US2494468A - Method for the continuous production of synthetic fibers - Google Patents

Description

Jan. l0, 1950 B. BoRzYKowsKl 2,494,468

METHOD FCR THE CONTINUOUS PRODUCTION oF SYNTHETIC FIBERs Filed Nov. 12, 1943 7 sheets-sheet 1 A TF0 R AfL-VY.

.Fo EO E950 B BoRzYKowsKl 2,494,468

METHOD FOR'THE CONTINUOUS PRODUCTION 0F SYNTHETIC FIBERS Filed Nov. l2. 1945 '7 Sheets-Sheet 2 Jan., E0, E950 B. BoRzYKowsKl 2,494,468

METHOD FOR THE CONTINUOUS PRODUCTION OF SYNTHETIC FIBERS 7 Sheets-Sheet 3 Filed Nov. l2, 1943 INVENToR. 1&)1/1140 www Afro/tmf y Jan; w, 1950 8 6 Aw m A 2 B. BORZYKOWSKI METHOD FOR THE CONTINUOUS PRODUCTION OF SYNTHETIC FIBERS 7 Sheets-Sheet 4 Filed Nav. 12, 194s INVENTOR.

' 5mm OVG Jan. w, yE950 B. BoRzYKowsKu NETHOO FOR THE CONTINUOUS PRODUCTION OE SYNTHETIC EIEERs 7 Sheets-Sheet 5 Filed Nov. l2, 194.3

mw @u mm. @my Wmv Jam, EG, i959 B. BoRzYKowsKl 2,494,468

METHOD FOR THF: CONTINUOUS PRODUCTION OF SYNTHETIC FTBERS Filed Nov. 12, 194s 7 sheets-sheet e BY QW AI77/W05 Y J, m9 11950 B. BoRzYKowsKl NETHOO FOR THE CONTINUOUS PRODUCTION 0F SYNTHETIC FIBERS '7 Sheets-Sheet 7 Filed NOV. `l2, 1943 IN V EN TOR. lfm an/y/Qw/' BY ffm .427? RNE' X Patented Jan. l0, 1950 METHOD FOR THE CONTINUOUS PRODUC- TION OF SYNTHETIC FIBERS Benno Borzykowski, New York, N. Y., assignor to ilmingto Swiss Borvisk Company, W

n, Del.

Application November l2, 1943, Serial No. 510,004

4 claims. l

This invention relates to a method for the continuous or direct production of synthetic twisted or untwisted fibers and yarns suitable for direct use on textile machines.

The term direct or continuous used in this specification with regard to the herein described manufacturing process indicates that from the moment the spinning mass is extruded through the forming orifices the formations are conducted through a plurality of treating phases and converted into endless finished fibers, cut staple bers and staple fiber yarn intermediates, staple ber yarns and finished endless threads, without having been previously wound on drums, reels, bobbins or into cakes, packages or the like.

The term "solidification used in this specification includes any kind of conversion of a suitable basic not solid raw material, for instance, also a molten spinning mass into a solid filament.

The term lament denominates the products obtained by solidification of the extruded spinning mass formations while being in an unfinished state. The articles obtained in an untwisted form after the solidified filaments have been subjected to finishing treatments are termed in this specification finished fibers. The twisted finished endless fibers are termed threads These fibers may be converted within the framework of this invention into staple fibers, staple ber yarn intermediates such as tops, slivers, rovings and finished staple fiber yarns of a predetermined denier and lwith a predeterminedv number of individual bers.

This terminology is not different from the one customarily used in the art; however, it has been considered advisable to create a clear situation with regard to the technical nomenclature used in this specification in order to exclude misunderstandings.

Since the birth of' the art the production of synthetic bers and threads has been and is still being carried out as follows:

The spinning masses or spinning solutions are extruded in an approximately round, flat or similar shape from a single orifice, such as a capillary tube, or from a number of openings in the nozzle or spinnerette, and the formations are conducted either through appropriate media, for instance heated air, when working according to the socalled dry spinning process, where the volatile solvent is evaporated, or cold air where the spinning mass formations are chilled-or through a coagulation bath in the wet spinning process.

The freshly coagulated filaments are guided vertically to carriers, such as bobbins, reels, or

they are led vertically to godets which pull the filaments with a certain speed from the solidifying phase to individual pots driven at a high speed wherein the filaments are thrown by centrifugal force against the pot walls; thereby the filaments are twisted together and with the aid of a special guide simultaneously assembled in a cake.

For many applications synthetic fibers of a high tensile strength are required; this is obtained when the fibers are stretched during their formation by means of positively driven stretching devices; as described in my U. S. Patents Nos. 1,401,943 and 1,450,131. Fiber bundles of a heavy total denier having a high tensile strength and high flexibility are of great importance in the production of, for instance, rubber tire cords for heavy loads where threads of 2400 and possibly 4800 deniers preferably directly spun in one jet, are required. If using bobbins or pots, 250 gram packages will, therefore yield threads of a continuous length of only 800 m. in 2400' den. and of only 400 m. in 4800 den., whereas to avoid as much as possible big knots which such heavy deniers will produce in the cords, tire-fabrics and similar articles threads of many thousands of meters in length should be used.

The use of larger bobbins or pots to obtain threads of greater length having less knots is impractical and uneconomic for the following reasons: A

Larger bobbins or pots will cause a considerable reduction of the number of threads which would be produced per standard size spinning machine, and the larger cakes will complicate the finishing treatments and result in th formation of threads of inferior physical properties due to the constant reduction of the diameter of the collecting space in the pot, causing uneven tension of the thread.

The present day spinning machines which due to the complicated system of individual driving devices for each bobbin, each godet or each pot cannot be built at costs as low as other thread producing machines, and furthermore, the short life of said spinning machines and the high power consumption are further adverse factors.

Although in my U. S. Patents Nos. 1,401,943 and 1,450,131 I have shown the manner how to stretch the filaments during thevcoagulation by means of positively driven cylinder rotated with a higher circumferential speed than the cylinder which draws the fibers from the coagulation bath, the threads produced on the vertical spinning machines do not possess the properties obtainable stance, 1200 den. is spun with a speed of only 50 meters per minute, the thread in formation will remain in contact with the coagulation liquid in the trough for a fraction of a second only.

which is not suiiicient for such a heavy denier.

The dimculty to add drawing godets to the standard centrifugal pot spinning machine for the purpose of obtaining positive stretching actions between two godets is obvious, and it is also evident that the machine must become more complicated and crowded, when such a great number of godets are provided for these purposes; furthermore, it is a highly inefcient procedure to wind each thread around each drawing godet and each stretching godet and to provide in order to prevent the threads to fall on from the godets or to slip upon the same glass or similar individual guides for each thread near each godet as this causes uncontrollable and uneven frictions and consequently variations in the orientation of the miscelles, of the tensile strength etc.

In order to fully understand the advantages of the invention particularly for the production of high tensile strength synthetic fibers, a description of the present methods used in the art seems appropriate.

In accordance with the present practice, the so-called high tenacity rayon .threads are, after having been dried and wound on bobbins, hereafter warped in a second operation in an untwisted or only slightly twisted stage on standard or special size rayon beams. Several hundred threads are spread out between the heads of the beams placed apart approximately 54 inches. The weightl of the yarn on the beam varies depending on the denier and number of the threads wound on the same, but it may well be assumed that the same will be about 800 lbs.

The reasons for the customary supply of said so-called high tenacity rayon threads on beams are that better mechanical properties are expected to result when the threads of the rayon warp are treated with an aqueous dispersion again on another specially built machine, stretched in the course of said treatment, again dried and wound on another beam.' Without going further into the question whether the quality of the iinished product can actually be improved by a second wetting, stretching, drying and beaming, there can be no doubt that even if this would be a simple procedure but could be avoided by my process and apparatus, there would be an important advance in the art of production of high tenacity rayon.

However, the complicated and unpractical procedure above referred to is considerably increased when the following is considered:

From a beam of 54 inches upon which, as stated. several hundred threads are wound, the threads must be conducted to as many twisting spindles to be provided with the required twist for the tire cords. Several hundred spindles in a row require many times the space ofthe beam 4 even if smallest size twisting spools are used in order to bring the spindles closer together; this again causes much more knots in the cords in comparison with the use of big size spindles and twisting bobbins.

The object of the invention is the production of synthetic fibers by the wet or dry spinning process from any kind of raw material, by using a special simple and inexpensive equipment for the formation and, if required, stretching, neutralizing, impregnating, drying or for other treating steps by conducting horizontally all of the great number of the iilamentvbundles produced on the entire machine to a common and not to an individually driven device for each bundle and leading the same from the moment the filaments are extruded from the spinnerettes through all the required treating stages with a great production speed and by winding the same in the finished form in practically endless length as single or plied bundles of capillary bers in untwisted form on special reels suitable to form, if required, a

beam or on any other carrier suitable for the l direct use on textile machines.

, A further object of said new process and equipment is, as above stated, to produce said threads with a much higher tensile strength, greater iiexibility, thorough impregnation with latex containing dispersions, perfect adhesion of the same tol a greater length has been wound on the collecting device than extruded per time unit from the spin- A nerette and hereafter coaguiated in the precipitation medium. Upon further investigation confirmed by practice I was surprised to find that much better results are obtained when the following rules are observed:

That in the viscose (cellulose xanthogenate) process, for instance the spinning solutions have a higher concentration than normally used, namely at least 8% preferably lil-12% cellulose contents.

That the viscose be fresh or in the first stage of its maturity, namely C12 or Cra stages. Under no circumstances shall the viscose change into xanthogenate:

(CqEoOxh CntCS BNa or into a higher polymerization described as a' necessity, e. g. in German Patent No. 187,369 and still used in the industry.

That the precipitation (coagulation) must not be sudden but slow so that the filaments shall remain in a semi-plastic stage during the several stages of stretching and elongation, as hereafter more fully described. In the case of fresh vis- A cose to produce 300 den. with a speed of 150-180 the size or denier of each capillary filament and the size or denier of each bundle of filaments and further depending on the tensile strength, flexibility and elasticity required in the final product; at any rate, the stretching shall be carried out in two or more stages whereby between the first i and second and the subsequent stretching stages to shrink or'- 2' l agents nor to the quantities thereof to be susthe thread shall be given a chance contract to a certain extent.

For certain purposes, as for the production of cords for rubber tires, rubber belting, skatingrequirements and the applications of the final rollers and the like, the filaments must be treatedA with suspensions containing latex, resins etc.

The difiiculty which the rubber tire producers have in obtaining a thorough impregnation even of cotton threads having more or less fuzzy or rough surfaces with rubber and the proper adhesion of the same to the filaments is well known. These difiiculties are increased considerably when synthetic, e. g. viscose fibers, having a smooth surface are treated with such rubber suspensions. Numerous processes have been proposed to overcome these obstacles. According to British Patent 435,395 a suggestion is made to wind the fibers on perforated beams and treat the thus produced cheeses by soaking the latex through the same and removing the excess latex with air pressure and thereupon double and twist the undried threads by machines of the flyer or ring traveler type.

While investigating the problem of treating synthetic threads with dispersions I found that these difficulties may be avoided by using the process forming another object of my invention which comprises as an important object (1) Impregnating the fibers with dispersions A in such a manner that each individual filament is subjected to this type of treatment. This aim is achieved at a time when the capillary filaments are yet untwisted, lie parallel to each .other and are not dried as yet. Sometimes it may-be of great importance that the threads should be impregnated and at the same time stretched orshrunk, thereupon dried and wound, beamed untwisted or twisted in the same continuous operation and hereafter, eventuallyalso in the same continuous operation united under certain temperature and pressure with other materials.

(2) Adding to the spinning mass, for instance' to the viscose solution, one or a mixture of several ingredients usually employed in the latex dispersion which are soluble or remain in colloidal form in said spinning solutions, but after preon the individual capillary :fiber forming a rough surface or a. somewhat porous surface if leached out from the formations. i

A very small admixture of these agents to the spinning mass sumces for these purposes inasmuch as the aqueous latex dispersion due to the present invention is applied on each capillary thread before the filaments are dried, viz. immediately after the washing and before desulphurisation, but after squeezing out the surplus of the washing liquid from the filaments by rollers or other means as hereafter more fully described. The latex dispersion penetrates easily into the soft, not entirely solidied filaments and .ad-,

heres strongly to the rough surface threof.

Latex dispersions usually containin addition to other ingredients sulphur, carbon black and zinc oxide; 23% of .these substances in admixture with a barium compound calculated on the weight of the cellulose in the viscose solution emulsifiedand finely dispersed therein vwill in mostl cases be sumcient to produce .a rough surface on each capillary filament. g The latex dispersion will penetrate quite deeply into each capillary filament even without using an appropriate wetting agent.

I do not limit myself to the above recited pended in the'viscose or other spinning masses as the same can vary considerably depending on the products. 'I vhezadmixture of a barium compound to the viscose-solution given by way of examplevonly shows to the man skilled in the art one Vway hovvv ether, resin, protein and even on natural fibers,-

by incorporating into the starting material or by the impregnation of the nished fibers with bodies having the characteristics of the barium compound, i. e. to remain finely dispersed in the spinning or impregnating solutions and upon a precipitation of the same to form coarse grains of an insoluble` precipitate, such as barium sulphate on and in the fibers which after thorough washing to remove the soluble salts, remain practically insoluble in water.

(3) In addition to or independent of the above cited process to procure a, proper anchoring of the latex dispersion tothe synthetic fibers, the fresh formations after having undergone the stretching or positive elongation, but before they are entirely set, being subjected in course of the further operation to a mechanical surfaceA crimping action, for instance passing the samev over grooved-rollers, as more fully described heretherein has a kind of a fuzzy surface, also facilitates a proper anchoring or adhesion of the latex dispersion; A

As apparentv vfrom the above, it is the :main object of the invention to obtain in one single 5 continuous operation continuous s thetic fibers, cipitation of theformations -adhere firmly in and yn tion to greatly simplify the manufacture and im-` prove the quality of synthetic fibers and yarns and to accordingly enhance the economy ofthe production.

It is an equallyim'portant object of the invention to obtain the finished synthetic fibers,l

threads and yarns as substantially endless and knotless bodies. 4

It is also an object of the invention to carry out the treatments adapted to convert the endless bers into staple bers, staple ber intermediates, such as tops, slivers and the like, and staple ber yarns, when they are still untwisted and in substantially parallel alinement.

It is an essential object of the invention to produce chemically and mechanically uniform articles.

It is an important object of the invention to exclude manual handling with its accompanying injuries to the ber and to accomplish the manufacture of the nal articles in one continuous operation.

It is also an object of the invention to improve the mechanical properties of the synthetic bers, threads, intermediates and yarns and particularly their tensile strength and flexibility,

absorptiveness for surface roughening agents,`

and to reduce brittleness.

It is an important object of the invention to provide a manufacturing method which permits an easy variation of the working conditions and in conformity therewith of the mechanical properties, of the denier of the finished threads, of the surface characteristics, without an interruption of the continuity of the manufacturing procedure.

It is also an object of the invention to modify the surface conguration of the threads in the regular course of the manufacture for a specified use.

It is an object of the invention to improve the sanitary conditions oi' the manufacturing installations and to prevent contamination of the air with fumes and sprays emanating from the various treatments.

It is another object of the invention to increase the working capacity of themanufacturing appliances or spinning units.

With these and further objects in view which will become apparent as this specication proceeds, the invention is illustrated by way of ex.

ample in the attached drawings in its application to the production of substantially endless and irnotless synthetic untwisted or twisted bers and wound up ber bodies and to the conversion of the fibers into staple fibers, staple ber intermediates and staple ber yarns, in a form ready for use on textile machines.

With the above recited purposes' and other purposes in view which will become apparent as this specification proceeds the invention is by Way of example illustrated in the annexed drawings as applied to a Wet spinning process.

It is, however, Well understood that any not solid spinning masses may be employed in conjunction with this invention adapted to be converted by solidication into filaments, bers and ber bundles.

In the drawings,

Figs. l and la is a vertical sectional view of a part of a spinning machine to be used for the production of synthetic nished bers in conformity with this invention,

Fig. 2 is a top plan view of a part of the ma.- chine shown in Fig. l,

Fig. 3 is a front elevation of a conveyor roller for use in the operation of the machine,

Fig. 4 isa vertical sectional view of a modication of a part of the spinning machine shown in Fig. l, including superposed coagulation baths.

Fig. is a vertical frontv elevation of a reel assembly for upwindlng the finished bers,

Fig. 6.

Fig. 10 is a front elevation of an auxiliary device for use in the treatment of the filaments,

Figs. 1l and l2 are vertical sectional elevations of two modifications of the machine shown in The solidilying zone As shown in the drawings my horizontal spinning machine comprises a table I and a plurality of coagulating and treating troughs supported on foundation blocks 3 and encased in enclosure 2. Openings IIO are provided in the walls of the enclosure 2 which is closable by slides III; 'a dome I I2 is located in the ceiling of the enclosure for the accumulation of gases and vapors which are withdrawn therefrom. Grooves II3 provided in table I serve to collect and to discharge waste liquid.

Candle lters 4 for the nal filtration of the spinning solution are mounted on table I which extends transversely through the entire operating width of the machine.

Pipe systems I3 and l.Il for the supply of the spinning solutions are located underneath table I. Pumps I5 driven by gears Ill are connected with supply pipes I3, I4. Pipes 5 connect the candle filters with the spinnerettes 6 which feed into the coagulation baths.

According to the present exemplification of the invention three coagulation baths 1,-., I

are provided which are located in direct succession in the longitudinal direction of the machine, and contained in troughs I0, II, I2. Each of these coagulation troughs extends transversely through the entire operating width of the machine or of the adjacent spinnerettes. The troughs are divided by removable partitions I6 in adjacent compartments I1 to receivethe filaments produced by' the individual spinnerettes. If it is desired to increase the productive ca pacity' of the spinning machine without enlarging the operating width two sets of pumps and fed systems, double sets of lters located on the table in staggered relationship may be installed as shown in Figs. l and 2.

'I'hls arrangement is particularly useful if instead of, for instance, 1100 denier 2200 denier bers with the double amount of filaments are.

required for certain purposes such as the man- A ufacture of tire cords.

In this case partitions I6 are removed and larger compartments I8 are formed, receiving two bundles of laments I9 from two spinnerettes which are united by a guide cylinder 20 to form one lament bundle.

This modication of the invention may be advantageously used in combination with the staggered arrangement of the candle filters.

Conveyor roller aggregates composed of a plurality, for instance, three rollers 2i, 22, 23 are mounted above coagulation bath 1. 'These rollers extend transversely to the longitudinal extension of the machine through its full operating width. the operating with of the machine mvy substantially corresponding to the operating width of all spinnerettes.

The conveyor roller aggregates perform functions which are highly important inasmuch as the size and the properties of the fibers are largely influenced by their specific operation. 'I'he location of the conveyor roller aggregates is adjustable in the longitudinal direction of the machine; this makes it possible t vary the distance thereof from the spinnerettes or the coagulating path between the spinnerettes and the conveyor rollers. Needless to state that other ways may be used to vary the coagulating path.

The coagulating path may be constant if a specific fiber or yarn with certain properties as to its tensile strength and elongation or other properties is to be produced at a predetermined speed; if, however, different types of fibers,

threads or yarns with derent properties or of a change of the productlon speed is desired, the distance of the roller aggregate from the outlet of the spinnerettes may be adjusted by displacement of the same or by displacement of partition wall H in the longitudinal direction to shorten or lengthen at will the operating path or length in the coagulating baths.

A further important function of the rollers which are partly positively driven is to exert a stretching action upon the filaments which in a general way is recited in my Patents 1,401,943 and 1,450,131; this stretching treatment adds in a specific manner greatly to the success of the present continuous process, as explained in a later part of this specification.

All filaments extruded from all spinnerettes of the machine are transported by roller 2i through coagulation bath 'l and maintained underneath its level by guide cylinder 20; instead of the guide cylinders other suitable guiding devices such as guide hooks may be used.

The conveyor rollers are made from materials which are not attacked by the chemicals used in the process, such as organic solvents, oils, etc.; they should preferably have a, sumciently large circumference so that the filaments will not slip or slide thereon.

Roller 2i draws all the filaments i@ produced in the machine with a predetermined speed from the coagulating solution without any or with a very small tensioning action in order to avoid breakage of the tender semi-gelatinous filaments.

Roller 22 rotated at a greater circumferential speed than roller` 2i will stretch or elongate the filaments accordingly, whereas roller 23 will, depending upon the changing requirements, be either rotated with a somewhat lower speed to reduce the stretching action or with a higher circumferential speed than roller 22 to exert an additional stretching or elongating action.

If, for instance, roller 2l draws 100 m. of the filaments per minute from the coagulation bath, roller 22 may be operated to draw 110 meters per minute; this will result in an elongation of If roller 23 is then driven to draw only 109 meters per minute, the shrinkage or retraction of the laments between rollers 22 and 23 will be one meter and the total elongation 9%.

This retraction is very advantageous if, depending on the denier of each capillary filament, a high tensile strength in addition to an average elasticity of the finished fibers is desired; if, however, a lower elasticity is required and a higher tensile strength, an additional elongation between the rollers 22 and 23 may be advisable.

Depending upon the number of the capillary l filaments to be assembled in the individual bundles and on the tension imparted to the same when conducted through the various producing stages, the conveyor rollers may be provided with grooves 25, Fig. 3, which also prevent the lament bundles from being entangled.

To further assist and to promote the action of the grooves and to prevent the slipping out and breaking away of the individual filaments from the bundles a device is located in the traveling path of the filaments before they reach the conveyor rollers 2|, 22, 23, which I prefer to denominate as a false or incomplete twister.

This device, shown in Figs. 1 and 10, is composed of two rods 26, |21. These rods are mounted on a beam 39 extending through the width of the machine; the rods are staggered as shown in Fig. 10. The change of the traveling direction imparts to the filaments a slight twisting action.

Partition wall H5 may be made displaceable in the traveling direction of the filaments, which displacement serves, as previously explained, to vary the coagulation path.

The adjustment of the coagulation path which may be obtained by any other suitable means is of great importance for the operation of my continuous process because the longer or shorter contact with coagulating liquids of dierent composition, for instance acidity, greatly inuences the coagulating procedure and correspondingly the nal properties of the coagulated filaments.

The filaments discharged from roller aggregate 2i to 23 are conducted into coagulation bath t and kept therein under the level of the coagulating fluid by means of cylinders 20. The filaments are then drawn from this coagulation bath by rollers 2l, 20, t. In conformity with the above remarks the coagulation in the ilrst bath l can easily be adjusted to obtain an uncomplete coagulation, whereupon the filaments during their passage through roller aggregate 2l-23 are stretched between rollers 22, 23 shrunk or additionally stretched between rollers 22, 23 and then conducted into the second coagulation bath 8.

Roller 2l acts as a mere transport means. Roller 28 pressing by inertia on the filaments is rotated by friction and removes in cooperation with roller 2l excessive coagulation liquid. Roller 29 is driven at a greater circumferential speed than roller 2l and therefore exerts a corresponding stretching action upon the filaments, whereas roller 30 is operated in a manner which is similar to that of roller 23, that is with a higher or lower circumferential speed than that of roller 29.

A permanent orientation of the miscelles is hereby effected in the ibrous filaments.

Roller 3l cooperates with roller 30 in the same manner as roller 28 with roller 2l.

Rollers 30, 3i may be provided with projections or teeth 33 to produce on the incompletely solidied filaments surface irregularities in the form of rings or grooves before they are conducted into media adapted to convert the same into the iinished fibers. The subdivision of the coagulation into individual stages or baths which renders it possible to control the same in such a manner that the filaments in the first stage or bath are incompletely coagulated and that the coagulation is then continued and completed in the additional baths or coagulating stages is, as already previously stated, an important element of the invention. Whereas in the rst stage 1 of the coagulation practically no or so little pull or tension is exerted on the freshly formed illamentsthat they pass through bath 1 in the freely suspended horizontal disposition, the iilaments after leaving bath I are stretched on their way to the second bath 8 by rotating roller 22 with a circumferential speed in excess to the speed of roller 2|. A further stretching or shrinking action may be applied to the iilaments by adjustment of the circumferential speed oi rollers 21, 2l, 30.

A principle oi feeding the coagulating liquid is employed in connection with my invention which as yet has never been and could not have been applied to the vertical manufacture of synthetic illaments, nbers and threads.

In accordance with this novel supply system the coagulating liquid is introduced into the coagulating troughs in countercurrent to the traveling direction oi the nlaments. The successful realisation oi this feed principle is rendered possible by my continuous horizontal process. The fresh precipitation liquid heated to the required temperature is preferably supplied at that end of the troughs which is opposite to the illament entering end.

The application of the countercurrent principle makes it possible to gradually reduce the alkalinity oi' the laments, to contact the extruded spinning mass with a coagulating medium oi lowest acidity which is gradually increased/as the solidilcation of the laments progresses.

The countercurrent feed of the coagulating liquid has resulted in a surprising improvement of the mechanical properties of the threads and particularly the tensile strength.

In accordance with the above explained principle supply tubes 34 for the coagulating liquid are mounted near to the rear end of the troughs, and vertical branches 35 extending into the troughs are connected to this main feed tube. The overiiowing liquid passes into discharge funnels 31 and from there into discharge pipes 33.

The lament drawn from the coagulation bath meets the fresh coagulation liquid having the highest degree of acidity which gradually decreases in proportion to the increase of solidiilcation. The feed velocity of the coagulating liquid and the acid concentration is so calculated that in the vicinity of the nozzles, where the iet of the spinning solution immerges into the coagulant, a state of near neutrality but of suilicient acidity prevails to prevent alkalization of the coagulant. Tis countrcurrent feed system is not restricted to coagulation solutions, but is likewise usable with any other solidifying medium, such as hot or cold air, gas and the like.

The third and final solidiiying bath 9 is equipped in a similar manner as the proceeding coagulation baths 1 and 8.

The third roller aggregate 4I, 42, R3. 44. Fig. 1a, constructed similarly to roller aggregate 21 to 3|, with the only omission of roller 3i, draws the maments out of trough 9.

A modified arrangement oi' the coagulation equipment is shown in Fig. i, whereby the manufacturing capacity oi the machine is greatly increased without enlarging the operating width.

For this purpose a plurality oi superposed staggered spinnerettes 6 may be provided in trough 48, or a plurality oi' superposed coagulating troughs 45 and 48 with several superposed rows of spinnerettes i may be installed.

By extruding the spinning solutions into the coagulation troughs 45, 46 two superposed rows of filaments bundles I9 are produced which are conducted through the coagulating bath and emerge from the bath over guide rollers 41. The filaments are drawn from the baths by positively driven rollers 48 located in a dripping trough 49 and jointly discharged into a coagulation bath 53. They are conducted by a three roller aggregate 50, 5i, 52 which is similarly constructed to roller aggregate 2|, 22. 23, into another coagulation bath and subjected to further treatment in the same manner as described in conjunction with Figs. 1 and 1a.

Il' the threads are used for the manufacture of tire cords or for similar purposes, where they are treated with a sulphur containing rubber or latex dispersion, the spinning machine can be made much shorter as the desulphurizing, washing, bleaching, washing, acidifying and washing may be elimin-ated.

If the threads are used for standard weaving and knitting purposes requiring only standard tensile strength and elasticity and need not be purely white, the spinning machine can also be shortened by using another treatment step forming a part of this invention, namely the application of only one agent which will convert the coagulated unpurified iilaments in one single operation in its purified form.

If, for instance, a viscose spinning solution is used, a treatment consisting of (1) Washing the threads wound on perforated bobbins or collected in pots in the shape of cakes on special machines to ,absolute neutrality,

(2) Desulphurizing with a hot sodium suliide is replaced by passing the slightly rinsed, still acid laments into a hot solution of sodium sulte. The concentration oi this solution may be varied in dependence upon the size (denier) of the individual ilaments, the number of the nlaments in each bundle, the speed oi production and other working conditions.

The sodium sulilte dissolves the sulphur contained in and deposited on the surface of the illaments; on the other hand it reacts with the acid ci the coagulation bath adhering to the filaments and neutralizes the same whereby one part of the NazSOa is decomposed under the formation of H2803 which exercises a bleaching action on the filaments. The sodium sulite solution at the same time eliminates the salts contained on the fibers. A 2% sodium suliite solution and a treating temperature of between 60 to 65 C. will in most cases give satisfactory results.

The thus treated filaments require only simple short rinsing with hot water; the above reierred to long tiresome series of apparatus. operations, space of installation, power, injury oi the fibers may thus be avoided.

Instead of sodium-sulte another agent acting in the same or similar manner may be employed.

The'same result is obtainable in the production of filaments from other starting materials, such as formations from a cuprammonium-cellu- 13 lose solution which may be treated, as above described, immediately after the elimination of its copper content with sulphuric acid. v

At the end of the iinishing stage and before the filaments are conducted into the drying zone, the following important treatment constituting an additional object of my invention may be employed.

The tension of the illaments is loosened but only to such an extent that they do not contact each other or do not slide on the bottom of the treating trough into which they are conducted A hot emulsion or solution is kept in the trough in constant circulation in order to penetrate into each individual capillary illament from which liquids contained therein from previous treatments have been squeezed out as much as possible through rollers or other appropriate devices.

The type oi emulsion or solution to be used for this treatment will depend upon the intended application.

If they are to be used (1) For a high twist as required for ne stocklugs or the like an easily saponiable oil or emulsion as usually used by throwsters to produce crape twist may be employed;

(2) For weaving warps the filaments may be sized with customary protein sizing compounds;

(3) For use in circular rashel or warp knitting machines a mineral oil emulsion will produce goed results;

(fl) For the direct production of a 100% spun rayon continuous yarn or a 100% partly spun and partly continuous rayon yarn produced in one simultaneous operation on my spinning machins, it is advantageous to use (a) In case of bright rayon where no dulling agents have been added to the spinning mass a slightly alkaline hot soap and vegetable oil emulsion containing, for instance, a nely divided barium or similarly acting compound; the iilaments are drawn through a bath made up of this agent and are then passed into an adjacent trough containing diluted sulphuric acid which precipitates an insoluble compound on the surface of the iibers giving the same a somewhat rough touch and dulled luster.

This treatment improves the adhesion of the cut staple fibers to each other and the conversion oi the same intospun rapon threads as hereafter more fully explained.

(b) In case dull threads are spun from solutions or masses into which oils and/or fats with an addition of a barium or similar compound has been admixed, it is suiiicient if the threads after having been freed from the residual uids oi foregoing treatments are drawn through a trough containing a hot sulphonated oil emulsion to prevent complete drying of the loose untwistecl capillary laments in the drying zone and to render the same more pliable and exible for further specially mechanical operations.

In order to start the operation of my horizontal spinning machine either provided with a series of successive single coagulation troughs, as shown in Figs. 1 and 1a, or with a multiple of superposed coagulation troughs having a multiple of superposed rows oi iilaments as shown in Fig. 4, each individual bundle of capillary laments emerging from the coagulation baths may rst be wound on reels 54, shown in Fig. 4, which rotate in troughs 55 containing sullphuric acid to convert the threads in cellulose hydrate.

As soon as all threads from all spinnerettes have been wound on these reels, the entire row of illamets is caught by a bar or the like and con ducted through the successive coagulating and treating baths, the drying zone and the subsequent stages of my machine, which will be more fully described as this specification proceeds. A8 soon as all rows of filaments have been set into operation in this manner, the work is continuous- 1y carried out without interruption, the troughs 55 with rollers 54 being discarded from the regular operation of the machine.

The fibers wound on the reels 54 may be used for the production of staple fibers or other suitable purposes.

In case the spinning of a bundle of filaments is interrupted, the restarting of the continuous spinning of the respective bundle may be carried out in the following manner:

'Ihe iilter or the nozzle or both are replaced; the extruded fresh filament bundle is attached to an adjacentcontinuous bundle at a suitable point after the extrusion and carried by the same through the entire machine; there it is wound on a new reel or bobbin or knotted together with the broken end.

The finishing and drying zone through the entire operating width of the machine are located in this zone in ldirect horizontal succession.

Treating liquids are supplied to the troughs according to the individual requirements. Only one trough t is shown in Fig. 1a for purposes of illustration. The laments are conducted through these nishing troughs by the same type of roller equipment and guiding means used in the soliditying zone.

A drying installation of customary construction indicated in the drawings lby cylinders 5l is arranged in direct horizontal succession to the nishing troughs.

Conveyor rollers 5t are provided to discharge the finished dry bundles 59 from enclosure 2.

Any modern drying equipment driven at a speed synchronized with the above described part of my continuous spinning machine will work satisfactorily if precautions are taken to properly deal with continuous untwisted fibers and provisions are made to have variable speed drives to control the stretching and shrinking of the filaments passing through the dryer in the manner as this is carried out in the case of rayon warps.

After-finishing sone Contrary to the customary procedure used in rayon manufacturing plants where the threads are wound on bobbins from which rayon warps are made on speci-a1 machines whereby many hundreds or some thousands of threads are wound on =a common beam from which, as described above, al1 the threads are led through another machine to be sized, dried and again wound a second time on beams, three alternative ways dealing with the dried continuous untwisted bers or fiber bundles are provided in conformity with my invention signifying s. marked deviation from andV a considerable advance inthe state of me art.y

(1) If it is the intention to-utilize the threads in the untwisted state, for instance, for further conversion into rayon cords, the dried. fiber bundles 68 eventually treated with a latex dispersion are wound on reels illustrated in Fig. 1 and Fig. 5, to assemble thereon great lengths of fibers.

This device comprises a plurality of reels Il! of a rather large diameter; the reels are mounted adjacent to each other on square shafts 6I. The reels are provided with square recesses 82 which are so dimensioned as to :be easily slid onto shafts 6I. Spacer rings 63 fastened on shafts 6I by screws 64 are provided to hold the reels on the shafts in such a manner that their center is in alinement with the center of the thread guide.

In order to be able to wind several bundles and larger quantities of the threads on each reel common shaft for each row which will turn each reel by friction devices will in certain cases .be desirable, for instance, if different lengths of threads are required on some of the reels, or if a fiber bundle was broken and restarted after a certain lapse of time so that the respective reel will hold less yarn when the thread was restarted a uniform tight winding of the threads on the respective reel could not be achieved with square shafts and square recesses, as all the reels would turn with the same speed.

The consumers of the yarn, for instance, cord producers, mount as many of these reels on similar shafts and run as many fibers from individual reels if required through dispersions or solutions as can be accommodated in the impregnating machines, leading hereafter the fibers from one or several adjacent reels directly and in straight line to the ring or similar twisting devises to obtain the required twist. Thereby not only the previously described unpractical way of twisting the threads which are unwound from big beams, but also the packing and transporting of the same is avoided. The reels S0 may preferably be made of light materials and provided with recesses 65 to reduce their weight.

(2) When twisted threads are required, l the bundles of the capillary fibers emerging from the drying zone are directly conducted to ring or similar well known twisting devices, which can also be installed in two or three superposed levels whereby increased space for bigger spools is obtained and the exchange of the spools filled with yarn against empty spools is facilitated.

(3) My above described new horizontal continuous spinning system affords also a most eilicient way for the direct production of synthetic fibers of an hitherto unknown entirely new construction, namely of an endless 100% direct denier spun staple fiber yarn of a predetermined denier and predetermined number of individual filaments.

The cut fibers produced by the wet spinning.

process are neutralized, washed, purified. for instance desulphurized, or decopperized, and treated by many other uids in the same manner as 7s Fig. 1. All the fiber bundles 59 produced on the 16 described above when dealing with continuous fibers, before they can be properlydried. This 'drying of wet cut staple fibers requires complicated and expensive devices, upkeep etc., due to the unfinished or embryonic stage of the dlaments, because in order to convert the same into finished fibers suitable for the various manipulations prior to and during the real spinning in the cotton, wool, worsted, fiax spinning mills on cotton or other spinning machines, preferably all the moisture content must be removed uniformly throughout the layers in the dryer, otherwise the fibers are damaged-during the opening.

As long as such staple fibers have been used for blending or mixing with natural fibers or other synthetic staple fibers, for instance viscose with wool, to diminish the quantity of wool and! or to obtain cross dyeing or other effects, it was comprehensible to a certain extent that the in parallel alinement produced synthetic fibers after having been cut into staple fibers were tangled up and thrown crosswise in all directions because the natural and synthetic fiber with which the staple fiber is to be blended must be well divided and mixed and therefore undergo anyhow the usual carding, combing, several drawing stages and rovings before the yarn can be spun on the ring spinning frame or a self-acting mule.

However, since a very large percentage of staple fibers is at present converted into and can be sold in large quantities as a 100% staple fiber yarn, this invention solves the following important problem. This problem comprises the direct production in one continuous operation on the synthetic filament spinning or coagulating equipment and without recourse to the usual preparatory and reel spinning machines now used in the textile industry of the following new type of synthetic spun fibrous articles:

(a) A continuous synthetic yarn made from any kind of proper starting material by solidifying, hardening or coagulating, treating the iilaments, if required, and simultaneously converting the same eventually in the same operation into a 100% finished spun yarn of a predetermined number and size of the individual filaments and diameter or denier of the finished yarn.

(b) The saine yarn as described under (a), but consisting partly of fibers cut into staples and partly of a continuous synthetic thread made at the same time from the same starting material on the same equipment.

(c) The same yarn as under (b) in which at the same time of producing the capillary filaments there is embodied another thread or threads made from another kind of cut or continuous synthetic or natural fibers.

(d) A continuous synthetic staple fiber roving, top or sliver of predetermined number of filaments for a predetermined yarn number wound in endless packages or appropriate reels, spools or the like, suitable for further conversion on standard spinning machines into yarn, cords, breeds, etc., as such or in combination with other synthetic staple fibers and continuous threads and/ or natural fibers and threads.

An apparatus for carrying out this important embodiment of my invention is exemplified in Fig. 6 and will be described hereafter with reference to its above recited four variations.

Variation a The apparatus is located in direct horizontal succession to the spinning machine shown in 17 entire machine are discharged from housing 2 and conducted by conveyor rollers 58, if the produced capillary threads do not possess a suicient rough or crimped surface or the required interber friction to obtain a strong yarn, into a trough 66 which is provided with a jacketed heating wall 61. A cylinder 68 is rotatably mounted in the trough to transport the bers through the same. An appropriate oil, for instance an oil used in blending wool, is charged into the trough and maintained therein at a suitable temperature and at a constant level. A nely divided non-slip resin or a similar compound may be added to the oil capable to assist in the production of the above mentioned surfaceconguration. The ber bundles are further transported by a pair oi' rollers 11, 18. These rollers squeeze out the surplus oil. -They are provided with heating means and with teeth or projections 19 which exert upon the bers passing between them, if required, a crimping or goffering action.

When the yarn to be produced does not require oil treatment .for treatment with similar agents, it may be nevertheless advisable to use rollers 11, 18 in order to produce the above referred to crimping action.

The ber bundles 59 are then transported to a roving or drawing frame. The type of this frame may be chosen in conformity with the length and the character of the staples to be cut and the kind of yarnto be produced. Before entering this drawing frame 88 the ber bundles are conducted in an unstretched state by smooth transport rollers 8| to a conically shaped smooth bar 82 which segregates or spreads out the bers of each bundle, and brought with the aid of rollers 83, 84 working in cooperation with an adjustable transport device 86 to the roving frame 80 to effect the further transport of the ber in each bundle in a substantially straight parallel alinement into the frame 80 which is' provided with three pairs of rollers 88, 89, 90.

Before the bers of each bundle reach the drawing trame 88 they are` cut by cutter 85 into staples of desired length. The knife is adjustably mounted on its support in order to cut the bers of each ber bundle separately into equal sections 81 of a required length, which are diagrammatically shown in Figs. '7 and 8; during the passage of the cut bers over the transport device 86 a lengthwise mutual displacement is effected of the same whereby overlapping ends are produced, shown by dotted lines II9 in Figs. '1 and 8. This purpose may be accomplished by varying the circumferential speed of rollers 83, 84 and of the rst pair of rollers 88 of the drawing frame 88. The formation of the overlapping ends of the cut bers is important as this results in a greatly improved coherence of the staple bers.

The cutter for each ber bundle may be provided with two inclined cutting edges forming between each other an approximately right angle; accordingly shaped cuts H8 are produced, as shown in Fig. '1.

The staple bers of each` individual bundle or a plurality of the same provided with overlapping ends forming a kind of a ribbon are conducted separately into the drawing frame represented by three roller pairs 88, 89, 90 where 18 transport devices 9| to twisting spindles oi customary design, such as yer 92 where they are converted into yarns.

For special purposes, e. g., the production of very ne spun synthetic ber yarns of, for instance, 150 den. two installations of the type shown in Fig. 6 may be arranged in vertically superposed relationship one above the other. This modication of the invention is shown in Fig. 11. The cutters 85 of thetwo superposed installations are so mounted as to cut in diagonally opposite directions.

Numbering adjacent ber bundles with cur rent numbers I, 2, 3 and so forth, as shown in Fig. 2, the ber bundles with numbers I, 3, 5

each composed, for instance, of bers to produce 50 den., are cut in the lower equipment and produce bands of parallelly alined staple bers.

cut in a shape indicated as group A in Fig. 8.

The ber bundles numbered with even numbers distance from the rollers than in the lowerl equipment; the bands of staple bers produced thereby are illustrated schematically as group B in Fig. 8. In order to obtain yarn of 150 den.. the bands of the staple ber bundles I, 2, 3 are combined after emerging from the transport rollers 9| of the upper equipment (Fig. 11), to form a sliver consisting of two bands shaped as shown in group B and one band shaped as shown in group A and sandwiched into a staggered product which is converted into a twisted yarn by the yer 92.

The twisting may also be accomplished with a ring twisting spindle 95, the roving being brought directly through the drafting rollers 94 to the twisting spindle 95 and wound on the bobbin 96 shown in Fig. 12. The thus alined overlapping sandwiched and staggered staple bers a synthetic ber intermediate, such as a. top,

sliver, roving, respectively is produced from each of the ribbons. The intermediates are transported by a, pair of transport rollers or other which with their spliced ends grab the neighboring bers in the manner of fangs, will even in the case of a ne product, as a, den. spun staple ber yarn is, .result in the production of a thread having a tensile strength and evenness which is not obtainable with any other system producing spun bers.

Variation b Yarns of partly cut bers and partly of continuous bers can be produced:

(1) By using only the lower cutting equipment and cutting in the same, for instance the uneven numbered bundles I 3. 5 sandwiching between two of them one continuous ber bundle of the even numbered bundles 2, 4, 6 if. from the upper system, and conducting the same directly to the twisting device,

(2) By using one band of cut bers and one continuous ber bundle,

(3) By using two uncut continuous bundles and one band of cut bers,

(4) By cutting with the upper or lower or bothequipments all bundles and guiding the bands of one or more ber bundles through the respective drawing and roving frames, adding before or during ,the twisting ofthe same a continuous untwisted or twisted thread of the same material fed from reels IIS, Ill, shown in Fig. l2.

Variation c `In case the thread to be produced should consist of, for instance, 25% wool, 50% viscose and 25% of acetate and the nished thread to be of 19 the size corresponding to, for instance the size oi' a thread of 1000 den., then the bers to be extruded from each spinnerette to be of 250 den.

and each of the two rovings or slivers wound on appropriate bobbins or reels 250 den. The two kinds oi' rovings are united with the band of nbers and lead simultaneously through the drawing, roving and twisting devices, as shown in Fig. 12. In this case the roving consisting of the three different materials after leaving the upper rollers 9| are led through the lower rollers V9| to the flyer 92 as indicated by the dotted line, and not to the upper twisting spindle and bobbin 94, Fig. 12.

Variation d It is obvious from the foregoing that my invention embraces also the manufacture of products listed as variation d even though the same are not converted into finished spun yarn, the essence of my invention being the production by an uninterrupted direct or continuous process on a new type of equipment at a high speed of endless or continuous untwisted synthetic iibers with the enumerated properties which are wound simultaneously in great length on special carriers and without unwinding .can be used as such directly on textile machines or simultaneously twisted and wound as iinished threads in great length on appropriate carriers for the direct use on textile machines; furthermore, after having been eventually crimped, dried, etc., during their production cut into staple fibers and transformed in the same operation into staple fiber intermediates, such as rovings or slivers possessing a predetermined number of iibers and denier, the production being carried out in a horizontal equipment on which the path of coagulation, the degree of stretching, shrinking, the time of treating, drying, etc., can be varied at will.

Due to the continuity of my horizontal process an access to the precipitation bath is only required if and when a spinnerette must be renewed. The parts of the machine where gases, bad odors, vapors or the like are generated, are entirely enclosed by housing 2 and efdciently ventilated, access to each enclosed part being provided by openings like IIU. The bobbins or reels when filled with yarns are exchanged for empty ones at the far end of the machine when the fibers are finished and dried.

The same advantages are achieved when iibers are produced from masses which are solidified by air or other gases.

It is admitted that in the latter case the manu" facture may be carried out at a higher speed than by the wet spinning process on the standard vertical machines; however, all of the above cited drawbacks adherent to the vertical system requiring drawing, stretching etc., of each individual thread by many separately driven devices and the high costs of such machines remain at a considerably increased rate. On the other hand, the above referred to advantages of my process and the possibility to improve the quality of the threads during their production by the easy variation of the positive stretching and /or shrinking action, by the impregnating, sizing or other treating action performable as one continuous operation with the cutting of the fibers and their conversion into yarn oi' spun fibers are not obtainable in the hitherto customary system of vertical spinning.

In addition to the advantages and the advance in the art derived from the use of my invention in connection4 with the wet spinning processes 20 the important advantage of improved sanitary conditions must be considered.

When in the performance of the present vertical methods a bobbin or a pot is filled with threads, each oi' the many thousands of the still acid threads must be cut and the completed bobbins or pots must be replaced by empty ones. Depending on the size of the yarn and the production speed such operations must be performed very often, sometimes every thirty minutes. The working personnel is at each exchange manipulation exposed to the injurious action of the fumes, bad odors and gases developed from carbon disulphide and other agents given up by the viscose and/or cuprammonia, protein and the like spinning solutions, when the same enter in the coagulation bath. Everybody who is familiar with this industry is well aware of the great number of workmen in the rayon industry suffering especially from eye and similar illnesses.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is understood that I do not limit myself to the i specific embodiment thereof shown and described in the specification.

It is also understood that my invention is equally applicable to all methods and apparatus where spinning masses are extruded into a solidifying medium to produce synthetic bers.

I claim:

1. A method for the continuous production of synthetic filaments comprising extruding a spinning solution through adjacent spinnerettes into a coagulating bath, producing by adjustment of the concentration of the bath ingredients partially eoagulated filaments while maintaining the same in the bath in a separated horizontal and unsupported position, drawing the partially coagulated filaments by a multi-roller unit through at least one additional coagulatlng bath to complete the coagulation, hereupon drawing the completely coagulated laments by a multiroller unit through at least one after-treating bath to produce the finished filaments, maintaining the iilaments in the said additional coagulating bath and in the after-treating baths in the separated unsupported horizontal position and under tension and subjecting the laments during their passage through the multi-roller units to a successive stretching and shrinking action by said rollers.

2. A method for the continuous production oi' synthetic filaments comprising extruding a spinning solution through adjacent spinnerettes into a coagulating bath, producing by adjustment of the concentration of the bath ingredients partially coagulated filaments while maintaining the same in the bath in a separated' horizontal and unsupported position, drawing the partially coagulated iilaments by a multi-roller unit through at least one additional coagulating bath to complete the coagulation, hereupon drawing the completely coagulated filaments by a multi-roller unit through at least one after-treating bath to produce the finished filaments, maintaining the filaments in the said additional coagulating bath and in the after-treating baths in the separated unsupported horizontal position and under tension and subjecting the laments during their passage through the multi-roller units to a stretching action by said rollers andto a shrinking action.

3. A method for the continuous production of synthetic filaments comprising extruding a spin- 21 ning solution through adjacent spinnerettes into a coagulating bath, producing by adjustment of the concentration of the bath ingredients partially coagulated laments while maintaining the same in the bath in a separated horizontal and unsupported position, drawing the partialLv coagulated iilaments by a multi-roller unit through at least one-additional coagulating bath to complete the coagulation, hereupon drawing the completely coagulated illaments by a multiroller unit through at least one after-treating bath to'produce the ilnished filaments, maintaining the laments in/the said additional coagulatlng bath and in the after-treating baths in the separated unsupported horizontal position and under tension and subjecting the laments during their passage through the multi-roller units while still containing the coagulating liquids to a successive stretching and shrinkingactionbysaid rollers.

4. A method for the continuous production of synthetic laments comprising extruding a spinning solution through adjacent spinnerettes into a coagulating bath, producing by adjustment of the concentration of the bath ingredients partially coagulated laments while maintaining the same in the bath in a separated horizontal and unsupported position, drawing the partially c0- agulated filaments by a multi-roller unit through at least one additional coagulating bath to complete the coagulation, hereupon drawing the completely coagulated filaments by a multi-roller unit through at least one after-treating bath to produce the nished filaments, maintaining the filaments in the said additional coagulating bath and in the after-treating baths in the separated unsupported horizontal position and under tension and subjecting the iilaments during their passage through the multi-roller units to a multiple stretching and shrinking actionV by said rollers.

BENNO BORZYKOWSKL vio 22 REFERENCES CITED lThe following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 923,777 Delubac June 1, 1909 1,707,164 Karplus Mar. 26, 1929 1,770,412 Leuchs July 15, 1930 1,910,879 Berstein May 23, 1933 1,951,094 Koch Mar. 13, 1934 1,956,600 Taylor May 1, 1934 1,957,508 Taylor May 8, 1934 2,022,961 Hoelkeskamp Dec. 3, 1935 2,041,338 Harrison May 19, 1936 2,053,123 Alles Sept. 1, 1936 2,090,560 Ubelohde Aug. 17, 1937 2,166,740 Karplus July 18, 1939 2,199,882 Inokuchi et al. May 7, 1940 2,246,735 Kline et a1 June 24, 1941 2,255,834 Taylor et al. Sept. 16, 1941 2,315,265 Lovett Mar. 30, 1943 2,317,152 Costa et al. Apr. 20, 1943 2,328,307 Thurmond Aug. 31, 1943 2,334,325 Heim Nov. 16, 1943 2,345,622 Mothwurf Apr. 4, 1944 FOREIGN PATENTS Number Country Date 124,714 Austria May 15, 1931 209,923 Germany Aug. 25, 1908 346,511 Great Britain Apr. 16, 1931 379,880 Great Britain Sept. 8, 1932 379,935 France Sept. 23, 1907 499,671 Great Britain Jan. 27, 1939 625,049 France Apr. 16, 1927 733,717 France July 18, 1932 OTHER REFERENCES I. R. I. Trans., 8, 316, 1933, Fiber impregnation, E. A. Hauser and Miss M. Huenermoerder. Briefed in Latex and Rubber Derivatives by F. Marchionna. PD. 519-520. Copy in Div. 38.

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