Melt spinning structure development

Fig. 14.5 Morphological model of structures developed in as-spun HDPE. Take-up velocities are (a) very low (b) low (c) medium and (d) high. [Reprinted by permission from J. E. Spruiell and J. L. White, Structure Development during Polymer Processing Studies of the Melt Spinning of Polyethylene and Polypropylene Fibers, Polym. Eng. Set, 15, 660 (1975).]...

J. R. Dees and J. E. Spmiell, Structure Development During Melt Spinning of Linear Polyethylene Fiber, J. Appl. Polym. Sci. 18, 1053 (1974). 

Ternary blends from a thermotropic liquid crystalline polymer, PEN, and PET were prepared by melt blending and melt spinning to fibers. The mechanical properties of ternary blend fibers could be significantly improved by annealing at 180°C for 2 h. This is attributed to the development of more ordered crystallites and to the formation of more perfect crystalline structures. The interfacial adhesion between PEN and liquid crystalline polymer phases is enhanced when the blends are processed with dibutyl-tindilaurate as a reactive catalyst to promote transesterification. 

Kim, K.H., Cho, H.H., Ito, H., Kikutani, T., 2008. Fiber structure development in high-speed melt spinning of poly(trimethylene terephthalate) (PIT)—on-line measurement of birefringence. J. Polym. Sci. B Polym. Phys. 46, 847 56. 

Choi, C.H. White, J.L. (1998). Comparative study of structure development in melt spinning polyolefin fibers. Intem.Polym.Proc., Vol.l3, Issue 1, pp. 78-87. 

Choi, D. White, J.L. (2000). Structure development in melt spinning syndiotactic polypropylene and comparison to isotactic polypropylene. Intern.Polym.Proc., Vol.15, Issue 4, p>p. 398-405. 

Dees, J.R. Spruiell, J.E. (1974). Structure development during melt spinning of linear polyethylene fibers.. Appl.PolyntSci., Vol. 18, Issue, Issue 4, pp.1053-1078. 

Spruiell, J.E. White, J.L. (1975). Structure development during polymer processing - studies of melt spinning of polyethylene and polypropylene fibers. Polym.Eng.Sci, Vol. 15, Issue 9, pp.660-667. 

Gulgunje P, Bhat G, Spruiell J. Structure and properties development in poly(phenylene sulfide) fibers, Part I effect of material and melt spinning process variables. J Appl Polym Sci 2011 122(5) 3110-21. 

Figure 1 provides a simplified process schematic. An excellent general reference on fiber spinning is A. Ziabicki, Fundamentals of Fiber Formation, Wiley, New York (1976). ISBN 0471982202. A classic article which emphasizes structure development during melt spinning is J.R. Dees and J.E. Spruiell, 7. AppL Polym, ScL, 18, pp. 1053-1078 (1974). 

Nadella, H., Henson, H.M., Spruiell, J.E. and White, J.L. (1977) Melt spinning of isotactic polypropylene structure development and relationship to mechanical properties.. Appl. Polymer Sci., 21, 3003-22. 

Samon J M, Schultz J M, Hsiao B S, Seifert S, Stribeck N, Gurke I, Collins G and Saw C (1999) Structure development during the melt spinning of polyethylene and poly(vinylidene fluoride) fibers by in situ synchrotron small- and wide-angle X-ray scattering techniques, Macromolecules 32 8121-8132. 

Swierenga and co-workers [79,80] in two articles described in detail their development of the calibration model used for PET measurements. Van Wijk et al. [72] summarized from their work that Raman spectroscopy can be used for determining the dye uptake or measuring one or more structural parameters or mechanical properties of polymeric fibers. Based on the results of their work, the authors stated that Raman spectroscopy was useful for studying melt-spinning thermoplastics, such as polyester, polyamide, polyolefins, and alternating copolymers of carbon monoxide and olefins so-called polyketones and, in addition, for polymers which are spun from solution such as cellulose, aromatic polyamides, polyketones, aromatic polyesters, and polyolefins. 

The work on auxetic polymers arising from microporous structure has continued. Aider-son et al. [120], in an attempt to produce auxetic material in a more easily usable form, have used melt-spinning to produce auxetic polypropylene fibres. This work was developed further, by way of a study of the processing parameters for melt-spinning of auxetic polypropylene, polyester and nylon fibres [121]. Ravirala et al. [122] have produced auxetic polypropylene film using melt extrusion. Less conventionally, Alderson et al. [123] have produced auxetic polyethylene by a combination of powder compaction and sintering, without an extrusion step. 

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