US2090669A - Artificial fiber - Google Patents

Description

1937- v c. DREYFUS ET AL 2,090,669

ARTIFICIAL FIBER Filed March 29, 1934 INVENTORS 0. DR EYFUS uo W. wan-mm o ORNEYS Patented Aug. 24, 1937 UNITED STATES PATENT OFFICE ARTIFICIAL man Delaware Application March 29, 1934, Serial No. 717,928

10 Claims.

This invention relates to the permanently distorting of textile yarns and the like and more particularly relates to distorting or crimping staple fibers, containing organic derivative". of cellulose or other cellulosic derivative.

An object of the invention is to impart more bulk to yarns, fabrics and the like and to increase the binding power between filaments of yarns built from fibers of discontinuous length, known in the textile art as staple fibers and spun yarn. Other objects'of the invention will appear from the following detailed description.

Fig. 1 is a side view partially in section of a device for carrying out this invention.

Fig. 2 is a fragment of a modified form of crimping roll to be used on the device shown in Fig. l.

Crimped or distorted staple fibers are of advantage in the manufactureof yarns and the 20 like. Prior to this invention, synthetically produced staple fibers have been straight and undistorted or at the most only slightly curved.

We have found that the web flowing from a dofiing cylinder on a rotary fiat card holds to- 5 gether much better with crimped synthetic fibers than in the case of synthetic fibers that contain no distortions and that this is due to the fact that with crimped synthetic fibers, there is a tendency of one fiber to hook into another or 30 other fibers.

Distorted and crimped staple fibers form a bulkier and stronger sliver on the carding machine and this bulkier sliver may be more easily drafted or more easily and uniformly reduced 35 in size, as by stretching and produces more uniform and strongeryarns than the synthetic undistorted staple fibers. By the economic and expeditious method and device of this invention there is produced a simple and effective means 40 of imparting distortions to fibers in particular to synthetic fibers that otherwise are undistorted.

By this invention there is produced, a more uniform and stronger web of such fibers on the dolling cylinder in carding, and a bulkier and more 45 uniform drafting sliver may be formed, that,

spun to a yarn produces a yarn of more covering power and higher strength. The fibers, due to their interlocking structure, are more easily processed and do not separate or blow out of place 50 while in the loose sliver or card.

According to this invention fibers or filaments, usually synthetic filaments thathave little or no distortions, are pressed between serrated faces or other engraved or embossing faces, while in a 55 softened or plasticized condition to permanently impress into the fibers, distortions that are preferably closely spaced. The preferred form of this invention is to pass the filaments or fibers between serrated faces, the serrations of which intermesh, thereby bending the fiber or filament several times along a unit length. The bends or distortions may vary as to the number per inch from 1 to 30 or above, but for common use between 6 and 16 bends per inch of fiber is quite effective and practical. The bends or distortions may also vary or not vary in size and frequency along the length of the fiber.

The serrated faces may be on fiat plates but preferably the process is made continuous by feeding a band or rope of yarns or filaments between nip rolls, the faces of which are serrated and the serrations of each fit approximately in the serrations of the other. The faces of the nip rollers may be brought into close contact and pressing relation with the fibers by means of weights, spring pressure, hydraulic pressure or any other means. It is also preferred that the pitch of the ridges of the serrations should vary in accordance with the denier of the filaments, straws and high denier filaments requiring a coarser pitch.

It is preferred that the pressure applied by the pressing devices described should be controlled in order that it should not be so severe upon the filaments or yarns under treatment as to damage them. For this purpose, the pressing surfaces should be so mounted that they are held out of direct contact with one another and are thus prevented from cutting the yarns. Thus, if rollers are used having patterned or serrated surfaces, the patterns or serrations should preferably be such as to intermesh without allowing contact between the surfaces of the rollers, and the rollers should be positively and preferably adjustably spaced apart, and synchronously driven. By these means the yarns or filaments passing be tween the rollers are distorted, the clearance between the rollers being small enough for the application of a distinct pressure upon the yarns or filaments, while at the same time there is no application of a cutting action on the filaments.

formed into a band similar to a warp that is passed through the pressing device to receive distortion and then cut into staple lengths. This band of filaments may, however, be cut into staple 5 lengths prior to entering the pressing device.

The band of filaments may be formed by drawing the same from bobbins or other suitable packages as in forming a warp by means of a creel 01' they may be drawn directly from a plurality of spinning machines where they are produced.

In this form of the invention, it is preferable to employ yarns having no or a low degree of twist so that the individual filaments may readily be separated from each other in an openingup process after being crimped. It may be desirable, however, to produce yarns in which the individual lengths consist of a few fibers twisted together, in which case yarns may be employed having a substantial degree of twist. This invention is also applicable to distorting single yarns of continuous filaments.

When the filaments are to be treated while arranged in a warp-like band the serrations on'the pressing devices may be such as to run at right angles to the band or obliquely thereto. Obviously when the distortions are run obliquely to the band and at the same time with an irregular frequency along the length of the filament, the number and position of the distortions will vary from filament to filament when the yarn or band is subsequently cut into short lengths at right angles to the band. In this manner a mixture of fibers having unlike distortions are produced that have better spinning properties.

This invention is applicable to the distortion of yarns, filaments and fibers artificially produced such as reconstituted cellulose, made by either the viscose process or the cuprammonium process, and the ethers, esters and substituted prodnets of cellulose. It is of special application to the treatment of the organic derivatives of cellulose filaments that contain for example organic esters or ethers of cellulose or mixed esters and/or ethers of cellulose. Examples of organic esters of cellulose are cellulose acetate, cellulose formate, cellulose propionate and cellulose butyrate, while examples of cellulose ethers are ethyl cellulose, methyl cellulose and benzyl cellulose.

The yarns and filaments may contain a plasticizer either as a coating or incorporated into the filaments. They may also contain effect materials such as pigments, filling materials, dyes or lakes, fire retardants, deelectrifiers, sizes and lubricants. Examples of fire retardants are beta chlornaphthalene, triphenyl phosphate and tricresyl phosphates. Examples of lubricants are olive oil, teaseed oil, mineral oil, alone or with aids and protective materials such as oleic acid, phenol, benzene, cyclohexanol, etc. Examples of filling and weighting materials are powdered metal, oxides, carbonates and sulfates of metal, other fibers and organicmaterials that, incorporated with the yarns, tendto absorb light. The yarns or filaments may be weighted with tin, lead or other weighting metal compounds. Examples of sizes are wax, gelatines with or without hydroscopic and lubricating material, starches, gums, glycerides, resins, etc. Examples of materials which, added to yarn, form an electrical conductor of the yarn thus preventing the retention of a static electric charge on the fibers, are inorganic hydroscopic salts such as calcium chloride, calcium nitrate, etc. and the mono-, di-, or tri-etha-' nolamine salts of the fatty acids. These effect materials may be incorporated in the yarn by adding the same to the spinning solution from which the yarns are spun or they may be added to the yarns along with a swelling agent just prior to distorting them.

Where serrated rollers are employed, the feed rate of the yarns or filaments, through the nip rolls may vary considerably according to the pressure on the yarns, temperature, and the softener and/or solvent used. The feed rates may be from 50 to 300 or more meters per minute. We find that the distortions may be made more permanent by employing heat and thus one or both of the pressing members may be heated. The heat employed will vary with the nature of the fiber to be distorted, its melting point, if any, the speed of distorting, the thickness and size-of the band being acted upon and the amount and nature of the softening agent and/or solvent employed.

In processing fibers of the reconstituted cellulose type, according to this invention, any of the usual softening agents for these fibers may be employed. Thus; in processing fibers of reconstituted cellulose formed as viscose, cuprammonium or denitrated nitrocellulose, a 5% aqueous solution of sodium hydroxide, potassium hydroxide or ammonia may be applied to the yarns prior to their treatment in the pressing device. In this case, either one or both of the pressing members should be heated to a temperature sufficient substantially to dry the fiber. The alkali should then be removed, preferably before further proccasing, to avoid its corrosive properties and irritation on the hands of operatives. The alkali may be removed by fiowing water onto a package of the material or it may be readily removed by extraction with alcohol.

In processing fibers of thermoplastic derivatives of cellulose, as cellulose acetate, swelling agents, restricted solvents and solvents restricted by dilution with non-solvents may be employed. Here also it is of advantage to use heated pressing members or distorting faces so that the distortions may be imparted permanently and the fibers may not be further distorted or undistorted by winding up or future processing. The particular solvent employed will be governed by the type of material and the effect materials'that it contains, care being exercised in view of the action of certain so-called restricted solvents or swelling agents and plasticizers, becoming at elevated temperatures actual solvents or such powerful plasticizers that the yarn disintegrates readily under pressure. Examples of suitable softeners and restricted solvents for cellulose acetate are steam, water, aqueous alcohol, alcohol, aqueous acetone, dilute ethylene dichloride in benzene, etc. Preferably the vapors of these solvents should be removed by fan or other means. Such vapors may be recovered by'the usual methods, as by absorption. When steam is employed as the softening agent it may be applied to the yarn by passing the yarn through a steam chamber located close to the crimping device such that the heat and moisture of the steam is present in the yarn at the time the pressure is applied thereto.

A unique effect may be produced by applying dyestufi during the crimping or distorting process or prior thereto while applying the softening material to the yarn. This is particularly effective where the thermoplastic derivatives of cellulose are employed in that many of the swelling agents or restrictive solvents, plasticizers and softening agents are solvents for dyes that have an afllnity for derivatives of cellulose. Thus in dyeing and distorting yarns of cellulose acetate,

both benzene and ethylene dichloride are strong,

solvents for general dyestuffs which dye thermoplastic derivatives of cellulose and 10-20% of ethylene dichloride dissolved in benzene is a good swelling or softening agent for fibers composed of cellulose acetate with an acetyl value of 45% combined acetic acid or more.

Where water or steam is used as a softening 2o agent and heated rolls with a temperature of 80100 C. are employed for distorting the fibers, the dyestufis may be applied to the fibers from a normal printing paste, which may or may not contain a softening agent. In this case, it is preferable, although not essential, to age the printed and distorted fiber by steaming at normal or increased pressure prior to scouring as this improves in general the fastness of the dye.

Many beautiful effects may be imparted to the resulting fabric by applying to the yarns during distortion an irregular or intermittent pattern. This may be effected by passing the band of yarns in contact with printing rolls furnishing dye on their passage to the nip rolls, distorting rolls or presses. Or the fibers may be intermittently saponified. A further effect may be obtained by. applying a thickened print paste to the band of yarns being fed to the distortion presses and causing the male and female parts of the presses to engage so that the yarn is pressed unevenly in each distortion thereby forming an uneven distribution of the coloring matter as the part of the filament pressed most will contain less dyestufi, see Fig. 2.

Improved properties may be imparted to the resulting yarn by forming same of crimped filaments that vary in denier alorrg their length. The denier may be varied by intermittently changing the conditions in the spinning ,cabinet 50 or by varying the pressure in the spinning head in the formation of the filaments.

In the foregoing description there is described the process of crimping or distorting fibers, yarns, etc. with or without coloring or otherwise 55 treating the fiber. This process may or may not be a process separate from processes involving the initial formation of synthetic yarns. Thus the distorting of filaments may be conducted simultaneously with such initial formation proc- 60 ess. In such a process, a band of filaments or yarnfrom one or a plurality of spinning jets, on issuing from the spinning chamber, cell or bath, is led through a pair or more of distorting rolls and then to cutters or to a winding 65 device. This is particularly of economical advantage in employing thermoplastic derivative of cellulose fibers spun from solutions of organic solvents such as acetone, alcohol, ethylene dichloride and the like. Here the spinning condi- 70 tions may be adjusted so that sufilcient residual solvent may remain in the yarn as it reaches the crimping or distorting rolls, thereby imparting sulficient plasticity or softening action to the filaments for the crimping or distorting process. "15 For the purpose of retaining residual solvent,

say 8 to 30%, in the yarn until it reaches the crimping presses, adjustment may be made in the normal spinning conditions, such, for example, as lowering the temperature, shortenin the length of the spinning cell or the path of travel of the yarn therethrough, increasing vapor pressure of solvent or solvents employed and by adding solvent-retaining materials to the spinning solution. In the wet method of spinning corresponding changes may be made.

From the crimping presses the yarn may be wound into packages from which it is cut into staple lengths or the band may be grouped together and may or may not be treated with various coating materials and cut by a device as disclosed in U. S. application S. No. 695,503. Thus, by a continuous purely mechanical process the yarns may be formed, crimped, coated and cut to staple lengths ready to be carded or otherwise processed.

In Fig. 1 of the drawing is shown a frame If consisting of two spaced apart upright bearing members. These frame members are suitably secured to a base i2 as by lag screws l3. Mounted in the lower part of the frame members are bearings ll for supporting a serrated or engraved roll l6. Slidable blocks I] are mounted in guideways l8. In the blocks are bearings IQ for supporting a serrated roll 20, the serrations of which are adapted to register with the serrations of roll E6. The blocks I? are supported by comparatively strong springs 2| that hold the blocks in the uppermost position allowed by the setting device consisting of threaded hand screws 22 having hand pieces 23, and threaded holding means 24 suitably fastened to the upright members II. The setting device is adapted to maintain the two serrated rollers at any desired distance apart. It is preferable that both rollers be positively and. synchronously driven. The driving means may be of any suitable construction. Means may be supplied. such as electrical resistance, steam or open flame, to heat either one or both rollers.

On the feed side of the rollers is a trough 26 having a roll 21 suitably journaled therein, which roll may be of metal, wood or a roll covered with a wick material. In operation a softening agent, to which may be added a lubricating, deelectrifier or other liquid, is placed in the trough 26 thus supplying the'liquid to the roll 21 across which the yarns or warp-like band of yarns are drawn. By this means the yarn is supplied with an even treatment of treating material. For example, if the yarns are drawn from packages and not direct from the spinning cabinet, a restricted solvent or softening agent, either alone or mixed with another suitable agent, may be applied.

In Fig. 1 the serrations on the rollers are shown as normal serrations in which the malev and female parts are equivalent to each other thus exerting an even pressure on theyarns throughout the length of the yarns. In Fig. 2 is shown a side view of fragments of two rollers the male and female parts of which are not equivalents andthus .an alternate heavy and light pressure is applied to the yarn. The yarn held between the parts of the rollers 28 are pressed very heavily I while the parts of the yarn held between the parts of the rollers 29, although pressed, are not pressed as tightly as that between the parts of the rollers 28. By using this type of serration and ap-,

plying a thick printing paste with the device 26-41 the yarn is crimped and the paste is pressed into thick concentration on the apexes 01' the crimp and thinned out on the straight portions of the crimp. The yarn may be aged or subjected to steam to fix the dye and then scoured to remove the excess paste, dyeing the 5 yarn a darker shade where the dye was concentrated.

In operation a band of yarns ll drawn from a creel or a plurality of spinning jets is drawn over the coating furnishing device 26-21 where it is suitably coated and then between the rollers l6 and 20 where a crimp is imparted to the yarn.

After leaving the crimping rollers the yarn may be formed into packages or further processed according to U. 8. application S. No. 695,503. In place of the furnishing device 2621 there may be employed a steam chamber through which the yarns are drawn and subjected to wet or dry steam at atmospheric or superatmospheric pressure.

It is to be understood that the foregoing description is givenmerely by way of illustration and that many variations may be made therein, without departing from the spirit of our invention.

Having described our invention, what we de- 25 sire to secure by Letters Patent is:

1. A device for crimping filaments which comprises a-pair of intermeshing corrugated rollers of such'contour that when meshed they provide nonuniform clearance, the apices of the corrugations 30 being substantially fiat.

2. A device for crimping filaments which comprises a pair ofcoacting spaced corrugated rollers, the apices of the corrugations being substantially flat and means for adjusting the spacing of said 35 rollers.

3. Process for the production of artificial filaments of improved characteristics, which com prises pressing organic derivative oi cellulose v tificial filaments, while said filaments are in a r 40 softened condition, between intermeshing corrugated surfaces, the pressure of which varies at intervals along the length of the filaments so as to impart to the filaments both a general crimp along their length and local distortions at the points of varying pressure.

' 4. Process for the production of artificial filaments of improved characteristics, which comprises pressing artificial filaments containing cellulose acetate, while said filaments still contain a substantial proportion 01' residual solvent, between intermeshing corrugated surfaces, the pressure of which varies at intervals along the length of the filaments so as to impart to the filaments both a general crimp along their length and local distortions at the points of varying pressure.

5. Process for the production of artificial filaments of improved characteristics, which comprises subjecting organic derivative of cellulose artificial filaments to the action of heat and pressing the same between intermeshing corrugated surfaces, the pressure or which varies at intervals along the length 01 the filaments so as to impart to the filaments both a general crimp along their length and local distortions at the points of varying pressure.

6. Process for the production of artificial filaments of improved characteristics, which comprises subjecting artificial filaments containing cellulose acetate to the action of heat and pressing the same between intermeshing corrugated surfaces, the pressure of which varies at intervals along the length of the filaments so as to impart to the filaments both ageneral crimp along their length and local distortions at the points of varying pressure.

'7. Process for the production 01' artificial filaments of improved characteristics, which comprises subjecting organic derivative of cellulose artificial filaments to the action or steam and pressing the same between intermeshing corrugated surfaces, the pressure or which varies at intervals along the length of the filaments so as to impart to the filaments both a general crimp along their length and local distortions at the points of varying pressure.

8. Process for the production 01' artificlat filaments 01' improved characteristics, which comprises subjecting artificial filaments containing cellulose acetate to the action of steam and pressing thesame between intermeshing corrugated surfaces, the pressure of which varies at intervals along the length of the filaments so as to impart to the filaments both a general crimp along their length and local distortions at the points or varying pressure.

9. Artificial organic derivative of cellulose filaments having a general crimp along their length and also having local distortions at the crests and troughs of said crimp along the length of the filaments.

10. Artificial organic derivative of cellulose staple fibers having a general crimp along their I length and also having local distortions at the crests and troughs of said crimp along the length of the fibers.

CAMILLE DREYFUS. WILLIAM WHI'IEHEAD.

Images