ABSTRACT
I. Introduction ................................................................. 684 II. Semicrystalline Hot Compaction Research
Studies.......................................................................... 686 A. Polyethylene...................................................... 686 B. Polypropylene.................................................... 699
C. Polyesters .......................................................... 704 1. Polyethylene Terephthalate
(PET).................................................... 704 2. Polyethylene Naphthalate.................. 710
D. Nylon 66 ............................................................ 712 E. Other Semicrystalline Polymers:
Polyetheretherketone (PEEK), Polyphenylene Sulphide (PPS) and Polyoxymethylene (POM)................................. 714 1. Polyphenylene Sulphide (PPS) .......... 714 2. Polyetheretherketone (PEEK)............ 715 3. Polyoxymethylene (POM) ................... 716
III. Conclusions .................................................................. 716 Acknowledgments................................................................. 721 References............................................................................. 722
I. INTRODUCTION
The hot compaction of oriented fibers to produce large section products brings together two research themes that have been pursued at Leeds University for many years. First, there is the development of manufacturing procedures for high stiffness and high strength oriented polymers [1]. The routes chosen by Leeds have always involved deformation in the solid state either by tensile drawing
[2] or die drawing [3] to very high draw ratios or by hydrostatic extrusion [4]. These developments have been matched by similar developments elsewhere, notably the gel spinning process invented by Smith and Lemstra [5] for high strength polyethylene fibers and the extensive studies of Porter and Weeks [6] using ram extrusion to produce very high stiffness and strength oriented polymers. Second, at Leeds there has been a program of research devoted to studies of oriented fiber composites, where the fibers have been either glass, carbon or high modulus polyethylene fibers [7].
