Dynamics of hot-tube spinning from crystallizing polymer melts

Jarecki, Leszek; Ziabicki, Andrzej; Blim, Anna

doi:10.1016/s1089-3156(99)00034-3

Cited by 16 publications

(30 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Fast drawing of the filament is observed in the pneumatic melt spinning under supersonic air jets, located in relatively narrow range of the spinning axis next to the extrusion point. And so, non-linear stress-optical relation is used to specify local birefringence of the amorphous polymer, ∆n a (z), and local amorphous orientation factor, f a (z), under the tensile stress ∆p(z), derived basing on the non-Gaussian conformational statistics of flexible chain macromolecules [29]: …”

Section: Modeling Of Uniaxial Air-drawing Of the Polymer Meltmentioning

confidence: 99%

“…K max , T max , D 1/2 and A > 0 are material parameters. The Avrami index n = 2 is assumed for the on-line oriented crystallization [29]. Equation (12) has been proposed by Ziabicki [16] for non-isothermal, oriented crystallization in quasistatic approximation and not too high amorphous orientations basing on phenomenological analysis and symmetry reasons where the parameter A can be determined from an independent experiment [33].…”

Section: Modeling Of Pneumatic Melt Drawing Of Polypropylene Super-thmentioning

confidence: 99%

See 1 more Smart Citation

Modeling of pneumatic melt drawing of polypropylene super-thin fibers in the Laval nozzle

Blim¹,

Jarecki²,

Błoński³

2014

Bulletin of the Polish Academy of Sciences: Technical Sciences

View full text Add to dashboard Cite

Abstract. Melt spinning of the fibers by supersonic air jet in the Laval nozzle is a novel, efficient and energy saving method of formation of super-thin fibers. In the process, polymer melt is extruded from a row of orifices and fast drawn by the pneumatic forces. In the modelling, air velocity, temperature and pressure distributions are computed from the k-ω aerodynamic model. Computations of the polymer air-drawing dynamics are based on the mathematical model of melt spinning in a single-, thin-filament approximation and Phan-Thien/Tanner non-linear viscoelasticity of the polymer melt. Axial profiles of the polymer velocity, temperature, tensile stress and rheological extra-pressure are computed. Influence of the Laval nozzle geometry, initial air compression, an initial melt temperature, a polymer mass output and the diameter of the melt extrusion die is discussed. The role of the polymer molecular weight, melt viscosity and relaxation time is considered. Example computations show the influence of important processing and material parameters. In the supersonic process, a high negative internal extra-pressure is predicted in the polymer melt under high elongation rates which may lead to cavitation and longitudinal burst splitting of the filament into a high number of sub-filaments. A hypothetical number of sub-filaments at the splitting is estimated from an energetic criterion. The diameter of the sub-filaments may reach the range of nano-fibers. A substantial influence of the Laval nozzle geometry is also predicted.

show abstract

Section: Modeling Of Uniaxial Air-drawing Of the Polymer Meltmentioning

confidence: 99%

Section: Modeling Of Pneumatic Melt Drawing Of Polypropylene Super-thmentioning

confidence: 99%

Modeling of pneumatic melt drawing of polypropylene super-thin fibers in the Laval nozzle

Blim¹,

Jarecki²,

Błoński³

2014

Bulletin of the Polish Academy of Sciences: Technical Sciences

View full text Add to dashboard Cite

show abstract

“…4 in Eq. (12) is 2D heterogeneous nucleation rate [37,55,56] given by (13) where K^ = 10® N/m"* is kinetic parameter and ks = 1.3806506 x 10"2^J/K is the Boltzmann constant. In Fq.…”

Section: Nucleation Temperature and Critical Cooling Rate For Amorphomentioning

confidence: 99%

“…In other types of melt spinning for polymer fiber or thread, melt jet is drawn by spinning wheel in the stream's falling direction and then spun out below the wheel [11][12][13][14][15][16][17]. Unlikely, there is no jet impingement onto the spinning wheel and no distinct melt pool forming on the wheel top surface in these so-called "side-casting" melt spinnings.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical and Analytical Modeling of Free-Jet Melt Spinning for Fe75−Si10−B15 (at. %) Metallic Glasses

Wang

Mitra

2014

Journal of Heat Transfer

View full text Add to dashboard Cite

Amorphous fiber, ribbon, or film is produced through melt spinning. In this manufacturing process, a continuous delivery of amorphous material is simultaneously dependent on the wheel spinning rate, metallic liquid viscosity, surface tension force, heat transfer inside the melt pool and along the substrate, and other parameters. An analysis of a freejet melt spinning for fiber manufacture has been performed to relate the process control parameters with amorphous formation. We present a numerical simulation of transient impingement of a free melt jet with a rapidly rotating wheel, along with theoretical estimates of melt ribbon thickness, to investigate dynamical characteristics of the flow in melt pool. The nucleation temperature and the critical cooling rate are predicted in the paper for alloy Feys-Siio-Bjs (at. %). Thermal conduction is found to dominate undercooling in melt spinning by comparing the temperature and velocity measurements with our numerical simulation and the analytical solutions.

show abstract

Crystallization‐controlled limitations of melt spinning

Ziabicki

Jarecki

2007

J of Applied Polymer Sci

View full text Add to dashboard Cite

A numerical simulation of melt spinning reveals bifurcation of dynamic solutions leading to limited spinning conditions. The bifurcation phenomenon is controlled by stress-oriented crystallization and crystallinitydependent polymer viscosity. Under the conditions of bifurcation, the space of the spinning conditions (take-up velocity Â filament thickness) splits into three regions corresponding to amorphous fibers, partially crystalline fibers, and inaccessible conditions. Major factors affecting the maximum spinning speed and minimum filament thickness for melt-spun poly(ethylene terephthalate) are analyzed.

show abstract

Dynamics of hot-tube spinning from crystallizing polymer melts

Cited by 16 publications

References 10 publications

Modeling of pneumatic melt drawing of polypropylene super-thin fibers in the Laval nozzle

Modeling of pneumatic melt drawing of polypropylene super-thin fibers in the Laval nozzle

Numerical and Analytical Modeling of Free-Jet Melt Spinning for Fe75−Si10−B15 (at. %) Metallic Glasses

Crystallization‐controlled limitations of melt spinning

Contact Info

Product

Resources

About