Effects of time-dependence on the fine structural change annealed at a constant temperature (85_??_115°C) under either a less load or a constant length, regarding the heating process as its base were investigated by measurements of X-ray, density and birefringence. And the mechanism of crystallization and the effects of orientation for various stretched P. E. T. fibers are discussed. The results obtained are as follows:
1) The (density_??_logarithmic time) curves of the various stretched fibers under a free contraction are shown as a sigimoid, and the time, when it starts to make a greater density suddenly, shifts towards shorter time as both draw ratio and temperatures of immersion bath increase. Corresponding to the time-dependence on density change, the birefringence of higher stretched fibers of more than draw ratio: 2.5 increases positive value with time, but that of lower stretched ones less than draw ratio: 2.0 show negative value, and their absolute values decrease with lowered draw ratio. Applied the Avrami's equation to the (density)_??_(logarithmic time) curves, Avrami's index (n) is 3 or 4 for lower stretched fibers; n equals to 1 or 0<n<1 for higher stretched ones, and constants of crystallization rate (k) become larger with increased draw ratio.
2) The (density_??_logarithmic time) curves of various stretched fibers undeer a constant length may be similar to its behavior under a free contraction and the time started in making greater density suddenly shifts towards further shorter time as compared with heating under a free contraction. The changes of birefringence with time may be similar to its time-dependence under a free contraction, except for 2.0 of a draw ratio. The sample of a draw ratio: 2.0 does not show negative birefringence under a constant length even though the density becomes greater and show a weakly positive birefringence. The Avrami's index (n) calculated from the (density_??_logarithmic time) curves under a constant length, may be generally smaller than that under a free contraction, and furthermore the constants of crystllization rate larger. These results may be due to the contribution of the thermal shrinking strss occured during the heating under a constant length.
3) The conversion in the signs of birefringence (either positive or negative) for stretched fiber of a draw ratio: 2.0, due to the different heated conditions may be explained by considering the rotative orientation of the (100) plane.
4) When the density, birefringence and logarithmic time curves for same fibers at a different temperatures are compared, it is found that master curves can be made of superposition by lateral shift along the lomarithmic time scale within temperatures of this experiment, independent of heated conditions. And it is found eviently from these master curves that a different heated conditions may affect time-dependence on birefringence for the stretched fiber of a draw ratio: 2.0, that is, the absolute values increase with time. While birefringence changes the negative value under a free contraction and the positive minimum value under a constant length, corresponding to the time started in making a sudden greater density and thereon.

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In order to investigate the effects of the drawing conditions (draw ratio and drawing temperatures) on the mechanical properties of hot drawn P. E. T. fiders in water with the different oriented properties of their crystallite, the measurement of stress-strain characteristics for these fibers was made at a constant rate of deformation. In addition, the temperature characteristic of dynamic modulus E' and loss modulus E' for these fibers, closely related with thermal molecular motion in the amorphous region, was obtained by mechanical tanδ meter of the direct reading type over the temperature range between 20°C and 180°C at a constant frequency of 106 c. p. s. The results obtained are as follows:
1) On the stress-strain curves of the drawn at 70°C and non-heated specimens, the flow part of molecular chain becomes longer with lowered draw ratio and the reinforcement effect due to the strain-crystallization begins to occur at higher strain. The lower stretceed and heated fibers with the folded chains crystallite become more brittle. Beyond the yield region, stress for the higher stretched and heated fibers increases in proportion to increased strain, and fibers break down.
2) The stress-strain characteristic of the drawn fibers (draw ratio: 2.0) at various temperatures of drawing bath varies according to the oriented properties of their crystallites, that is, the stress-strain behavior of the stretched fiber at 60°C becomes almost similar to that of the higher stretched at 70°C, and the stretched fibers at 80° or 90°C show same stress-strain behaviors as that of the lower stretched at 70°C.
3) Temperature of the loss perk α_a for lower stretched at 70°C and heated fibers shifts towards higher temperature with increasing draw ratio (107°C→114°C). Relation between temperature of α_a-absorption and draw ratio for the higher stretched fibers at 70°C shows the same tendency to the lower stretched ones (107°C→121°C). Their intensities of maximum absorption of loss modulus E''_max become higher with increased degree of crystallinity X_d due to the oriented effects of molecular chain in the amorphous region. There exists a point of the structural transformation in between 2.0 and 2.5 of draw ratio. While the values of E''_max for the lower stretched fibers do not scarecely change, as the contribution of amorphous birefringence Δn_a•(1-X) for these fibers increase, values of E''_max for the higher stretched ones become larger with increase of Δn_a•(1-X). The values of dynamic modulus E'at room temperature for various stretched fibers become higher with increased draw ratio. Beyond transition temperature of α_a-absorption, E' values at 140°C for the higher (draw ratio: 3.8) and the lower (draw ratio: 1.0) stretched fibers may be about 1/3 and 1/15 of E' at room temperature respectively.
4) While the values of E''_max for the stretched fibers with negative birefringence at higher temperature of drawing bath above 70°C become smaller in inverse proportion to the increased degree of crystallinity X_d, E''_max value for stretched fiber at 60°C with the fiber-like oriented properties becomes larger. The effects of drawing temperature on the relations of E''_max Δn_a•(1-X) and E''_max_??_Δn_c•X become the same in relation between E''_max and X_d.

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The lints among those separated objects of this classificatory action by pneumatical force under the taker-in cylinder are consisted of the same staple diagramatically to the lints contained in the waste under the taker-in part. And those are nearly similar to the lints contained in the waste by the flat bar part. Hence, the classification with the length of fiber as that of cage cylinder are not performed, but that with the terminal velocity are performed. The terminal velocity of lints contained in the waste under the taker-in part are more than 0.6-0.65m/sec at least, so those lints are limited to those adhered to the immature fiber, part of seed, etc. or a few lints mixed in trashes, except the unsatisfactory opened lints. Therefore, the loss of lint in this part are relatively very small to another parts, the effective cleaning ratio is maximum, and the most effective cleaning action is performed in this cleaning mechanism of the experimental card. And the decrease of waste in this part is not desirable since the quantity of waste in this part are offsets each other with those of the flat part, but it is more important from the view point of proper cleaning effect to classify impurities possible as much as by maintaing the pneumatical action to convey the lints that have the terminal velocity slower than 0.6-0.65m/sec.
To improve the composite cleaning action of this experimental card is to improve the more effective classificatory action at taker-in cylinder part. And the operating condition of this card to obtain the maximum effective cleaning ratio, is to decrease the loss of lints by increasing the quantity of lap feed, and to improve the efficiency of cleaning by multiplying the revolution of taker-in cylinder as much as possible. In addition it is more desiable to have suitable width between undersheet and taker-in cylinder to have minimum suction force by the cage blower to convey those lints, and to maintain the slower revolution of cage cylinder lest it obstructs to transfer those lints to the cylinder.

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The effects of heat-treatments of acrylic fibre on its fine structure have been investigated to discuss the relation between dyeing properties and fibre structure.
Samples of Orlon 42 were treated with hot water (100-150°C), steam (100-150°C), and hot air (100-200°C) without tension, and then their fine structures (orientation, crystal size and crystallinity) were checked by means of X-ray diffraction.
X-ray scattering intensities were measured with a Shimadzu diffractometer using Geiger counter and Cu K_a radiation.
The dynamic loss tangent was measured over a range of temperature from 20° to 170°C with a Toyo-Sokki dynamic viscoelastometer using 138 cps. And the temperature-range properties of Astrazon Blue FGL on the fibres were examined.
The results of measurements were as follows: The degree of orientation is decreased, the crystal size increased, and the crystallinity slightly increased by both the wet heat-treatment and dry heat-treatment.
Two loss tangent maxima occures at about 120°C and 135°C. The loss peak at 120°C may be due to the motion of segments in the amorphous region, and the other loss peak at 135°C may be due to the motion of segments in the intermediate region between crystalline and completely amorphous regions.
The heights of the loss peaks increases on wet heat-treatment, but decreases slightly on dry heat-treatment.
This may be explained by the conversion of some part of intermediate regions into amorphous. region on wet heat-treatment, and vice versa on dry heat-treatment.

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The effects of heat-treatments of acrylic fibre on levelness of dyeing have been studied.
1) Samples of Orlon 42 heat-treated by three methods (hot water, steam, and hot air) were dyed alongside untreated fibre in the same bath with cationic dye (polymethine, azo and anthraquinone derivative) and disperse dye (diphenylamine, azo and anthraquinone derivative) so that they would compete for adsorption of a limited amount of dye, and the colour difference was measured. The influence of chemical constitution and molecular size of dye on level dyeing of heat-treated fibres. are considered. The large dye molecules are very sensitive to the difference of heat-treatment temperature. The practical implications of the results are discussed.
2) On the other hand samples of Orlon 42 were treated with (a) steam_??_steam, (b) hot air_??_hot air, and (c) steam_??_hot air without tension, and then dyed alongside the untreated fibre in the same bath with cationic dye or disperse dye, and the color difference was measured. The rate of dyeing is determined by the highest tempratures of wet heat-treatment.

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