The jet stretch as a factor in wet spinning

Perepelkin, K. E.; Pugach, B. M.

doi:10.1007/bf00546506

Cited by 5 publications

(5 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The draw down ratio is defined as the ratio of the tow velocities, exiting-to-entering the zone of interest. The spin draw (sampling point I), or draw applied during coagulation, calculated from the apparent entering and exiting velocities, was less than 1, which has been observed by others [12][13][14][15][16][17]. The tow velocity entering coagulation was calculated using the known, constant volumetric flow rate of the dope, and the dimension of the spinneret, and was used, uncorrected for viscoelastic die swell of the extruded jets, for the velocity calculation.…”

Section: IV Iii Iimentioning

confidence: 99%

Properties of PAN Fibers Solution Spun into a Chilled Coagulation Bath at High Solvent Compositions

Morris

Weisenberger

Rice

2015

Fibers

View full text Add to dashboard Cite

Abstract:In this work, multifilament, continuous polyacrylonitrile (PAN) fiber tow was solution spun mimicking industrial processing at the small pilot scale (0.5 k tow), while carefully altering the composition of the coagulation bath, in order to determine the effect on the resulting fiber shape, density, orientation, and tensile properties at varying points in the spinning process. Novel here are the abnormally high coagulation bath solvent compositions investigated, which surpass those often reported in the literature. In addition, the coagulation bath was maintained at a slightly chilled temperature, contrary to reported methods to produce round fibers. Further, by altering the composition of the bath in a step-wise fashion during a single spinning run, variations in all other process parameters were minimized. We found that with increasing solvent composition in the coagulation bath, the fibers not only became round in cross section, but also became smaller in diameter, which persisted down the spin line. With this decrease in diameter, all else equal, came an accompanying increase in apparent fiber density via a reduction in microvoid content. In addition, molecular orientation and tensile properties also increased. Therefore, it was found that inadequate understanding of the coagulation bath effects, and spinning at low coagulation bath solvent compositions, can hinder the ability of the fiber to reach optimum properties.

show abstract

Section: IV Iii Iimentioning

confidence: 99%

Properties of PAN Fibers Solution Spun into a Chilled Coagulation Bath at High Solvent Compositions

Morris

Weisenberger

Rice

2015

Fibers

View full text Add to dashboard Cite

show abstract

“…In wet spinning, which is commonly used for production of PAN precursor fibers, the jet stretch is almost always less than 1. [7][8][9][10] This is because, when the fibers are extruded out of the spinneret, they will swell immediately to some extent and hence reduce the velocity, which is called the jet swell effect (or Barus effect). [11] In addition, if the jet stretch is greater than 1, the fibers are often damaged or broken.…”

Section: Introductionmentioning

confidence: 97%

“…[3][4][5][6] However, as regards the effect of the subsequent jet stretch, which is one of the crucial spinning parameters, on the fiber structure and properties, there are still some inconsistent views and explanations. [7][8][9][10] The jet stretch is generally quantified as the ratio of the take-up velocity of the coagulated fiber from the coagulation bath to the extrusion velocity of the spinning solution. In wet spinning, which is commonly used for production of PAN precursor fibers, the jet stretch is almost always less than 1.…”

Section: Introductionmentioning

confidence: 99%

Effect of Jet Swell and Jet Stretch on the Structure of Wet-Spun Polyacrylonitrile Fiber

Ouyang

Chen

Zhang

et al. 2011

Journal of Macromolecular Science, Part B

View full text Add to dashboard Cite

The jet swell effect in the wet spinning of polyacrylonitrile (PAN) fiber was studied by optical microscopy and the jet swell ratio was obtained through directly measuring the diameter of the freely extruded fibers. For reflecting the actual drawing situation of the fibers in the coagulation process, the jet stretches were then corrected from the apparent values to the true values, and their effect on the cross-sectional morphology, internal structure, and orientation of the wet-spun PAN fibers was studied by optical microscopy, scanning electron microscopy, and X-ray diffraction, respectively. The results showed that jet stretch plays an important role in eliminating the adverse effects caused by the jet swell effect and affects the fiber structure; PAN fibers of uniform denier, dense and homogenous structure, and high orientation can only be obtained at a suitable jet stretch.

show abstract

“…Attempts have been made to describe its influence on PAN fiber's structure and properties 4–6. As for stretching in bath, some literatures of early days7, 8 demonstrated the influence of jet stretch on the spinning process and properties of polyester, polyvinyl alcohol, viscose fiber, etc. But opinion as regards the influence of the jet stretch on the fiber properties was not unanimous.…”

Section: Introductionmentioning

confidence: 99%

Investigating the jet stretch in the wet spinning of PAN fiber

Zeng

Zhao

et al. 2007

J of Applied Polymer Sci

View full text Add to dashboard Cite

The jet stretch of wet-spun PAN fiber and its effects on the cross-section shape and properties of fibers were investigated for the PAN-DMSO-H 2 O system. Evidently, the spinning parameters, such as dope temperature, bath concentration, and bath temperature, influenced the jet stretch. Also, under uniform conditions, the postdrawing ratio changed as well as that of jet stretch. When coagulation temperature was 358C simultaneously with bath concentration of 70%, jet stretch impacted obviously the cross-section shapes of PAN fiber, but had little effect when the temperature was below 108C or above 708C. As the jet stretch ratio increased, the crystallinity, crystal size, sonic orientation, and mechanical properties of the as-spun fiber changed rapidly to a major value for jet stretch ratio of 0.9 where the cross section of as-spun fiber was circular. With further increasing of jet stretch ratio, the properties changed slightly but the fiber shape was not circular. The results indicated that appropriate jet stretch, under milder formation conditions in wet-spinning, could result in the higher postdrawing ratio and circular profile of PAN fiber, which were helpful to produce round PAN precursor with minor titer and perfect properties for carbon fiber.

show abstract

The jet stretch as a factor in wet spinning

Cited by 5 publications

References 3 publications

Properties of PAN Fibers Solution Spun into a Chilled Coagulation Bath at High Solvent Compositions

Properties of PAN Fibers Solution Spun into a Chilled Coagulation Bath at High Solvent Compositions

Effect of Jet Swell and Jet Stretch on the Structure of Wet-Spun Polyacrylonitrile Fiber

Investigating the jet stretch in the wet spinning of PAN fiber

Contact Info

Product

Resources

About