220 ◽  
Author(s):  
Jit Pal ◽  
Nimesh Kankariya ◽  
Sunita Sanwaria ◽  
Bhanu Nandan ◽  
Rajiv K. Srivastava
Keyword(s):  
Molecular Weight ◽  
Weight Reduction ◽  
Melt Spinning ◽  
High Strength

Melt spinning of high-strength fiber from low-molecular-weight polypropylene

2015 ◽  
Vol 56 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Qianchao Mao ◽  
Tom P. Wyatt ◽  
An-Ting Chien ◽  
Jinnan Chen ◽  
Donggang Yao
Keyword(s):  
Molecular Weight ◽  
Melt Spinning ◽  
High Strength ◽  
Low Molecular Weight ◽  
High Strength Fiber

Molecular Weight Discrete Distribution-Induced Orientation of High-Strength Copolyamide Fibers: Effects of Component Proportion and Molecular Weight

2021 ◽  
Author(s):  
Jialiang Zhou ◽  
Qianqian Wang ◽  
Chao Jia ◽  
Mugaanire Tendo Innocent ◽  
Weinan Pan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Discrete Distribution ◽  
High Strength

High-Speed Melt Spinning of Sheath-Core Bicomponent Polyester Fibers: High and Low Molecular Weight Poly(ethylene Terephthalate) Systems

1997 ◽  
Vol 67 (9) ◽  
pp. 684-694 ◽  
Author(s):  
J. Radhakrishnan ◽  
Takeshi Kikutani ◽  
Norimasa Okui
Keyword(s):  
Molecular Weight ◽  
High Speed ◽  
Melt Spinning ◽  
Ethylene Terephthalate ◽  
Maxwell Model ◽  
Low Molecular Weight ◽  
Structural Development ◽  
Solidification Temperature ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Sheath-core bicomponent spinning of high molecular weight poly (ethylene terephthalate) (hmpet, IV = 1.02 dl/g) and low molecular weight pet (lmpet, IV = 0.65 dl/g) is done at a take-up velocity range of 1 to 7 km/min. The structures of the individual components in the as-spun bicomponent fibers are characterized. Orientation and orientation-induced crystallization of the hmpet component are enhanced, while those of the lmpet component are suppressed in comparison to corresponding single component spinning. Numerical simulation with the Newtonian model shows that elongational stress in the hmpet component is enhanced and that of the lmpet decreases during high-speed bicomponent spinning. The difference in elongational viscosity is the main factor influencing the mutual interaction between hmpet and lmpet, which in turn affect spinline dynamics, solidification temperature, and structural development in high-speed bicomponent spinning. Simulation with an upper-convected Maxwell model shows that considerable stress relaxation can occur in the lmpet component if the hmpet component solidifies before lmpet. A mechanism for structural development is also proposed, based on the simulation results and structural characterization data.

scholarly journals The nanostructuring of ultra-high-molecular-weight polyethylene in thermal and mechanical fields as revealed by DSC

2021 ◽  
Vol 2103 (1) ◽  
pp. 012095
Author(s):  
L P Myasnikova ◽  
A K Borisov ◽  
Yu M Boiko ◽  
A P Borsenko ◽  
V F Drobot’ko ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Melting Temperature ◽  
Mechanical Characteristics ◽  
Thickness Distribution ◽  
High Strength ◽  
High Modulus ◽  
Know How ◽  
First Time ◽  
Ultra High Molecular Weight

Abstract The ultra-high-molecular-weight polyethylene reactor powders are widely used for the actively developing solvent-free method for producing high-strength high-modulus PE filaments, which includes the compaction and sintering of a powder followed by orientational hardening. To find an appropriate regime of the technological process, it is important to know how the nanostructure changes when transforming from a powder to a precursor for hardening. Nanocrystalline lamellae are characteristics of the powder structure. For the first time, the DSC technique was used to follow changes in the thickness distribution of lamellae in ultra-high-molecular-weight polyethylene reactor powder on its way to a precursor for orientation hardening. It was found that the percentage of thick (>15 nm) and thin (10 nm) lamellae in compacted samples and those sintered at temperatures lower than the melting temperature of PE (140°C) remains nearly the same. However, significant changes in the content of lamellae of different thicknesses were observed in the samples sintered at 145°C with subsequent cooling under different conditions. The influence of the lamellae thickness distribution in precursors on the mechanical characteristics of oriented filaments was discussed.

Experiment and FE Analysis of Compression of Thick Ring Filled with Oil

2018 ◽  
Vol 767 ◽  
pp. 141-148
Author(s):  
Yoshiki Tatematsu ◽  
Mitsuka Morimoto ◽  
Kazuhiko Kitamura
Keyword(s):  
Weight Reduction ◽  
High Strength Steel ◽  
Metal Flow ◽  
High Strength ◽  
Fe Analysis ◽  
Inner Diameter ◽  
Save Energy ◽  
The Ideal

Reducing automobile weight has been necessarily accelerated to save energy and improve drivability. Accordingly, use of high strength steel and hollow sections help in weight reduction. In this study, the effect of trapped oil has been investigated to improve the metal flow in upsetting of a hollow workpiece using no mandrel. It was found that the ideal deformation without friction between the dies and the workpiece was nearly achieved when a low and thick ring with trapped oil was upset. The inner diameter of the oil-filled ring was expanded more than that of the benchmark ring. The effect of the expansion of the ring and the reduction of the friction proved helpful in trial forming of a gear preform.

scholarly journals The Production of Material with Ultrafine Grain Structure in Al-Zn Alloy in the Process of Rapid Solidification

2014 ◽  
Vol 14 (2) ◽  
pp. 57-62
Author(s):  
M. Szymaneka ◽  
B. Augustyn ◽  
D. Kapinos ◽  
S. Boczkal ◽  
J. Nowak
Keyword(s):  
Rapid Solidification ◽  
Melt Spinning ◽  
Hot Extrusion ◽  
High Strength ◽  
Strength Properties ◽  
Grain Structure ◽  
Ultrafine Grain ◽  
Plastic Working ◽  
Metal Treatment ◽  
Ultrafine Grain Structure

Abstract In the aluminium alloy family, Al-Zn materials with non-standard chemical composition containing Mg and Cu are a new group of alloys, mainly owing to their high strength properties. Proper choice of alloying elements, and of the method of molten metal treatment and casting enable further shaping of the properties. One of the modern methods to produce materials with submicron structure is a method of Rapid Solidification. The ribbon cast in a melt spinning device is an intermediate product for further plastic working. Using the technique of Rapid Solidification it is not possible to directly produce a solid structural material of the required shape and length. Therefore, the ribbon of an ultrafine grain or nanometric structure must be subjected to the operations of fragmentation, compaction, consolidation and hot extrusion. In this article the authors focussed their attention on the technological aspect of the above mentioned process and described successive stages of the fabrication of an AlZn9Mg2.5Cu1.8 alloy of ultrafine grain structure designated for further plastic working, which enables making extruded rods or elements shaped by the die forging technology. Studies described in the article were performed under variable parameters determined experimentally in the course of the alloy manufacturing process, including casting by RS and subsequent fragmentation.

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