Artificial filament and method for its production

May 21, 1935. w. _MENDEL 2,002,153

ARTIFICIAL FILAMENT AND METHOD FOR ITS PRODUCTION

Filed April 13, 1933

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INVENTOR

W/LL/AM Me/IPEL

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Patented May 21, 1935

2,002,153

UNITED STATES PATENT OFFICE

2,002,153

ARTIFICIAL FILAMENT AND METHOD FOR ITS PRODUCTION

William Mendel, Beverly, N. J., assignor to Sylvania Industrial Corporation, Fredericksburg, Va., a corporation of Virginia

Application April 13, 1933, Serial No. 665,864

Claims.

This invention relates in general to artificial filaments adapted to be woven, braided or otherwise utilized in fabrics and millinery, and to a process and a spinneret for forming the same 5 from viscose solutions and the . like. More particularly it relates to· an artificial horse-hair filament commonly known as “visca”, and includes correlated improvements and discoveries whereby the production and properties of artificial fila10 : ments are enhanced.

According to the Dictionary of Tariff Information 1924, visca is known in the trade as sinaline, visca. lame and artificial silk bands; In appearance; it closely resembles ribbon. ; straw of 13 . artificial silk—a name applied to it—being lustrous and .flexible, and having a surface slightly striated and crinkled. It is manufactured in sizes varying ,from a thread ^-2 mm. wide to ribbonlike bands 21 mm. wide.

Visca is used substantially the same -way as straw, either alone or in combination with chip or hemp, for making hat braids. It is also employed with warp or filling of cotton, artificial silk or metal thread, in the weaving of _ millinery 23 all-overs.

. In the art to which this invention appertains, it has long been desired to have a visca strand of covering ability per unit of weight equal to or greater than that afforded by rough natural 30 straw. It was also the desire that the artificial filament should show the principal surface and ornamental characteristics of rough; straw, that is, the surface should have a rough, scintillating appearance in reflected light. The artificial 35 strands of the prior art have smooth unbroken surfaces of high gloss, and are lacking in covering power and ornamental effect;

It is an object of the invention to provide an improved “visca” filament or strand, of surface 40 characteristics such that the reflection of light therefrom; will produce a scintillating optical and decorative effect in imitation of that; produced by rough natural straw.:

Another object of the invention is to provide; 45· a visca filament haying a relatively large solid body section and thin crinkled fin sections extending from the body section longitudinally of the, filament.

It is a further object of the invention to provide 50; a spinneret having an orifice of such, shape as to impart to plastic bodies extruded therethrough the cross-sectional characteristics of the improved filament.

An additional object of the invention is to pro55 vide a filament produced from a viscose solution which is characterized by having a shriveled relatively? large body section, thin crinkled; fin sections joined to? said: body and radially disposed upon the surface and; extending longitudinally of the Oft- body and having helical, twists and multitudinous:

(Cl. 18—8) facets adapted to reflect light with a scintillating effect.

Still another object of the invention is to pro vide a process for the production of artificial filaments haying a unique appearance and of 5 greater covering power than natural straw and.....

which can be readily, economically and efficiently produced on a commercial scale.

Other objects of the invention .will in part be obvious and will in part appear hereinafter. 10

In the practice of the invention a visca filament such, for example, as an artificial horsehairfilament may be formed of any suitable viscous solution or plastic mass; for example a cellulose solution such as viscose (sodium cellu- is lose xanthate) or a solution of a cellulose ester, cellulose ether, cellulose oxyether and other cellulose derivatives in a suitable solvent.

An artificial straw or visca filament of improved properties is obtained by. extruding a suit- 20 able viscous solution,or plastic mass through a spinneret having, a body portion provided with . an orifice characterized by a relatively large central section and relatively thin slot-shaped orifices extending- radially therefrom, coagulating 25 the - extruded strand under tension, and, after purification, drying the strand free of. tension, whereby an uneven shrinkage occurs in the thick body section relative to the thin fins. Further, by coordinating the speed of spinning with the 30 amount of stretch given the raw strand, as well '' as the process of drying, the uneven .shrinkage of the several -parts.can be widely augmented. When thus prepared, the finished visca filament has a helical twist of a few times per. meter and the 35 thin fins, owing.to.their crinkled and convoluted form, impart to the surface a rough, scintillating optical effect in reflected light, similar. to, but more decorative than that shown by the more expensive natural straws utilized in this art. 40

The invention accordingly comprises an article of manufacture possessing- the features, properties arid relation ‘ of elements, and an improved spinneret having the. features of construction, combination:. of- elements and? arrangement of. 45 parts, and a process comprising the several steps? and the relation, cf one or more of such steps with respect to each of the others, all as exemplified in the following detailed disclosure, and the scope of the invention, will be indicated in the 50 claims.

For a fuller understanding of the nature and objects of the invention, reference should be made to_; the following detailed description taken in conjunction, with, the accompanying drawing, 55 in which:

Fig. 1 represents, a top plan view, greatly enlarged, of one modification of the novel spinneret of this invention.

Fig. 2 is a diagrammatic view in elevation, 60.

2,002,153 partly in section, illustrating certain steps of my improved process.

Fig. 3 represents a fanciful view, greatly enlarged, of a novel visca filament which may reci suit from the use of the spinneret shown in Fig. 1.

Fig. 4 represents a sectional view, of the strand of Fig. 3 taken along the line 4—4 thereof.

In Fig. 1 there is shown an illustrative modification of a novel spinneret comprising a body 10 portion which is provided with a relatively large centrally disposed orifice I. This is shown as substantially circular, and it may have, for example, a diameter of about 0.021 inch. The slot-shaped orifies 2, extending radially and con15 necting with the orifice, are each preferably of a length equal to or greater than the diameter of the central orifice. These slot-shaped orifices may be, for example, about 0.030 inch in length and about 0.005 inch in mean width. The outer20 most ends of the slot-shaped orifices preferably are enlarged or flared outward slightly and the corners 3 thereof rounded to enable the viscous solution to flow past the end walls of the slotshaped orifices at approximately the same rate 25 ' as from the central orifice.

It will be observed that the novel spinneret may be designed with an orifice having, in general, the characteristic cross-sectional form desired in the finished fllament. If a filament of great 30 roughness is desired, the number of fins may be increased to three, four or more by employing a spinneret having an orifice giving an enlarged body section, and three, four, or more slot-shaped orifices extending radially therefrom. A flla35 ment having a single fin may be prepared by use of a spinneret having a relatively large orifice and a single fin, but such filaments show a pronounced tendency to curl, which for certain purposes may lessen their utility. It is therefore 40 preferred to employ a spinneret having two or more slot-shaped orifices disposed about the central orifice. These slot-shaped orifices may be symmetrically or asymmetrically disposed with respect to the orifice.

A suitable apparatus for preparing filaments by use of the improved spinneret is shown diagrammatically in Fig. 2, in which a viscose or the like solution supplied through a conduit 4, is extruded through an improved spinneret 5 into a 50 suitable hardening bath 6 contained in a vessel

7. The hardened strands 8 are stretched as spun by being carried over a rotating pulley or godet 9 from which they may descend through a funnel ! 0 into a rotating centrifugal spinning box ! I 55 wherein the strands are twisted and simultaneously coiled against the sides to form a so called “cake” i2. The spinning box i i is preferably of the “bucket” type.

If the peripheral speed of the pulley 9 drawing 60 off the filament is 50 meters per minute (spinning speed) , and the speed of the rotating box is 100 meters per minute, the twist produced in the filament should be turns per meter of filament spun. The number of twists per unit of length may be varied as desired, but the filament has a greater resemblance 70 to natural rough straw when the number of twists is not more than five per meter.

The cake 12 of raw visca may be subjected to the usual processes of purification and finishing. For example, when the filament is prepared from 75 a viscose solution the cake 12 may be treated in succession to the action of a dilute acid or acid salt solution, a desulphurizing agent, a bleaching agent, and then washed and glycerinated. During drying the filament preferably is maintained substantially free of tension. The unequal 5 shrinkage of the thick body section relative to the fins results in the fins becoming crinkled and convoluted, and further there is a slight increase in the number of twists per unit of length of the strand, when drying is thus carried out. 10

It will be realized that without transcending the scope of the invention, the visca filament may be dyed, or rendered opaque by the use of suitable dies and pigments, and may be waterproofed, fireproofed and otherwise treated or decorated. 15

It will be seen that the invention accordingly comprises an improved spinneret of novel design and an article of manufacture produced by the use of the same, as an artificial horse-hair or visca filament characterized by a shriveled cylin- 20 drical body section having crinkled fin sections joined to said body and radially disposed upon the surface longitudinally of the body section. The crinkled, convoluted fins and the shriveled body section afford multitudinous facets adapted 25 / to reflect light with a scintillating effect highly desired in the art. This improved filament has a covering power per unit of weight greater than that of prior artificial horse-hair or visca of cylindrical cross-section and has an ornamental effect 30- / equal to or greater than that of the higher priced rough natural straws. The availability of this novel artificial horse-hair in continuous lengths permits a wide variety of weaving, knitting and braiding operations to be performed by machinery 35 instead of by hand as necessitated by the use of natural straw.

Since certain changes may be made in the above article, the improved spinneret and the process for producing the same, and different em- 40 ' bodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in 45 a limiting sense except as specified in the appended claims.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein de- 50 · scribed, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

The expression “visca” as used in the claims is intended to cover an artificial filament as defined 55 in the “Dictionary of Tariff Information”, U. S. Tariff Commision, Washington, D. C. 1924.

Having described my invention, what I claim as new and desire to