US2880112A

US2880112A - Textile-like fabric and method

Info

Publication number: US2880112A
Application number: US558568A
Authority: US
Inventors: Arthur H Drelich
Original assignee: Chicopee Manufacturing Corp
Current assignee: Chicopee Manufacturing Corp
Priority date: 1956-01-11
Filing date: 1956-01-11
Publication date: 1959-03-31
Anticipated expiration: 1976-03-31
Also published as: GB851410A; GB850288A; DE1106285B

Description

. March 31, 1959 DREUCH 2,880,112

TEXTILE-LIKE FABRIC AND METHOD Filed Jan. 11, 1956 THERMOPLASTIC K R00 Borvns WASHABLE Nmvwoveu Baa/21c FIaER CROSS DIMENSION or R00 6on0 ATTORNEY! United States Patent 2,880,112 TEXTILE-LIKE FABRIC AND METHOD Arthur H. Drelich, Springfield, Mass assignor to Chicopee Manufacturing Corporation, a corporation ofMassachusetts Application January 11, 1956, Serial No. 558,568

29 Claims. (Cl. 117-37) The present invention relates to fibrous nonwoven fabrics, i.e., fabrics produced directly from fibers without the use of conventional spinning, weaving, knitting, or felting operations, more particularly to such fabrics which are open and porous and possess textile-like hand and drape as well as considerable strength, and methods for making these fabrics.

Nonwoven fabrics of various types have become increasingly important in the textile field during the past decade because of their low cost of manufacture for a given coverage compared to fabrics formed by weaving or knitting spun fibers and because of certain properties such as absorbency, fluffy or downy surface characteristics, and the like, which are peculiar to these fabrics.

As distinguished from felts, Which often "are described as being nonwoven, this invention is concerned with fabrics wherein the fibers are not compacted but instead are relatively loosely assembled parallel to the major plane of the fabric forming myriad small interstices between them. Additionally, the fibers lie in positions which are somewhat fiat or generally parallel to the major plane of the fabric extending in various directions parallel to this plane overlapping, intersecting and supporting one another to form a relatively open porous structure.

Such fabrics are conventionally manufactured at the present time by producing a more or less tenuous web or layer of loosely associated fibers, preferably of textile length or over, using any one of a variety of well-known procedures or techniques and then subjecting the layer to a bonding operation to adhere the individual fibers together. Bonding has been effected by various techniques ranging from the deposition of resins or the like by overall impregnation to the printing of these materials in spaced discrete areas of the layer, and includes techniques wherein binder powders or fibers are distributed at random in the layer to form bonds.

In general, all of the prior art nonwoven fabrics can be divided into two groups; those which possess relatively good strength but are more or less stiff and board-like, possessing more of the properties of paper or board than of a woven textile fabric, and those which possess textilelike softness and drape but are relatively low in strength and are not at all suitable for applications where launderability is a prerequisite. v

The present invention contemplates a fabric which surprisingly possesses washability and superior strength, as well as textile-like softness and drape. This combination of properties, particularly the combination of washability, on the one hand, and textile-like softness and drape, on the other, is unique in nonwoven fabrics of the character described. Due tothis unusual combination of properties, this fabric is particularly adapted for use as a lining material for clothing, particularly where such materials may be worn next to the body, for inner and outer wear in general, for washable towels, napkins, tablecloths, handkerchiefs, and the like, sanitary napkins,

2,880,112 Patented Mar. 31, 1959 surgical dressings, draperies, curtains, reusable indus trial fabrics, as well as in a variety of other applications where the combination of these properties is important.

According to this invention, a multiplicity of elongated bonds, more or less in the form of short strips or bars, are relatively closely spaced in a layer of overlapping and intersecting fibers to anchor the fibers by surrounding and imbedding them in the bonds at least 2 or 3, preferably more, times along the length of approximately every fiber. The bonds preferably have a cross dimension of the order of about 5 to 10 times the average diameter of the structural fibers and are heat fused. These bonds extend in a plurality of diverse directions generally parallel to the major plane of the fabric, on the average crossing or intersecting most of the fibers at least several times along the length of each of the fibers. The bonds are spaced sufiiciently apart to provide a multiplicity of unbonded fiber areas between bonds wherein a high degree of the textile properties of the original fibrous layer is preserved. The resulting fabric is strong and washable due to the strong closely spaced bonds and the relatively high degree of fiber intersections by the bonds, While at the same time possessing a high degree of the softness and drape of the original unbonded fibrous layer.

The elongated bonds preferably are formed in the fabric by distributing elongated binder members or rods approximately uniformly, ordinarily at random, in the fibrous layer, and then fusing the rods to cause them to flow into or through the thickness of the layer to imbed a relatively large number of fibers, as described above.

The rods are fused and caused to flow by the application of heat and pressure to form strong bonds Which surround and anchor the fibers. The rods, which con veniently may be in the form of cut lengths of monofilaments, preferably have an average cross dimension or diameter before fusing of the order of about 2 or 3 to 10 times the average diameter of the fibers, and about 5 to 10 times this diameter after fusing, as mentioned above.

I am aware that it has been proposed to use thermoplastic binder particles or fibers to bond together the fibers of a web or bat to form a flexible absorbent structure. In general, the binder members proposed have been of the same order of size as the fibers to be bonded and in the form of powder or a similar state of fine division, textile fibers of the same general diameter as the structural fibers to be bonded, and the like. Bonds are formed in these fabrics by heating the binder members to a sticky or coalescent state and then applying a relatively high amount of pressure to cause them to adhere to the structural fibers. In such fabrics when strength is desired the structural fibers are bonded to fiber by a relatively great number of very closely spaced particles or bonding fibers scattered throughout the breadth and thickness of the web. Due to the great number of bonds and their correspondingly close spacing, such fabrics are stiffened and compacted to a degree adversely affecting their left and handle. On the other hand, when softness is desired a much smaller number of particles or bonding fibers are used with the result that strength is sacrificed and, of course, washability is not obtained.

I have invented a fabric wherein the elongated or rod bonds are spaced in the fabric sufficiently far apart to allow the structural fibers to predominate in determining hand, drape, flexibility, absorbency, and the like, while at the same time being spaced close enough to one another to provide washability and strength. For this purpose the bonds should be large enough that they may be spaced sufficiently far apart for hand, drape and the like Without sacrificing washability and strength, and small enough that they may be spaced sutficiently close for washability and strength without sacrificing the For effective bonding for desired textile-like qualities. this purpose and to enhance the textile-like qualities of the fabric, the structural fibers lie in positions which are generally flat or parallel to the major plane of the fabric and extend in a plurality of diverse directions parallel to this plane, overlapping and intersecting one another. The fibers are relatively loosely assembled parallel to the major plane of the fabric and relatively closely assembled through the thickness of the fabric with intersecting fibers supporting one another to form an open porous structure.

Preferably, the bonds formed are substantially solid and extend through the fabric almost from one surface to I the other, imbedding a relatively large number of fibers as mentioned above, with the result that the fibers are held firmly where they pass through the bonds. In general, each rod bond is at least large enough in transverse cross section to imbed a relatively large number of fibers,"

overlapping one another five fibers deep in the layer.-

Since, as indicated above, the bonds may extend .com-' pletely through the layer, each bond may be as deep as the layer at the bond, in which case the bond may imbed as many fibers in depth as there are in the layer. 'The layer may be many more than five fibers deep. In general, fiber depth varies with web weight assuming the same size fibers to be used. Since it is preferred that the rods have a length to width ratio of at least about 10 to 1, ordinarily a single rod bond may imbed about fifty or many more fibers which may pass through the bond anywhere in or along its depth or length. Those portions of the fibers passing through the bonds are held As mentioned hereinbefore the rod bonds must be spaced close enough to one another to provide washability and strength. When the rod bonds are distributed substantially uniformly in the fabric, average spacing may be estimated for a unit area or unit distance in any direction in the major plane of fabric. Conveniently, the number of bonds in a representative unit area, say a square inch, may be counted and the square root of the number obtained may be taken to estimate the average number of bonds per linear inch in any direction in the fabric. For instance, in a fabric bonded with rod bonds about $1 inch in length and 0.003 inch in average cross dimension and having about 800 bonds per square inch,

the estimated average number of bonds per linear inch in any direction in the fabric is about 28.3. This generally is satisfactory from the standpoint of washability.

In general, by rods is meant elongated bonding mem- ,bers having ,length-to-width ratios preferably of the order (of at least 10 to l, which may be in the form of cut lengths of monofilaments as described hereinbefore.

However, this ratio may be considerably lower under .upon a number of factors.

segments between bonds generally are less compacted in this direction, providing a multiplicity of fibrous pillows" which preserve the softness of the fabric. If the bonds formed by the rods are not spaced sufficiently, the fabric approach about 3 to 1.

certain, conditions and under some conditions may even The dimension across the rods if they are in the form of filaments may be expressed in terms of filament or rod diameter and similarly in terms of rod denier. Optimum rod diameter depends For instance, for bonding a water-laid layer of viscose rayon staple of approximately 0.0005 inch in diameter, excellent results have been obtained using rods of nylon 6 (polycaprolactam) with sizes ranging between 10 and 60 denier, corresponding roughly to rod diameters of about 0.0012 to 0.0034 in'ch. Under most conditions rod size should be between about 10 and 100 denier, corresponding roughly to about 0.0012 to 0.004 inch, preferably between about 10 and 35 denier, corresponding roughly to about 0.0012

5 to 0.0026 inch. Corresponding ranges for the average will be stiffened. If the rods are too small, there will not be sufiicient bonding material to provide the desired strength and washability when the bonds are spaced to provide the desired textile-like hand, drape, and the like.

Textile-like softness and drape in fabrics are qualities which are well-known and recognized by those skilled in the art and even by consumers, but have not as yet been reduced to satisfactory quantitative measurement. In general, nonwoven fabrics of the character herein described possessing these qualities are soft, drapable, pleasant to handle and without palpable roughness due to the intermittent bonds.

In general, by washability is meant the ability of the fabric to withstand washing by modern techniques without serious effects on its appearance or strength with the result that the fabric is suitable for reuse for the same purpose after laundering. A single cycle wash in a modern horizontal tumbler washer, such as a Bendix home washer, may be used as a test for this purpose, although at least two or three or even more Washes are preferred. Prior art nonwoven fabrics which do not possess washability may fail by breaking off of fibers between bonds or by the splitting or disintegration of the bonds themselves,

with the result that the fabrics no longer have utility for their intended purpose. This particularly is true of fabrics comprising fibers of absorbent materials such as viscose rayon, which weaken considerably when wet.

An important element affecting washability is the closeness of the spacing between bonds. Rod bonds having a cross dimension of the order of several, preferably about 5 to 10 times the average diameter of the fibers may be spaced sufliciently close to one another when distributed in the fabric substantially uniformly, yet at random, to provide washability, while at the same time allowing the structural fibers to predominate in determining the physical characteristics, i.e., the hand, drape, flexibility, and the like, of the resulting fabric.

cross dimension of the rod bonds reflect the expansion of the rods which occurs during fusing. For instance,

bond cross dimensions between about 0.0025 and 0.005 inch are known to be suitable, while those between about 0.0025 and 0.0045 inch are preferred.

, While rod length is not as critical as rod diameter, it

" nevertheless is important both from the standpoint of effective bonding, and the ease and flexibility of fabric formation; Rods varying between about and 1 inch or over in length have been used effectively although somewhat shorter lengths may be used. For greater effectiveness, best strength, softness and uniformity of fabric, rods below about A inch in length are preferred. The over-all amount or percentage of bonding material or binder in the fabric is an important factor affecting fabric characteristics. If there is not sufficient binder On the other hand, if there is too much, the fabric will be relatively stiff and possess a harsh hand, generally being low in softness, absorbency and other textile characteristics. The optimum binder content for a given fabric according to this invention depends upon a number of factors including the nature of the binder material, the size and shape of the binder members and their arrangement in the fabric, the nature and length of the structural fibers, total fiber weight, and the like. For instance, for plasticized cellulose acetate rods ranging between 0.002 and 0.004 inch in diameter and viscose rayon structural fibers of about 1.5 denier, the optimum binder content by weight of the fabric appears to be in the neighborhood of 25 percent. For nylon 6, rods ranging between 10 and 40 denier and the same size viscose rayon fibers, optimum binder content may range between about 10 and 15 percent by weight. The most practical range of binder content for most materials ap pears to be between about 3 and 35 percent of the weight of the fabric. Binder contents between about 5 and 20 percent generally are preferred.

In general, the average thicknessof'thefabriewill vary with the weight of the fibers employed. It is also true that somewhat different bonding problems may arise in forming light and heavy fabrics. For maximum efficiency in the use of rods according to this invention, a layer of structural fibers weighing at least about 400 grains/sq. yd. is preferred. Satisfactory fabrics according to this invention may be produced from fibrous layers weighing between about 150 grains/sq. .yd., or slightly lower and about 1200 grains/sq. yd. or even higher. Above about 2000 grains/sq. yd., thefabric may assume more of the characteristics of a fibrous bat than an open porous fabric of the type described.

In accordance with this invention, the rods may be distributed amongst the structural fibers during or after formation of the fibrous layer. The layer, with or without the rods, may be formed by any one of a number of conventional techniques for depositing or arranging fibers in a web or layer. These techniques include carding, garnetting, airlaying, papermaking methods, and the like. Individual webs or thin layers formed by one or more of these techniques may be laminated to provide a thicker layer for conversion into a fabric. In general, in such a layer the'fibers in the layer extend in a plurality of diverse directions in general alignment with the major plane of the fabric overlapping, intersecting, and supporting one another to form an open porousstructure.

In order to provide this open structure of overlapping, intersecting fibers, relatively long textile-like fibers above normal papermaking. lengths, of close to normal textile length, say of about inch to 2 inches or longer, are preferred, although shorter fibers, somewhat below inch in length, as for example certain papermaking fibers, may be used, particularly if they are mixed with longer fibers. It is preferred that the shorter. papermaking fibers be unbeaten or substantially unhydrated.

Rods having average cross dimensions between about 0.0012 and 0.004 inch maybe distributed in the fibrous layer during or after 'its formationby any. one of the above techniques. The rods may be distributed in the layer during formation in carding, garnetting, and the like, by blending rods of close to textile length, say in the order of /2 inch or longer, with the fibers of conventional textile blending techniques and then carding or garnetting the blended mixture. Likewise, the fibers from such a mixture may be dispersed in an air stream and collected on foraminous means to form a layer by any of a variety of well-known techniques, although shorter rods may be used for this purpose. Rods as short as 6, of an inch or somewhat shorter may be mixed with the structural fibers in an aqueous slurry and then run over a papermaking screen or wire, in accordance with conventional papermaking techniques, to forma rod containing layer in accordance with this invention. Rods may be distributed in a layer of structural fibers after it is formed by spraying or filtering an air stream containing the rods through the layer. Similarly, the rods may be dispersed in water or some other carrier fluid which may be filtered through a layer supported on a foraminous screen, or other techniques may be employed for sifting or sprinkling the rods in the layer as uniformly as possible. The rods, like the fibers, are distributed approximately uniformly, ordinarily at random, in the layer, extending in a plurality of diverse directions generally parallel to the major plane of the layer. The rods intersect and are supported by many fibers along their length, and, depending to a large extent upon the number of rods and their length, the rods themselves may overlap to a greater or lesser extent or hardly ever.

Bonds are formed by applying heat and pressure to the web or the fibrous layer to fuse the binder material and cause it to surround the fibers and imbed them in the rods. Prior to fusing, the rods, may lie in various positions in the fibrous layer or webwithrespect to its thicksq. inch or an equivalent roll pressure.

6 ness. They may rest primarily on one side of the web if separately deposited from that side, or they may be more centrally located. However, it is safe to say that wherever they lie, they are supported primarily by the overlapping, intersecting fibers of the web. The rod containing layer is subjected to means capable of applying pressure to both surfaces of the layer at the sametime. Heat may be applied before or during the application of pressure. Thus, the layer may be placed under or between heated platens such as in a Carver press, passed under rollers which are themselves heated, run between pressure rollers located in an oven, or the like, or the layer may first be heated and then, while still hot, run

between unheated calenders or the like whichapply the desired pressure. Sufiicient heat is applied to melt or fuse the binder material in the rods to allow the binder 'to flow slightly under the influence of the pressure 'applied to pass substantially through the web and imbed the fibers passing above and below the binder members. Both the temperature and pressure applied should be'controlled so that the rods do not distort undesirably and lose their general shape; If the melted binder in agiven rodwere absolutely free to flow, it would tend to assume an approximately'spherical shape due to surface tension. If too high a temperature is applied, this surface tension effect may cause the binder members to shrink or form into a ball, despite the other forces, i.e., the pressure applied, the frictional and capillary restraining influences of the fibers, etc., which tend to prevent this.

For a given binder, there is roughly an optimum temperature range for bonding within which the binder members must liquify and flow under the relatively gentle pressure appliedand not merely become tacky. For instance, for nylon 6 rods, excellent bonds may be formed at a temperature of around 425 F. with the web containing the rods under a platen pressure of about 50 lbs. per

Similarly, superior fabrics "have been bonded with plasticized ethyl celluloserods at a temperature of about 415 F. with the web under a pressure of about 50 lbs. per sq. inch. If too high a pressure is applied, the fused binder may be caused to spread excessively in the web thereby weakening the bond and detracting from fabric qualities.

The invention may be illustrated further by reference to the attached drawings, wherein:

Fig. l is an enlarged schematic .plan view of a portion of a nonwoven fabric according to one embodiment of this invention.

Fig. 2 is an even more greatly enlarged schematic broken sectional view roughly along the line 22 of Fig. 1.

Fig. 3 is a very greatly enlarged schematic sectional view through a portion of one of the rod bonds of Fig. 1', taken lengthwise of the bond.

Referring to Figs. 1 and 2 there is shown, on an'enlarged scale, a portion of a fabric comprisinga layer of overlapping, intersecting fibers 11 which are bonded or held together by a multiplicityof spaced substantially solid rdd bonds 12 which extend through the thickness of the fabric substantially from one surface to the other as shown in Fig. 2. As a result, the bonds 12 are spaced in the major plane of the fabric AA and more or less at the same level in the fabric with respect to this plane. Also, as shown particularly in Fig. 2, the fibers 11 lie in positions which are generally flat or parallel to the major plane of the fabric. As shown in Fig. 1, the fibers 11 extend in a plurality of diverse directions in the planes where they lie. This would be true whether or not the fibers 11 on the layer of Fig. l were predominantly oriented in one direction, as in a card web, or have no particular orientation, as in a random web. The fibers are relatively loosely assembled parallel to the major plane of the fabric, forming myriad small openings or interstices 13 between them as shown roughly in Fig. 1, and are relatively closely assembled through the thickness of the fabric, i; e.','

ing between bonds.

overlapping and lying on top of oneanother, roughly as shown in Fig. 2.

The rod bonds 12, in turn, are arranged approximately uniformly, yet at random, in the fabric, extending in a plurality of diverse directions substantially parallel to the major plane of the fabric A--A. Some of the bonds 12 intersect or cross one another as shown at d, e, and f in Fig. 1. As mentioned hereinbefore, the extent of crossing of bonds is in part a function of their length. Bond crossing may occur more or less frequently than shown in Fig. 1 with the use of longer or shorter rods. The total number of bonds or the rod content of the web also affects bond crossing and, again, this may vary above and below that generally shown in Fig. 1 to change the spac- Parallel to the major plane of the fabric, each rod bond 12 intersects a large number of fibers 11, as shown in Fig. 1. Due to their closeness and thefact that the bonds are arranged substantiallyuniformly and extending in a plurality of diverse directions, it would be extremely difficult for any of the fibers 11 to find a position in the fabric which would not intersect several bonds 12. It is preferred that, on the average, the fibers 11 are bonded at least 2 or 3 times along their length, preferably more, to assure the desired strength and washability. This is of particular importance in fab.- rics wherein the fibers are oriented predominantly in one direction, such as one formed from superimposed card webs extending in the same direction, since in these fabrics it is even more important that virtually all of thefibers extending in this direction are bonded several times.

The over-all cross dimension D of the rod bonds in the fabric of Figs. 1 and 2 is considerably greater than the original diameter of the rods from which these bonds were formed. The increase in the cross dimension of the binder members is believed to be due mainly to the capillary spreading of the fused binder material under heat and pressure. The nature of this spreading will be discussed more fully in connection with Fig. 3. Normal spreading or increase in the cross dimension of the bonds over that of the rods, themselves, may be low for relatively large rods and much higher for smaller rods. For example, for rods in the order of to denier, the bonds may have cross dimensions twice as great as the original rod diameter or even greater. However, the length of the rods does not change significantly since spreading apparently is confined substantially to an increased in rod width, rather than length.

Each bond 12 inbeds or surrounds a large number of fibers which are held firmly thereby. Those portions of the fibers passing through the bonds are held by the binder in relatively compacted positions with respect to the thickness of the fabric, while the fiber segments between bonds generally are less compacted in this direction, providing a multiplicity of fibrous pillows or fiuffy web areas 14 which preserve the softness of the fabric. This may be caused by compacting the web to apply pressure during bonding. The fiber containing bonds 12 will remain compacted to a large extent, whilethe fiber segments in the web areas 14 between bonds will tend to spring back to their original positions after pressure is removed.

The result of binder flow or movement is illustrated to an extent in Fig. 3, which is a very greatly enlargd sectional view through a portion of one of the rod bonds 12 of Fig. 1. In this figure, the fibers 11 are shown imbedded in a particular rod bond 12 and extending through the bond in section and in elevation generally in the direction of the major plane of the fabric. The binder material extends substantially from one surface of the fabric to the other, although indentations 16 are shown adjacent these surfaces. Of course, these irregularities would not be apparent when viewing the fabric with the naked eye. The bond 12, itself, is not an absolutely solid mass of binder material extending without interruption from one surface of the bond to the other. Under most conditions, the bonds contain some air-pockets or hollow spots 17.

As mentioned hereinbefore, nylon 6, or polycaprolactam, is considered to be particularly suitable for use in the binder members of this invention. Other binder materials, which may be employed with some variations in properties depending upon the conditions of application and the size, shape, and number of the rods include plasticized cellulose acetate, plasticized ethyl cellulose, nylon 11 such as sold under the trademark Rilsan by Organico, S.A., of France, saran, polyamides other than nylons 6 and 11, polyvinyl chloride, polyethylene, polyurethane, polystyrene, polyvinylidene cyanide, and the like.

Generally speaking, fibers of almost any material may be used for structural purposes in forming fabrics according to this invention. However, relatively flexible fibers are preferred. Fibers possessing particular qualities may be employed to contribute the same or related properties to the resulting fabric. For instance, relatively absorbent fibers are preferred when a fabric possessing high absorbency is desired. Natural fibers of animal or vegetable origin and artificial fibers whether of materials such as regenerated cellulose or true synthetics such as nylon or the like, may be employed. Fibers of cellulosic materials, such as viscose rayon, cotton, wood and the like, may be used, although as mentioned hereinbefore, the wood fibers should berelatively long and substantially unhydrated for best results.

Nylon 6, nylon 11, plasticized ethyl cellulose and plasticized cellulose acetate rods seem to be particularly suitable for bonding viscose rayon and, in general, form superior bonds with fibers of this and other cellulosic materials. Since viscose rayon fibers, themselves, are very weak when wet, the fact that webs or layers of viscose rayon fibers may be bonded according to the invention to form washable nonwoven fabrics is a surprising demonstration of the efiicacy of this bonding system.

The following examples are illustrative of certain fabrics and methods according to this invention.

Example I A nonwoven fabric weighing approximately 600 grains/sq. yd. is formed from a mixture comprising about 75 per cent by weight of inch, 1.5 denier, viscose rayon fibers .0005 inch in diameter and the remainder, about 30 denier, inch plasticized ethyl cellulose rods about 0.0025 inch in diameter. The fibers and the rods are thoroughly mixed to form an aqueous slurry which is drained through a papermaking wire, to deposit a web of fibers in which the rods are distributed substantially uniformly. The web containing the rods is heated to about 420 F. to fuse the ethyl cellulose. Approximately this temperature is maintained while the fibrous layer is subjected to a platen pressure of about 50 lbs/sq. inch to force the rods and fibers into close bonding contact with one another. An absorbent fabric is formed having excellent strength, wet and dry, as well as superior softness and drapability. The fabric also is capable of being washed by modern techniques, such as described hereinbefore, without serious loss of any of these qualities.

Example 11 A fibrous rod containing layer weighing about 400 grains/sq. yd. is formed by the papermaking techniques described in the foregoing example from a blend or mixture comprising approximately percent by weight of inch, 1.5 denier, viscose rayon fibers 0.0005 inch in diameter and the remainder, 15 denier, 5 inch nylon 6 rods about 00017 inch in diameter. The layer is heated to approximately 425 F. while under a platen pressure of about 50 lbs./sq. inch or an equivalent nip pressure in a heated calender to bond the fibers and the rods together. A superior nonwoven fabric is formed which possesses excellent washability and also is absorbent, soft, fibrous, and textile-like in nature.

Example III A similar fabric to that of Example IIis produced in the same way at a temperature of 375 F. from the same materials combined in the same proportions, with the exception that the rods are of nylon 11 instead of nylon 6 and are /8 inch instead of inch long. This fabric exhibits equivalent properties to that of Example II with a very slight decrease in tensile strength.

Example IV A fibrous Web comprising somewhat larger nylon 6 rods distributed substantially uniformly therein and weighing together with the rods about 1200 grains/ sq. yd. is formed according to the method of Example I from a mixture of fibers and rods comprising about 86 per cent by weight of inch, 1.5 denier, viscose rayon fibers about 0.0005 inch in diameter and the remainder, 35

denier, $1 inch nylon 6 rods about 0.0026 inch in di-.

ameter. As in Example III, the layer is subjected to a pressure of about 50 lbs/sq. in. at 425 F. to form a washable fabric according to this invention.

Example V A fabric in which the structural fibers are oriented predominantly in one direction is formed from a mixture of about 75 percent by weight of one inch, 1.5 denier viscose rayon fibers and the remainder approximately 1.5 denier cotton fibers about one inch in length and 0.0005 inch in diameter. This mixture is processed by conventional textile techniques to form a multiple ply layer of card Webs of 400 grains/sq. yd. Approximately percent by weight of 15 denier nylon 6 rods about 0.0017 inch in diameter, approximately inch long, is uniformly distributed on the surface of the web by filtering techniques from an aqueous suspension of the binder rods. Heat and pressure is applied as in Example IV to fuse the binder and form a Washable fabric having the characteristics of this invention.

Example VI A fabric in which the structural fibers are arranged in a random or isotropic fashion is formed from 85 percent by Weight of bleached cotton fibers about one inch long uniformly suspended in an air stream with 15 percent of A inch, 15 denier nylon 11 rods about 0.0017 inch in diameter, and then condensed on a foraminous member to form a continuous layer of fibers and rods weighing about 800 grains/sq. yd. The web containing the rods then is heated to approximately 375 F. while being subjected to a pressure equivalent to a platen pressure of about 50 lbs/sq. inch to force the rods and fibers into close bonding contact with one another. An absorbent fabric is formed having a high degree of textile-like properties and superior durability and washability.

Example VII A fibrous rod-containing layer weighing about 800 grains/sq. yd. is formed by the papermaking techniques described in the foregoing Example I from a blend or mixture comprising approximately 80% by Weight of inch, 3 denier nylon fibers about 0.0008 inch in diameter sold as nylon 66 by E. I. du Pont de Nemours, Inc., and the remainder l5 denier inch nylon 11 rods about 0.0017 inch in diameter. The layer is heated as in Example III and a product is formed which is resilient, tensile-like and washable, and which after washing possesses a springy wool-like hand.

Example VIII Another rod-containing layer weighing about 800 grains/sq. yd. is formed by the techniques of the previous example from about 85 percent by weight of 3 denier cellulose acetate fibers about V2 inch long and approximately 0.0008 inch in diameter and the remainder l5 denier nylon 11 rod's about A inch long and about 0.0017 inch in diameter. The layer may be treated under heat and pressure in accordance with Example III to form a washable fabric possessing textile-like hand and drape.

Having now described the invention in specific detail and exemplified in the manner in which it may be carried into practice, it will be readily apparent to those skilled in the art that innumera'ble variations, modifications, applications, and extensions of the basic principles involved may be made without departing from its spirit and scope. Thus, the fabrics of the present invention may be employed in a host ofways that will be-readily apparent to the skilled artis'an. We, therefore, intend to be limited only in accordance with the appended patent claims.

What is claimed is:

1. A soft, textile-like washable nonwoven fabric comprising a layer of overlapping, intersecting fibers lying in positions generally parallel to the major plane of the fabric and extending in a plurality of diverse directions parallel to said plane, the fibers being relatively closely assembled through the thickness of the fabric and relatively loosely assembled parallel'to the majorplane of the fabric forming myriad small interstices between them, and a multiplicity of approximately uniformly distributed and diversely oriented heat fused rod bonds lying in positions generally parallel to the major plane of the fabric, having an average cross dimension in the order of 5 to 10 times the average diameter of the fibers and an average long dimension at least about inch, said bonds being in general spaced relatively closely but sufiiciently apart to provide a multiplicity of relatively fluify unbonded fiber areas between bonds, the bonds comprising between about 3 and 35- percent by weight of the fabric.

2. A washable nonwoven'fabric according to claim 1 wherein the bonds comprise between about 5 and 20 percent by weight of the fabric.

3. A soft, textile-like washable'nonwoven fabric comprising a layer of overlapping, intersecting fibers lying in positions generally parallel to the major plane of the fabric and extending in a-plurality of diverse directions parallel to said plane, the fibers being relatively closely assembled through the thickness of the fabric and relatively loosely assembled parallel to the major plane of the fabric forming myriad small interstices between them, and a multiplicity of approximately uniformly distributed and diversely oriented heat fused rod bonds having an average cross dimension in the order of 5 to 10 times the average diameter of the fibers and an average long dimension at least about g inch, said bonds anchoring the fibers by imbedment in the bonds and being in general spaced relatively closely but sufficiently apart to provide a multiplicity of relatively fiuffy unbonded fiber areas between bonds.

4. A Washable nonwoven fabric according to claim 3 wherein the rod bonds comprise a water resistant thermoplastic material.

5. A washable nonwoven fabric according to claim 4 wherein the rod bonds comprise nylon.

6. A washable nonwoven fabric according to claim 5 wherein the rod bonds comprise polycaprolactam.

7. A washable nonwoven fabric according to claim 5 wherein the rod bonds comprise a polyamide of undecylic acid.

8. A washable nonwoven fabric according to claim 4 wherein the rod bonds comprise polyethylene.

9. A Washable nonwoven fabric according to claim 4 wherein the rod bonds comprise cellulose acetate.

10. A washable nonwoven fabric according to claim 4 wherein the rod bonds comprise ethyl cellulose.

11 11. A washable nonwoven fabric according to claim 3 wherein the layer comprises cellulosic fibers.

12. A washable nonwoven fabric according to claim 11 wherein the layer comprises regenerated cellulosic fibers.

13. A washable nonwoven fabric according to claim 11 wherein the layer comprises viscose rayon.

14. A washable nonwoven fabric according to claim 11 wherein the layer comprises natural vegetable fibers.

15. A washable nonwoven fabric according to claim 14 wherein the layer comprises cotton fibers.

16. A washable nonwoven fabric according to claim 3 wherein the layer comprises nylon fibers.

17. A soft, textile-like washable nonwoven fabric comprising a layer of overlapping, intersecting fibers lying in positions generally parallel to the major plane of the fabric and extending in a plurality of diverse directions parallel to said plane, the fibers being relatively closely assembled through the thickness of the fabric and relatively loosely assembled parallel to the major plane of the fabric forming myriad small interstices between them, and a multiplicity of approximately uniformly distributed and diversely oriented heat fused rod bonds lying in positions generally parallel to the major plane of the fabric, having an average cross dimension in the order of to times the average diameter of the fibers and an average long dimension at least about inch, said bonds being in general spaced apart sufficiently to provide a multiplicity of relatively flufiy unbonded fiber areas between bonds, but being sufiiciently close to one another that substantially every fiber is intersected by said bonds a plurality of times along its length.

18. A soft, textile-like washable nonwoven fabric comprising a layer of overlapping, intersecting fibers lying in positions generally parallel to the major plane of the fabric and extending in a plurality of diverse directions parallel to said plane, the fibers being relatively loosely assembled parallel to the major plane of the fabric forming myriad small interstices between them, and a multiplicity of approximately uniformly distributed and diversely oriented heat fused rod bonds lying in positions generally parallel to the major plane of the fabric, having an average'cross dimension in the order of 5 to 10 times the average diameter of the fibers and an average long dimension at least about inch, said bonds being in general spaced relatively closely but sufficiently apart to provide a multiplicity of relatively fiuffy unbonded fiber areas between bonds, the bonds comprising between about 3 and 35 percent by weight of the fabric and the fibers being relatively compacted with respect to the thickness of the fabric where they pass through the bonds and less compacted in this direction between said bonds.

19. A washable nonwoven fabric according to claim 18, wherein the fibers in said layer weigh between about 150 and 2000 grains per square yard.

20. A soft, textile-like washable nonwoven fabric comprising a layer of overlapping, intersecting fibers lying in positions generally parallel to the major plane of the fabric and extending in a plurality of diverse directions parallel to said plane, the fibers being relatively closely assembled through the thickness of the fabric and relatively loosely assembled parallel to the major plane of the fabric forming myriad small interstices between them, and a multiplicity of approximately uniformly distributed and diversely oriented heat fused rod bonds lying in positions generally parallel to the major plane of the fabric and having an average cross dimension between about 0.0025 and 0.005 inch and an average long dimension at least about ,4, inch, said bonds being in general spaced relatively closely but sufiiciently apart to provide a multiplicity of relatively fluffy unbonded fiber areas between bonds, the bonds comprising between about 3 and 35 percent by weight of the fabric.

21. A washable nonwoven fabric according to claim 20, wherein the average length of the rod bonds is not more than about 0.25 inch.

22. A washable nonwoven fabric according to claim 20, wherein the rod bods comprise a water resistant thermoplastic material.

23. A washable nonwoven fabric according to claim 22, wherein the thermoplastic material is polycaprolactam.

24. A washable nonwoven fabric according to claim 22, wherein the thermoplastic material is the polyamide of undecylic acid.

25. A washable nonwoven fabric according to claim 22, wherein the layer comprises viscose rayon fibers.

26. A soft, textile-like washable nonwoven fabric comprising a layer of overlapping, intersecting fibers lying in positions generally parallel to the major plane of the fabric and extending in a plurality of diverse directions parallel to said plane, the fibers being relatively loosely assembled parallel to the major plane of the fabric forming myriad small interstices between them, and a multiplicity of approximately uniformly distributed and diversely oriented heat fused rod bonds lying in positions generally parallel to the major plane of the fabric having an average cross dimension between about 0.0025 and 0.005 inch and an average length at least equal to inch but not more than about 0.25 inch, said bonds being in general spaced relatively closely but sufficiently apart to provide a multiplicity of relatively fluffy unbonded fiber areas between bonds, the fibers being surrounded and imbedded in the bonds and relatively compacted with respect to the thickness of the fabric where they pass through the bonds and less compacted in this direction between said bonds.

27. A soft, textile-like washable nonwoven fabric comprising a layer of overlapping, intersecting fibers lying in positions generally parallel to the major plane of the fabric and extending in a plurality of diverse directions parallel to said plane, the fibers being relatively closely assembled through the thickness of the fabric and relatively loosely assembled parallel to the major plane of the fabric forming myriad small interstices between them, and a multiplicity of approximately uniformly distributed and diversely oriented heat fused rod bonds lying in positions generally parallel to the major plane of the fabric and having an average cross dimension between about 0.0026 and 0.0045 inch and an average length between about 0.030 and 0.25 inch, said bonds being in general spaced relatively closely but sufficiently apart to provide a multiplicity of relatively fluffy unbonded fiber areas between bonds, the bonds comprising between about 5 and 20 percent by weight of the fabric, and the fabric weighing between about and 1200 grains/sq. yd.

28. The method of forming a soft, textile-like washable nonwoven fabric which comprises distributing a multiplicity of heat fusible rod binder members having an average cross dimension between about 0.0012 and 0.004 inch and an average long dimension at least inch but not more than about 0.25 inch, approximately uniformly yet at random in a loosely assembled layer of overlapping, intersecting structural fibers, said layer comprising a predominate proportion of fibers above about 0.25 inch in length, said rods being relatively closely spaced and arranged to lie generally parallel to the major plane of the layer and to extend in a plurality of diverse directions parallel to said plane, and applying heat and pressure thereto to fuse the rods and cause movement of the binder into the thickness of the layer to imbed and anchor a majority of the fibers which passed above and below the rods in the layer, said heat and pressure being controlled to fuse the binder without destroying the general shape of the rods.

29. The method of forming a washable nonwoven fabric according to claim 28, wherein the binder is caused to move substantially through the thickness of the layer and to imbed substantially all of the fibers which passed above and below the rods in the layer.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Goldman Apr. 26, 1904 Shoemaker Dec. 30, 1930 5 Osborne Jan. 28, 1947 Reed June 29, 1948 14 Goldman Mar. 30, 1951 Heritage Sept. 25, 1951 Ness Dec. 21, 1954 Daugherty Jan. 4, 1955 Petterson Apr. 5, 1955 Ness Apr. 5, 1955 Petterson Apr. 5, 1955

Claims

1. A SOFT TEXTILE-LIKE WASHABLE NONWOVEN FABRIC COMPRISING A LAYER OF OVERLAPPING, INTERSECTING FIBERS LYING IN POSITIONS GENERALLY PARALLEL TO THE MAJOR PLANE OF THE FABRIC AND EXTENDING IN A PLURALITY OF DIVERSE DIRECTIONS PARALLEL TO SAID PLANE, THE FIBERS BEING RELATIVELY CLOSELY ASSEMBLED THROUGH THE THICKNESS OF THE FABRIC AND RELATIVELY LOOSELY ASSEMBLED PARALLEL TO THE MAJOR PLANE OF THE FABRIC FORMING MYRIAD SMALL INTERSTICES BETWEEN THEM. AND A MULTIPLICITY OF APPROXIMATELY UNIFORMLY DISTRIBUTED AND DIVERSELY ORIENTED HEAT FUSED ROD BONDS LYING IN POSITIONS GENERALLY PARALLEL TO THE MAJOR PLANE OF THE FABRIC, HAVING AN AVERAGE CROSS DIMENSION IN THE ORDER OF 5 TO 10 TIMES THE AVERAGE DIAMETER OF THE FIBERS AND AN AVERAGE LONG DIMENSION AT LEAST ABOUT 1/2 INCH SAID BONDS BEING IN GENERAL SPACED RELATIVELY CLOSELY BUT SUFFICIENTLY APART TO PROVIDE A MULTIPLICITY OF RELATIVELY FLUFFY UNBONDED FIBER AREAS BETWEEN BONDS ,THE BONDS COMPRISING BETWEEN ABOUT 3 AND 35 PERCENT BY WEIGHT OF THE FABRIC.