BackTraditional and recently developed methods of staple spinning such as
ring, rotor, air Jet, friction and wrap spinning are
limited by high costs of production and/or versatility in terms of range of counts, staple
lengths an fiber types that can
be spun. However, of the recently developed technologies, air jet spinning appears to be
the most promising due to its
high rate of production and the range of counts that can be produced. Being a recent
invention, very little has been
published about the process, the yarn structure and the yarn properties. This study is
primarily devoted to investigating
the effect of process parameters such as the ratio of main draft to break draft and first
nozzle pressure (keeping total
draft and second nozzle pressure constant) on the structure and properties of air jet spun
yarns.
A method for characterizing the air jet spun yarn structure in terms of the component
fiber configurations has been
developed and used to study the effect of the ratio of drafts and the first nozzle
pressure on the structure. An attempt
has been made to relate the structure to yarn properties such as breaking load, breaking
elongation, hairiness and
evenness. It has been concluded that the ratio of drafts and first nozzle pressure
significantly affect the yarn structure
and, hence, the resultant yarn properties. In addition, a mechanism for the behavior of
air jet spun yarns during tensile
loading has been-proposed and the principle of false twisting has been used to explain the
formation of the yarn
structure.