US2926415A

US2926415A - Textile staple fibers and production thereof

Info

Publication number: US2926415A
Application number: US639971A
Authority: US
Inventors: Jr Roger C Griffin
Original assignee: Reynolds Metals Co
Current assignee: Reynolds Metals Co
Priority date: 1957-02-13
Filing date: 1957-02-13
Publication date: 1960-03-01
Anticipated expiration: 1977-03-01

Description

March 1950 R. c. GRIFFIN, JR 2,926,415

TEXTILE STAPLE FIBERS AND PRODUCTION THEREOF Filed Feb. 13, 1957 mvsmon ROGER c. GRIFHN JR.

BY 2% I ATTORNEY ADHESIVE METAL FILM entially to the surface of the TEXTILE STAPLE FIBERS AND PRODUCTION THEREOF Roger C. Griifin, Jr., Lakeside, Va, assignor to Reynolds Metals Company, Richmond, Va., a corporation of This invention relates to method and apparatus for producing staple fibers from sheets of resilient, heatsettable material, and to staple fiber and yarns made by said method.

Textile filaments are made from sheet materials in some cases, in order to obtain flat instead of round surfaces for maximum reflectance. These filaments are conventionally produced by laminating sheets of clear film with a bright layer of metal therebetween, and slitting the sheet as it is moved past a series of close-set blades which are fixed or have rotating circular edges. The result is a continuous-filament yarn,'which is useful for some purposes, but is not Well suited for use in making staple fiber for spinning with'other fibers. In addition to the ico controlling the cut, the width of the fibers can be varied from uniform widthto atapered wedge shape, or otherwise. Because of the nature of the process, the width of the fiber can be made much narrower than in the.

case of comparable fibers produced by conventional methods.

, other details, objects and advantages, reference is now problems of crimping the yarn and chopping it up into staple lengths, it is difiicult to space the conventional slitting blades so that they will'cutnarrowly and also with the required degree of accuracy, andconsequently the minimum width of continuous filament yarn (e.g., about i 0.008 inch) is coarser than desired for staple fiberlpurposes.

.In accordance with the present invention, bright reflective staple fiber of laminated construction is produced ,in a width range of about 0.002 toabout 0.006 inch),

and have .reverse bends heat-set in the resilient film material, which enables the fibers to be-spun and woven into .falbrics where the reflective surfaces of the fibers of the invention occur at random in .a pleasingly irregular pattern. The narrow width, preferablyabout 0.004 inch,

machines. 'The ornamental effect can be varied by producing the fibers of the invention .in a wedge shape, as viewed normal to the laminate, in which case. the relatively wide ends of the bright staple tend to come preferyarn and stand out as particularly bright spots in the fabric.

The method of the invention enables bright laminated or otherstaple fibers to be produced in anoveland efiicient ,..manner. instead of chopping up continuous-filaments into staple, or forming the thread sinusoidally after .it. has been severed from the sheet, the, invention contemplates heat-setting corrugations in aresilient sheet, and :cutting the fibers from the sheet transversely of the direction of corrugation. into ribbonswhich are corrugated lengthwise, and which have a widthequal to the desired length of the fibers. When the ribbons are successively sliced across their ends, the severed-fibers are automatically of the desired length and.bent,,as viewed edgewise of the fiber, to-give the interlocking capability required of textile fibers. By

The sheet is preferably divided.

made to the accompanying drawingspwhich show, for purposes of illustration only, a present preferred embodiment of the invention. In the drawings:

Figure l is a semi-diagrammatic side view of apparatus .for corrugating and slicing lengths of sheet material to form the staple yarn of the invention; I

Figure 2 is a plan view of the apparatus shown in Figure l; I

Figure 3 is a section taken on the line IlI--III in Figure 2, enlarged and partially broken-away;

Figure 4 is a semi-diagrammatic perspective view of a ribbon of corugated laminate and of a fiber cut therefrom in accordance with the invention;

Figure 5 is a plan view of the fiber shown in Figure 4, normal to the laminate; 1 v

Figure 6 is an end view of the fiber shown in Figure 5; and

Figure 7 is a semi-diagrammatic section taken on the line -VlIVl1 in Figure 5, enlarged and partially broken away.

Referring now more particularly to the drawings, Figures l and 2 show several ribbons 10 being fed between between an upper retainer bar and a lower cutter bar 1% spaced closely below the bar 16 and projecting slightly beyond it. .The

rollers

12 and 14 heat-setcor a cutter roll 22. A motor 24 drives the roll 22 through gears 26, and also drives

thecorrugating rolls

12 and 14 through variable speed drive belt 28. Corrugating rolls 7 l2 and i4, and the cutting roll 22, are thus. driven .in a

timed relation to each other, which is predetermined to control the width of the pieces of textile staple fibers 32 cut from the ends of the ribbons it}. ,The fibers are of generally rectangular form in plan, but can be made wedge shaped by varying the angle of approach of the ribbons to the cutter roll, or .by using successive cutter bladesof different helical pitch. As viewed edgewise,

the fibers have wave-like bends as a result of their, re-

siliently springing back to the wavy form of the corrugations heat-set in the ribbons 10. The severed fibers are collected and spun into yarn, which .is subsequently woven (e.g., du Pont Mylar), or cellulose acetate butyrate,

and then laminating another sheet of like film over "the .metallized surface, usually with .a layer of transparent adhesive thereb etween; see Figure 7. Instead of the sec pair of

corrugating rollers

12 and 14, and thence pass- 3 nd film, a protective coating of clear or colored lacquer can be applied over the metal, or over the whole fiber. Foil can be used for the metal layer, but it is much thicker and heavier, and consequently makes it more difficult to card the staple fiber. Colors may be introduced if desired, but for the purposes of the present invention the added weight of the conventional three-layers of film for color fiber is undesirable, and instead it is preferred to use two layers of dyed film instead, or a single layer of clear film with a colored lacquer coating over the whole fiber.

A fixed electrical heating element 34 extends through one end of the corrugating roller 12, for substantially the whole length of the roller, along its central axis. The roller is hollow and preferably made of metal, and the element 34 radiates heat to warm the outer surface of roller 12 and thus to heat-set the ribbons 10. The other corrugating roller 14 does not need to be heated from within, and it is preferably made of stiff rubber to grip the ribbons firmly for heat setting and to pass them on toward the cutter roll. A series of circular ribs 36 extend around each of the

rollers

12 and 14, and the nip of these rollers extends in a sinusoidal curve. A screwdown mechanism adjusts the pressure between the rollers '12 and 14 in order to grip the ribbons and press them between the ribs 36 during the heat-setting of the corrugations in the ribbons.

The following examples illustrate the operation of the invention:

FIRST GROUP OF EXAMPLES A sheet of 0.0005 inch thick transparent film of polymerized ethylene glycol terephthalate (du Pont Mylar) was coated on one side with a layer of aluminum (about one micron thick) condensed from avapor of aluminum under high vacuum, and the metallized side was secured by a conventional transparent adhesive to a second sheet of a like film. The resultant laminated sheet was slit into ribbons 2 inches wide, and these ribbons were run through ribbed rollers, one of rubber and one of metal heated to about 400 F. outer surface temperature. The rollers formed and heat-set corrugations (about seven in each ribbon) extending along the length of the ribbons, and the ends of the ribbons were then fed at a rate of about 6 feet per minute over a cutter bar to a cutter roll having helical blades rotating at about 835 t.p.m. to cut from the ribbons fibers having a length of 2 inches, a substantially uniform width of about 0.004 inch, a thickness of close to 0.001 inch, and a series of substantially sinusoidal curves in each fiber as viewed edgewise (the curves were made with approximately straight tops and sides in order to give a slightly squared effect for good interlock with other fibers). The fibers thus produced were made into yarn with 2 inch, 3 denier black du Pont Orlon crimped staple fiber (round homogenous fibers of a polymer consisting principally of acrylonitrile), in a weight proportion of 2% laminated fibers and 98% Orlon, by the following procedure:

(a) The Orion fiber was opened on a Davis and Furber Mixing Picker;

(b) The two groups of fibers were laid out in several layers as a sandwich blend;" 7

(c) The blend was opened once through the Mixing Picker, and then carded into 75 grain silver on the breaker section of a Davis and Furber Woolen Card, drawn once to 75 grain sliver on a Whitin Draw Frame (six doublings), and spun into 1.2s (cotton count) roving;

(d) Half the roving was spun into 12/ 1 yarn with 11.2 t.p.i. Z-twist on Whitin F2 Spinning Frame using a single creel;

(e) The other half was spun into 6/1 yarn with 8.0 t.p.i. Z-twiston Whitin F2 Spinning Frame with a double creel.

Other speciments of yarn were similarly prepared, ex-

v c'ept for variations in the weight ratios of the fibers used,

and the strength characteristics of the aforesaid yam are indicated in the following table:

Table l Proportion of Laminated Fibers Average Corrected to to Or10n" Count Skcin N omlnal Break Count 7/1 220.0 196.0 (12/1) 10. 8/1 218.0 196.0 (12/1) 12. 2/1 178. 3 181.2 (12/1) 11. 8/1 150 147. 5 (12/1) 5. 9/1 473 465 ((3/1) 5 7/1 475 451 (611) 6 2/1 398 411 (ti/l) 25%/15%.-- 6 0/1 318 318 (6/1) The average skein break in the tables refers to the force in pounds required to break the yarn in a standard pendulum-type yarn tensile testing machine (load on loops).

SECOND GROUP OF EXAMPLES A second group of yarn specimens was prepared, following the procedure described above, except for the substitution of 64's Fine Wool, dyed black, in place of the Orlon fibers described above. The strength characteristics of the resultant wool-blend yarns are indicated in the following table:

Table 11 Weight Proportion of Laminated Average Corrected to Fibers and Wool Count Skein Nominal Break Count ADDITIONAL EXAMPLE Count, 1.41 grain/yard) yarn with 8.0 t.p.i. Z-twist on 8.

Davis and Furber Simplex Spinning Frame.

The resultant yarn had a cotton count of 5.8/1s and an average skein break of 139.7 pounds (135.0 pounds when corrected to nominal cotton count of 6/1s).

The laminated bright staple fibers of the invention can be used in a wide variety of ways, but the most important present use is in spun yarn, which is later woven or knitted, usually with other yarns, into fabrics. The fibers of the invention can be used in very small proportions, such as about 0.1% by weight, with other staple fibers in yarns, to give a bright flecked appearance. When used in larger proportions, the fibers of the invention give an increasingly brighter appearance, which is accentuated by the observed fact that these fibers tend to concentrate at the outer surface of the spun yarn, when spun with other fibers of lighter weight (such as illustrated in the examples). At the same time, increased proportions of the fibers of the invention tend to decrease the strength of the yarn, when the proportion becomes large. In the light of these considerations, the present preferred upper limit of the proportion by weight of the fibers of the invention in spun yarn with other fibers is about 60%.

ticing the same.

While I have illustrated and described present preterred embodiments of the invention and methods of prac- It will bc understood that the invention may be otherwise variously embodied and practiced within the scope of the following claims.

I claim: 1

1. A method of producing staple textile fiber of a predetermined length and substantially rectangular crosssection, comprising the steps of feeding a strip lengthwise to a rotary cutter, said strip including a layer of resilient transparent film and having a width equal to said predetermined fiber length, heat-setting corrugations in the strip as it advances, said corrugations extending lengthwise of the strip, and operating the cutter to cut the strip successively across its leading end successively into narrow pieces of staple textilefiber which resiliently assume a.

bent shape corresponding to the shape of the corrugations.

2. A method of producing staple textile fiber of a predetermined length and substantially rectangular crosssection, comprising the steps of feeding a strip lengthwise "to a rotary cutter, said strip comprising a sheet of transparent film, and a layer of bright reflective metal adhering to the film, and said strip having a Width equal to said predetermined fiber length, heat-setting corrugations in the strip as it advances, said corrugations extending lengthwise of the strip, and temporarily flattening the leading end of the strip and operating the cutter to shear the strip successively across its flattened leading end into narrow pieces of staple textile fiber which resiliently assume a bent shape corresponding to the shape of the corrugations.

3. A method of producing crimped fibers, comprising the steps of forming a series of corrugations in a resilient sheet, feeding the sheet endwise in the direction of the corrugations and successively cutting the leading end of the sheet transversely across the corrugations, while temporarily holding the leading end flat, to sever narrow pieces which resiliently assume a bent shape corresponding to the shape of the corrugations.

4. Textile staple production. apparatus comprising a pair of corrugating rolls each having ribs therearound in interfitting relation with the ribs of the other roll, means to heat the periphery of at least one of said rolls, a cutter roll having a series of spaced helical blades mounted around its periphery, a cutter bar adapted to cooperate with said blades and positioned between the corrugating rolls and cutter roll, means adjacent the cutter bar to hold a resilient strip of corrugated material flat as it passes over the cutter bar, and driving connections to the corrugating rolls and cutter roll to rotate the corrugating rolls in timed relation to the cutter roll, whereby a strip of material fed to the corrugating rolls is corrugated and its corrugated end is progressively fed by the corrugating rolls to the cutter roll to be transversely severed across the end into successive narrow pieces of crimped staple textile fiber.

5. Textile staple production apparatus comprising a pair of corrugating rolls each having ribs therearound in interfitting relation with the ribs of the other roll, means to heat the periphery of at least one of said rolls, a cutterroll having a series of spaced helical blades mounted around its periphery, a cutter bar adapted to cooperate with said blades and positioned between the corrugating rolls and cutter roll, means adjacent the cutter bar to hold a resilient strip of corrugated material flat as it 2,106,896 McCullouch et al. Feb. 1, 1938 2,321,757 Lodge June 15, 1943 2,407,109 Smith Sept. 3, 1946 2,416,209 Oppenheim Feb. 18, 1947 2,439,814 Sisson Apr. 20, 1948 2,446,097 Nelson July 27, 1948 2,506,667 Hall May 9, 1950 2,541,181 Welton Feb. 13, 1951 12,547,880 Meyer et a1 Apr. 3, 1951 2,714,569 Prindle et al Aug. 2, 1955 2,717,423 Uhlig et al. Sept. 13, 1955 2,758,357 Goodhue Aug. 14, 1956 2,772,994 Lacy Dec. 4, 1956 passes over the cutter bar, and driving connections to the corrugating rolls and cutter roll to rotate the corrugating rolls in timed relation to the cutter roll, whereby a strip of material fed to the corrugating rolls is corrugated and its corrugated end is progressively fed by the corrugating rolls to the cutter roll to be transversely severed across the end into successive narrow pieces of crimped staple textile fiber, said timed relation being effective to cut staple fiber having a width as measured between the cut edges in a range of about 0.002 to about 0.006 inch.

6. Textile staple production apparatus comprising a I pair of corrugating rolls each having ribs therearound in interfitting relation with the ribs of the other roll, one of the corrugating rolls being a hollow metal roll and the other corrugating roll being of rubberlike material, heating means inside the said metal roll to heat its periphery, a cutter roll having a series of spaced helical blades mounted around its periphery, a cutter ba-r adapted to cooperate with said blades and positioned between the corrugating rolls and cutter roll, means adjacent the cutter bar to hold a resilient strip of corrugated material fiat as it passes over the cutter bar, and driving connections to the corrugating rolls and cutter roll torotate the corrugating rolls'in timed relation to the cutterroll, whereby a strip of material fed to the corrugating rolls is corrugated and its corrugated end is progressively fed by the corrugating rolls to the cutter roll to be transversely severed across the end into successive narrow pieces of crimped staple textile fiber.

7. A method of producing staple textile fiber of a predetermined length and substantially rectangular crosssection, comprising the steps of feeding a strip lengthwise to a rotary cutter, said strip comprising a sheet of transparent film, and a layer of bright reflective metal adhering to the film, and said strip having a width equal to said predetermined fiber length, heat-setting corrugations in the strip as it advances, said corrugations extending lengthwise of the strip, and temporarily flattening the leading end of the strip and operating the cutter to shear the strip successively across its flattened leading end into narrow pieces of staple textile fiber which resiliently assume a bent shape corresponding to the shape of the corrugations, said feeding and cutting steps being synchronized to produce fibers having an average width between their cut edges of about 0.002 to about 0.006 inch.

References Cited in the file of this patent UNITED STATES PATENTS