Abstract
Findings of theoretical and experimental researches on the winding yarn cnrves around the weft pirns are reported.
The displacement Z of the contact point between yarn and pirn or yarn layer surface along the pirn's central axis is calculated by the following equation;
where, form of pirn or yarn layer is cylindrical, spindle, revolving speed is constant and traversing motion of yarn guide is expressed by A (1-cosKw).
w: revolving angle of the spindle
r: radius of the cylindrical pirn or yarn layer
d: distance between the pirn or yarn layer surface and traversing yarn guide
A: amplitude of a traverse
K: speed ratio between the traverse motion and spindle revolution
If the pirn or yarn layer is conical form;
where r: mean radius of the pirn or yarn layer
In the equations (1) and (2) above, the first term expreses the traverse motion and the second term expreses the deflection between the yarn motion around the pirn and the yarn guide motion.
It is noted that the focuses of the weft yarn curves around the pirn obtainied by the experimental method almost coincide with the calculation by the equations (1) & (2), and the larger d and K are the large becomes the deflection between the yarn motion around the pirn and the yarn guide motion.
