US2465130A - Method of setting twist in threads or yarns - Google Patents

Description

v March 22, 1949. T. H. STORY 2,465,130

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Arroz/wy Patented Mar. v2z, 1949 ME'monoFsE'r'rING TWIST rumanos oa YAaNs Theodore H. Story,

,Tof Delaware Merchantville, N. J., assigner to Radio Corporation of America, a corporation Application May 30, 1945, Serial No. 598,709

5 Claims. (Ci. 28-72) wound and this results in knots or the like which hinder the free use thereof. To overcome this dimculty, it has been proposed to set the balance or the twist by heating the yarn for from 2 to 6 hours, depending upon the particular thread or yarn involved, in humid atmospheres having a relative humidity of 70 per cent or higher. While such processing overcomes the aforementioned diiculty, it is quite time consuming and therefore a definite limitation upon the rate of production of the yarn or thread.

To increase the speed ofproduction of the yarn, it has been proposed to subject the same to treatment in a vacuum. In general, the time required to set the twist is thus cut down to the order of about a half hour after the proper vacuum has been obtained. However, a sizable amount of time is required to create the vacuum. to say nothing of the fact that the high pressure vessels, seals, pumps, and other components of the vacuum systems are quite expensive.

To overcome the foregoing objections, it has been proposed heretofore to place the yarn packages or cakes, as they are known, in wax paper or similar moistureproof bags or envelopes and to subject the packages or cakes to the iniluence of a high frequency electric field. This ileld vaporizes the residual moisture in the yarn (which may be of the order of 10 per cent to 14 per cent) and establishes a humid atmosphere within the bag. As the yarn package -cools in the presence of the expelled vapor, the twist therein sets more or less. However, this process requires individual handling and wrapping of each of the yarn packages and therefore renders the process expensive, particularly for small packages. Moreover, the wrapping of the individual packages sometimes presents a problem.

The primary object of my present invention is to provide an improved method of setting the twist or balance in yarn, thread or the like of dielectric material which will not be subject to the above mentioned diiculties.

More particularly, it is an object of my present invention to provide'an improved method oi setting the twist of yarns' of dielectric material which will require a much shorter time than is required by prior art methods.

It is also an object of my present invention to provide an improved method of setting the twist of thread, yarn, cord, and the like which can be carried out at relatively low cost and in a highly efficient manner.

In accordance with my present invention, I first subject that package of yarn or thread to a substantially uniform high frequency electric field which rapidly heats the dielectric thread substantially uniformly throughout until steam is generated uniformly throughout the entire yarn package. The package is then immediately placed in vessels or chambers having a highly humid atmosphere for suiiicient length of time to setthe twist. These vessels or chambers may be lled with live steam, for example. The time required to carry out the entire process will vary with the material being treated but' will, in all cases, be only about 10 per cent of that required to set the twist by steam alone. Thus, for example, in the case of rayon, the thread can be heated in about a half minute o r a minute to 212 F. by reason of the dielectric losses produced in the rayon to thereby vaporize the residual moisture therein, after which the hot package may be placed in a steam room for about, 10 minutes. The initial heating (that is, by means of the high frequency electric field) can be carried out in the open or free atmosphere, if desired, so that the packages need not be Wrapped or otherwise conned, while the steam heating takes place in a closed or confined vessel. It will be apparent,

therefore, that my present invention entirely' eliminates the need for Wrapping the thread, avoids the use of a vacuum, and yet greatly reduces the time required for the complete process.

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, as well as additional objects and advantages thereof, will best be understood from the following description when read in connection with the accompanying drawing in which Figure l is a partly sectional and partly diagrammatic View of one form of twist setting apparatus for carrying out my present invention,

Figure 2 is a top plan view of a portion thereof, and

Figure 3 is a view similar to Figure 1 of a somewhat diiferent form of apparatus for carrying out my present invention.

necessary by the Referring more particularly to the drawing wherein similar reference characters indicate corresponding parts throughout, there is shown a steam chamber l which is supplied with steam through an inlet pipe 3 from which the condensed moisture is withdrawn through a pipe E. The chamber i includes a platform or table 'l in alignment with and immediately adjacent to an endless conveyor` or belt 9 which passes over an insulated plate il and around a pair of pulleys i3, one of which may be power driven. The plate II supports an electrode i 5 for cooperation with a second electrode il, both connected through a transformer l 9 to a source of high frequency electrical energy 2 l, such as a vacuum tube oscillation generator. Packages of yarn 23, which may be in the form of spools, bobbins, quills, cones, tubes or the like (formed by winding in a multiplicity of layers a thread or yarn constituted by a plurality of individual filaments or strands which are twisted together) may be placed on the belt 9 which advancesI them between the electrodes i5 and I1. The uniform, high frequency electric field set up between the electrodes U5 and [Il rapidly heats the packages 23 substantially uniformly throughout the entire length of the thread I by reason of the dielectric losses therein and causes the residual moisture in the packages to be vaporized. Beyond the electrodes l5 and il, the belt 9 advances the packages 2t through an inlet chute into the vessel or chamber l which is maintained at a relative humidity of '70 per cent or more. As the packages 22 pass through the chamber l, they gradually cool and, When' they emerge through the exit chute 2l, the twist in the threads thereof have become set.

The apparatus shown in Figure 3 is similar to that shown in Figure 1. Here, however, the inlet and exit chutes 25 and 2l are omitted and the steam chamber i is provided with inlet and outlet openings 25d and LZ'la instead. The beit 9d in this modication is arranged to pass through the entire length of the chamber l and therefore feeds the packages 23 therethrough in spaced relation to each other, whereas in Figure l they are in contact with each other. Also, in the apparatus of Figure 3, the electrodes i511 and i la are both within the chamber i, so that the packages 23 are heated by radio frequency energy While they are already exposed to or submerged in the humid atmosphere. As in the case of the system of Figure 1, the packages 22 are heated rapidly by the dielectric losses produced therein when subjected to the high frequency electric iield, and, as they cool within the humid atmosphere. the twist in the threads thereof becomes set.

Wherever, in this speciiication, 1l have used the terms yarn, thread "cord and the like, 1 intend these to be the equivalent of and synonymous with each other, since my present invention is applicable to all', and whether for setting the twist or for effecting the 'balance thereof. Al though I have shown and described two forms of apparatus for carrying out the method of my present invention, it will undoubtedly be apparent to those skilled in the art that many other ways and other forms of apparatus are possible for this purpose. I therefore desire that my invention shall not be limited except insofar as is made prior art and by the spirit oi the appended claims.

I claim as my invention;

region to a humid atmosphere until the twist has been set.

2. The method of setting the twist of moisture containing thread constituted by a plurality of strands of dielectric material twisted together which comprises first subjecting said thread, while unconfined, to the influence of a substantially uniform, high frequency electric eld of sunicient intensity to rapidly heat said thread substantially uniformly by reason of the dielectric losses produced therein whereby to substantially uniformly expel moisture from said thread, and then, while said thread is still hot, subjecting it in a confined region to a humid atmosphere unt1l the twist has been set.

3. The method of setting the twist of thread according to claim 2 characterized in that said thread is subjected to said electric field while exposed to the free atmosphere.

4. The method of setting the twist of thread according to claim 2 characterized in that said thread is subjected to said electric field at one location, and characterized further in that the heated thread is substantially instantaneously thereafter transferred to another location to be subjected to said humid atmosphere.

5. Apparatus for setting the twist of thread constituted by a plurality of strands of vdielectric material twisted together which comprises means for advancing the thread along a path successively past an unconned location and a conned location, means for subjecting said thread to the influence of a high frequency electric field at said unconned location, and means for subjecting said thread to humid atmosphere at said confined location.

THEODORE H. STORY.

REFERENCES CITED The following references -are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Daily News Record (New Yorki, May 25, 1944. Page 14.

Journal of Commerce and York) May 25, 1944. Page 13.

Wall Street Journal, May 25, 1944. Page 5. Textile World, August 1944. Pages 96, 97 and Thermex High Frequency Heating. Corp. Louisville, Ky., pages 9-11.

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