The research described was primarily concerned with working towards the solution of
the problem of yarn tension control when building conical packages on an open-end
spinning machine at yarn delivery speeds of 500 m1min"cause of the total lack of
published work on the mathematical modelling of the parameters affecting tension
variation, a considerable amount of effort was spent in the establishment of this basic
understanding. This mathematical analysis appears, in the main, in the appendices to
this thesis. In addition to the analysis of yarn tension variations depending on machine
geometry parameters, mathematical models have also been produced which predict
the effect on tension of fitting curved distribution bars of various shapes.
The work includes the development of concept ideas which appeared capable of
providing routes for solution of the tension control problem. These ideas were
evaluated and compared against a design specification which was also developed as
part of this research. Two promising concepts were selected for detailed investigation.
These were: a pneumatic passive compensator and, a positive mechanical
The pneumatic compensator was a novel idea which was conceived by the author, and
which eventually provided a solution which met the design specification in every way.
The mechanical compensator was shown to be a far less attractive concept with
several serious problems which have been explored but not eliminated. A preliminary
investigation of a third concept involving microprocessor control was not sufficiently
well developed at the time of publication to be included in this thesis.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.