US3887070A

US3887070A - Package of crimped thermoplastic synthetic yarns and method of winding up same

Info

Publication number: US3887070A
Application number: US397358A
Authority: US
Inventors: Koji Tajiri; Fumio Nagatoshi; Masateru Terano
Original assignee: Teijin Ltd
Current assignee: Teijin Ltd
Priority date: 1972-09-18
Filing date: 1973-09-14
Publication date: 1975-06-03
Anticipated expiration: 1992-06-03
Also published as: CA1008433A

Abstract

A package of crimped thermoplastic synthetic yarns, and especially the polyamide type synthetic yarn, which can provide excellent knit or woven fabrics without the formation of streaks, regardless of the conditions of the winding atmosphere or the knitting or weaving atmosphere. This package has either a winding hardness of above 70* when the moisture content at its inner layered portion is less than the equilibrium moisture content at the humidity of the knitting or weaving atmosphere or a winding hardness of less than 70* when the moisture content at its inner layered portion is greater than the equilibrium moisture content at the humidity of the knitting of weaving atmosphere.

Description

United States Patent Tajiri et al. [45] June 3, 1975 PACKAGE OF CRIMPED THERMOPLASTIC 2,325,127 7/1943 Gladding 242/159 SY IC YARNS AND METHOD 3,450,371 6/1969 Phillips 242/159 WINDING UP SAME P E G E L rzmary xammer eorge owrance [75] Inventors 6 i Fumlo l s Assistant ExaminerDouglas B. Farrow asateru cram of Mlhara Attorney, Agent, or F irm-Sherman & Shalloway Japan [73] Assignee: Teijin Limited, Osaka, Japan [57] ABSTRACT [22] Filed: Sept. 14, 1973 A package of crimped thermoplastic synthetic yarns, 7 I and especially the polyamide type synthetic yarn, [J] Appl' 397358 which can provide excellent knit or woven fabrics without the formation of streaks, regardless of the [30] Foreign Application Priority Data conditions of the winding atmosphere or the knitting Sept. 18,1972 Japan 47-92847 Weaving atmosphere- This Package has either a Nov. 1, 1972 Japan 47-10879 Winding hardness of above when the moisture tent at its inner layered portion is less than the equilib- 52 U.S. c1 206/392; 242/159 hum moisture Content at the humidity of the knitting 51 Int. Cl 865d 65/16; 865d 85/04 or weaving atmosphere a Winding hardness Of less 58 Field of Search 206/392 497- 242/159 than when the moisture comer" at its inner ered portion is greater than the equilibrium moisture 56 References Cited content at the humidity of the knitting of weaving at- UNITED STATES PATENTS mosphere' 1,996,791 4/1935 Blake 222/159 6 Claims, 3 Drawing Figures RELATIVE HUMIDITY OF KNITTING OR WEAVING ROOM 6O RH C) 4O RH CRIMP DEVELOPMENT RATE 1%) 8 %RH %RH 1 G UMI ITY WINDN H 0 TOVORH %RH O 0.1 0.2 0.3 0.4 0.5 0.6 0.7

WINDING TENSION /de) PATEIIIEIIIIIII 3 I915 3,887,070

RELATIVE HUMIDITY OF KNITTING OR WEAVING ROOM 60 %RH (20C) -WINDING TENSION /de) CRIMP DEVELOPMENT RATE (70) 0 Fig. 2A Fig. 25

PACKAGE OF CRIMPED THERMOPLASTIC SYNTHETIC YARNS AND METHOD OF WINDING UP SAME This invention relates to a package of crimped thermoplastic synthetic yarn and, in particular. to a package whose hardness has been controlled in accordance with the moisture content of the yarn contained at the inner layered portion of the package to prevent the formation of streaks in the knit or woven fabrics made from the foregoing crimped yarn. The invention also relates to a method of winding up such a package.

Heretofore, in winding up crimped thermoplastic synthetic yarns onto a package, for the mere reason that when crimped yarns that have been imparted crimp by such mechanical means as the false twist crimping treatment or the stuffing crimping treatment or other means are held under high tension their crimp properties usually decline, with the consequence that the crimp properties imparted during the crimping treatment are not fully demonstrated, the usual practice was to wind up the yarn at a low tension ranging from several milligrams per denier to several tens of milligrams per denier to obtain a package of low hardness ranging between 30 and 60 (the hardness as specified by the .118 Method K6301).

However, in the case of this type of conventional package, there is the drawback that in making knit or woven fabrics by unwinding the package difficulty is experienced in obtaining knit or woven fabrics having a satisfactory hand (properties such as surface evenness and fitting property), since streaks would form in the fabric due to irregularity of the crimp development property of the crimped yarn, or the crimped yarn would not demonstrate the desired value as regards its rate of crimp development. As regards the irregularity of the crimp development property, this can be solved to a certain extent by making the atmosphere at the time of the windup of the package and that at the time of the knitting or weaving operation (especially their humidity) about the same. However, as a practical mat ter, while it would be possible to adjust the humidities of the yarn processing plant and the knitting or weaving plant in a rough manner, to make these humidities substantially the same would be extremely costly. Further, the adjustment of such other factors as weather or climate would be practically impossible. Again, the conventional package has such additional shortcomings as that its properties exhibit great changes depending upon the type of atmosphere it has been left to stand in, or that its unwinding property is poor. Hence, various troubles are caused by such a package during'the time of its knitting or weaving.

SUMMARY OF THE INVENTION A primary object of the present invention is therefore to provide a package of crimped thermoplastic synthetic yarn not having the drawbacks of the conventional package, such as hereinbefore noted, as well as a method of winding up such a package thereby making it possible to make knit or woven fabrics without streaks and of satisfactory hand.

Another object of the invention is to provide a package of crimped thermoplastic synthetic yarn in which there is no irregularity of crimp development property regardless of the differences between the humidity of the atmosphere at the time of the windup of the package and the humidity at the time of the knitting or weaving operation.

A still another object of the invention is to provide a package of crimped thermoplastic synthetic yarn which is not substantially affected by the atmosphere in which it is left to stand.

A further object is to provide a package of crimped thermoplastic synthetic yarn which demonstrates smooth unwinding properties during the time of the knitting or weaving operation.

In general, the rate of crimp development of a package of crimped thermoplastic synthetic yarns, and espe cially the polyamide type crimped synthetic yarn, varies depending upon the windup conditions (especially the tension at the time of the windup), as hereinbefore noted, as well as the atmospheres at the time of the windup and at the time of the knitting or weaving of the fabric (especially the humidity of the atmospheres).

As a result of our detailed researches as to what effects the tension at the time of the windup and the humidities at the time of the windup and at the time of the knitting or weaving operation would have on the rate of crimp development of the crimped yarn, as well as our recognition that the irregularity of the rate of crimp development is based on the difference in the moisture content of the crimped yarn between the inner layered portion and the outer layered portion of the package, we found that if the tension at the time of the wind-up is adjusted to a prescribed value the irregularity of the rate of crimp development could be eliminated and at the same time the desired rate of crimp development could be obtained even though there is a difference between the humidity at the time of the windup and either the humidity at which the yarn was left to stand or the humidity at the time of the knitting or weaving operation.

Thus, there is provided according to this invention a package of crimped thermoplastic synthetic yarn which is characterized in that the package either has a winding hardness of to when the moisture content of the yarn at the inner layered portion of the package is less than the equilibrium moisture content at the relative humidity of the atmosphere to be used at the time of the knitting or weaving operation or has a winding hardness of less than 70 when the moisture content of the yarn at the inner layered portion of the package is greater than the equilibrium moisture content at the relative humidity of the atmosphere to be used at the time of knitting or weaving operation.

There is further provided according to this invention a method of winding up a package of crimped thermoplastic synthetic yarn, the method comprising either winding up the yarn at a winding tension of at least 0.15 gram per denier while adjusting the relative humidity of the winding atmosphere at below the relative humidity of the atmosphere to be used at the time of the knitting or weaving operation or winding up the yarn at a winding tension less than 0.15 gram per denier while adjusting the relative humidity of the winding atmosphere at above the relative humidity of the atmosphere to be used at the time of the knitting or weaving operation.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully described hereinafter with reference being had to the accompanying drawings, in which:

FIG. 1 is a graph showing how changes take place in the rate of crimp development depending upon the winding tension and the winding humidity; and

FIGS. 2-A and 2-B are schematic views illustrating the forces that act on the yarn when a false twist formed crimped yarn wound up on a pirn package is being unwound from the package.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The moisture content of a thermoplastic synthetic yarn, and especially the polyamide type synthetic yarn, usually changes in accordance with the humidity of its surrounding atmosphere. In the case of a wound package, the outer layered portions (i.e., the peripheral portion, and in the case of the pirn package, the tapered portion, or in the case of the cheese package, the two end portions) achieve an equilibrium moisture content corresponding to the relative humidity of the atmosphere surrounding the package while, on the other hand, there is practically no change in the moisture content of the inner layered portion of the package, a moisture content corresponding to the relative humidity at the time of'the windup being maintained over a prolonged period of time. Hence, a difference occurs in the moisture contents of the inner layered portion and the outer layered portion of the package in correspondence with the difference between the relative humidity of the atmosphere surrounding the package, generally the atmosphere at the time of the knitting or weaving operation, and the relative humidity at the time of the windup. An example will be given for explaining this difference in moisture contents. When a denier 6 filament yarn of nylon is submitted to a false twist treatment in which the number of false twists is 6000 T/m and heat-setting temperature is 180C, following which the yarn is wound up on a pirn, this yarn has a moisture content of about 3.0 percent. Now, when this package is left standing in an atmosphere of 20C. and relative humidity of 65 percent, the moisture content of the inner layered portion of this package shows practically no change, but the outer layered portion (i.e., the peripheral and tapered portions) changes to an equilibrium moisture content relative to the atmosphere in which it is left standing of 4.2 percent.

The moisture content is obtained in the following manner. After sampling about 5 grams of the yarn, its weight W is determined, following which the yarn is air dried for 3 hours at 105C. The dried yarn is then cooled in a desiccator, after which its weight W is determined. The moisture content is then calculated as follows:

Moisture content W W /W X 100 (percent) In the case of the polyamide type crimped synthetic yarn, the rate of column development at the time the package is being unwound, as hereinafter fully described, becomes smaller at that portion where the moisture content is high as compared with that portion where the moisture content is low. Hence, in the case such as hereinabove described, the rate of crimp development of the crimped yarn of the tapered portion of- By the expression inner layered portion" of the package, as used herein, is meant the crimped yarn layer portion located at a depth of at least 2 centimeters from the surface of the package, while-the expression outer layered portion of the package denotes that portion located within 5 millimeters of the surface of the package.

While the rate of crimp development of the crimped yarn varies depending upon its moisture content as hereinbefore noted, it also is greatly influenced by the winding tension that is applied during the windup as explained hereinafter by reference to FIG. 1.

FIG. 1, wherein the winding tension is represented as abscissa and the rate of crimp development is represented as ordinate, graphically shows the changes in the rate of crimp decelopment when the moisture content and the winding tension (and hence the hardness of the package) are varied, the moisture content of the crimped yarn being varied in this case by varying the humidity surrounding the crimped yarn (either the humidity of the winding atmosphere or the humidity at which the package is left to stand). The rate of crimp development shown in FIG. 1 was obtained in the following manner. That is, the wound package was left to stand for about two weeks to stabilize its moisture content and tension. The crimped yarn was then sampled from the package onto a reel of about 40-cm size under a tension of 0.15 gram per denier at a temperature and humidity corresponding to the atmosphere that would be encountered during the knitting or weaving operation, the size of the sample crimped yarn being made about 1000 denier. The sample was then applied a load of 2 mg per denier and the length of the hank l was measured 2 minutes later. A further load of 0.1 gram per denier was applied, and the length of the hank 1,, was measured 2 minutes later. The rate of crimp development was then calculated as follows:

Crimp development rate Z l/l X 100 (percent) The rate of crimp development obtained in this manner corresponds satisfactorily with the amount of crimp that develops during the knitting or weaving operation. When the dispersion of this value exceeds 10 percent, it was found that streaks would form in the knit or woven product.

When a detailed examination of FIG. 1 is made, the following facts are revealed. First of all, it was considered that the rate of crimp development would decline when the yarn was wound up under high tension, and hence it was the practice to carry out the winding at a low tension of several mg per denier to several tens of mg per denier to obtain a package of low hardness, i.e., one having a hardness of 30 to 60 (a value determined with a spring type rubber hardness meter as specified by the .IIS Method K6301). However, it can be seen that there was rather a decline in the rate of crimp development with such a low tension and it is seen that contrary to the experience there is surprisingly an increase in the rate of crimp development when the hardness of the package was made more than by winding up the package at a high tension of above 0.15 gram per denier. To be sure, as can be seen from FIG. 1, a large rate of crimp development is also demonstrated when the winding tension is a very low value of close to zero, but as a practical matter in the case of a low tension such as this the winding density becomes exceedingly small and the package would collapse during high tension is conceivably clue to the fact that the fi- 7' bers shrink at low tension and the shrinkage acts to decrease the curvature of the crimps, whereas at high tension, the shrinkage is not permitted and with stretching of such a degree, there is a complete elastic recovery.

Accordingly, when the windup is carried out at low tension, crimps are not developed during weaving or knitting to worsen the stretchability and surface eveness, whereas in the high tension windup, crimps are well developed during weaving or knitting to improve the stretchability and surface eveness of the resulting woven or knitted fabric.

Next, referring to FIG. 1, an examination of the relationship between the winding humidity of the crimped yarn (and hence its moisture content) and the rate of crimp development will be made. In the first place, it can be seen that the lower the winding humidity, the higher the rate of crimp development that is obtained. This is conceivably due to the following reason. When the crimped yarn is one whose moisture content is lower than the equilibrium moisture content relative to the knitting or weaving atmosphere, the yarn on becoming free as a result of having been unwound from the package absorbs moisture at the same time. Now,

the plasticizing effect of this moisture has a promotional effect on the release of the tension, with the consequence that the development of crimps is enhanced. On the other hand, in the case of a crimped yarn having a higher moisture content than the equilibrium mois ture content relative to the knitting or weaving atmosphere, the yarn on becoming free as a result of having been unwound from the package discharges moisture, with the consequence that the plasticizing effect due to the moisture is lost and hence the development of crimps becomes less.

On further examination of FIG. 1, the following fact will become apparent. That is, in the case where the winding humidity is greater than the knitting or weav ing humidity (i.e., where the moisture content of the crimped yarn is greater than the equilibrium humidity relative to the knitting or weaving atmosphere), if the windup is carried out at a tension less than 0.15 gram per denier, there is an area where fluctuations in the rate of crimp development ascribable to the difference of the moisture content of the crimped yarn are exceedingly small.

Further, when the winding humidity is less than the knitting or weaving humidity (i.e., where the moisture content of the crimped yarn is less than the equilibrium moisture content relative to the knitting or weaving at: mosphere), quite a contrary phenomenon occurs, and it is seen that when the windup is carried out at a tension of above 0.15 gram per denier, and preferably above 0.25 grams per denier, fluctuations in the rate of crimp development ascribable to the difference of the moisture content of the crimped yarn are slight.

These tendencies, as seen in FIG. 1, were substantially the same even when the relative humidity of the knitting or weaving room was varied.

The fact that the difference in the rate of crimp development ascribable to the difference of moisture content is slight means that the allowable range of fluctuations in relative humidity at the time of processing becomes wide, and moreover, even though a difference in the moisture contents between the inner layered portion and the outer layered portion of a package occur, i.e.,:even though there is a difference in the winding humidity and the knitting or weaving humidity, since there is only a slight difference in the rate of crimp development, there is no formation of irregularties in the knit or woven product.

When the foregoing observations in connection with FIG. 1 are coordinated, an appreciation of the followingfacts will be had.

1. When the moisture content of the inner layered portion of the package (this corresponds to the winding humidity) is adjusted at less than the quilibrium moisture content relative to the knitting or weaving atmosphere (this corresponds to the knitting or weaving humidity) and the crimped yarn is wound up at a winding tension of above 0.15 gram per denier, and preferably above 0.25 gram per denier, to obtain a package having a hardness of at least 70, and preferably at least 80, not only can the rate of crimp development be enhanced, but also its difference ascribable to the difference between the winding humidity and the knitting or weaving humidity can be reduced. However, if the winding tension employed is too great, plastic deformation will be set up in the crimped yarn as a result of its elastic limit being exceeded. Hence, the upper limit of the winding tension should preferably be set at 1.0 g per denier, preferably 0.7 gram per denier.

2. When the moisture content of the inner layered portion of the package is adjusted at above the equilibrium moisture content relative to the knitting or weaving atmosphere and the crimped yarn is wound up at a winding tension less than 0.15 gram per denier to obtain a package having a hardness of less than 70, the rate of crimp development is small but the fluctuations in the rate of crimp development ascribable to the difference between the winding humidity and the knitting or weaving humidity can be made very small.

Hence, it will be seen that, provided'the package is either one in which the moisture content of the inner layered portion is less than the equilibrium moisture content at the relative humidity of the knitting or weaving atmosphere and which has a winding hardness of above 70, and preferably 80 to 95, or one in which the moisture content of the inner layered portion is above the equilibrium moisture content at the relative humidity of the knitting or weaving atmosphere and which has a winding hardness of less than 70, it is posi sible to make knit or woven products having no streaks.

Again, when a product having a high rate of crimp I development is desired from the standpoint of its hand,

etc., it is possible to form a package that can make the desired knit or woven product by adjusting the humidity of the winding atmosphere at less than the humidity of the knitting or weaving atmosphere to be used and winding up the yarn at a winding tension of above 0.15

the atmosphere at the time of winding of the package, the moisture content of the fibers at the outer layered portion of the package changes to that determined by the humidity of the atmosphere at which the package is left to stand. Hence, the outer layered portion of the package is adversely affected depending upon the conditions at which it is left to stand from the time of its winding to the time it is used in the knitting or weaving operation, with the consequence that there arises the possibility of causing the formation of streaks in the knit or woven product.

It is thus preferred that the package, after its formation, be hermetically packed with a moistureimpermeable material under an atmosphere identical to that under which the package was formed, thus ensuring that the outer layered portion of the package is not affected by the atmosphere at which the package is left to stand.

As the procedure to be used for accomplishing this hermetical packing, that of fuse-sealing the package using as the moisture-impermeable material a thermoplastic polmeric material such as polyethylene or polypropylene is preferred. However, good results are had even by such a procedure as placing the package in a bag prepared from a moisture-impermeable material and closing the opening of the bag with a rubber band or the like.

Now, of the crimped thermoplastic synthetic yarns, the false twist crimped yarn which has been imparted crimps by false twisting, as a finished yarn of greatest versatility at the present time, is being used in various areas such as for outer garments, underwear, socks and womens hosiery, panty hosiery, etc., but this false twist crimped yarn possesses torques as well as crimps as an inevitable result of the principles by which the crimping process operates. At times, troubles are experienced during the unwinding of the package on account of this torque. This will be explained by reference to FIG. 2-A. FIG. 2-A illustrates the case of a pirn package that has been wound up in the Z direction by imparting a true twist to the false twist crimped yarn having an S twist. As shown in FIG. Z-A, the yarn receives at the unwinding point 1 a force A upwardly of the bobbin as a result of the unwinding operation. On the other hand, the yarn possesses a torque due to the falst twist, as noted above. Since the package has been wound up in the Z direction by imparting a true twist to the crimped yarn having a falst twist in the S direction, this torque has a force B which rolls in an upward direction over the surface of the pirn package. Hence, the force A resulting from the unwinding and the sorce B ascribable to the torque act in substantially the same direction to cause not only an excessive unwinding of the yarn but also a slipping off of the yarn from the tapered portion in the form of a loop, after which this loop becomes entangled as a result of the torque. This entanglement then either gets introduced into the knit or woven fabric before it has been unravelled to greatly impair the quality of the fabric or becomes caught on the needles or other parts of the knitting or weaving machine to cause yarn breakage. This tendency is especially marked when the unwinding point 1 has arrived in the vicinity of the upper tapered portion of the package.

FIG. 2-B illustrates the case of a pirn package consisting of false twist crimped yarn of S twist which has been wound up by rotating the bobbin in the S direction. When this package is being unwound, the yarn receives at its unwinding point a force C in the upward direction of the bobbin. On the other hand, the torque ascribable to the false twist and having a rolling force in the S direction comes to have in the case of this package of FIG. 2-8 a force D rolling over the surface of the package towards the bottom of the bobbin. Since the forces C and D act against each other, these force offset each other, with the consequence that troubles such as occur in the case of the package shown in FIG. 2-A do not arise.

Thus, it will be appreciated from the foregoing discussion that in the case where a false twist crimped yarn having torque is to be wound up on a package it is preferred that the winding is carried out such that the torque acting on the yarn as a result of the false twist becomes at the unwinding point a force rolling in a direction opposite to that of the force acting on the yarn as a result of the unwinding of the yarn.

While the case of a pirn package has been illustrated and explained, the foregoing explanation also apply equally to the case of such other packages as the cheese and cone packages. However, since, in the case of the pirn package, there is a recessed portion at the bottom of the bobbin for engaging, say, the spindle of a ring twisting apparatus, or there is a protector covering the exposed meltallic part, or the yarn end for which the winding step was started remains, difficulty is experienced in unwinding the yarn towards the bottom of the bobbin axis, and thus the unwinding is usually carried out towards the upper part of the bobbin axis. Hence, in the case of the pirn package, for achieving a smooth unwinding of the yarn as hereinabove described, it is necessary to carry out the winding of the yarn by rotating the bobbin. in the same direction as that used in false twisting the yarn in the crimping treatment.

EXAMPLE 1 A 20 denier/6 filament drawn yarn of nylon 6 was imparted crimps by the conventional crimping process, after which the yarn was wound up by varying the windmg tensions as well as the relative humidities of the winding chamber to prepare several packages having inner layered portions of varying moisture contents. These packages were left standing for over a day in knitting rooms of varying relative humidities to prepare several classes of packages whose inner layered portions and outer layered portions had varying moisture the other hand, the symbol A denotes that the surface evenness is intermediate between that of the symbol 0 and that of the symbol X. The fitting property is evaluated by the length of the stocking immediately after its knitting, as measured from below the welt of the thigh portion to the toe. The shorter this length is, the more 7 satisfactory is the fitting property. The moisture content was determined in. the following manner. A given amount of the sample is taken and weighed (W following which the sample is dried for 3 hours at C.

and thereafter cooled for 40 minutes in a desiccator containing silica gel. The sample is then weighed (W again, and the moisture content is calculated as follows:

Moisture content W W- ,/W X 100 (percent) On the other hand, the package hardness was determined with a spring type hardness tester Model A in accordance with the 11S Method K6301. The results obtained are shown in Table 1.

fect that the surface unevenness and fitting property are reduced.

Furthermore, as is seen by comparing Sample No. 10 with Samples Nos. 11 and 12, when the hardness is above 70, and the inner layer moisture content is less than the moisture content ofthe outer layer. streaks are scarcely formed even if the moisture content of the Table 1 Winding Knitting Moisture content chamber Winding room lnner Outer Length of Sample humidity tension humidity Hardness layered layered Surface stocking Presence No. (RH (g/de) (RH (C.) portion portion eveness (mm) of streaks l 49 0.04 64 60 3.0 4.2 X 610 Yes 2 49 0.15 64 75 3.0 4.2 O A 560 No 3 49 0.35 64 85 3.0 4.2 O 510 No 4 49 0.5 64 95 3.0 4.2 O 490 No 5 68 0.03 49 60 4.5 3.0 X 710 No 6 50 0.04 49 60 3.0 3.0 X 660 No 7 69 0.3 49 85 4.5 3.0 X 630 Yes 8 62 0.4 44 90 4.0 2.6 X 640 Yes 9 56 0.4 56 90 3.5 3.5 A- O 580 No 10 49 60 0.4 64 90 3.0-3.8 4.2 O 520 No 1 l 68 79 0.4 64 90 4.5-5.3 4.2 A 600 Yes 12 49 60 0.04 64 60 3.03.8 4.2 X 640 Yes 13 68 79 0.03 64 60 4.55.3 4.2 X 700 No In the first place, it is seen from Table 1 that in the case of the stockings knit from a package having a hardness of above 70 and in which the moisture content ofthe inner layered portion (the equilibrium moisture content relative to the humidity of the winding chamber) was less than the moisture content of the outer layered portion (the equilibrium moisture content relative to the humidity of the knitting or weaving room), i.e., packages in accordance with the present invention (Samples 2, 3, 4, 9 and 10), the hand (surface evenness and fitting property) was satisfactory and, in addition, no streaks were present. Next, in the case of the stockings knit from a package having a hardness of less than 70 and in which the moisture content of the inner layered portion was less than that of the outer layered portion (Samples 1 and 12), the formation of streaks was noted. On the other hand, in the case of the stocking knit from the package having a hardness of above 70 and in which the moisture content of the inner layered portion was greater than the outer layered portion (Samples 7, 8 and 1 1), it can be seen that the product was slightly inferior with respect to both its hand and presence of streaks.

Packages (Samples No. 5, 6 and 13) having an inner layer moisture content greater than the outer layer moisture content and a hardness of not more than 70 have difficulty of developing streaks, but there is a deinner layer, namely the windup humidity, fluctuates to some degree.

EXAMPLE 2 The false twisting treatment of a 64 denier/6 filament undrawn yarn of nylon 6 was carried out under the conditions of false twists numbering 6200 T/m and a heater temperature of 185C, using a drawing and frictional type false twister. In carrying out this false twisting treatment, the winding tension at the time of the 0 portion. The so obtained samples having varying moisture contents and winding tensions were left to stand for at least one day in knitting rooms of given relative humidities and percent) and were thus conditioned so that there would be a difference in the mois- 45 ture contents of the inner layered and outer layered portions of the pirn. The so prepared packages were then fed to a 4-feeder seamlessstocking knitting machine in an atmosphere identical to that at which they were left to stand. The stocking obtained from these 50 packages were then examined for streaks, with the results shown in Table 2. The moisture content and hardness were determined as in Example 1.

Table 2 Winding Knitting Moisture content chamber Winding room lnner Outer Presence Sample humidity tension humidity Hardness layered layered of No. (RH (g/de) (RH (C.) portion portion streaks l 0.07 64 62 4.2 4.2 No 2 0.07 64 63 4.6 4.2 No 3 0.07 64 65 5.3 4.2 No 4 50 0.07 64 63 3.1 4.2 Yes 5 40 0.07 64 61 2.3 4.2 Yes 6 65 75 0.3 64 4.3 5.0 4.2 Yes 7 66 75 0.06 64 60 4.3 5.0 4.2 No 8 65 0.1 54 66 4.2 3.4 No 9 55 70 0.1 54 67 3.54.6 3.4 No 10 40 0.1 54 66 2.3 3.4 Yes 11 50 40 0.1 54 68 3.1 2.3 3.4 Yes [2 55 70 0.4 54 2 3.5 4.6 3.4 Yes It is seen from Table 2 that stockings knit from packages having a hardness of less than 70 and in which the moisture content of the inner layered portion was greater than that of the outer layered portion, i.e., packages in accordance with the present invention, (Samples 1, 2, 3, 7, 8 and 9) had no streaks. On the other hand, in the case of the stockings knit from packages having a hardness of above 70 and in which the moisture content of the inner layered portion was greater than that of the outer layered portion (Samples 6 and 12) as well as the stockings knit from packages having a hardness of less than 70 and in which the moisture content of the inner layered portion was less than that of the outer layered portion (Samples 4, 5, l and l l it is seen that there were formations of streaks.

We claim:

1. A package of a crimped yarn of thermoplastic synthetic fibers, said package either being one having a winding hardness of above 70 when the moisture content of the yarn at the inner layered portion of the package is less than the equilibrium moisture content at the relative humidity of the atmosphere to be used at the time of the knitting or weaving operation or being one having a winding hardness of less than 70 when the moisture content of the yarn at the inner lay- 12 ered portion of the package is greater than the equilibrium moisture content at the relative humidity of the atmosphere to be used at the time of the knitting or weaving operation.

2. A package according to claim 1 wherein said crimped yarn of thermoplastic synthetic fibers is of a polyamide type synthetic fiber.

3. A package according to claim 2, said package having a winding hardness of above the moisture content of the inner layered portion of said package being adjusted such that it is less than the equilibrium moisture content at the relative humidity of the atmosphere to be used at the time of the knitting or weaving opera tion.

4. A package according to claim 3 in which the winding hardness of the package is from to 5. A package according to claim 2 wherein said package is hermetically wrapped with an impervious material.

6. A package according to claim 5 wherein said impervious material is a thermoplastic high molecular substance, said package being fuse-sealed by said material.

Claims

1. A package of a crimped yarn of thermoplastic synthetic fibers, said package either being one having a winding hardness of above 70* when the moisture content of the yarn at the inner layered portion of the package is less than the equilibrium moisture content at the relative humidity of the atmosphere to be used at the time of the knitting or weaving operation or being one having a winding hardness of less than 70* when the moisture content of the yarn at the inner layered portion of the package is greater than the equilibrium moisture content at the relative humidity of the atmosphere to be used at the time of the knitting or weaving operation.

3. A package according to claim 2, said package having a winding hardness of above 70*, the moisture content of the inner layered portion of said package being adjusted such that it is less than the equilibrium moisture content at the relative humidity of the atmosphere to be used at the time of the knitting or weaving operation.

4. A package according to claim 3 in which the winding hardness of the package is from 80* to 95*.

5. A package according to claim 2 wherein said package is hermetically wrapped with an impervious material.