THE EFFECT OF POLYMER MELT RHEOLOGY AND MELT SPINNING DYNAMICS ON THE ULTIMATE FINENESS OF PET FIBERS IN HIGH-SPEED SPINNING PROCESSES

Poly(ethylene 2,5-furandicarboxylate) (PEF) is regarded as a bio-based alternative or complementary polyester for the widely used fossil resource-based polyester, poly(ethylene terephthalate) (PET). High-speed melt spinning of PEF of low and high molecular weight (L-PEF, H-PEF) was conducted, and the structure and properties of the resultant as-spun fibers were investigated. The occurrence of orientation-induced crystallization was confirmed for the H-PEF at the take-up velocity of 6.0 km/min, the highest speed for producing PET fibers in the industry. Molecular orientation and crystallinity of the as-spun fibers increased with the increase of take-up velocity, where the H-PEF fibers always showed a higher degree of structural development than the L-PEF fibers. The tensile modulus of the high-speed spun H-PEF fibers was relatively low at 5 GPa, whereas a sufficiently high tensile strength of approximately 500 MPa was measured. These values are adequately high for the application in the general semi-engineering fiber field.

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Effect of Polycondensation Catalyst on Fiber Structure Development in High-Speed Melt Spinning of Poly (Ethylene Terephthalate)

Polymers ◽

10.3390/polym11121931 ◽

2019 ◽

Vol 11 (12) ◽

pp. 1931 ◽

Cited By ~ 1

Author(s):

Eun Seon Kim ◽

Hyun Ju Oh ◽

Hyun-Joong Kim ◽

Chun Gi Kim ◽

Seong Yoon Park ◽

...

Keyword(s):

High Speed ◽

Melt Spinning ◽

Crystallization Rate ◽

Structural Development ◽

Melt Crystallization ◽

Fiber Structure ◽

Structure Development ◽

Scanning Calorimetry ◽

Pet Fibers ◽

Induced Crystallization

We conducted a preliminary study on fiber structural development in the high-speed melt spinning of environmentally friendly polyethylene terephthalate (Ti-PET) synthesized with 25 ppm of titanium-based catalyst, which was compared with conventional PET (Sb-PET) synthesized with 260 ppm of antimony-based catalyst. Gel permeation chromatography of Ti- and Sb-PET resins of intrinsic viscosity 0.63 confirmed that both resins have similar molecular weights and distributions. However, differential scanning calorimetry revealed that the Ti-PET resin exhibited a lower melt–crystallization peak and isothermal melt-crystallization rate than the Sb-PET resin. High-speed melt spinning of the Ti- and Sb-PET was possible up to a spinning velocity of 6 km/min. Two-dimensional wide-angle X-ray diffraction analyses showed that the molecular orientation of the obtained as-spun Ti- and Sb-PET fibers increased with spinning velocity, and a highly oriented, crystalline structure by orientation-induced crystallization started to appear from 5 km/min. Notably, Ti-PET fibers showed a lower degree of crystalline structural development and lower tensile strength compared with Sb-PET fibers under the high-speed spinning conditions. Our results suggest that the catalyst in PET resins can act as nucleating agents in thermal- and orientation-induced crystallization, and that differences in catalyst content can influence PET fiber structure development under extreme conditions in high-speed melt spinning.

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Polymer melt rheology

10.1533/9780857092984 ◽

1994 ◽

Cited By ~ 35

Author(s):

F. N. Cogswell

Keyword(s):

Polymer Melt ◽

Melt Rheology

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Polymer Melt Rheology and Flow Birefringence

10.1007/978-3-642-68822-5 ◽

1983 ◽

Cited By ~ 244

Author(s):

Hermann Janeschitz-Kriegl

Keyword(s):

Polymer Melt ◽

Flow Birefringence ◽

Melt Rheology

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Fiber Formation and Structural Development of HBA/HNA Thermotropic Liquid Crystalline Polymer in High-Speed Melt Spinning

Polymers ◽

10.3390/polym13071134 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1134

Author(s):

Bo Seok Song ◽

Jun Young Lee ◽

Sun Hwa Jang ◽

Wan-Gyu Hahm

Keyword(s):

Mechanical Properties ◽

Shear Rate ◽

High Speed ◽

Melt Spinning ◽

Liquid Crystalline Polymer ◽

Liquid Crystalline ◽

Crystalline Polymer ◽

Fiber Formation ◽

Structural Development ◽

Thermotropic Liquid Crystalline Polymer

High-speed melt spinning of thermotropic liquid crystalline polymer (TLCP) resin composed of 4-hydroxybenzoic acid (HBA) and 2-hydroxy-6-napthoic acid (HNA) monomers in a molar ratio of 73/27 was conducted to investigate the characteristic structure development of the fibers under industrial spinning conditions, and the obtained as-spun TLCP fibers were analyzed in detail. The tensile strength and modulus of the fibers increased with shear rate in nozzle hole, draft in spin-line and spinning temperature and exhibited the high values of approximately 1.1 and 63 GPa, respectively, comparable to those of industrial as-spun TLCP fibers, at a shear rate of 70,000 s−1 and a draft of 25. X-ray diffraction demonstrated that the mechanical properties of the fibers increased with the crystalline orientation factor (fc) and the fractions of highly oriented crystalline and non-crystalline anisotropic phases. The results of structure analysis indicated that a characteristic skin–core structure developed at high drafts (i.e., spinning velocity) and low spinning temperatures, which contributed to weakening the mechanical properties of the TLCP fibers. It is supposed that this heterogeneous structure in the cross-section of the fibers was induced by differences in the cooling rates of the skin and core of the fiber in the spin-line.

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Biodegradable fibers of poly(3-hydroxybutyrate) produced by high-speed melt spinning and spin drawing

Journal of Polymer Science Part B Polymer Physics ◽

10.1002/1099-0488(20001101)38:21<2841::aid-polb130>3.0.co;2-# ◽

2000 ◽

Vol 38 (21) ◽

pp. 2841-2850 ◽

Cited By ~ 68

Author(s):

G. Schmack ◽

D. Jehnichen ◽

R. Vogel ◽

B. T�ndler

Keyword(s):

High Speed ◽

Melt Spinning

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

Textile Research Journal ◽

10.1177/004051759706700908 ◽

1997 ◽

Vol 67 (9) ◽

pp. 684-694 ◽

Cited By ~ 28

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.

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