Preparation of high-modulus and high-strength nylon-6 fibre by the zone-annealing method

In order to produce ultra-high strength fibre, a new method which was developed in our laboratory, called the zone-annealing method', has been applied to nylon-6. In spite of very simple apparatus and easy procedure, the dynamic modulus of the zone-annealed fibre was 10.8 × 10¹⁰ dyne cm^?2, which corresponds to 2.2–4.0 times that of the high-tenacity fibre available commercially. To elucidate the effectiveness of the zone-annealing process, the relationship between mechanical properties and superstructure of the fibre obtained has been investigated. It was found that the structure of the amorphous regions, especially the orientation of amorphous chains, played an important role in improving the mechanical properties. The principle and the characteristics of this method are also described in this paper.