US 2277049 A
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Description (OCR text may contain errors)
Patented Mar. 24, 1 942 Raymond E. Reed, Walpole, Mass., assignor to The Kendall Company, Walpole, Mass, a corporation of Massachusetts No Drawing. Application November 6, 1939, Serial No. 303,021
23 Claims. (Cl. 154-2) This invention relates to textile products and to methods of manufacturing goods of this character.
It is the chief object of the invention to produce novel textile materials having many characteristics similar to those of fabrics or felts, although differing radically from them in structural characteristics and having advantages peculiar to themselves and which will be described more fully hereinafter. The invention also includes thicker, more bulky bodies made of ordinary textile fibers. It is a further object of the invention to devise methods of manufacturing these novel textile products which will be much simpler and more economical than the common textil fabricating processes, such as spinning, weaving,
knitting, felting, and the like.
In one aspect the invention involves the formation of a unitary fibrous structure by working unifiable textile fibers, as hereinafter described, into a web, bat, or other suitable form, and then, while in such form, uniting said fibers in such a manner as to produce a coherent, unified body or mass in which the strength,- softness, resilience, flexibility, density, absorbency, and other physical properties are predetermined but may be varied substantially in accordance with the results desired.
I am aware that it has been proposed heretofore to make fibrous structures by methods in which the fibers of a preformed web, bat, or other fibrous body are, by means of a binder added after the web has been formed, united directly to each other without weaving or other textile operations. This has been done, for example, by impregnating a preformed fibrous web with rubber latex or some other binder. Such a method has the objection, however, of coating all, or at least the greater portions, of the surfaces of the fibers and locking them together, thus greatly reducing the pliability of the individual fibers and also destroying their individual freedom of movement, with a consequent stiffening of the resulting structure. In order to overcome this difliculty it has also been proposed to produce a discontinuous bonding of the fibers of such a body by sifting into the fibrous mass a binder in the form of a fine powder having thermoplastic properties, and subsequently heating the mass sufliciently to melt the particles of binding material, thus causing them to adhere to the fibers with which they are in contact and to secure these fibers together. In attempting to practice this method, however, it has been found impossible to control or distribute the binder with that degree of uniformity necessary to make a satisfactory product. There seems to be no wayof predetermining or controlling the final' placement of the binder particles in the fibrous body. Consequently, effective control of the structure or characteristics of the final product is lacking.
The present invention aims to overcome both of the objections above mentioned and to devise a structure composed of intermingled, unspun or heterogeneously arranged textile fibers bonded to each other in a controlled and predetermined manner, the nature and extent of which bonding can be varied in accordance with the desired results. That is, the bonding may be such as to produce a very soft, flexible, cloth-like fabric having a good drape, or to make considerably firmer fibrous structures.
I have found that such products can be made by mixing fibers of textile length potentially adapted to act as binders, though normally failing to exhibit such characteristics, with nonbinder textile fibers, forming a web therefrom, and then unifying the web through the action of some appropriate agent, such as heat, which serves to activate the binder fibers and thus to make them bond to the non-binder fibers and to each other. For example, fibers of cellulose acetate may be mixed and dry assembled with cotton fibers in suitable proportions in a picker lapper, and the mixture then maybe carded and formed into a web, preferably in a cotton carding machine, although a wool carding machine or garnet may be used. During these operations the different kinds of fibers become intimately comingled so that when this web, or a plurality of such webs superposed, is subsequently heated, or subjected to the action of some other softening agent'for the cellulose acetate fibers, their normally latent adhesive or coalescent characteristics are developed and they can then be made to adhere to, or to bond with, the cotton fibers, and to each other. Such action may be promoted by pressing the fibrous body while the binder fibers are still in a softened condition.
, By the foregoing method the binder constituent, normally consisting of separated individual fibers, may be distributed substantially uniformly throughout the fibrous mass. Because of the fact that it is in a fiber form instead of in a. powdered condition, it will subsequently retain its position in the fibrous body. After the activating step has been completed the fibers are so united that no substantial movement of them out of the relationship determined by the unifying step takes place. Thus, the resulting product has a strong resistance to physical and chemical disruptive forces.
An important advantage of the process is that no specific arrangement or organization of the fibers is required except to produce the intermingling of them necessary to distribute the binder fibers substantially uniformly throughout the mass. Such incidental orientation of the fibers as occurs in connection with the mixing operation and the working of the fibrous mass into the form of a web is not only not objectionable from the standpoint of this invention but contributes to the uniformity and homogeneity of the finished product. Some such arrangement of 'the fibers occurs necessarily in performing these operations in. textile machines of the common forms. For example, a cotton card produces some parallelizing of the fibers and it should be understood that in the subsequent use of such terms as unarrayed, unspun, or "heterogeneously arranged, it is intended to include carded webs, or those made by similar processes, in which either some intentional or some incidental parallelization or arrangement of the fibers takes place, these terms being intended to distinguish from spun, woven, braided, knitted, or similar structures, the integrity of which depends solely upon some specific arrangement of fibers or yams. While some definite organization of fibers may be made for the purpose of this invention, the integrity of the product does not depend on such an arrangement but rather on the union or coalescence of the fibers. In this connection it should also be pointed out that while a cotton card is fed from a lap previously made in a picker lapper and the mixing of the fibers takes place largely in the latter, nevertheless a carding step is very useful in this process because of the fact that it works the mixture of fibers into a web in which the fibers are more uniformly and homogeneously arranged, such web, or a plurality of such webs superposed, being admirably adapted for the subsequent unifying operation.
A very considerable class of fibers suitable for use as binders in accordance with this invention is available. For example, various fibers comprising esters and ethers of cellulose, are suitable, such as those made of cellulose acetate, cel-v lulose formate, cellulose propionate, cellulose butyrate, ethyl cellulose, and benzyl cellulose. Fibers made of mixed esters, such as cellulose acetate-propionate, also are very useful. Others of an entirely different chemical nature, however, may be used, such as those made of vinyl polymers and those of the polyamide type, an important example of which is that known com- ,mercially as Nylon. The invention is not limited to use with any particular kind of binder fibers provided they have those characteristics suitedto the purposes of this invention and are of sumcient length. Necessarily, the particular fiber used in the manufacture of any given product will be selected in accordance with the requirements of that product. That which I have found most satisfactory, particularly in connection with the manufacture of products in which cotton fiber forms the predominating constituent, is composed of cellulose acetate, either with or without a plasticizer.
For the non-binder fibers, any of those commonly used in the textile industry may be employed satisfactorily in the manufacture of these tures of my invention pertain to cotton fibers and more particularly to bleached cotton fibers but wool, silk, rayon of the regenerated cellulose type, such as viscose, and others, are entirely suitable for use in this process considered in its broader aspects.
It may also be observed that all the fibers above mentioned, both binder and non-binder, are of the general nature of those used in the manufacture of textile fabric in textile machinery of common commercial types, and that, consequently, these fibers may aptly be called textile fiber While it is an important object of this invention to eliminate the necessity for the slower and more expensive textile operations, such as spinning and weaving, nevertheless the fact that the thermoplastic or binder fibers are of textile length and have these textile characteristics, as well as the cotton, wool, silk, or other fibers with which they are mixed, is an important advantage in the present invention for the reason that it makes itpossible to mix the fibers and work them into the form of a, fieece, web, or bat in ordinary textile machinery, such as picker lappers and cards. 5
The operation of unifying the fibrous mass into a coherent structure should be controlled in accordance with the nature of the binder and ening action. That found most practical is heat,
but solvents may be used in some cases. Plasticizers, which exert a softening action, may be used in conjunction with the binder fibers to facilitate the activating effect'of the heat.. All of the binder fibers above mentioned are thermoplastic. That is, they have the property of being softened byheat and hardening upon cooling again, these changes in physical condition taking place without any material chemical deterioration. Accordingly, the preferred method of effecting unification is to pass the web or other fibrous body through a heating chamber, between heated plates or heated rolls, or through any other suitable apparatus capable of raising the temperature of the web to the desired degree.
' ing or changing their respective positions in the mass. Assuming, for example, that the web consists of a mixture of cotton and cellulose acetate products, alt wugh here again, they will naturalfibers, it may be treated with acetone of such concentration or in such solvent mixtures as to superficially dissolve or soften the binder fibers.
If pressure is tobe used the web may thenbe passed between pressure rolls.
The nature of the solvents employed neces- 'sarily will be determined by the character of the binder fibers and other practical considerations. A wide variety of solvents for the various binder :Qfibers above mentioned are known, including "acetone,
methyl" alcohol, methyl cellosolve, propylene oxide, methyl acetate, ethyl acetate, acetic acid, diacetone, chlorobenzene, chloroform, toluol, carbon tetrachloride, and diethyl ether.
Whether or not pressure is used in the unifica-' tion process will depend chiefiy upon the nature of the binder and non-binderfibers used and of the character of the final product desired. Pressing necessarily results in bringing a single binder fiber into contact with a greater number of contiguous fibers of both kinds than otherwise would be the case and thus to increase the number of individual bonds with an accompanying increase in strength. It tends strongly to reduce the softness, flexibility and draping qualities of the productand to give it greater firmness and rigidity. Whether to use pressure, and the degree of pressure to be employed, if it is used; therefore will depend upon theresults desired, the nature of the binder and softening agent used and other practical considerations.
That the nature of the bonding, coalescence or association of the fibers with each other produced by the unification may take several forms will be evident from the character of the unification process above described. All of these fibers have normally latent adhesive or other coalescent properties which may be developed and made active by any of the unifying agents above discussed. For example,. in subjecting the mixed fiber web to a suitable temperature, the thermoplastic fibers will attain a softening stage which,
of plasticizing agents in the composition of the binder fibers. Such agents are useful not only in facilitating the unificationprocess per se and controlling the strength of the bonds, but also in modifying the physical characteristics of the tion from paper and similar articles.
binder fibers in the final product. Such properties as softening point, pliability, toughness, and the like, may be controlled in this way. Consequently, the nature and proportion of the plasticizer or plasticizers used can be selected in accordance with either or both of these requirements. In addition, the character of the final unified product can be modified or varied by.the degree of pressure used in the process of unification, the temperature employed during this step, and by the length of time occupied by it. Plasticizers also may-be used to modify any of these factors.
It should be clearly understood that it is not always necessary to carry the softening action to such a point that the binder 'fibers will wet the non-binder fibers or will adhere to them in order to produce a unification entirely satisfactory for many purposes.. A softening of the hinder constituent to the point where it is plastic but not adhesive, when the, pressure is applied, is suiilcient for many purposes. Apparently the unification so efiected is due to thedeforming of the binder fiberswhile in a softened condition and in some cases the embedding of the nonbinder fibers in them. Since the fibers are mutually entangled or interlaced throughout the mass, the act of embedding the non-binder fibers in the binder fibers efiects a mechanical engage-.
ment of these constituents in such a manner as to produce a coherent body having ample tensile strength for many purposes and a flexibility valuable for some uses. If the softening of the binder fibers is carried further so that they weld to each other, even though they may not actually I adhere with any substantial degree of strength to the cotton or other non-binder fibers, a still stronger product is produced, apparently due to a firmer mechanical entanglement of the latter in the former, coupled with the embedding of a considerable proportion of. one in the other. Here the binder material appears to form a three-dimensional network, ma'ze or framework in which the non-binder fibers are intermingled,
interwined, interlocked and, at some points,'me-
chanically embedded or otherwise bonded.
Various combinations of this mechanical interlocking with a direct adhesion or welding of the fibers to-each other can be produced. It will readily be appreciated that the different relationships which the two types of fibers may be made to assume with reference to each other in these ways has an important bearing on such qualities as pliability, drape, firmness, porosity, and the like, and that they are correspondingly useful in controlling the nature of the final product. It should be observed that in all of these products the individual fibers, at least those of the non-.
binder type, have considerable freedom of movement relatively to their neighbors, except at their points of union, bonding, or coalescence with the binder constituent, and this characteristic sharply differentiates products made by this invenin paper the fibers are extremely short, theaverage fiber length even in strong papers, such as kraft and rope papers, being less than a sixteenth of an inch, and they are so cemented or bonded together by hydrated or beta cellulose that one fiber has'practically no freedom of movement relatively to its neighbor, whereas in the products provided by this invention the fibers are,
much longer, they contain no degraded cellulose binder, and the greater portions of the lengths of the individual fibers are left free from attachment to, or coalescence with, adjacent fibers. While an individual fiber below the surface of a web made by'this method may have its freedom,
of movement restricted by thev presence of neighboring fibers due-to the density'of a particular web, nevertheless the fibers are not bound to-' gether in any such way as they are in products made by paper processes, and this relative freesuch that the product may'have a very flu fiy,
napped, or long fibered surface, either on one or 7 both sides, depending on the technique used in producing it. Sheet materials resembling outing fiannels in general appearance and capableof use for many of the purposes for which the latter are customarily employed may be produced by this method, and they are well adapted for, such uses as pads, linings for receptacles, the
. done, depending the properties of the non-binder fibers. Also,
since thefibers are relatively long, only-a very small percentage of the fibers in an average batch of uncombed cotton staple as it comes from a carding machine being less than half an inch in length and running from that to one and a quarter inches or more, and since they may have only very few, say one or two, points of anchorage to the binder fibers in some of these products, it is entirely feasible to make sheeted products which are very soft, pliable and fiufiy.
The bond, union, or other relationship of the fibers to each other produced by the various methods above described and which is relied upon mainly to give the fibrous: body its stability and strength is frequently herein designated as coalescence," and the methods of treatment as depend mainly on coalescing, whether or not these terms are used in their strict or technical sense. Consequently, where such terms appear hereinafter they will be used ,to convey themeaning just described.
As above indicated, the strength of the fiber-to fiber bonds may be increased'when desired and the creation of such bonds may be facilitated by using binder fibers which have been treated with a plasticizing agent, or in which a plasticizer has been used in the composition of the fiber. Some of the synthetic resins, such as Glyptals, Vinyls, Santolites," Rezyls" and, in fact, any resin compatible with the material of the fiber used also may be incorporated in the composition of the fibers to increase the strength of the fiberto-fiber bond.
One example of the production of a web in accordance with this invention, and unified by heat and pressure, is as follows:
A binder fiber having good thermoplastic properties should be selected, such as those commercially available prepared from ethyl cellulose, cellulose acetate, or polymerized vinyl acetate, polymerized vinyl chloride, :or mixtures of these, together with suitable plasticizers, if desired. Binder fibers consisting of two parts of cellulose acetate and one of paratoluene ethyl sulphon- Wamide may be used satisfactorily, the latter being one of the well known plasticizers. One hundred twenty (120) pounds of such fibers are mixed with twenty-e17 hundred and eighty (2880), pounds of cottoi lbers in a picker lapper. The lap is fed to a card which cards the 'fiber mixture and works into the form of a web. A plurality of such v .bs may then be superposed, whether this is don and the extent to which it is non the thickness and character of the product desired. Assuming thatit is desirable to have the product run, say, 2.7 square yards to the pound, the webs from twentyfour cards may be superposed. The composite web so produced is fed through a four-roll calender in which the rolls are arranged in a vertical series and are maintained at a temperature of, say, 450 F. The web enters the nip of the two top rolls, passes around and between the two middle rolls, and finally through the nip of the two bottom rolls. A satisfactory speed is twelve yards per minute. In a machine which has been used satisfactorily for this purpose the rolls are fifty inches long, twelve inches in diameter, and
an hydraulic lift of about eleven thousand pounds coalescable fibers, while or a mixture ofsolvents, such a unifying process involves inherent objections which are avoided by the use of heat, or a combination of heat and pressure. Among these disadvantages may be mentioned the tendencyof the solvent to destroy the fiber structure, to smear the adhesive over thenon-binder fibers, the difiiculty of producing the exact'degree of unification desired, the necessity for recovering the solvent used in order to reduce manufacturing costs, and the high industrial risk involved due. bothto the fire hazard accompanying the use of such solvents and also to thefact that most of them have toxic properties. The heat and pressure method, however, avoids all ofthese difiiculties, it is readily controlled, is economical, .and can be performed at a high rate of production.
While, as above pointed out, the nature of the products made in accordance with this method can be predetermined and varied widely so that sheeted materials which are soft, pliable, and have a good drape can readily be produced, nevertheless when such a product includes a high proportion of bleached cotton fiber and the unification is performed under a relatively high degree of pressure, the web as it comes from the calender is very likely to be in a stiff condition and wanting in those properties of pliabllity and drape which are essential in replacing woven fabrics where such characteristics as softness and conformability are required. This condition occurs, only, when bleached cotton fiber is used, substantially no difficulty of this nature being experienced with raw cotton or with other fibers.
I have discovered, however, that if such a product is wet out thoroughly as, for example, by running it through a bath of water and then drying it, the material undergoes an astonishing change in characteristics. very dense, stiff and board-like as it comes from the calender increases surprisingly in thickness when so treated and becomes a soft, cloth-like material having excellent conforming properties.
The explanation of this remarkable'change in the characteristics appears to lie in the fact that the unifying process produces not only the coalescence above referred to, but it also bonds the bleached cotton fibers to each other. In words, a duplex system of bonds is produted, one
system being dependent upon the presence of the the other are pressurev induced, cottcn-to-cctton bonds. The subsequent water softening treatment destroys the latter bonds, leaving only the former.
Polar liquids other than water maybe substituted for it in making these products in which.
bleached cotton fiber is used and which are freed from cotton-to-cotton bonds. Aqueous solutionsordispersions of one of the sulphonated oils, glycerine or glucose, or aqueous emulsions of mineral oil may be used in the production of these fabrics, both for their polar characteristics and also for their softening efiect.
Naturally the proportions of the two general types of fibers used will be varied in accordance with the requirements of the final product desired, it being only essential to include a sufilcient percentage of the binder fibers to give the' A web which may be other binder fibers may be, increased to anything desired.
The invention includes fibrous sheet materials having a wide range of properties, it being entirely feasible to make products varying greatly in thickness by t method. Some may have the extreme limp es of delicate textile fabrics,
while others may have the firmer and less pliable properties desirable for certain linings, for stillening fabrics,'or the like. Since binders are obtainable which are permanently waterproof and substantially unafi'ected by moderately hot or' coldwater, fabrics can readily be made by this method which can be laundered and used in essentially the same manner as cloth. In addition,
necessary strength and stability to the. final structure. Beyond this'point the proportion of with relatively long lengths of,'a high proportion of said fibers free from attachment to other fibers. v
2. A textile sheet material comprising a carded web of heterogeneously mixed textile fibers of different types, one type'of said fibers having latent coalescent properties and both'kinds of the manufacturing operations are so simple and are so readily adapted to common textileequipment up to and including carding, that these materials can be manufactured at a very reasonable cost. For most products it is highly desirable that erties and'the other type being cotton textile fibers, both kinds of fibers being bonded together by the coalescence of the fibers at intersecting points and being secured thereby in a relatively fixed relationship to each other with relatively the binder fibers, even though thermoplastic,
shall not be sticky or tacky at normal temperatures. Ingeneral, it is necessary also that they have the capability of being heatedand reheated repeatedly without sufiering material deterioration either in'color or chemical composition. This is an important requirement, for
example, in those goods which must be laundered and subjected to ironing or mangling operations. Such fibers as cellulose acetate, ethyl cellulose, and the vinyl compounds above mentioned, are thoroughly satisfactory for such uses.- Some chemical compounds of a similar nature, however, such as nitrocellulose, are not suitable for these purposes since .they tend to break down when heated suificiently for unificationpurposes and undergo a chemical degeneration usually with an objectionable modification of color. Such a compound is not a true thermoplastic material.
It is an'advantage of many of the products embodying this invention that they retain all or the greater part ofthe plasticizer which was originally incorporated in the binder fibers so that these fibers maintain their softness and pliability and are not easily fractured. The points of unification or coalescence also are pliable and more highly adhesive than they would be otherwise, and the whole fabric is tougher and more flexible.
Likewise, these bonds and the binder fibers remain heat sensitive so that if for any reason, as for example due to laundering, they become weakened or broken, the process of ironing at suitable temperatures will re-create the bonds or create new points of coalescence which will perform the functions of those whichhave been destroyed. In this way the fabric is recreative or self-regenerative.
- I This application is a continuation, in part, of I my copending application Ser. No. 30,022, filed July 5, 1935.
Having thus described my invention, what I desire to claim as new is:
1. A textile sheet material comprising a plu rality of superposed carded webs of heterogeneously mixed textile fibers of .difierent types, one type of said fibers having latent coalescent properties and both kinds of fibers being bonded together by the coalescent characteristics of the fibers of the latter type and being secured thereby in a relatively fixed relationship to each other,
long lengths of the cotton fibers free from attachment to other fibers. a
4. A textile sheet material comprising a plurality of superposed carded webs of heterogeneously mixed textile fibers of different types, one type of said'fibers having latent coalescent properties andserving as binder'fibers and the other type being non-binder fibers consisting essentially of cellulose, both kinds of said fibers being bonded together by coalescence at intersecting points and secured thereby in a relatively fixed relationship to each other, the non-binder fibers being free of direct fiber-to-fiber union with each other and said points of coalescence being spaced by such distances thatrelatively long lengths of the non-binder fibers are free from attachment to other fibers.
5. A textile sheet material comprising a web of heterogeneously, mixed ,binder and non-binder textile fibers, the binder fibers being thermoplastic, the two kinds of fibers being bonded together by heat and pressure induced points of coalescence, and being secured thereby in a'relatively fixed relationship to each other but with relatively long lengths of non-binder fibers free from attachment to other fibers.
' 6. A textile sheet material comprising a carded web of heterogeneously mixed binder and nonbinder'textile fibers, the binder fibers being thermoplastic, .the two kinds of fibers being bonded together by heat and pressure induced points of coalescence, and being secure thereby'in a relatively fixed relationship to'each other but with relatively long lengths of non-binder fibers free from attachment to other fibers.
7. A textile sheet material comprising a plurality of superposed carded webs of heterogeneously mixed binder and non-binder fibers, the binder fibersl being theromplastic and the nonbinder fibers consisting essentially of cellulose, the two kinds of fibers being bonded together by heat and pressure induced points of coalescence and. being secured thereby in a relatively fixed relationship to each other but with relathe cellulose acetate fibers, the points of coalescence being so distributed throughout the mixture that relatively long lengths of a high percentage of the fibers are free from attachment to'other fibers.
9. A textile product comprising a carded web of hetemgeneously mixed cotton textile fibers and cellulose acetate fibers provided with a plasticizer, the two sets of fibers being bonded together at spaced points in a relatively fixed relationship to each other by the coalescent characteristics of the cellulose acetate fibers, the points of coalescence being so distributed throughout the mixture that relatively long lengths of a high percentage of the fibers are free from attachment to other fibers.
10.. A textile product comprising a carded web of heterogeneously mixed cotton textile fibers and cellulose acetate fibers provided with a plasticizer, the two sets of fibers being bonded together at spaced points in a relatively fixed relationship to each other by heat and pressure induced bonds, the points of coalescence being so distributed throughout the mixture that relatively long lengths of a high percentage of the fibers are free fromattachment to other fibers.
11. A textile sheet material comprising a web of heterogeneously mixed theromplastic binder fibers of textile length and cotton textile fibers, with the cotton textile fibers predominant, the two kinds of fibers being bonded together by spaced heat and pressure induced bonds and being secured therebyin a relatively fixed relationship to each other, the product being substantially free from cotton-to-cotton bonds.
12. A cloth-like textile sheet material comprising a web of heterogeneously mixed bleached cotton textile fibers and textile binder fibers'having normally latent coalescent properties, the binder fibers being bonded to each other and to the cotton fibers by pressure induced bonds and the coalescent characteristics of the binder fibers, and the cotton fibers being substantially free of any bonding to each other, thereby giving to the material added thickness and softness.
13. A cloth-like textile sheet material composed essentially of a web of heterogeneously mixed bleached cotton textile fibers and textile thermoplastic binder fibers, the binder fibers being bonded to each other and to the cotton fibers by heat and pressure induced bonds, and the cotton fibers being substantially free of any bonding to each other, thereby giving to the material added thickness and softness.
14. That improvement in methods of making textile structures which consists in making a web in which textile fibers and binder fibers having normally latent coalescent properties adapted to be developed by heat are intimately dry mixed with each other in an unspun or heterogeneous relationship, heating said web and thereby developing the coalescent properties of said binder fibers, and, while the latter fibers are so rendered coalescent, pressing the web to unite the two kinds of said fibers to each other in a, relatively fixed relationship, and thereby to produce a unified sheeted structure but with textile structures, which consists in heterogeneously mixing textile binderfibers having normally latent coalescent properties with other textile fibers until the binder fibers are distributed substantially throughout the fibrous mass, carding said mixture and thereby producing a web composed of the mixed fibers, and subsequently 75 in ima y i e c d'with e h other in an subjecting said web to a coalescing operation to causethe binder fibers to bond the other fibers together, thereby to produce a unified sheeted structure.
.16. That improvement in methods of making textile structures, which consists in heterogeneously mixing textile binder fibers having normally latent coalescent properties with cotton textile fibers until the binder fibers are distributed substantially throughout the fibrous mass, carding said mixture and thereby producing a web composed of the mixed fibers, superposing a plurality of such carded webs, and subsequently subjecting said composite web to a coalescing operation to cause the binder fibers to bond the other fibers together, thereby to produce a unified sheeted structure.
17. That improvement in methods of making,
. textile structures which consists in heterogego neously mixing thermoplastic binder fibers with cotton textile fib'ers until'thepinder fibers are distributed substantially throughout the fibrous mass, carding said mixture and thereby producing a web composed of the mixed fibers, superposing a plurality of such carded webs, heating the composite web and thereby developing the coalescent properties of said binder fibers, and, while the latter fibers are so coalescent, pressing the composite web to unite the two kinds of fibers to each other and thereby to produce a unified sheeted structure.
18. That improvement in methods of making textile structures which consists in heterogeneously mixing thermoplastic binder fibers with non-binder textile fibers until the binder fibers are distributed substantially throughout the fibrous mass, carding said mixture and thereby producing a web composed of the mixed fibers, bringing a plurality of such carded webs into superposed relationship, and continuously moving said superposed webs between pressing rolls heated sufiiciently to develop the coalescing properties of said binder fibers, thereby uniting the two kinds of fibers to each other to produce a unified sheeted structure.
19. That improvement in methods of making textile products of the character described, which consists in making a web from a mixture comprising thermoplastic textile binder fibers and 0 a high percentage of bleached cotton fibers in- 'termingled with each other in an unspun relationship, subsequently unifying said web by heat and pressure, thereafter wetting the unified web thoroughly with a polar liquid to release pressure induced cotton-to-cotton bonds formed during said unifying step, and thereafter drying the web.
20. That improvement in methods of making textile products of th character described, which consists in making a web from a mixturecomprising thermoplastic textile binder fibers and a high percentage of bleached cotton fibers intermingled with each other in an unspun relationship, subsequently unifying said web by heat and pressure, thereafter wetting the unified relatively long lengths of said textile fibers free from, attachment to said binder fibers. H
15. That improvement in methods of making web thoroughly with an aqueous liquid effective to release only pressure induced cotton-to-cotton bonds formed during said unifying step, and thereafter drying the web.
21. That improvement in methods of making 22. That improvement'in methods of making textile products of the character described, which consists in making a web in which textile bleached cotton fibers and textile binder fibers having normally latent coalescent properties are intimately intermingled with each other in an unspun relationship, subjecting "said web to the action of an agent serving to develop the coalescent properties of said binder fibers, pressing the web while said fibers are so softened and therebyunifying said web and subsequently fiumng said web by thoroughly wetting it with water and thereafter drying it.
23. A textile sheet material comprising a web of heterogeneously mixed binder and non-binder textile fibers, the binder fibers being thermoplastic,.the two kinds of fibers being bonded together by heat-induced points of coalescence, and
being secured thereby in a relatively fixed relationship to each other but with relatively long lengths of now-binder fibers free from attachment to other fibers.
RAYMOND E. REED.