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Studies on the orientation phenomena by fiber formation from polymer melts. Part I. Preliminary investigations on polycapronamide
Author(s) -
Ziabicki Andrzej,
Kedzierska Krystyna
Publication year - 1959
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1959.070020403
Subject(s) - spinning , velocity gradient , materials science , polymer , birefringence , orientation (vector space) , relaxation (psychology) , temperature gradient , deformation (meteorology) , fiber , melt spinning , composite material , mechanics , optics , geometry , physics , psychology , social psychology , mathematics , quantum mechanics
The problem of the mechanism of macromolecule orientation occurring in the formation of fibers from polymer melts has been qualitatively analyzed. As a result of birefringence, x‐ray, and spinning stress investigations carried out on polycapronamide fibers, the main parameters determining orientation have been established. They are the parallel velocity gradient along the spinning length, G = dV/dl , and the relaxation factors. The deformation ratio S (the ratio of final to original linear velocity), analogous to the draw ratio λ = 1/1 0 in the cold‐drawing process, has no influence on the degree of orientation. The orientation by spinning is not accompanied by any such structural transformations as occur through cold‐drawing. The fibers spun at high velocity gradients consist of well‐oriented β‐polycapronamide. It is thus assumed that the orientation proceeds in the region of the liquid melt‐stream as a result of simultaneous action of velocity gradient and thermal relaxation. This mechanism, analogous to that causing the familiar streaming orientation of polymer solutions in capillaries or in a Couette apparatus, is different in principle from that of the cold‐drawing process.