Embossed Nonwoven Wiping And Cleaning Materials

Abstract

An embossed nonwoven fabric having a textured character and fabriclike qualities of softness and hand and suitable for wiping surfaces having aqueous and/or oleaginous liquids and/or more viscous semisolids thereon comprising a web containing at least one layer of overlapping, intersecting fibers, a pattern of intermittantly spaced, embossed, compacted or densified fibrous areas lying in the planes of both surfaces of said web of overlapping, intersection fibers, and a pattern of unembossed, uncompacted fibrous portions lying between said planes and connecting said embossed, compacted fibrous areas.

Description

This invention relates to nonwoven fabrics and more particularly to embossed nonwoven fabrics having improved wiping rates or cleaning efficiencies and well suited as wiping or cleaning materials for surfaces having aqueous and/or oleaginous liquids and/or more viscous semisolids thereon.

In the past, nonwoven fabrics comprising at least one layer of overlapping, intersecting fibers have been used as wiping and cleaning materials for aqueous and/or oleaginous liquids and/or more viscous semisolids, such as water, syrups, aqueous solutions, chemicals, oils, fats, waxes, greases, cosmetics, etc. and have met with considerable commercial success. However, it is always desirable to improve the properties and characteristics of existing commercial products and, in the case of wiping and cleaning materials, to enhance their wiping rates and cleaning efficiencies.

Typical examples of nonwoven fabrics which are suitable for wiping, cleaning, and related purposes are noted in U.S. Pat. Nos. 2,039,312, 2,676,364, 2,705,688, 2,862,251, and 2,834,703. It is a primary purpose of the present invention to improve the wiping rates and cleaning properties and characteristics of such nonwoven fabrics and like materials.

It has been discovered that such a purpose may be achieved by embossing or compacting the layer or layers of overlapping, intersecting fibers which form the nonwoven fabrics or the like in such a way that the embossed or compacted areas lie in the planes of both top and bottom surfaces of such nonwoven fabrics and therefore directly contact the liquids or semisolids to be wiped or cleaned. Such has been found to improve the fluid absorbency and retentivity of the nonwoven fabric and to enhance its wiping and cleaning efficiency. Also, and perhaps more importantly, the wetting rate is enhanced due to the compacted structure of the embossed areas which provide capillarity, coupled with avenues of rapid liquid flow into the body of the nonwoven fabric.

It has further been discovered that a textured character and fabriclike qualities of softness and hand as well as loft, resiliency, and drape may be retained in the embossed, compacted nonwoven fabrics if the embossing or compacting takes place intermittently in spaced, discrete areas on both surfaces of the nonwoven fabric and wherein unembossed or uncompacted portions having high loft and bulk lie between the planes of the surfaces of the nonwoven fabrics and connect the embossed, compacted areas.

The embossed area must not cover the entire surface of each side of the nonwoven fabric. Such overall embossing or compacting will yield a stiff, boardy wiping fabric which is entirely undesirably and unsatisfactory. The embossed, compacted areas must therefore be interrupted by other areas which are not embossed or compacted, or by voids or gaps in the planar surface of the nonwoven fabric. In the event that the compacted areas join one another to form an open network or interconnected grid, such is to be considered as spaced or interrupted embossed areas, provided they meet the other requirements set forth in this specification.

To more clearly define the nature of the present invention, reference is made to the following specification and accompanying drawings wherein there are described and illustrated preferred embodiments of the invention. This is intended primarily to disclose the invention more fully but not to limit it. With reference to the accompanying drawings:

FIG. 1 is an idealized, fragmentary cross-sectional view of embossing plates or embossing rolls such as were used in the prior art for embossing nonwoven fabrics;

FIG. 2 is an idealized, fragmentary cross-sectional view of an embossed nonwoven fabric of the prior art resulting from the use of the embossing plates or embossing rolls of FIG. 1;

FIG. 3 is an idealized, fragmentary cross-sectional view of the improved embossing plates or embossing rolls, taken on the line 3--3 of FIGS. 5 and 6, as are used in applying the principles of the present invention;

FIG. 4 is an idealized, fragmentary cross-sectional view of an embossed nonwoven fabric, taken on the line 4--4 of FIG. 7, resulting from the use of the embossing plates or embossing rolls of FIG. 3;

FIG. 5 is an idealized, fragmentary perspective view of a portion of parts of a pair of mating embossing plates used to make the improved embossed nonwoven fabrics of the present invention;

FIG. 6 is an idealized, fragmentary plan view of the mating embossing plates of FIG. 5, disclosing the spatial relationship of the embossing lands of both embossing plates;

FIG. 7 is an idealized, fragmentary perspective view of a portion of an improved embossed nonwoven fabric of the present invention resulting from the use of the embossing plates of FIGS. 5 and 6;

FIG. 8 is an idealized, fragmentary plan view of a modified form of mating embossing plates having circular embossing lands of use in the application of the principles of the present invention.

FIG. 9 is an idealized, fragmentary cross-sectional view of a modified form of mating embossing plates, taken on the line 9--9 of FIG. 12, showing embossing lands of different size and having different compacting forces of use in the application of the principles of the present invention;

FIG. 10 is an idealized, fragmentary plan view of a modified form of mating embossing plates having a diamond-embossing grid and diamond-shaped embossing lands of use in the application of the present invention;

FIG. 11 is an idealized, fragmentary schematic view in elevation showing the use of rotatable embossing rolls of use in the application of the principles of the present invention;

FIG. 12 is an idealized, fragmentary plan view of the mating embossing plates of FIG. 9, disclosing the spatial relationship of the embossing lands of the mating embossing plates;

FIG. 13 is an idealized, fragmentary plan view of a variation of the mating embossing plates of FIGS. 9 and 12 but disclosing a variation in the sizes of the embossing lands of the mating embossing plates;

FIG. 14 is an idealized, fragmentary plan view of a variation of the mating embossing plates of FIGS. 9 and 12 but disclosing another variation in the sizes of the embossing lands of the mating embossing plates;

FIG. 15 is an idealized, fragmentary plan view of a modified form of mating embossing plates having diamond-shaped embossing lands on one surface and a grid plate formed with circular holes as the embossing land of the cooperating embossing surface;

FIG. 16 is an idealized, exploded, fragmentary cross-sectional view taken on the line 16--16 of FIG. 15 showing the mating embossing plates and the embossed wiping cloth resulting from the operation of such mating embossing plates;

FIG. 17 is an idealized, fragmentary perspective view of a modification of the pair of mating embossing lands such as illustrated in FIG. 5 but disclosing an additional technique for forming embossed compacted channels between the embossed areas in one surface of the nonwoven fabric and the embossed areas in the other surface of the nonwoven fabric; and

FIG. 18 is a further modification of the channel-forming techniques of FIG. 17 but showing embossed compacted fibrous channels at all four corners of the embossed areas of the embossed nonwoven fabric.

Embossed nonwoven fabrics for various purposes are well known in the textile and related industries, as noted in U.S. Pat. No. 2,834,703 and particular reference is made to FIG. 3 of this patent showing a specific embossed nonwoven fabric for cosmetic and related purposes. In the methods disclosed in this prior art patent, embossing plates or embossing rolls having mating surfaces or lands such as illustrated in cross section in FIG. 1 of this specification are used and an idealized cross section of the resulting embossed nonwoven fabric is illustrated in FIG. 2 of this specification.

It is to be appreciated that, when the embossed, nonwoven fabric of FIG. 2 of this specification is used for wiping or cleaning purposes, the unembossed, uncompacted areas which extend beyond the plane of the nonwoven fabric come into more intimate contact with the surface to be wiped or cleaned than do the embossed, compacted areas which lie in the plane of the nonwoven fabric. This results in a wiping or cleaning action which has been found acceptable in the prior art but which is improved by use of the principles of the present invention.

According to the principles of the present invention, the formation and basic construction of the embossing plates or embossing rolls is modified whereby a novel, improved embossed nonwoven fabric is obtained. As shown in FIG. 3 of this specification, upper and lower mating, embossing plates 10 and 12 are used wherein the respective embossing lands 14, 16 and 18, 20 are parallel but offset with respect to each other and to the plane of web 11 of one or more layers of overlapping, intersecting fibers constituting a nonwoven fabric, whereby the compacted areas 22, 24 (See FIG. 4) of the resulting embossed nonwoven fabric 26 are similarly parallel but offset.

Also, as noted in FIG. 4, fibrous portions 28, 30 extend slantingly and angularly from the intermittently spaced embossed, compacted fibrous areas 22 lying in one surface of the nonwoven fabric 26 to the intermittently spaced, embossed, compacted fibrous areas 24 lying in the other surface of the nonwoven fabric 26. These fibrous portions 28, 30 are unembossed and uncompacted and retain their original softness, bulk, and loft and provide fabriclike qualities of softness and hand, as well as loft, resiliency and drape to the embossed nonwoven fabric 26.

The compacted areas 22 and 24 thus form a pattern of intermittently spaced, separate and discrete, embossed, compacted fibrous areas which lie in the planes of the substantially parallel top and bottom surfaces of the nonwoven fabric, whereas the unembossed, uncompacted portions 28, 30 lie between these planes and hingedly connect the embossed, compacted areas. With such a configuration, it is to be appreciated that, when the embossed, nonwoven fabric 26 of FIG. 4 is used for wiping or cleaning purposes, an entirely new principle and cleaning action is involved wherein the compacted areas 22, 24 come into more intimate contact with the surface to be wiped or cleaned than do the uncompacted areas 28, 30. As will be pointed out hereinafter, such principles result in an enhancement of the wiping and cleaning efficiency.

It is to be pointed out, moreover, that the compacted areas have superb liquid-wiping efficiency and act in the fashion of wiping blades or barriers which "snowplow" liquids, greases, and semisolids. Also, the "pockets" or voids 29 (See FIG. 4) in the structure of the nonwoven fabric hold the grease or other materials being wiped out of direct pressing contact with the surface being wiped.

In FIG. 5, there is illustrated one form of the lower embossing plate 12 capable of making one typical embosidment of the embossed nonwoven fabric of the present invention. The embossing surfaces or lands 16 of the lower embossing plate 12 are squares and are arranged in substantially parallel-spaced checkerboard rows. The upper embossing plate 10 which possesses substantially parallel-spaced checkerboard rows of embossing surfaces or lands 18 is shown fragmentarily, in order to avoid confusing FIG. 5, but its action and mating embossing function with the lower embossing plate 12 is obvious.

FIG. 6 discloses a plan view of the spatial relationship of the embossing lands 16 and 18 of the lower and upper embossing plates 12 and 10, respectively. The intermittent spacing and arrangement of these lands is such that one pair of lands (14, 16, for example) forces the nonwoven fabric in one direction to be compacted in one surface of the nonwoven fabric whereas an adjacent pair of lands (18, 20 for example) forces the nonwoven fabric in the other direction to be compacted in the other surface of the nonwoven fabric.

The resulting three-dimensional, embossed effect is well illustrated in FIG. 7. It is to be appreciated, however, that such an effect is the result of having embossing lands with mating square cross sections. Such specific cross sections are merely illustrative of the present invention. Other geometric shapes and figures may, of course, be used, and include, for example, polygons, including triangles, rectangles, diamonds, pentagons, hexagons, octagons; curved figures such as circles, ellipses, ovals, etc., or combinations thereof. Irregular figures and designs may also be used such as hearts, stars, or even symbols or insignia such as fleur-de-lis, crowns, coronets, etc.

Patterns in the forms of grids or interconnected lines which may be continuous or discontinuous, narrow or broad, straight or wavy, may be used. Their general direction or orientation may be in the machine or long direction, parallel to the predominant fiber orientation, if a card web is used, or they may be in the cross or short direction, perpendicular to the predominant fiber orientation, or they may be diagonally or angularly positioned, as desired or required.

FIG. 8 discloses the spatial arrangement of circular geometric figures 32, 34 as the mating embossing lands; other arrangements and the use of other shapes or figures are also of use. These are not shown in the drawings as their arrangement and use is believed clear.

It is not essential that the same geometric shape or figure be used on each side of the nonwoven fabric. Nor is it essential that the same amount of surface coverage of compacted area be present on each side of the nonwoven fabric. For example, FIG. 9 discloses a cross section of mating, embossing plates 36 and 38 wherein large rectangular embossed, compacted areas 40 are formed on one surface of the nonwoven fabric 41 and small rectangular embossed, compacted areas 42 are formed on the other surface of the nonwoven fabric 41. Unembossed or uncompacted fibrous portions 44 and 46 are noted as lying between the top and bottom surfaces of the nonwoven fabric and angularly and slantingly join the compacted areas 40, 42 in a hinged relationship.

The relative size and relationship of the embossing lands of the mating, embossing plates 36 and 38 is more clearly illustrated in FIG. 12 and reference thereto will indicate that the small embossed areas 42 are formed by the small lands 116 which are approximately one-quarter the dimensions of the large lands 118 which form the large embossed areas 40. As a result, the total area of the small embossed area 42 is only one-sixteenth of the total area of the large embossed area 40.

The relative size and spatial relationship of the lands of the cooperating mating, embossing plates or lands may be varied widely depending on the needs or requirements of the particular situation. For example, in FIG. 13, there is illustrated a pair of embossing lands 216 and 218 which vary in relative size to a greater degree than the previous pairs of lands shown in FIG. 12.

In FIG. 14, the variation in size of the pair of lands 316 and 318 is increased to even a greater degree. Also, it is to be noted that the shapes of the lands have been varied from the previous square-square relationship to a square-rectangle relationship.

FIG. 10 discloses a simplified plan view of mating embossing plates whereby diamond-shaped compacted areas are capable of being formed on one surface of the nonwoven fabric by means of diamond-shaped lands 50 and a relatively thin diamond grid of compacted lines is capable of being formed in the other surface of the nonwoven fabric by a corresponding relatively thin diamond-grid land 52. This, of course, results in different patterns on each surface of the resulting nonwoven fabric.

The diamond-shaped lands 50 are, of course, integral with one member of a pair of cooperating mating embossing plates and the diamond-grid land 52 is, of course, integral with the other member of the pair of cooperating mating embossing plates.

The majority of these geometric figures can be produced by machine shop milling procedures. However, in the event that such procedures are difficult or uneconomical to carry out for a particular shape or figure, then other known techniques are readily available in the art. Such other techniques include engraving, etching, electrodeposition, perforated plate sleeves, etc.

Regardless of the shape, form or number of geometric figures which are involved, it is essential that there be a pattern of intermittently spaced, separate, discrete embossed compacted areas in at least one plane of the surfaces of the nonwoven fabric. Such a configuration will insure the positioning of the compacted densified areas where desired and will also insure that the unembossed, uncompacted portions do not lie in the planes of the surfaces of the nonwoven fabrics or extend beyond such planes but lie between these planes and do not directly contact the surfaces to be cleaned.

FIGS. 15 and 16 illustrate the use of a rather unusual pair of cooperating, mating, embossing plates 90 and 92. Plate 90 is formed from a platelike member 91 from which a plurality of circular holes 94 have been removed, for example, by drilling. The holes are aligned in parallel rows which nest or fit together in a staggered relationship as seen in FIG. 15. It is to be appreciated that the surface or area 104 around the circular holes 94 actually forms the embossing lands of plate 90. The apertured platelike member 91 is relatively thin and is secured to a base 93 and the two elements form one member of the pair of cooperating mating embossing plates 90 and 92.

The other member of the pair of cooperating mating embossing plates is the plate 92 which possesses a plurality of diamond-shaped lands 96 which are so positioned that they are aligned with the circular holes 94 and can be moved reciprocatingly within the space created by these circular holes.

Consideration of FIG. 16 will reveal that diamond-shaped lands 96 will cooperate with the opposed surfaces 98 of baseplate 93 to form an embossed compacted fibrous area 100 in the nonwoven fabric 102. Also, at the same time, the upper surface 104 of the embossing plate 90 will cooperate with the opposed surface 106 of the mating embossing plate 92 to form embossed compacted fibrous areas 108 of the nonwoven fabric 102. Again, it is to be noted that a pattern of unembossed, uncompacted fibrous portions 110 and 112 are formed and that they are within the plane of the embossed nonwoven fabric and hingedly and slantingly connect the embossed areas 100 and 108 in the same way as described previously.

The result of such application of the principles of the present invention will yield a two-faced fabric. One side will have a series of intermittently spaced, discrete diamond-shaped embossed areas, whereas the other side will have a compacted area corresponding to that of the surface of plate 91.

Embossing plates which reciprocate rectilinearly in their embossing action have been found to be capable of satisfactory use and have many advantages. However, the use of rotatable embossing rolls is desirable in many instances, particularly where large scale manufacturing production is involved.

In FIG. 11, there is illustrated a typical arrangement involving the use of rotatable mating embossing rolls 60, 62. Projections or embossing lands 64, 66 extend from the surfaces of the rolls 60, 62, respectively, somewhat generally resembling gear teeth, and cooperate with the surfaces 68, 70, respectively, of the opposed rolls 62, 60. In this way, a plurality of webs of overlapping, intersecting fibers constituting a substantially flat nonwoven fabric 72 is introduced between the embossing lands and opposed surfaces and is embossed in an offset manner as described herein. This yields compacted areas 74, 76 which lie in the planes of the surfaces of the nonwoven fabric 72 and are connected hingedly and angularly by unembossed and uncompacted portions 78, 80. The compacted areas are intermittently spaced not only radially by the embossing rolls which is equivalent to a lengthwise direction of the nonwoven fabric but they may also be intermittently spaced axially by removing portions of the projections 64, 66 at regularly spaced location in an axial direction. This intermittently spaces the compacted areas in a widthwise direction of the nonwoven fabric. Squares, diamonds, and rectangles would be the most common form of embossing lands employed on such rotatable rolls, although any geometric shape or figure is possible.

In the embodiments of the invention described and illustrated thus far, the compacted fibrous areas in one plane of the nonwoven fabric are separate and distinct from the compacted fibrous areas in the other plane of the nonwoven fabric. This is usually desirable but in some cases it may be desired to connect them with relatively narrow, fibrous channellike members which are also embossed or compacted whereby fluid flow therealong is expedited.

One method of accomplishing this is illustrated in FIG. 17 wherein the principle is illustrated in the formation of merely one channellike member. In this Figure, the nonwoven fabric being embossed is omitted for purposes of clarity. A pair of adjacent embossing lands 416 and 418 are shown and it is to be appreciated that upward relative movement of land 416 will form a compacted or embossed fibrous area on its upper surface. At the same time, downward relative movement of land 418 will form a compacted or embossed fibrous area on its lower surface. Such has been described previously. These compacted areas would normally not be connected. However, a pair of channel-forming lands 420 and 422 are formed adjacent to and integral with the lands 416 and 418, respectively, and have sloping surfaces 424 and 426 which oppose each and come together to emboss or compact a slanting channellike fibrous compacted strip which extends angularly between the embossed areas in the surface of the nonwoven fabric.

FIG. 18 discloses the application of such channel-forming techniques to a nonwoven fabric 430. Four square-shaped compacted areas 432 are shown which exist in one plane of one surface of the nonwoven fabric 430. One square-shaped compacted area 434 is shown which exists in the other plane of the other surface of the nonwoven fabric 430. Four channellike members 436, 438, 440 and 442 are shown connecting all these compacted areas, whereby fluid flow between these areas is facilitated and expedited.

The degree of compaction or the amount to which the fibrous areas can be densified is controlled and regulated by the clearance between the embossing lands and the opposed embossing surfaces. A moderate compaction yields excellent wiping and capillarity along with good resilience, softness and hand. Heavier compaction facilitates bonding characteristics where such properties are of interest, particularly if any potentially softenable and fusible thermoplastic fibers or materials are used. Reference to FIG. 9 will reveal that the degree of compaction need not necessarily be the same on both sides of the nonwoven fabric but may be different. The degree of compaction is controlled and regulated by changing the clearances between the embossing lands and the cooperating opposed embossing surfaces.

In FIG. 9, the embossing lands and cooperating opposed embossing surfaces are closer together in the formation of the small embossed area 42 than are the embossing lands and cooperating opposed embossing surfaces which form the large embossed area 40. As a result, the embossed area 42 is much more compacted and bonded together than the embossed area 40.

The compression forces required to obtain the degree of compaction required will vary widely within the principles of the present invention. Compression forces of from about 100 pounds per square inch to about 10,000 pounds per square inch have been found satisfactory. However, from about 100 to about 1,000 pounds per square inch is preferred as such avoids the destructive effects of crushing and cutting occasionally noted at very high pressures for some patterns. The time intervals for the application of such compressive forces will also vary widely and, within the principles of the present invention, good results are obtainable using application times of approximately one two-hundredth of a second to about one one-hundredth of a second or more. Such a time interval is also classifiable as substantially instantaneous. If it is desired to apply the compressive forces at elevated temperatures, such may be done at temperatures of from about 212.degree. F. to about 450.degree. F., with preferable limits being from about 250.degree. F. to about 350.degree. F.

Normally, the natural moisture regain of the cellulosic fibers is sufficient in order to obtain satisfactory results. Such natural moisture regain is normally in the area of from about 6 percent to about 10 percent. On occasion, if it is desired, additional moisture may be applied to bring the moisture content up to 30 percent or 60 percent, or even more, where additional moisture and compaction is desired.

The amount of surface coverage of the compacted areas in the planes of the surfaces of the nonwoven fabric may vary widely and, as pointed out herein with particular reference to FIG. 9 and 10, need not be equal. Within the broader aspects of the present invention, however, the surface coverage of the compacted area on each side of the nonwoven fabric may be as low as a fraction of 1 percent and as high as about 90 percent. Within the narrower and more preferred aspects, however, the surface coverage of the compacted areas on each side of the nonwoven fabric is in the range of from about 10 percent to about 40 percent.

By a judicious selection of the shape of the geometric pattern for each side of the nonwoven fabric and by varying the amount of surface coverage for each side, different properties and characteristics can be created in each side whereby a two-sided product is obtained with a different function or use for each side.

The nonwoven fabrics of the present invention normally comprise fibrous materials of a cellulosic origin inasmuch as the fluid absorbency and retentivity of such fibrous materials is best suited for the purpose of the present invention. Cotton fibers, rayon, cotton linters, wood pulp, and the like are exemplary of such cellulosic materials. When the fiber length of such materials is very short, as in the case of cotton linters or woodpulp fibers, and create difficulties in handling and processing, they are preferably either mixed in varying proportions with fibers of greater length and thus handled and processed, or they may form the central layer of a three layer sandwich in which the two outer layers comprise longer fibers.

Other fibers, such as polyolefinic, polyester, nylon 6 or 66, acrylics, modacrylics, fluorocarbon, spandex, acetate, etc. or other natural fibers such as wool, silk, etc., may be used in varying percentages, from about 5 percent by weight up to about 25 percent by weight, or even more, where special properties or characteristics are desired in the final product. The thermoplastic fibers noted above are of use particularly if some degree of softening and thermoplastic fusion is desired.

The nonwoven fabrics of the present invention comprise one or more layers of overlapping, intersecting fibers and are preferably derived from card webs wherein the individual fibers are relatively more oriented in the long or machine direction. However, they may also be prepared by various air-laying techniques or similar processes whereby the nonwoven fabric is relatively more isotropic.

The nonwoven fabrics may be processed according to the principles of the present invention in an unbonded state, or, if desired, they may be lightly bonded by any of the many known bonding agents common in the nonwoven industry and then embossed in such lightly bonded condition.

The embossing and compacting may take place with the nonwoven fabrics in relatively dry condition, that is, merely containing the natural moisture regain which under normal conditions is about 6-10 percent by weight but in some cases may range up to about 20 percent by weight under conditions of high humidity and high temperature. If desired, some additional moisture or steaming up to 60 percent moisture or more may be resorted to in order to obtain a greater set in the embossed compacted areas.

The embossing plates or rolls may be operated at room temperatures or at elevated temperatures, if desired, and temperatures up to 212.degree. F. or even as high as 450.degree. F. may be employed to accentuate the set of the fibers and to improve their shape retention. Such elevated temperatures may also be restored to if thermoplastic fusible fibers are included and it is desired to obtain some degree of fiber softening and fusing thereof.

A light spray of a resin or other coating or impregnant may be applied by roller or padding techniques to the embossed, compacted nonwoven fabric, after embossing, preferably only on the embossed, compacted areas to enhance the shape-stability of the embossed nonwoven fabric. Too heavy a resin treatment, particularly on the unembossed, uncompacted portions, would be undesirable for many purposes, particularly when softness, drape and hand are desired in the final product.

The resin or other coating which is applied to the nonwoven fabric after embossing need not necessarily be applied to both sides. If desired, it may be applied only to one side or, if desired, two different resins or coatings may be applied whereby a two-sided product is obtained. For example, a gritty or abrasive binder may be applied to one side and a soft and yielding binder may be applied to the other side whereby a "scrubber-wiper" nonwoven fabric is obtained.

If desired, the nonwoven fabrics may be strengthened by the inclusion therein of reinforcing fabrics or other structures, such as, gauze, woven or nonwoven scrim, warp sheets, plastic screening or netting, and the like. Again, the addition of such materials would depend upon the requirements and needs of the particular situation.

The nonwoven fabrics of the present invention vary widely in weight. The minimum weight is dictated by the amount of fibers required to form a web or sheet which can be handled during subsequent processing. As such, web weights may be as low as about 170 grains per square yard but normally fall in the area of at least about 400 grains per square yard. The upper limit is dictated by the particular fabric requirements involved and normally range up to about 1,200 grains per square yard. Heavier weights are, of course, possible, depending upon the particular circumstances involved.

The invention will be further described in greater detail by reference to the following examples wherein there are set forth specific embodiments of the invention which are intended to illustrate the concepts involved but not to limit the same.

In the following Examples, reference will be made to wiping rates of various fabrics. These are the results of comparative tests and are obtained as follows: a rotatable turntable having a diameter of 20 inches and somewhat generally resembling a record player turntable is made of the surface to be wiped, usually plateglass. A thin film of the aqueous or oleaginous material to be wiped is applied to the surface of the turntable such as by a multiroll applicator to insure even, controlled film application. If the film is clear and colorless, a dye may be added to make it visible. The wiping fabric is then placed on the turntable and a known weight is placed on the fabric to insure a known constant wiping pressure against the turntable. The turntable is then rotated at a constant speed (r.p.m.) and the rapidity of wiping the surface clean or the wiping rate is determined by direct observation. The results do not represent absolute values; they are all relative values but they do represent true and reproducible comparisons between different wiping fabrics.

EXAMPLE I

A pair of cooperating mating embossing plates as illustrated in FIGS. 5 and 6 is prepared to the following specifications: 5 grooves per inch, cut in two directions at right angles; groove width is 0.125 inch; groove depth is 0.0625 inch; land width is 0.075 inch; top and bottom mating embossing plates are identical and mated as shown. There are 25 squares per square inch in each plate; each square having an area of 0.005625 square inches. The surface coverage of each set of lands is 14.1 percent. The fabric of FIG. 7 is prepared.

These mating embossing plates are used to emboss an unbonded woodpulp-filled card web sandwich comprising outer layers of slightly prebonded KEYBAK rearranged apertured nonwoven rayon card webs each weighing 125 grains per square yard and a centrally located woodpulp layer weighing 350 grains per square yard, thus making a total weight of 600 grains per square yard.

Comparison of the wiping rate of such an embossed wiping fabric with a nonwoven fabric which is identical in all respects thereto except that it is not embossed reveals that the embossed wiping fabric has a twofold improved wiping rate over the unembossed wiping fabric for a water film on a glass surface. The wiping rate of the embossed wiping fabric is substantially improved twofold over an unembossed wiping cloth for wiping an oil film on a glass surface.

EXAMPLE II

A pair of cooperating mating embossing plates as illustrated in FIGS. 15 and 16 is prepared to the following specifications: the circular holes are drilled in a plate member to five-sixteenths inch (0.3125 inch) diameters and are aligned with one-sixteenth inch (0.0625 inch) spacing between adjacent aligned circular holes. Horizontal alignment, from right to left, as noted in FIG. 15 is involved here. As a result, there are 20 circular holes per 7.50 inches of plate member, or 2.67 circular holes per inch in one direction. In the other direction, which is vertical, from top to bottom, as viewed in FIG. 15, due to the 60.degree. nesting or staggered relationship of the circular holes, there are 20 circular holes per 10.875 inches of plate member, or 2.92 circular holes per inch. As a result, there are a total of 7.8 circular holes per square inch of plate member. The area of each circular hole is 0.0767 square inch. This creates a total area of the circular holes of 0.60 square inch per square inch of plate. The embossing area of the perforated drilled plate is therefore 1 square inch less 0.60 square inch or 40 percent.

With regard to the diamonds, there are also 7.8 diamond lands per square inch and each diamond has a long diagonal of about 0.30 inch and a short diagonal of about 0.173 inch with an apex angle of about 60.degree.. The area of a diamond is therefore 0.0263 square inch and the total embossing area for 7.8 diamonds per square inch is 0.205 square inch or 20.5 percent.

These mating embossing plates are used to emboss an unbonded woodpulp-filled card web sandwich comprising outer layers of KEYBAK rearranged apertured nonwoven rayon card webs each weighing 125 grains per square yard and a centrally located woodpulp layer weighing 350 grains per square yard, thus making a total weight of 600 grains per square yard.

Comparison of the wiping rate of such an embossed wiping fabric with a nonwoven fabric which is identical in all respects thereto except that it is not embossed reveals that with regard to usage on the perforated drilled plate side, the embossed wiping fabric has a 3.5 fold improved wiping rate over the unembossed wiping fabric for a water film on a glass surface. With regard to usage on the diamond embossed side, the improvement is fivefold. The wiping rate of the embossed wiping fabric is substantially improved over an unembossed wiping cloth for wiping an oil film on a glass surface. On the diamond side, the improvement is sixfold; on the perforated plate side, the improvement is over ninefold.

EXAMPLE III

A pair of cooperating mating embossing plates as illustrated in FIG. 10 is prepared to the following specifications: the long diagonal of the diamond land is approximately seven-sixteenths inch and the short diagonal is approximately five-sixteenths inch. The area of one diamond is 0.0683 square inch and, since there are 5.48 diamonds per square inch, the total embossing area in 1 square inch of plate due to the diamond lands is 0.373 square inch or an embossing area of 37.3 percent of the plate surface.

With regard to the embossed area created by the grid, the embossing area is 34.5 percent.

These mating embossing plates are used to emboss an unbonded woodpulp-filled card web sandwich comprising outer layers of KEYBAK rearranged apertured nonwoven rayon card webs each weighing 125 grains per square yard and a centrally located woodpulp layer weighing 350 grains per square yard, thus making a total weight of 600 grains per square yard.

Comparison of the wiping rate of such an embossed wiping fabric with a nonwoven fabric which is identical in all respects thereto except that it is not embossed reveals that, with regard to usage on the diamond embossed side, the embossed wiping fabric has over a fourfold improved wiping rate over the unembossed wiping fabric for a water film on a glass surface. With regard to usage on the grid embossed side, the improvement is over fivefold. The wiping rate of the embossed wiping fabric is substantially improved over an unembossed wiping cloth for wiping an oil film on a glass surface, fourfold for the diamond side and fivefold for the grid side.

EXAMPLE IV

The procedures of example I are followed substantially as set forth therein except that the square lands on one side measure 0.1 inch .times. 0.1 inch and the square lands on the other side measure 0.025 inch .times. 0.025 inch (see FIGS. 9 and 12). There are 13.22 square lands per square inch in each plate. One embossing plate with the large square lands has a surface coverage of 13.2 percent and the other embossing plate with the small square lands has a surface coverage of 0.83 percent.

These mating embossing plates are used to emboss an unbonded woodpulp-filled card web sandwich comprising outer layers of KEYBAK rearranged apertured nonwoven rayon card webs each weighing 125 grains per square yard and a centrally located woodpulp layer weighing 350 grains per square yard, thus making a total weight of 600 grains per square yard.

Comparison of the wiping rate of such an embossed wiping fabric with a nonwoven fabric which is identical in all respects thereto except that it is not embossed reveals that the embossed wiping fabric has a substantially improved wiping rate over the unembossed wiping fabric for a water film on a glass surface. The wiping rate of the embossed wiping fabric is also substantially improved over an unembossed wiping cloth for wiping an oil film on a glass surface.

EXAMPLE V

The procedures of example I are followed substantially as set forth therein except that the square lands on one side measure 0.15 inch .times. 0.15 inch and the square lands on the other side measure 0.025 inch .times. 0.025 inch (see FIG. 13). There are 13.22 square lands per square inch in each plate. One embossing plate with the large square lands a surface coverage of 29.7 percent and the other embossing plate with the small square lands has a surface coverage of 0.83 percent. These mating embossing plates are used to emboss an unbonded woodpulp-filled card web sandwich comprising outer layers of KEYBAK rearranged apertured nonwoven rayon card webs each weighing 125 grains per square yard and a centrally located woodpulp layer weighing 350 grains per square yard, thus making a total weight of 600 grains per square yard.

Comparison of the wiping rate of such an embossed wiping fabric with a nonwoven fabric which is identical in all respects thereto except that it is not embossed reveals that the embossed wiping fabric has a substantially improved wiping rate over the unembossed wiping fabric for a water film on a glass surface. The wiping rate of the embossed wiping fabric is also substantially improved over an unembossed wiping cloth for wiping an oil film on a glass surface.

EXAMPLE VI

The procedures of example I are followed substantially as set forth therein except that the embossing land areas on one mating embossing plate are rectangular and measure 0.2 inch .times. 0.15 inch and the embossing land areas on the other mating embossing plate measure 0.025 inch .times. 0.025 inch. (See FIG. 14). There are 13.22 embossing land areas per square inch in each plate. One plate with the large rectangular lands has a surface coverage of 39.7 percent and the outer plate with the small square lands has a surface coverage of 0.83 percent.

These mating embossing plates are used to emboss an unbonded woodpulp-filled card web sandwich comprising outer layers of KEYBAK rearranged apertured nonwoven rayon card webs each weighing 125 grains per square yard and a centrally located woodpulp layer weighing 350 grains per square yard, thus making a total weight of 600 grains per square yard.

Comparison of the wiping rate of such an embossed wiping fabric with a nonwoven fabric which is identical in all respects thereto except that it is not embossed reveals that the embossed wiping fabric has a substantially improved wiping rate over the unembossed wiping fabric for a water film on a glass surface. The wiping rate of the embossed wiping fabric is also substantially improved over an unembossed wiping cloth for wiping an oil film on a glass surface.

Although the present invention has been described with reference to specific embodiments thereof, it is to be appreciated that such has been done for illustrative purposes and that the present invention is not to be considered limited thereby, except as noted in the appended claims.

Claims

What is claimed is:

1. An embossed nonwoven fabric having a textured character and fabriclike qualities of softness and hand and suitable for wiping surfaces having aqueous or oleaginous liquids or more viscous semisolids thereon comprising a fibrous web containing at least one layer of overlapping, intersecting fibers, a pattern of intermittently spaced, embossed compacted fibrous areas lying in the planes of both surfaces of said web of overlapping, intersecting fibers, and a pattern of unembossed, uncompacted fibrous portions lying between said planes and connecting said embossed, compacted fibrous areas. An embossed nonwoven fabric as defined in claim 1 wherein the embossed compacted fibrous areas are in the form of

polygons. 3. An embossed nonwoven fabric as defined in claim 1 wherein the

embossed compacted fibrous areas are in the form of squares. 4. An embossed nonwoven fabric as defined in claim 1 wherein the embossed

compacted fibrous areas are in the form of diamonds. 5. An embossed nonwoven fabric as defined in claim 1 wherein the embossed compacted fibrous areas cover from a fraction of 1 percent to about 90 percent of

the surfaces of each side of said embossed nonwoven fabric. 6. An embossed nonwoven fabric as defined in claim 1 wherein the embossed compacted fibrous areas cover from about 10 percent to about 40 percent of the

surfaces of each side of said embossed nonwoven fabric. 7. An embossed nonwoven fabric as defined in claim 1 wherein the embossed compacted fibrous areas are substantially the same on each side of said embossed

nonwoven fabric whereby the surface coverages thereof are the same. 8. An embossed nonwoven fabric as defined in claim 1 wherein the embossed compacted fibrous areas are different on each side of said embossed

nonwoven fabric whereby the surface coverages thereof are different. 9. An embossed nonwoven fabric as defined in claim 1 wherein the embossed compacted fibrous areas are compacted to substantially the same degree of

compaction. 10. An embossed nonwoven fabric as defined in claim 1 wherein the embossed compacted fibrous areas are compacted to different degrees of

compaction. 11. An embossed nonwoven fabric as defined in claim 1 wherein the intermittently spaced, embossed compacted fibrous areas lying in the plane of one surface of said web are connected to the intermittently spaced, embossed compacted fibrous areas lying in the plane of the other

surface of said web by channels of embossed compacted fibrous areas. 12. An embossed nonwoven fabric having a textured character and fabriclike qualities of softness and hand and suitable for wiping surfaces having aqueous or oleaginous liquids or more viscous semisolids thereon comprising a carded fibrous web containing at least one layer of overlapping, intersecting fibers, a pattern of intermittently spaced, embossed compacted fibrous areas lying in the planes of both surfaces of said web of overlapping, intersecting fibers, and a pattern of unembossed, uncompacted fibrous portions lying between said planes and connecting said

embossed, compacted fibrous areas. 13. An embossed nonwoven fabric having a textured character and fabriclike qualities of softness and hand and suitable for wiping surfaces having aqueous or oleaginous liquids or more viscous semisolids thereon comprising a fibrous web containing at least one layer of overlapping, intersecting fibers, a pattern of intermittently spaced, embossed compacted fibrous areas lying in the planes of both surfaces of said web of overlapping, intersecting fibers, and a pattern of unembossed, uncompacted fibrous portions lying between said planes and slantingly and angularly connecting said embossed, compacted fibrous

areas. 14. An embossed nonwoven fabric having a textured character and fabriclike qualities of softness and hand and suitable for wiping surfaces having aqueous or oleaginous liquids or more viscous semisolids thereon comprising a fibrous web containing at least one layer of overlapping, intersecting fibers, a pattern of intermittently spaced, embossed compacted fibrous areas lying in the planes of both surfaces of said web of overlapping, intersecting fibers, said planes being substantially parallel but offset with respect to each other, and a pattern of unembossed, uncompacted fibrous portions lying between said substantially parallel but offset planes and connecting said embossed, compacted fibrous

areas. 15. An embossed nonwoven fabric having a textured character and fabriclike qualities of softness and hand and suitable for wiping surfaces having aqueous or oleaginous liquids or more viscous semisolids thereon comprising a fibrous web containing at least one layer of overlapping, intersecting fibers, said layer being so embossed that a portion of one surface thereof lies in one plane and a portion of its other surface lies in a substantially parallel but offset plane with respect to the first plane, a pattern of intermittently spaced, embossed compacted fibrous areas lying in the planes of both surfaces of said web of overlapping, intersecting fibers, and a pattern of unembossed, uncompacted fibrous portions lying between said planes and connecting said embossed, compacted fibrous areas.