US2072926A - Production of textile or other materials - Google Patents

Description

March 9, 1937. w. 1. TAYLOR PRODUCTION OF TEXTILE OR OTHER MATERIALS Filed Jan. 5, 1951 WILLIAM L TAYLDR INVENTOR flaw ATTORNEYQ Patented Mar. 9, 193'? PRODUCTION OF TEXTILE OR OTHER MATERIALS William Ivan Taylor, Spondon, near Derby, Engv land, assignor to Celanese" Corporation -'oi'--- America, a corporation of Delaware Application January 5, 1931, Serial N6."5os,63v

In Great Britain February 26, 1930,

3 Claims.

This invention relates to theunion of a number of artificial filaments of smaller cross-section into unitary filaments of larger cross-section.

According to the invention a number of associated artificial filaments which are in a soft or sticky condition are subjected to stretching, with the result that the filaments adhere together to form a unitary filament of large cross-section. The unitary filament has a full-round cross-section, with a smooth or comparatively smooth surface. It may, however, be flattened, crinkled, or embossed by subjection to pressure, for example In the manner described in U. S. application S. No. 406,356 dated November 11, 1929.

The sticky condition necessary to enable the filaments to adhere under the action of the stretch may be brought about in any suitable way. For example, a liquid having a solvent, softening, or swelling action on the substance of the filaments may be applied to the filaments in limited quantity, and preferably in the form of an extremely thin film, by means of a wick, or a rod, roller, or the like surface moistened with the liquid as described in U. S. application S. No. 393,287 dated September 17, 1929. Likewise, the liquid maybe applied as a spray or in vapour form, or the filaments may be led through a bath of the liquid.

The solvent may be applied intermittently along the length of the filaments, for example, in the manner described in U. S. Patent No. 1,909,192, with the result that on the application of the stretch intermittent lengths of the filaments are united together, while the remainder of the filaments retain their original independent character.

The operations mentioned above may take place continuously with the production of the filaments, or subsequently thereto.

A further method which may be adopted in carrying out the invention is to apply the stretch to the filaments at such a stage in their production that they are still soft or sticky by reason of a content of. residual solvent. Thus, in the manufacture of filaments of cellulose acetate or other organic derivatives of cellulose by the dry or evaporative'method, the filaments may be caused to unite into a unitary filament after they have left the spinning cell by making use of the combined efiect of stretching and the small quanmy of residual solvent still contained in the filaments, provided that the filaments are stretched over asumciently long The effect of the residual solvent in this connection it may Be increased by ifiemairig in the s inning solution a material suchasfor example vinyl acetate, which has a tendency toremain in the filaments for a longer period than the volatile solvent, e. g. acetone used in the spinning solution, and to keep them in a tacky condition for a longer period. v I A still further method consists in applying heat to. filaments of a thermoplastic character, such as cellulose acetate, to soften them sufficiently to form a unitary filament under the action of the applied stretch, Heat may also be used to assist in'the union of the filaments in any of the methods according to the invention which rely on the softening of the filaments by materials appliedto or contained in the filaments.

It is to be noted that unitary filaments produced without stretch, as for example by the methods described in U. S. application S. No. 393,287 dated September 17, 1929, may be of a relativelyi bulk'y; character probably on account.

of enclosed air spaces, andirregularities due to the retention to 'some'degreeofthe form of the individual primary filaments. The nature of the cross-section of the productptthe presentinvention will depend inthis -naspect upon the degree of stretch applied to the filaments, and the degree of softness or stickiness, greater stretch, and/or greater stickiness, whether due to residual solvent or to the application of further solvent and/or heat, resultingin a product having a smoother surface and a more solid cross-section. By controlling the factors of stretch andsoftness or stickiness, a product having any desired crosssection within a large range may be produced. An intermittently coalesced product, consisting of alternating lengths of unitary filament and. filamentary thread may beproduced if desired by the intermittent application 01 either of the above softening agencies, or,"ifjsufi'icient stretch be employed, a product consisting of alternate lengths of smooth,roun'd unitary "filament, and bulky, irregular unitary filament "may be 'obtained. Q p r The nature of the product may be modified by further treatment and theaddition of other materials to the filaments of which 'th'eproduct is made. Thus, there may be incorporated withthe product-dyes; or other=effect materials',f or metallic or other strands orf'w'ires'. O'rflagair'ij a product: having a low o'rreducedlustremaybeproduced by suitable delustrin'g t'reatme'rits.-' Any or all of these effects may be produced along the whole length of-the product or'.intermittently along portions of. the length thereof:

Several ways of carrying out the invention will now be described by way of example with reference to the accompanying drawing, principally with respect to the production of unitary filaments of cellulose acetate or other organic derivatives of cellulose continuously with their production by the dry or evaporative method, but it is to be understood that the following description is in no way limitative.

Fig. 1 shows a method of carrying out the invention continuously with the production of filaments by the dry or evaporative method.

Fig. 2 shows a method of carrying out the invention in the course of a bobbin-to-bobbin winding operation.

Referring to Fig. 1, a bundle of filaments II is extruded from a jet or nozzle I2 downwardly into a current of evaporative medium passing through a spinning cell or chamber I3, the major portion of the volatile solvent employed in the spinning solution being evaporated from the filaments before they leave the cell. The filaments associated in the form of a thread are drawn from the cell by a feed roller I5 and proceed to a further roller I6 whose peripheral speed is greater than that of the feed roller I5 so that the thread I4 is stretched to a slight extent. Before or after passing round the feed roller I5 (or first stretching roller) the filaments may be moistened by passage over a wick I1 with acetone or other suitable solvent, or softening or swelling agent. Examples of suitable solvents are low boiling solvents such as acetone (commercially pure, or mixed with water) ethylene dichloride and ethyl or methyl alcohol, dichlorethylene and ethyl or methyl alcohol etc., high boiling solvents or plastifiers such as diacetin, triacetin, ethyl lactate, diacetone alcohol (alone or mixed with water or alcohol) dibutyl tartrate or tricresyl phosphate, and mixtures thereof. The use of high boiling solvents or plastifiers imparts increased pliability to the product. Under the stretch applied between the two rollers I5, IS the filaments in'the thread I4 which have been rendered sticky by the solvent or the like adhere to each other to form a. single larger filament I8, which proceeds to a winding device I9, and is collected thereon.

Before or, more advantageously, after passing round the second stretching roller I6 the unitary filament I8 may be moistened with any suitable lubricant by means of a wick as shown at 20, the application of which material removes any residual stickiness which might cause the filament I8 to adhere on the package formed in the winding apparatus I9.

The operation above described may be carried out otherwise than continuously with the production of the filaments, for example, during a bobbin-to-bobbin, or other winding operation, as

shown in Fig. 2, wherein the filaments, associated in the form of a thread I4 are taken from a bobbin 2| and passed over a wick 22, or like device to render them sticky or tacky. After passing over the wick, the filaments are led successively round two rollers I5, I6, of which the second, I 6, rotates slightly faster than the first. The filaments coalesce under stretch to form a unitary filament I8, which passes over a. lubri-. eating wick 20, and proceeds to a winding device I9, by which it is collected in the form of a package. If desired, a flattened product may be obtained by the use of the roller 23, which is adapted to be pressed against the under side of the roller I6. The roller 23 may if desired, be

embossed or wavy to produce an embossed or crinkled product.

Means are shown in Fig. 2 for incorporating additional material in the unitary product. The

additional material 27 is associated with the r filaments I4 prior to stretching, such materials being preferably brought into a sticky or tacky condition by means of a solvent or softening material applied by a wick 28. If the same softening or solvent material is effective to both of the threads I4, 21 the wick 22 may be used for both.

The solvent or softener may be applied to the filaments in any suitable way, as in the form of a spray or vapour or by passing the filaments over wicks, as shown in the drawing, or rollers, rods, or other devices moistened with the requisite quantity of the solvent or the like. Similar methods may be adopted for the application of the lubricant, a wick being particularly suitable for this purpose.

Instead of applyinga solvent or the like to make the filaments sticky, adhesion of the filaments may be effected by stretching the thread of associated filaments while they are still not completely set. By the addition of suitable substances, such as for example, vinyl acetate, to the I spinning solutions of cellulose acetate or other organic derivatives of cellulose, the filaments may be maintained sticky for a longer period when this method of producing the unitary filaments is adopted.

It is even possible to utilize the small quantity of solvent remaining in the filaments spun from the usual solutions of the cellulose derivative in volatile solvents such as acetone after they emerge from the spinning cell to cause the filaments to unite, provided that a sufiiciently longrun say, 4 to 6 feet is given to the filaments between the feed roller and the stretching roller.

If heat is to be applied to the filaments to render them sticky, any of the methods indicated above, the filaments may be led round a heated roller (which may be the feed roller) or through a heated chamber before or during the application of the stretch.

After union of the filaments, further stretch may be imparted after another application of heat, or solvent or the like, or both, in order to improve the qualities of the filament and in particular to give it a smoother surface.

either alone, or in conjunction with It will be understood that the degree of stretch 7 necessary to effect the adhesion of the filaments is small, and that the denier of the unitary filament produced can be controlled by choosing such size or number of primary filaments as will give a unitary filament of the desired denier under the conditions adopted.

In order to produce a flattened, intermittently flattened, or crinkled or embossed product, the unitary filament produced in the manner indicated above may be led through nipping rollers, having appropriately formed surfaces, while they are still in a somewhat soft or sticky condition. Conveniently, the nipping rollers may be used to apply to the filaments the stretch by which they are caused to unite.

Composite threads containing two or more filaments of a continuous or intermittent unitary character or one or more such filaments together with one or more primary filaments may be formed by separately forming the unitary fila-v ments and associating the several filaments. prior to winding. If desired, a bundle of filaments proceeding from a spinning cell may be divided into groups, one or more of which may be formed into the unitary filaments before reassociation of the several filaments of the bundle.

In effecting the union of the small filaments into a single thread or into one consisting of lengths of unitary filaments alternating with lengths of individual filaments, it is advantageous to employ a thread of filaments which have been twisted together, the applied stretch then pulling the twisted filaments into intimate contact with each other and causing them to unite very firmly together.

Colour efiects may be produced on the unitary filaments by applying suitable dyestuffs at any suitable stage of the process of manufacture; that is, prior to the application of stretch simultaneously therewith, or after the filaments have coalesced. under tension to form the finished product. Where a coalescing solvent is applied and the dyestufi is applied prior or subsequently to application thereof, the said dyestufi should preferably be applied in the form of a solution in organic solvents, as described in U. S. application S. No. 284,673 dated June 11th, 1928. The dyestuff may be applied prior to the application of the coalescing liquid, by means of wicks, rollers, and the like in a continuous manner to produce uniform colour, or intermittently to form differential colour efiects. A further convenient mode of application of the dye is in solution in the coalescing solvent. Other modes of applying the dyestuff may also be used; for example the finished product may be dyed in hanks or in the form of other packages by any suitable known dyeing methods.

Products which are delustred or opaque may be produced in accordance with the invention, and this efiect may be obtained continuously along the length of the product or intermittently as desired. In the case of cellulose acetate or other organic derivatives of cellulose the delustred or opaque effect may be produced by subjecting the product to the action of water or other aqueous media, alcohol, steam or other delustring agency after coalescence. Another mode of obtaining this effect is to apply a soluble metal salt (such as a salt of barium, strontium or calcium) to the yarns or filaments (of whatever kind) about to be coalesced, either in the coalescing liquid or by separate application and then after coalescing to subject the product to a chemical treating bath that precipitates the metal in the form of an insoluble compound (such as sulphate, carbonate, or phosphate).

Ornamental eifects of the nature of differential color efiects or differential lustre may be produced by associating other yarns having different delustering or dyeing properties, or yarns which have been dyed or delustred in a diiferent manner, with the material to be coalesced, Examples of such yarns are those made of natural silk, wool and cotton, and (if thefilaments to be coalesced are of cellulose acetate or other organic derivatives of cellulose) viscose or other reconstituted cellulose yarns and vice versa. Metallized effects may be produced by associating with the material fine fiat metal bands, such as are used in making tinsel, or metallized threads or yarns, prior to coalescing. If desired, a bronze or aluminium powder or like material may be incorporated in the product at any suitable stage of manufacture to produce metallic or other effects. In the case of yarns or strands of additional materials which are not in a sticky or tacky condition, it is preferred that they should be incorporated during stretching, or towards the end of the stretching process, since the application of stretch to such materials might be liable to cause them to break, or to restrain the process so that stretching cannot be carried out on the sticky filaments themselves.

The invention is not of course limited to the production of unitary filaments from filaments of cellulose acetate or other organic derivatives of cellulose but may be applied to artificial filaments of the reconstituted cellulose type which are in a suitable sticky condition for adhesion under the application of stretch. Further, filaments of both types, when sticky or tacky may be used together for the purpose of the invention.

After the production of the unitary filaments or the composite threads containing them, they may be collected by any suitable reeling or winding, or twisting and winding operation.

What I claim and desire to secure by Letters Patent is:

1. Process for the production from a number of artificial filaments of a single filament of larger cross-section, said process comprising heating a number of filaments of a thermoplastic derivative of cellulose while they are associated together, and stretching said filaments while they are in a soft condition so as to cause them to merge permanently together to form a single filament of larger cross-section.

2. Process for the roduction from a number of artificial filaments of a single filament of larger cross-section, said process comprising heating a number of filaments of cellulose acetate while they are associated together, and stretching said filaments while they are in a soft condition so as to cause them to merge permanently together to form a single filament of larger cross-section.

3. Process for the production from a number of artificial filaments of a single filament of larger cross-section, said process comprising extruding a spinning solution of cellulose acetate in the form of a number of filaments, said solution containing vinyl acetate, associating said filaments while they are in a soft condition and stretching them so as to cause them to merge permanently together to form a single filament of larger cross-section.

WILLIAM IVAN TAYLOR.

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