Premium
Preparation of ultradrawn polyethylene by a novel radial‐compression method
Author(s) -
Griswold Phillip D.,
Porter Roger S.,
Desper C. Richard,
Farris R. J.
Publication year - 1978
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760180618
Subject(s) - materials science , composite material , polyethylene , compression (physics) , ultimate tensile strength , cylinder , elastic modulus , polymer , modulus , radial stress , extrusion , deformation (meteorology) , engineering , mechanical engineering
High density polyethylene has been ultradrawn at 80°C by a novel radial–compression method which involves the gradual buildup of highly‐stretched elastic (spandex) filaments around the circumference of a solid polymer cylinder. The sheath of tightly‐wound filaments generates a high‐radial pressure which forces the polyethylene cylinder to neck down, uniaxially extend, and ultradraw. The physical and mechanical properties of radially‐compressed polyethylene of maximum draw ratio, 40‐45X, were evaluated and compared with the same polymer ultradrawn in other stress fields. In most physical property categories, the radially‐compressed samples are virtually indistinguishable from samples prepared by solid‐state extrusion at higher temperature and pressure. The transparency and the maximum tensile modulus, 62 GPa, further confirm the effectiveness of radial compression in achieving ultradraw. An experimental technique for measuring the radial pressure generated by the winding of the highly‐stretched elastic filament is presented. The upper‐bound pressure in the radial‐compression experiments was less than 100 MPa.