The relationships between drawing condition and the properties of textured yarn and between texturing condition and the properties of textured yarn are investigated.
High crimpable textured yarn can be obtained, when an original yarn is drawn at draw ratio of about 3.6, and at about 100°Cof draw temperature.
For this reason, it is considered that a fiber structure is favored to be made during texturing process, rather than during drawing process.
The tenacity of textured yarn does not change when drawing conditions (draw ratio and drawing temperature) change.
It is desirable for the properties of textured yarn (tenacity and crimpability) that the drawn yarn is textured at 180°C and at 3% over feed.
Chemical component of this fiber is polyamide, but the physical behavior of this fiber (eg. conditions of drawing, texturing, rate of crystallization etc.) is similar as that of polyester fiber.

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We made a study of the transfer function of drafting process, between fed and delivery sliver thickness, when the velocity-change-point and fiber-length density functions are no change with time.
Following results are obtained :
(1) The transfer function between fed and delivery sliver thickness is shown the following equation :G_ω(s)=f_c((D-1)/s/V_f)1-f(s/V_f)/1-f(s/V_b)e-lds/V_f where f_c (p) is Laplace transform of f_c (x), velocity-change-point density function, and f (p) is Laplace transform of f (l), fiber-length density function.
(2) We were able to lead the transfer functions for the wide shape of density functions using the Pearson Ist type curve for the velocity-change-point and fiber-length density functions.
(3) Comparing the transfer functions by Bode diagram to change the kurtosis and skewness of density functions, following results are obtained.
(i) The greater the absolute value of skewness and the smaller the kurtosis of the velocity-change-point density function, the more desirable the drafting process property is.
(ii) The smaller including sign the kurtosis and skewness of fiber length density function, the more desirable the drafting process property is.
(iii) The most desirable drafting process is found when two constants of the Pearson Ist type curve, m1 and m2 are following; in the case of the velocity-change-point density function (m1 =0, m2=0) or (m1=1, m2=1), fiber-length density function (m1 =0, m2=1).

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This article aims to prevent the noise of the textile machinery. An experiment has been made to investigate the generation mechanism of the impact noise caused by the textile machinery and by their gear systems. An attempt has also been made to prevent the propagation of the vibration into each machinery part. The following conclusions have been obtained: (1) The machinery mechanisms should be improved not to propagate the rapid variation of an acceleration and of a force.(2) Damping materials and lubricants ahould be used to reduce the mechanical vibration.(3) The vibration-proof isolators should be inserted between the vibration source and the machinery parts to prevent the propagation of vibrations into the machinery parts.

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This article aims to investigate experimentally the effect of knot's type and the length of knot's end on the occurring probability of knitting defects, ie., knitting holes and to discuss the breaking point of yarn on knitting holes. Experiments were made by knitting 1x1 rib with a circular knitting machine using 40s cotton yarn.
The following results are obtained:
1) Comparing with the single weaver's knots, round knots cause much more knitting holes and machine stoppings.
2) On knitting, the yarn having knots breaks at the knitting side of knots.
3) On the single weaver's knot, the occurring probability of knitting holes increases with increasing a length of knot's end and decreasing a stitch density of knitted fabric.
4) On both knots, the occurring probability of knitting holes increases with increaing the rpm of the machine up to about 17 rpm, but decreases at 18 rpm.
5) On both knots, the stopping probability of the machine is proportional to the occurring probability of knitting holes.

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