In the previous papers, the authors statistically analyzed the short term thickness irregularity and blend ratio irregularity caused by drafting process.
This paper has statistically analyzed the tensile properties of blended yarn which has irregularities of yarn thickness and blend ratio with the following results:
1. A mechanical model of blended yarn has been obtained.
2. Probability density function of the strain under a given tension has been deduced based on the model.
3. Probability density function of the strength has been deduced based on the model.
4. With the increase in the thickness irregularity and blend ratio iregularity of blended yarn, the mean value and standard deviation of the strain increase. The influence of the thickness irregularity on the strain has been greater than that of the blend ratio irregularity.
5. With the increase in thickness irregularity and blend ratio irregularity, the mean value of strength decreases and the coefficient of variations in strength increases.

View full abstract

The purpose of this article is to develop a utilized device for preventing the thick and thin places in fabrics with the aid of the theoretical and experimental results obtained in previous reports.
The ability of the developed device has been looked into with the following results:
(1) The warp tensioning device comprising a whirl spring has a higher ability than that of the coiled spring system.
(2) The following two kinds of preventive devices against “set mark” have neen manufactured. One is of (i) the restraint type which restrains the tension roller only when the loom starts or stops; and or which does not restrain it only when the loom starts or stops. The other is of (ii) the contsraint type which pulls the easing roller positively only when the loom starts or stops.
(3) The devices showed a high degree of ability to prevent the “set mark” on the loom in which the shedding time is at top center or front dead center.
(4) The “set mark” on the water jet loom is not only caused by the difference in tension curve between the stop and start and the stationary running state, but also by the difference in the bending of the race. The latter has a greater influence.
(5) The device on the water jet loom is in principle based on the restraint type which is usable on the automatic cotton loom. It can satisfactorily eliminate the “set mark” caused by the difference in tension curves between the stop and start and the stationary running state.
(6) The compensating device for the pick spacing by pushing the pedal is useful for relieving the “set mark” caused by the difference in the values of the bending of the race.

View full abstract