US3112551A

US3112551A - Process for the manufacture of crimped filament yarns

Info

Publication number: US3112551A
Application number: US861357A
Authority: US
Inventors: Schmieder Felix; Hildebrandt Joachim; Krombach Walter
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1958-12-31
Filing date: 1959-12-22
Publication date: 1963-12-03
Anticipated expiration: 1980-12-03
Also published as: NL246697A; FR1243781A; BE586205A; DE1253862B; GB939314A; NL124204C; CH392766A

Description

3, 1963 F. SCHMIEDER ETAL 3,112,551

PROCESS FOR THE MANUFACTURE OF CRIMPED FILAMENT YARNS Filed Dec. 22, 1959 INVENTORS MPM? W ATTORNEYS United States Patent 3,112,551 PRBCESS FOR THE MANUFACTURE 6F CPED FILAMENT YARNS Felix Schmieder, Frankfurt am Main, Joachim Hildebrandt, Hattersheim (Main), and Walter Kromhach, Neuenhaiu, Taunus, Germany, assignors to Farbwerke Hoechst Alttiengesellschsit vormals Meister Lucius t Briining, Frankfurt am Main, Germany, a corporation of Germany Filed Dec. 22, 1959, Ser. No. 861,357 Claims priority, application Germany Dec. 31, 1958 Claims. (Ci. 28- -72.)

The object of the present invention is a process for the manufacture of potentially crimped filament yarns of synthetic linear high polymers such as, for example, polyethylene terephthalate, poly-e-caprolactam, polyhexamethylene-diamine adipate. By the term potentially crimped there is to be understood in this connection that multifilament yarns treated according to the invention are capable of crimping when allowed to shrink.

It has already been described that crimped filament yarns of linear polymers are obtained by heating a stretched filament yarn to a temperature of 30 to C. below the melting point, stretching the filament yarn beyond its yield point, cooling the filament yarn and deviating it at a sharp edge in such a manner that the threadine of the filament yarn forms an acute angle at the deviating edge, and then allowing the filament yarn to shrink. This process is carried out with the stretched filament yarn and constitutes, therefore, an aftertreatment .or a finishing operation.

Now we have found that potentially crimped filament yarns of linear high polymers, the crimping of which only appears after they have been subjected to a shrinking treatment, are obtained when the filament yarns, in the course of the continuous stretching to two to eight times their original length, are heated on one side for a short period by passing the filament yarn-s at a speed of more than 100 m./minute, preferably more than 300 m./minme, over a small surface heated at a temperature within the range of 300 to 900 C., preferably 500 to 600 C., while deviating the filament yarn in a manner such that the section of the filament yarn before the heated surface forms an angle of 130 to 170 with the section of the filament yarn after the heated surface. The filament yarn touches the small, highly heated surface over a distance of at least 0.3 mm. and at most 5 mm. The heated surface can, for example, be an electrically heated resistance wire having a diameter of, for example, 2 mm. When the filament yarn passes over such a surface at the high speed of, for example, 400 rn./minute, the time of contact is very short, and it has proved to be useful when said time of contact is within the range of 0.00008 to 0.01 second. When observing these conditions, the yarn is not heated thoroughly but only on one side due to the fact that its filaments are only heated on that side on which they have touched the heated surface for a short period of time.

When stretching the filament yarns of synthetic linear high polymers, there is often arranged Within the zone of stretching, i.e. between the feed roller and the drawing roller, 3. snubbing pin or a snub'bing roller, which may be heated or not heated, with the purpose of localizing the stretch point in the filament yam during the stretching process. The small, highly heated surface which the filament yam touches Whhe being deviated, shall then, according to the invention, be arranged between the snu bing device and the drawing roller.

In this process it has in many cases proved to be advantageous to moisten the filament yarn with water prior to being brought into contact with the heated small surface, possibly with the addition of a wetting agent. When proceeding in this manner, it is necessary to heat the wire to a higher temperature in order to attain the desired effect. In order to avoid that the heated surface is worn out by the filament yarn passing over it, it is expedient to cause the filament yarn slowly to move to and fro in a cross-direction to its threadline.

The process of the invention constitutes a considerable advance in the art inasmuch as it can be applied with little expenditure to the stretching machines customarily used for the manufacture of filament yarns which are mers exhibiting a good crimp effect in a simple and,

above all, economic manner. After having undergone the treatment according to the invention, the filament yarns first have a smooth appearance. Crimping only appears when the filament yarns are shrunk, for example, by heating them by air from 100 to 240 C., by water from to C., but also when brought into contact with a plate or roller having a temperature ranging from 100 to 240 C.

However, there can also be fabricated woven or knitted goods from the-still smooth filament yarns treated according to the invention, said woven or knitted goods being allowed to shrink by subjecting them to a treatment with hot air, hot Water, as mentioned above, or with a suitable solvent such as, for example, ethylene chloride or acetone, in the course of which treatment the filament yarns shrink and crimp thus imparting to the woven or knitted fabric a high degree of elasticity.

The FIGURE illustrates a form of apparatus for carrying out the process of the invention.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto:

Example 1 A meltspun undrawn multifilarnent yarn 1 consisting of 25 single filaments of polyethylene terephthalate was taken off the spinning bobbin by a feed roller 2 and a separating roller 3 at a speed of m./minute. In order to localize the stretch point, the yarn l Was passed once around a stationary snubbing rod 4 heated at 90 C. and having a diameter of 60 mm. The yarn was heated on one side by passing it over a resistance wire 5 electrically heated at 500 C. and having a diameter of 2 mm, While simultaneously deviating the yarn from the straight threadline in a manner such that the two sections of yarn before and after the hot Wire formed an obtuse angle of The yarn was drawn off by drawing roller 6 with separating roller 7 at a speed of 400 m./minute and the yarn, which had acquired a potential crimping, Was wound on a bobbin. When the yarn was allowed to shrink in the free state in boiling water, the yarn crimped and contracted to 40% of its original length.

Example 2 A spun yarn of polyethylene terephthalate of 660 deniers having 50 individual filaments was taken off the spinning bobbin by an unheated feed roller, around which the yarn was passed in several wraps, and conducted, also in several wraps, over a s-nubbing roller heated at 105 C. The yarn was then passed over a roller, installed in a water bath and driven by the friction of the yarn, and subsequently at an angle of 155 over a metal wire heated at about 840 C. to the drawing roller driven at a speed 4.4 times higher than that of the feed roller. In the course of this operation, the yarn was stretched down to deniers. When the yarn was then- Patented Dec. 3, 1963 A meltspun yarn of poly-e-caprolactam of 180 deniers having 9 individual filaments was taken off the spinning bobbin by an unheated roller around which the yarn was passed in several wraps, and was stretched between an unheated snubbing pin, around which the yarn Was passed at an angle of about 180, and a dnawing roller driven at a peripheral speed being four times as high as that of the feed roller at a draw-cit speed of 400- rnJrninute into a yarn of 45 deniers. The yarn is then passed at an angle of 140 over a Wire installed before the drawing roller and heated at 570 C. The yarn was then wound on a bobbin and processed into warp-knitted goods which were allowed to shrink in the relaxed condition at 180 C. Due to the yarn getting crimped, the goods had an especially soft and full handle.

We claim:

1. A continuous process for making intently crimped filament yarn of synthetic, thermoplastic, linear high polymers, said yarns being adaptable to crimping by subsequent shrinking, which process comprises drawing unstretched filament yarn by stretching said yarn to two to eight times its original length While heating one side thereof for 0.00003 to 0.01 second by passing said yarn at a speed of more than 100 meters/minute over a small surface heated at a temperature between 300 C. and

. 900 C., the yarn touching said heated surface only over a distance of 0 .3 millimeter to 5 millimeters and being changed in direction at the heated surface such that the yarn approaching the heated surface forms an obtuse angle of between and with the yarn leaving the heated surface.

2. A process as claimed in claim 1, in which the sur- 'face is heated at a temperature within the range of 500 to 600 C.

3. A process as claimed in claim 1, in which an electrically heated wire is used as heated surface.

4. A process as claimed in claim 1, in which the filament yarns, prior to passing over the heated surface, are moistened with water.

5. A process as claimed in claim 1, in which the filamerit yarns, prior to passing over the heated surface, are moistened with the aqueous solution of a wetting agent.

References Cited in the file of this patent UNITED STATES PATENTS 2,919,534 Bolinger et al Ian. 5, 1960 2,974,391 Speakman et a1. Mar. 14, 1961 3,024,517 Bromley et al Mar. 13, 1962 FOREIGN PATENTS 164,127 Australia July 15, 1955 564,382 Canada Oct. 7, 1958 558,297 Great Britain Dec. 30, 1943 780,755 Great Britain Aug. 7, 1957

Claims

1. A CONTINUOUS PROCESS FOR MAKING LATERNTLY CRIMPED FILAMENT YARN OF SYNTHETIC, THERMOPLASTIC, LINEAR HIGH POLYMERS, SAID YARNS BEING ADAPTABLE TO CRIMPING BY SUBSEQUENT SHRINKING, WHICH PROCESS COMPRISES DRAWING UNSTRETCHED FILAMENT YARN BY STRETCHING SAID YARN TO TWO TO EIGHT TIMES ITS ORIGINAL LENGTH WHILE HEATING ONE SIDE THEREOF FOR 0.00008 TO 0.01 SECOND BY PASSING SAID YARN AT A SPEED OF MORE THAN 100 METERS/MINUTE OVER A SMALL SURFACE HEATED AT A TEMPERATURE BETWEEN 300*C. AND 900*C. THE YARN TOUCHING SAID HEATED SURFACE ONLY OVER A DISTANCE OF 0.3 MILLIMETER TO 5 MILLIMETERS AND BEING CHANGED IN DIRECTION AT THE HEATED SURFACE SUCH THAT THE YARN APPROACHING THE HEATED SURFACE FORMS AN OBTUSE ANGLE OF BETWEEN 130* AND 170* WITH THE YARN LEAVING THE HEATED SURFACE.