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Studies on melt spinning. IV. Spinning through a ribbon die
Author(s) -
Han Chang Dae,
Lamonte Ronald R.,
Drexler Leonard H.
Publication year - 1973
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.1973.070170413
Subject(s) - birefringence , spinning , materials science , polypropylene , composite material , melt spinning , ribbon , optics , physics
An experimental study has been carried out to investigate effects of stretch ratio on molecular orientation in polypropylene monofilaments which are melt spun from a ribbon die into a water bath with an adjustable air gap distance between the two. By varying the air gap distance and the rate of stretching, a variety of filaments of different molecular orientations were obtained. Measurements were taken of fiber birefringence of finished filaments under a polarizing microscope with camera attachment and mercury lamp. It has been found, according to the already established relationship between the molecular orientation and birefringence, that the molecular orientation in polypropylene filaments is increased with the rate of stretching. Two other interesting observations were made. One was that the filaments form crimps whose frequency increases with the rate of stretching. The other was that the phenomenon of draw resonance was observed when the rate of stretching was increased beyond a certain critical value.