US2976578A

US2976578A - Method and apparatus for treating acrylic fibers

Info

Publication number: US2976578A
Application number: US712007A
Authority: US
Inventors: Virgil Richard
Original assignee: Templon Spinning Mills Inc
Current assignee: Templon Spinning Mills Inc
Priority date: 1958-01-29
Filing date: 1958-01-29
Publication date: 1961-03-28
Anticipated expiration: 1978-03-28

Description

R. VIRGIL March 28, 1961 METHOD AND APPARATUS FOR TREATING ACRYLIC FIBERS Filed Jan. 29, 1958 INVENTOR.

RICHARD VIRGIL ATTORNEY METHOD AND APPARATUS FOR TREATING ACRYLIC FIBERS Richard Virgil, Flushing, N.Y., assignor to Templon Spinning Mills, Inc., Mooresville, N.C., a corporation Filed Jan. 29, 1958, Ser. No. 712,007

7 Claims. (Cl. 19--'.37)

This invention relates to a method and apparatus for treating tow composed of acrylic fibers. More specifically, the invention concerns the thermal treatment of such tow in order to render the ultimate end product in the form of staple, much more uniform than heretofore in respect to stretch or extensibility.

An object of this invention is to provide an improved method and apparatus for continuously treating tow made up of acrylic fibers such as Orlon, acrilan or the like, wherein monofilaments move through successive sets of rollers running at differential speed in order to stretch the fibers, and further including heating means for heat treating the fibers in the tow to a predetermined elevated temperature. Furthermore, the tow is subjected to the action of breaker rolls after the same comes out of the heating means. In order to render the ultimate product more uniform as to extensibility, there is introduced a positive cooling means immediately after the heater means, whereby the heat treated tow is brought down to approximately room temperature very rapidly and immediately before the same passes through the breaker rolls.

Heretofore, it has been known in the art to heat treat such continuous filaments of acrylic fiber previous to passing the same through breaker rolls, in order to reduce the tow to staple. However, in such known procedures, it has been found that the ultimate yarns used in knitting or other textile operations were not uniform as to extensibility, such as is encountered when the yarns or the fabric derived therefrom are further processed in order to produce simulated wool-like eft'ects. With known procedures it has been not uncommon to find that knitted materials forming one portion of a garment would have greater dimension in a given direction than an associated part of such knitted fabric.

The present invention is designed to reduce materially the relatively wide range of extensibilities in the finished staple so as to stabilize the yarn for knitting or weaving operations.

in the drawing:

Fig. 1 is a diagrammatic representation of apparatus for treating tow including monofilaments of acrylic fiber, in accordance with the invention; and

Fig. 2 is an elevational view of the cooling roller which forms a portion of said apparatus.

Essentially, the method of this invention comprises passing the tow which is made up of monofilament fibers or the acrylic type, such as Orlon or Acrilan through successive sets of rollers operating at different speeds with an intervening heating plate which heats the moving fibers in the tow to temperatures of the order of 250 to 400 F. and stretches the same. Thereafter, the fibers are immediately passed over a cooling roller which is positively cooled by circulation of a refrigerating medium, such as cold or refrigerated water, the surface temperature of the roll being controlled in a manner to quickly bring the temperature of the heat treated tow to approximately room temperature; that is between 75 2,976,5i Patented Mar. 23, 196i to 85 F. The tow, thereafter, then moves from feeding rolls through conventional breaker rolls to a final set of delivery rolls for tensioning the filaments during the breaking operation. The thus stretched and treated fibers in the tow are passed through a narrowing tray and stufiing box in a manner conventional in the art.

It has been found that upon utilizing the staple fiber produced in accordance with this invention, the admixture of fibers as received from the device herein to gether with other fibers, also derived from this device, but which have been subjected to a relaxing procedure known in the art, namely by subjecting selected portions of the treated tow to a steam bath, that such admixture of stretched and relaxed fibers will produce a sliver which is quite uniform insofar as its ultimate stretch incident to further processing operations in connection with the weaving or knitting of the same.

As shown in Fig. 1, the apparatus embodying the instant invention includes

successive guide rollers

110, 11, 12 and 15 through which pass the tow T made of monofilaments of acrylic fiber. The tow T also passes through crowned rollers 13 and 14, respectively located between

guide rollers

11, 12 and 12, 15, whereby the filaments are spread into a fiat sliver.

The tow T then continues its movement through a set of adjustable pressure rollers 16 which may be adjustably spaced to provide a passage of proper thickness to pass the tow T on its way to a series of

feed rollers

17, 18, 19 and 20. From roller 20, the tow passes through a heater 21 comprising an upper heater platen 22 and a lower heater platen 23. Such platens may be electrically heated to raise the temperature of the moving tow to from 250 to about 400 F., in accordance with the specific fiber being treated and its ultimate usage. The platens are maintained at the selected temperatures by thermostatic control means, not shown. As the heated tow T leaves heater 21, it is passed to

delivery rollers

24, 25, 26 and 27. The tow T passes to a set of adjustable pressure rollers 32 which rotate at a speed greater than that of rollers 16, thus stretching the tow to the extent desired, the stretch ranging from about 20 to about 80%.

I The heated tow T now passes about a hollow roller 28 which is positively cooled, as by passing cold water therethrough. As shown in Fig. 2, the roller 28 may be provided with cold water inlet 29 and an outlet 30. A thermostatic control 31 on the inlet 29 is adapted to maintain a proper surface temperature for the roller 23.

The roller 28 is kept at a temperature which will quickly cool the heated tow T to temperatures ranging from about to about 85 F. The cold or refrigerated water passing through roller 23 may be derived from a source not shown and may take the form of a continuous circulatory system.

The tow T now passes from feed rollers 32 and to a set of delivery pressure rollers 33 which rotate at a predetermined speed somewhat faster than rollers lo and 32, to tension the tow T. Located between

pressure rollers

32 and 33 is a set of breaker rollers 34 which comprise projecting breaker blades 35. The rollers 34 are so arranged as to bring their breaker blades into meshing relation as indicated in the drawing and operative to deflect the moving tow T sharply or abruptly out of its path. This action breaks the monofilaments into staple. The tow containing the staple now passes from delivery rollers 33 to a narrowing tray 36 and is thereafter collected in a manner known in the art.

It has been found that acrylic monofilaments which have been heat treated at a temperature of about 265 F. and then rapidly cooled to about F., using the above described apparatus, produce staple, which upon subsequent processing and conversion into knitted or woven garments, shows excellent uniformity of stretch. Apparently the quick cooling of the heated filaments exerts a stabilizing action on the ultimateextensibility characteristics of the fiber.

Furthermore, it was found that the breaking action was more etficient when the tow has been treated in accordance with the instant invention. Thus the blades 35 produced a cleaner break and neps are substantially eliminated from the treated sliver.

It is understood that the several rollers shown are driven by means not shown, at speeds which will properly stretch the monofilaments while being heat treated and will tension the same during the subsequent breaking action.

As various changes might be made in the embodiment of the invention, without departing from the spirit thereof, it is understood that all matter herein disclosed is by way of illustration and shall not be deemed limiting except as set forth in the appended claims.

What is claimed is: V

1. The method of treating tow containing continuous monofilaments of acrylic fiber comprising continuously advancing the tow longitudinally, continuously stretching the advancing tow while heating the tow to a temperature of from about 250 to about 400 F., rapidly cooling the heated tow to a temperature of from about 75 to about 85 F, and thereafter breaking the treated tow to form staple.

2. In the method of converting monofilaments of acrylic'fiber to staple, the steps of simultaneously stretching and heating the fibers to a temperature of from about 250 to about 400 F., immediately thereafter quickly cooling the stretched and heated fibers to a temperature of from about 75 to about 85 F and thereafter breaking the fibers to form staple.

3. The method of converting tow containing continuous monofilaments of acrylic fiber into staple comprising advancing said tow, heating the advancing tow to a temperature of from 250 to 400 F., simultaneously stretching the heated filaments, quickly cooling the heated tow to a temperature of from 75 to 85 F., tensioning the cooled tow and intermittently deflecting the tensioned tow abruptly out of its path of movement to progressively break the tensioned filaments at the point of deflection.

4. The method of converting tow containing continu-,

4 taneously stretching the heated filaments, passing the heated stretched filaments through a cooling zone to rapidly reduce the temperature of the heated filaments to "about F., tensioning the treated filaments, and breaking the tensioned filaments.

5. Apparatus for converting tow containing continuous monofilaments of acrylic fiber into staple comprising means for advancing said tow, means for heating the advancing tow to a temperature of from about 250 to about 400 F., means for stretching the advancing heated tow, means for rapidly cooling the heated tow to a tem perature of from 75 to F., means for tensioning the treated tow and means for breaking the tensioned tow.

6. Apparatus for converting tow containing continuous monofilaments of acrylic fiber into staple comprising successive sets of rollers for advancing and stretching the tow, means for heating the advancing tow during the stretching operation to at least about 250 F., means adjacent the heating means for cooling the tow to a temperature of from about 75 to 85 F., means for tensioning the cooled tow including spaced sets of rollers operating at successively increased speeds, and means located between said spaced sets of rollers for intermittently deflecting the tow abruptly out of its path of movement to progressively break the tensioned filaments at the points of deflection.

7. Apparatus for converting continuous acrylic monofilaments into staple comprising two successive sets of rollers for advancing said filaments through a predetermined path, heater means located between said sets of rollers for heating the advancing filaments to at least about 250 F., cooling means located after the second set of rollers for rapidly reducing the temperature of the heated filaments to from about 75 to about 85 B, said sets of rollers operating at difierential speeds to tension and extend the heated filaments, a third set of rollers for receiving the advancing filaments from said cooling means, a fourth set of rollers operating at a speed higher than that of said third set of rollers for tensioning the advancing filaments, and means between said third and fourth sets of rollers for sharply deflecting the advancing tensioned filaments to break said filaments to form staple fiber.

References Cited in the file of this patent UNITED STATES PATENTS 2,096,795 Dreyfus Oct. 26, 1937 2,432,355 Truitt Dec. 9, 1947 2,649,623 Ingham Aug. 25, 1953 2,748,426 Wyatt June 5, 1956 2,920,176 Jorgensen Jan. 5, 1960

Claims

2. IN THE METHOD OF CONVERTING MONOFILAMENTS OF ACRYLIC FIBER TO STAPLE, THE STEPS OF SIMULTANEOUSLY STRETCHING AND HEATING THE FIBERS TO A TEMPERATURE OF FROM ABOUT 250 TO ABOUT 400*F., IMMEDIATELY THEREAFTER QUICKLY COOLING THE STRETCHED AND HEATED FIBERS TO A TEMPERATURE OF FROM ABOUT 75 TO ABOUT 85*F AND THEREAFTER BREAKING THE FIBERS TO FORM STAPLE.