US2647816A - Method of making a wound package and after-treating the same - Google Patents

Description

METHOD OF MAKING A WOUND PACKAGE AND AFTER-TREATING THE SAME O. A. BATTlSTA Filed July 10, 1948 Aug. 4, 1953 m. H ET m W m A f m Patented Aug. 4, 1953 UNI-TED? stares Orla-ndovA; Battista, Drexel'sHilLuBa assignor to American-v Viscose. Corporation,. Wilmington DeL, a .corporationmf Delaware Application J icy-:10, 1948, Serial No. 38,133

1 This inventiomrelatesz' torraamethodzof handling wound ipackagesixor'cakes'rofi filamentary material comprising regenerated: cellulose: from viscose; and or a? novel/shrinkable? wrappers adapted? to be? applied to: the: cakesxprior: tossuch handling; Freshlye'spun regeneratedsceilu'losesiromeviscose is'zsubjected'v toi a" series ofitafteretreating; liquids, including; bleaching and: desulfiding liquids; finally wash'edtiwith water; and: drie'di. In the conventional: practice, tli'evfilamentary material procee'ding from: the: spinning: bath is collected in: centrifugal spinningzbiickettto? form; a: so:- cazlledt rayonf cake andziscthen". after=treated and dfiedfinzthe :ca'kertfonns Theiaiteretreated and mashed regeneratednceilirlose iss in: theiform: of: a: highly swollen" gel, comprising. from: 2.001%; tor500%-5 by weight of water. The moisture; content-of; thercake -is:.-re duced to at least 7 to 12% during drying;v,and

asithcszwater is?removed;therfilamentary material 1 and ipaperwrappersxhaverbeen proposed iforthis:

One':=0f...thedifiicuities' in processing the cakes has: been the problem ofi providingr, them; with at. wrapper; WhiC'h'Wi-HQ accommodate thecake while the filamentary imaterial-isdn \theextended waters-swollen condition" resultingtfrom the liquid. treatmcnt; and then. shrinkiwithr the cake: as the watenisz-removed therei-rom' during the drw ingrsten When the cake draws raw-aye from. the wrapper: during 1: dry;ing,-.,v the-wrapper is too loose for; the: dried cake: and: slips? relatively- 01- thecake, Imaking; it\ difficult? to! handle=and z tending tordisturb. the thread layers] at-l the: outer and inner, surfaces oix-"ther-cake; Additionally, the ends: OfEKthQ WI'aJODGI' are =tucked inter-tithe hollow center of; the: cake and (when the r wrapperv does mat-shrink:-with-nthes cake; the 1005812611115 not the wrapper. occupy; thee centem ofz the. dried: cakeand-make it: difilcultcfor rthetoperatorr. to slip the cake without damaging,v the wrappen. 011.. perfo: ratednrodst on tubes suchiasareeused in suppnrte s- Claimsa (cits-155.29

ingthescake. during dyeingthereof. in: aisubse-r quent ope-ration.

Itlisa primary, object.oflthisiinvention to providv a wrapper'for protecting woundjpackages of regenerated cellulose from viscose during cone a; rayon cake-which isz-rinexpensivei and can: be thrownuaway? af terrone use: without L substantially increasing 1 the: cost: of: producing: :the thread; A further: object .is to'providera' shrinkablecprotecttive wrappenrwhichiisistrongzenorugh ton witha stand processing conditionssas IWeH'faSL-th'e moderatelyc rough handling; to which: the: processed cake is'ssubjectedr during-shipment: to. aa rewind; ing;.twisting'rorvotherr textilerworlcirrgfi device.

Theobjects of; the invention 3 are accomplished by providing; the-r cakes; i after-: collection?- of the filamentarymaterial and priorwto. liquid; processa ing with a:1iquidapermeableiprotective*papmelike coveiaor wrapper comprising fiberss-of asamaterial whichne'not:affectechas: such by 'aqueous' saponb fyingrmedia and fibers ofz'ar-celluloser ester; the fiberswbeingz: bcndedctogethern and! the fibers" in the: wrapper: occurring initially; im a: condition of potential unbalance, whereby, when: the wrappedr package is"; treated with: an" aqueous saponifying medium to decrease'cthe?ester:-content of the wrapper. by; removal 2 of; ester." groups; the celluloserester fibersmrewfree tosshrink and-draw theremainingfibersrwith:them toncause cockfling of such remaining fibers, with shrinkageiofr the wrapper as: a; whole: and: acquisition Of! a crepe effectr thereby:

Thef-wrapper. is: placed' on: the cakeewhicm is them subjected to. the liquid; aiteretreatments'; including an aqueous: saponifyinge, medium; washed anddriedi as by; centrifuging; or by exeposure towarmair currents or the: like;

The: cellulosevesterafibers; fromz-whiclr thesester groups are vre'moved by; the wsaponiiying medium, shrinkor contractwhen. the cake: is"; dried, and due to. the condition of potential unbalanceioi the fibers, shrinkagewof;the deeesterified fibers causes therremainingfibersto cockleor: buclclei Shrinkage-0f ther wrapperi occurs--simultaneouslyywith shrink ageof: thencake 0f,- regenerated' cellulose; during: drying; and, aftervcompletion. of therdrye ingz; operation; the shrunlc wrapper: fits closely against the: inner: and outer peripheries or, the cake:

By conditionr of potential: unbalance" of; the fibers is: meant any; relation of. the fibersv such that the' cellulcse ester fibers/are freeeto shrink and]:draw theeremaining'.fiberstwith them. The potential:unbalancevmawbe due: torthecpresence of? a: preponderance of! the cellulose: ester: fibers? oriramdom idistribu-tion 'ofzthe fibersvin. th'eYpIO'dI-F uct, ,onitmayybevdue -to--the= occurrence those fibersixat on on .the-:-surface-I- 0161a" thin feltr-likeguor paperi-likec .base; either atzlocalizedis areas t of: the

surface; ortat .allxrportions'soff' theatsurface; ,or! both; providcdthatrwl'iem the esterrfib'ersxoccurratsthie 3 surface there is not such intermingling of the fibers that shrinkage of the cellulose ester fibers would be opposed by the tendency of the remaining fibers to resist the shrinkage.

If the wrapper comprises a thin liquid-permeable paper-like product such as a thin felt-like product formed from a mixture of the two types of fibers, such' as may be obtained by commingling the fibers by any of the known methods, for example, carding, deposition from an inert fiuid conveying medium, etc., in order to insure the condition of potential unbalance the cellulose ester fibers must be present in an amount of at least 25%, and in the range of 55 to 70%, if the fibers are parallelized, 25 to 70% if the fibers occur in random disposition.

If the wrapper comprises a paper or paperlike product formed from the fibers of a material which is not affected as such by the aqueous saponifying media, and the cellulose ester fibers occur at the surface only, the cellulose ester fibers must be present in an amount not less than 7% by weight, and may be present in an amount of from 7% to 50% by weight, or more.

The de-esterification of the cellulose ester fibers may be partial or complete, with partial or. complete reconstitution of the cellulose.

I have found that the aqueous alkaline solutions commonly used at the desulfiding stage in the after-treatment of regenerated cellulose threads effect a sufficient decrease in the ester content of the wrapper to result in the desired shrinking and creping thereof during the drying step. The removal of the ester groups to render the wrapper shrinkable upon drying while it is in place on the cake can be effected, therefore, without modification of the conventional aftertreating procedures.

The invention is illustrated in the accompanying drawing in which Fig. 1 illustrates diagrammatically means for practicing one embodiment of the invention;

Fig. 2 illustrates means for practicing another embodiment;

Fig. 3 shows a tubular cake wrapper in accordance with one embodiment of the invention;

Fig. 4 shows an annular cake of thread having a wrapper in accordance with the invention, the cake being shown in the extended condition resulting from the liquid after-treatments, including treatment with an aqueous saponifying agent and washing, but prior to drying; and

Fig. 5 shows the cake after the drying operation, the wrapper being, as shown, creped and shrunken with the cake due to shrinkage of the de-esterified cellulose ester components.

The cellulose ester fibers may be in the form of discontinuous fibers, bundles of such fibers obtained by cutting or chopping a continuous filament yarn to the desired lengths, or a continuous filament or filament yarn may be distributed on the surface of the paper in a pattern such that the cellulose ester fibers occur locally on the paper. The term cellulose ester fibers as used herein is intended to include such fiber bundles as well as the fibers or filaments per se. The cellulose ester fibers may be bonded to the surface of a finished paper in any appropriate manner. If the cellulose ester is in plasticized condition, the paper on which they are distributed is heated, preferably under pressure, for example by passing it between heated calender rolls, to convert the cellulose ester to adhesive condition and bind fibers in the product together. In another embodiment, the cellulose ester fibers are bonded to the surface of the paper by means of a solvent for the ester, for instance, acetone, when the ester is cellulose acetate. When the cellulose ester fibers are deposited on the surface of a web of the other fibers, for example cellulose fibers, as a step in the manufacture of paper, they may be anchored to the surface by autogenous bonding of the fibers, or they may be bonded to the surface of the paper by means of a thin, continuous film of a film-forming material such as regenerated cellulose which is not itself affected by the saponifying agent used subsequently to remove ester groups.

A web of cellulose ester fibers may be deposited on the paper, either continuously or discontinuously, during the course of its manufacture, as shown in Fig. 1, which illustrates more or less diagrammatically that portion of a paper making machine located in general proximity to the head box. Referring to Fig. 1, the paper making wire screen I travels continuously and in the direction of the arrows under idling roll 2, around roll 3, through head box 4 and between the rollers 5 and I4. A water suspension of paper-making fibers of a material which is not affected as such by aqueous saponifying media for cellulose esters flows into the head box 4 through inlet 6, toward the continuously travelling inclined wire screen and, as the fibers reach the screen they are deposited on it, the water passing through the screen to a collector 1, and being returned to the system through the pipe 8. The fibers thus deposited on the screen are represented by fine lines 9. The sheet of paper is not completely formed until it reaches the point In which is the point of contact of the level of the fiber suspension with the moving screen. From point [0 the paper passes on to be finished in the usual manner.

At point I l, above the level of the fiber suspension in the head box, a suspension of cellulose ester fibers l2 in water is fed into the box, through an inclined trough l3, which may be provided with baffles if necessary. The outlet of trough l3 extends completely across the screen so that the suspension of cellulose ester fibers (indicated by the heavy lines I2) is deposited on the web across the width of the screen. The outlet end of the trough may be provided with an automatically operated trap door or the like, (not shown) to permit deposition of the suspension of plasticized cellulose ester fibers on the web of other fibers carried on the screen at spaced intervals along the web. The cellulose ester fibers are laid down on the surface of the already formed web, and occur on the surface with little penetration of the cellulose ester fibers into the web, and minimum intermingling of the two types of fibers.

The structure comprising the cellulose ester fibers is dried by passing it between heated rollers l5 and I6, and is then passed between the rollers I1 and I8 heated to the temperature at which the plasticized cellulose ester fibers are converted to a tacky adhesive condition, whereby the cellulose ester fibers are autogenously bonded to the paper fibers. The structure is then cooled, for example by subjecting it to cold air currents, to set the fibers in the bonded relation. The paper is then formed into a tube or sleeve-like member to provide the cake wrapper. The tube may be formed by overlapping the edges of the paper sheet, and subjecting the overloaded edges to heat and pressure whereby the cellulose ester fibers which occur at the edge are again activated to tacky condition, and bonded together to seal the edges. The tubular wrapper is then slipped over the rayon cake. to-be after-treated, the ends of the wrapper being tucked into the hollow center of the cake, and the wrapped cake is treated with the after-treating liquids, including an aqueous sa-poniiyingv medium, which may also. be a desulfiding medium for the thread, such as an aqueous solution of about 6.0% sodium sulfide and 0.5% sodium carbonate, finally washed, and dried, as

by centrifuging followed byexposure to circulat-v ing warm air currents.

As an example, when the Wrapped filamentary material is'desulfided using the solution or'sodium sulfide and sodium carbonate mentioned above, at a temperature of 40-45" C. for one-half hour, and the paper cake wrapper comprises 20% of cellulose acetate fibers, the percent combined acetic acid in the cellulose acetate component of the wrapper drops from 54 to 30%, and the wrapper shrinks correspondingly during the drying Step, with the development of crepe effects.

If unplasticixed cellulose ester fibers are laid down on the web carried by the travelling wire screen of the paper-making machine, they may be bonded to the surface by spraying or otherwise treating the paper with a solvent, or the paper may be provided with a thin film of a film--forming material, preferably regenerated cellulose, which will anchor the cellulose ester fibers to the paper, Means for practicing this embodiment of the invention is illustrated diagrammatically in Fig. 2, only a portion of the apparatus being illustrated, and the web I9 carrying the cellulose ester fibers 20 being shown as it passes from the travelling wire screen of Fig. 1. As an illustrative example, the structure carried by the screen may comprise 80% by weight of cellulose fibers and 20% by weight of cellulose acetate fibers, the ester fibers being in the form of bundles obtained by cutting or chopping 300 denier/80 filament cellulose acetate yarns having a twist of 2 turns per inch. The structure is dried by passing it between the heated calender rolls 2| and 22 which also serve to press the cellulose ester fibers against the web consisting of the other fibers. An aqueous solution of viscose of from 2 to 5% concentration is extruded onto the surface of the web carrying the ester fibers through the extrusion device 23, after which the product is passed through the vessel 24 containing an aqueous sulfuric acid coagulating and regenerating bath which regenerates the cellulose. After drying the paper carrying the cellulose ester fibers and regenerated cellulose film in any suitable manner, a suitable length of the paper is formed into a tube and sealed along its edges. For example, one edge may be brushed with a solution of cellulose acetate in acetone, and lapped over the other edge, the acetone evaporated, and the overlapped edges subjected to heat and pressure to seal them together.

A tubular cake wrapper in accordance with the invention is shown in Fig. 3, the cellulose ester fibers being in the form of bundles or yarn lengths distributed on the surface of the wrapper in a series of parallel strips or ribs 25. It will be understood that the cellulose ester fibers may occur at all portions of the surface of the paper base, the proportion of cellulose ester fibers being not less than 7% by weight. The upper limit for the cellulose ester fibers is not critical, but generally those fibers are used in an amount in the range of 7% up to 50%.

As shown in Fig. 4, the tubular paper wrapper is placed over the cake. When the cake is after-treated by liquids including an aqueous saponifying medium for the cellulose ester, the

ester groups are: removed, and the wrapper shrinks with the cake during the drying step, As shown in Fig. 5, the wrapper which fitted closely to the water-expanded liquid treated cake of Fig. 4, also fits closely against the surfaces of the dried and shrunkencake. Examples of, the cellulose ester fibers which may be used, in. plasticized. or. unplasticized. condition, are fibers of cellulose acetate, cellulose propionate, cellulose butyrate, and mixed cellulose esters such as cellulose ace.tate-butyrate..

Fibers of a material which is not affected as such by the saponifying medium, and suitable for makin the paper arenatural fibers such as wood, cotton, hemp, linen, abaca, or synthetic fibers such as regenerated cellulose fibers obtainable from viscose or cuprammonium. Such fibers may be of regular paper-making length or theymay be longer than normal paper-making length.

Generally, the alkaline desulfiding liquid which isalso a saponifying agent for the cellulose ester comprises an aqueoussolution of sodiumv sulfide which may or may not contain a small amount of other alkaline agents such as, for instance, sodium carbonate. However, other saponif ying agents may be used, if desired, and. it is within the scope of the invention. to treat the wrapped cake with a saponifying medium, at a stage separate from the desulfiding treatment, and prior to the final washing step.

If desired or necessary, the paper wrapper may be provided with 'a multiplicity of minute holes for increasing the porosity of the wrapper, prior to placing it over the thread cake.

The cellulose ester fibers may be activated by heat or the solvent to the point where they flow to form a film which is adhered to the surface of the paper, but preferably the fibers remain in essentially fibrous form in the wrapper. However, after the drying step, neither type of fiber occurs in its original condition, the de-esterified cellulose ester fibers being shrunken, with cockling of the remaining fibers to produce the creped effect.

The bonds between the fibers obtained by converting the cellulose ester fibers to adhesive condition by heating and then cooling the product to set the fibers in the bonded relation are not disturbed by the after-treating liquids. The fibers remain fixed in the bonded condition throughout the after-treatments and the drying step. The dried wrapper in which the fibers are unified by coalescence, i. e. by cellulose bonds, exhibits good tenacity and the dry Wrapped cake can be handled without tearing of the wrapper. Since the Wrapper shrinks with the cake, it can not slip relatively of the cake after the drying, and. this facilitates handling of the cake and prevents damage to the exposed layers of the cake due to brushing of the Wrapper thereagainst. Since the wrapper fits closely against both the inner and outer peripheries of the cake, the center of the cakes is left free to receive the rods or the like on which the wrapped cakes are supported for subsequent processing such as dyeing.

By a "liquid permeable paper-like cover or wrapper as used herein, is meant any permeable sheet material such as paper or thin felt-like products having good wet strength and of sulficient thinness and flexibility to be readily conformed generally to both the inside and outside peripheral surfaces of an annular thread or yarn package.

The above description and examples are intended to be illustrative only, and not to limit the scope of the invention. Any departure therefrom which conforms to the spirit of the invention is intended to be included within the scope of the appended claims.

I claim:

1. The method comprising distributing from about 20 to 50% by weight of cellulose ester fibers on a surface of an unperforated and unslitted sheet of liquid-permeable paper formed from cellulose fibers, said ester fibers being distributed only at spaced portions of the sheet, rendering the cellulose ester fibers adhesive and subjecting the sheet to pressure to obtain a sheet in which the ester fibers are autogenously bonded to the cellulose fibers, wrapping the unperforated sheet about all surfaces of an annular package of regenerated cellulose filamentary material freshly prepared from viscose, treating the wrapped package with aqueous after-treating liquids including an aqueous alkaline solution which is a desulfiding agent for the filamentary material and a saponifying agent for the cellulose ester to simultaneously desulfide the filamentary material and at least partially de-esterify the ester, finally washing the wrapped package, and thereafter heating all portions of the wrapped package to thereby (1) dry the filamentary material with shrinkage of the filamentary package and (2) shrink the sheet of bonded cellulose fibers and de-esterified cellulose ester fibers with the package.

2. The method of claim 1 in which the fibers 8 distributed on the sheet of cellulose fibers are cellulose acetate fibers and they are distributed in spaced parallel strips.

3. The method of claim 1 in which the desulfiding agent is an aqueous solution of sodium sulfide.

4. The method of claim 1 in which the desu1 fiding agent is an aqueous solution of sodium sulfide and sodium carbonate.

ORLANDO A. BATTISTA.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,847,269 Schur Mar. 1, 1932 1,912,625 Dreyfus June 6, 1933 1,961,914 Richter et al. June 5, 1934 1,968,356 Schmidt July 31, 1934 2,012,723 Lockhart Aug. 27, 1935 2,159,704 Levey May 23, 1939 2,208,653 Whitehead July 23, 1940 2,208,965 Dousma July 23, 1940 2,382,400 Decker et al. Aug. 14, 1945 2,414,833 Osborne Jan. 28, 1947 2,477,000 Osborne July 26, 1949 2,528,129 Francis, Jr. Oct. 31, 1950 FOREIGN PATENTS Number Country Date 502,045 Great Britain Mar. 10, 1939

Claims (1)

1. THE METHOD COMPRISING DISTRIBUTING FROM ABOUT 20 TO 50% BY WEIGHT OF CELLULOSE ESTER FIBERS ON A SURFACE OF AN UNPERFORATED AND UNSLITTED SHEET OF LIQUID-PERMEABLE PAPER FORMED FROM CELLULOSE FIBERS, SAID ESTER FIBERS BEING DISTRIBUTED ONLY AT SPACED PORTIONS OF THE SHEET, RENDERING THE CELLULOSE ESTER FIBERS ADHESIVE AND SUBJECTING THE SHEET TO PRESSURE TO OBTAIN A SHEET IN WHICH THE ESTER FIBERS ARE AUTOGENOUSLY BONDED TO THE CELLULOSE FIBERS, WRAPPING THE UNPERFORATED SHEET ABOUT ALL SURFACES OF AN ANNULAR PACKAGE OF REGENERATE CELLULOSE FILAMENTARY MATERIAL FRESHLY PREPARED FROM VISCOSE, TREATING THE WRAPPED PACKAGE WITH AQUEOUS AFTER-TREATING LIQUIDS INCLUDING AN AQUEOUS ALKALINE SOLUTION WHICH IS A DESULFIDING AGENT FOR THE FILAMENTARY MATERIAL AND A SAPONIFYING AGENT FOR THE CELLULOSE ESTER TO SIMULTANEOUSLY DESULFIDE THE FILAMENTARY MATERIAL AND AT LEAST PARTIALLY DE-ESTERIFY THE ESTERFINALLY WASHING THE WRAPPED PACKAGE, AND THEREAFTER HEATING ALL PORTIONS OF THE WRAPPED PACKAGE

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