US2958608A

US2958608A - Textile fabrics and methods of making the same

Info

Publication number: US2958608A
Application number: US729391A
Authority: US
Inventors: Kenneth H Barnard
Original assignee: Chicopee Manufacturing Corp
Current assignee: Chicopee Manufacturing Corp
Priority date: 1958-04-18
Filing date: 1958-04-18
Publication date: 1960-11-01
Anticipated expiration: 1977-11-01
Also published as: FR1278225A; DE1410236A1; GB898072A

Description

Nov. 1, 1960 K. H. BARNARD 2,958,608

TEXTILE FABRICS AND METHODS OF MAKING THE SAME 4 Sheets-Sheet 1 Filed April 18, 1958 FIGZ INVENTOR. KENNETH H. BARNARD ATTORNEY Nov. 1, 1960 K. H. BARNARD 2,958,608

TEXTILE FABRICS AND METHODS OF MAKING THE SAME Filed April 18, 1958 4 Sheets-Sheet 2 INVENTOR. KENNETH H, BA RNARD ATTORNEY Nov. 1, 1960 KQH. BARNARD 2,958,603

TEXTILE mamas AND METHODS OF MAKING THE SAME Filed April 18, 1958 4 Sheets-Sheet 3 INVENTOR.

KENNETH H BARNARD dim/mu T t mw ATTORNEY 2,958,608 TEXTILE FABRICS AND METHODS OF MAKING THE SAME Filed April 1a, 1958 Nov. 1, 1960 K. H. BARNARD 4 Sheets-Sheet 4 FIG INVENTOR. KENNETH H BARNARD ATTORNEY TEXTILE FABRICS AND METHODS OF MAKING TIE SAME Kenneth H. Barnard, Barnstable, Mass, assignor to ChHCOPQE Manufacturing Corporation, a corporation of Massachusetts Filed Apr. 18, 1958, Set. N0. 729,391

18 Claims. (Cl. 117.11)

The present invention relates to textile fabrics having a novel appearance and unique surface interest and to methods of making the same. More particularly, the present invention is concerned with the so-called nonwoven textile fabrics, i.e., fabrics produced from textile fibers Without the use of conventional spinning, weaving, knitting or felting operations, and to unique methods of creating embossed or three-dimensional effects in such non-Woven textile fabrics.

Although not limited thereto, the invention is of primary importance in connection with oriented or carded nonwoven fabrics composed of textile fibers, the major proportion of which are oriented predominantly in one direction. Typical of such fabrics are the so-called Masslinn nonwoven fabrics, some of which are described in greater particularity in U.S. Patents 2,705,498, 2,705,687 and 2,705,688, issued April 5, 1955, to R. W. Johnson, De Witt R. Petterson et al, and I. S. Ness et al., respectively.

Another aspect of the present invention is its application to nonwoven fabrics wherein the fibers are basically predominantly oriented in one direction but are also reorganized and rearranged in predetermined designs and patterns of fabric openings and fiber bundles. Typical of such fabrics are the so-called Keybak bundled nonwoven fabrics, some of which are described in greater particularity in U.S. Patent 2,862,251, issued December 2, 1958 to F. Kalwaites.

Still another aspect of the present invention is its application to nonwoven fabrics wherein the fibers are disposed at random and are not predominantly oriented in any one direction. Typical nonwoven fabrics made by such procedures are described in greater particularity, for example, in U.S. Patents 2,676,363 and 2,676,364, issued April 27, 1954, to C. H. Plummer et al.

Nonwoven fabrics made by any of the methods described in the above-mentioned patents have become increasingly important in the textile and related industry, primarily because of their low cost of manufacture for a given coverage, as compared to the cost of more conventional textile fabrics made by spinning, weaving, knitting, or felting. Examples of such products are as wrapping and packaging materials, surgical dressings and bandages, covers or other elements of sanitary napkins, hospital caps, dental bibs, eye pads, obstetrical pads, dress shields, diapers, diaper liners, casket liners, clothing interlinings and other articles of apparel, shoe liners, shoulder pads, skirts, hand towels, handkerchiefs, ironing board covers, industrial fabrics such as filters, tapes, bags, table napkins, curtains, draperies, etc. Because of this wide variety of uses, these nonwoven fabrics are available in a wide range of fabric weights of from as little as about 100 grains per square yard to as much as about 2000 grains or more per square yard.

Fabric stability and strength are usually created in such nonwoven fabrics by bonding with adhesive or cementitious materials. The bonding operation employed for stabilizing and strengthening nonwoven fabrics has taken 2,958,5d3 Patented Nov. 1, 1960 on many forms, one popular form being the intermittent bonding of the nonwoven fabric with a predetermined pattern of spaced, discrete binder areas or lines whereby the individual fibers passing through such binder areas or lines are adhered in a bonding relationship. One typical binder pattern is the diamond grid pattern, such as illustrated in the aforesaid R. W. Johnson patent. This diamond grid pattern will be used in this patent application primarily as illustrative of the present inventive concept. However, it is to be pointed out that such a pattern is essentially for illustrative purposes and the broader aspects of this invention are not to be construed as limited thereto.

It is also to be observed that the following description of the present invention will refer primarily to the use of viscose staple rayon and/ or cotton fibers in the basic preparation of the nonwoven fabrics. Again, such is primarily illustrative and other fibers may be used, either by themselves or in blends in various proportions with other fibers, as desired. Such other fibers include, for example, other natural fibers such as Wool and silk; synthetic fibers including other forms of rayon such as cuprammonium rayon or other regenerated cellulosic fibers including saponified cellulose ester fibers; cellulose ester fibers such as cellulose acetate and cellulose triacetate fibers; polyamide fibers such as nylon 6, nylon 66, etc.; acrylic fibers such as Acrilan, Dynel, Orion, Creslan, Verel, etc.; polyester fibers such as Dacron; vinyl fibers such as Vinyon, Saran, Velon, etc.; protein fibers such as Vicara; fluorocarbon fibers such as Teflon; dinitrile fibers such as Darvin; nitrile fibers such as Zefran; and so forth.

It is not essential that all the fibers be of staple or equivalent length, i.e., from about /2 inch in length up to about 2 /2 or 3 inches in length. Shorter fibers, such as wood pulp fibers, cotton linters, asbestos fibers, and the like, having lengths from about /2 inch down to about /8 inch or even less may be added in various proportions up to about 50% by weight, or even as high as by weight, particularly where the original method of fabric formation involved a fluid deposition of the fibers, such as in a papermaking process, or in air deposition techniques.

Substantially all prior art nonwoven fabrics, regardless of the type of fibers used or of the particular bonding techniques employed, however, have usually suffered from certain inherent disadvantages and Weaknesses which have militated against their more wide-spread acceptance and use by the industry and by the ultimate consumer.

For example, due to the nature of the fibrous construction and the alignment and orientation of the individual fibers in such prior art nonwoven fabrics, they have been rather thin, drab and fiat and often lacking in fullness and softness. This, of course, is objectionable to the industry and to the consumer inasmuch as such fabrics tend to feel papery and deficient in bulk and loft.

One method which has been employed previously in the textile industry to avoid thinness and flatness in many forms and types of fabrics has involved the use of steel embossing rolls whereby various engraved designs or patterns can be impressed upon the fabric. Such a method has been used extensively but has not found complete acceptance in the industry since it is extremely expensive due to the high cost of the engraving rolls and their associated apparatus. This high cost of the engraving rolls and associated apparatus leads to another disadvantage in that only a limited number of different designs is available to a particular manufacturer who cannot economically afford to keep a large variety of such costly rolls on hand. Additionally, the rates of production when such rolls are used are relatively low, inasmuch as time is required for the embossing to set.

3 Such embossing roll methods therefore leave considerable room for improvement in the industry.

It has now been determined that nonwoven fabrics lacking fullness and softness may be processed whereby a full and soft hand may be obtained more easily, along with greater bulk, increased weight, improved tensile strength and enhanced tear resistance. Additionally, the nonwoven fabrics can be made at higher production rates and at less expense. The processed nonwoven fabrics possess excellent surface interest, are not thin, drab, or flat, and do not have a papery hand. They actually have a textile-like appearance and hand along with a lively resilience or bounce and any resemblance to paper or drab, paper-like nonwoven fabrics has disappeared.

More specifically, it has now been found that such desirable properties may be obtained by intermittently bonding the fabrics with a predetermined pattern of spaced binderareas or lines and then selectively mechanically working the intermittently bonded fabrics, whereby the binder areas remain relatively smooth and unchanged, whereas the unbonded fabric areas become relatively highly puffed or distended out of the plane of the basic fabric, thus giving it an unusually desirable embossed appearance along with the required properties of fullness and softness.

It has also been found that the degree to which the fabric becomes puifed or distended can be readily controlled, whereby areas of puffed or distended fabric may alternate with areas of smooth and unchanged fabric to yield an intermittently striped effect. The transition from a puffed area to a smooth area may be abrupt to yield sharply defined striped areas, or it may be gradual whereby areas having relatively low or no puffs gradually blend into areas of relatively high puffs to yield a soft, waved effect.

Other advantages and benefits of the present inventive concept will become apparent from a consideration of the following description which is to be construed with reference to the accompanying drawings wherein:

Figure 1 is a plan view on an enlarged scale approximately 3:1, diagrammatically illustrating a portion of a nonwoven fabric such as illustrated in Figure 3 of U.S. Patent 2,705,498, after it has been processed by the methods of the present invention;

Figure 2 is a cross-sectional view of the nonwoven textile fabric of Figure 1, taken on the line 2-2 thereof in the direction indicated;

Figure 3 is a cross-sectional view of the nonwoven textile fabric of Figure 1, taken on the line 3-3 thereof in the direction indicated;

Figure 4 is a fragmentary elevation on a reduced scale, showing one form of apparatus suitable for carrying out the methods of the present invention;

Figure 5 is a plan view of the nonwoven fabric widthreducing roll of the apparatus of Figure 4;

Figure 6 is a fragmentary elevation on a reduced scale, diagrammatically showing still another form of apparatus suitable for carrying out the methods of the present invention; and

Figure 7 is a photomacrograph on an enlarged scale approximately 10:1 of a plan view of a portion of a nonwoven textile fabric of the present invention, over eighteen months after its original processing.

Referring now to Figures 1, 2 and 3, there is shown a fibrous nonwoven fabric 70, somewhat basically similar to the diamond grid pattern bonded Masslinn nonwoven fabric of Figure 3 of U.S. Patent 2,705,498, after it has been processed by the methods of the present invention. Only a few rows of binder areas or

lines

71 and 72 are illustrated of the predetermined binder pattern or design but such is believed sufiicient to describe the present invention. As shown, the binder areas or

lines

71 and 72 are at an angle of about 65 to the long axis of the nonwoven fabric 70. Any other angle may be selected, however, such as from about 25 to about 4 depending upon the requirements of the particular nonwoven fabric. Unbonded fabric areas 73 of the fibrous nonwoven fabric 70 are shown lying between and bounded by the binder areas or

lines

71 and 72. It is to be noted that the unbonded fabric areas 73 have the form of diamonds or lozenes, the long and cross dimensions of which will depend upon the spacing and angular relationship of the

binder areas

71 and 72 and upon the extent of the mechanical working of the nonwoven fabric. The long and cross axes of the nonwoven fabric 70 and other nonwoven fabrics referred to herein are indicated by arrows.

Another geometric binder pattern which is applicable to the present invention is a hexagon pattern, such as illustrated in Figure 5 of U.S. Patent 2,705,498. Still another geometric binder pattern which is applicable to the present invention is a square pattern, as illustrated in Figures 13 and 14 of U.S. Patent 2,705,498.

It is not necessary that the binder lines be continuous or that they be straight. They may be discontinuous or broken, or they may be curved or sinuous.

Other patterns, including rectangles, parallelograms, triangles, or combinations of various polygons, and even arcuately, sinuously or curved geometric figures such as dots, annuli, ellipses, ovals, and the like, as well as other geometric figures which are regularly or irregularly shaped, are also possible. In such instances, the binder areas or lines would not always be straight but would be correspondingly arcuate, sinuous, curved, angular or irregularly formed. Examples of such geometric patterns and their physical dimensions may be found in the Petterson and Ness Patents 2,705,687 and 2,705,688 previously mentioned.

One common factor, however, is to be particularly noted in all these patterns, namely, that the total surface of the binder areas or lines of the nonwoven fabrics of Figures 1 through 3 should not substantially exceed about 35 of the total surface of the nonwoven textile fabric, and should preferably be less than about 30% and down to about 10% of the total surface of the nonwoven textile fabric. If substantially greater than about 35% of the total surface of the nonwoven fabric is coated or impregnated with the binder areas or lines, then the textile-like properties and other advantageous characteristics may be substantially sacrificed. This maximum, value of about 35% surface coverage by the binder areas or lines holds true regardless of their form or shape, whether they are continuous or discontinuous, connected or discrete, straight or curved, regular or irregular, etc. This loss of textile-like properties and characteristics is strikingly true for nonwoven fabrics which are overall bonded, that is with approximately surface coverage by the binder, wherein substantially none of the advantageous features of the present invention is obtained.

The percentage by weight of binder add-on to the nonwoven fabric of Figures 1 through 3 may be varied within relatively wide ranges depending upon the specific binder employed and the type, weight and thickness of the fabric. For some binders, as low as about 1% to about 10% by weight has been found sufficient; for other fabrics and other binders, as high 'as about 20 to about 35% by weight has been found preferable. Within the more commercial aspects of the present invention, however, from about 1 /z% to about 25% by weight has been found satisfactory.

The spacing of the binder areas is fairly critical and depends to -a large extent upon the length of the fibers used in the making of the-nonwoven fabric, upon the type of binder used in the bonding operation, and upon the properties and characteristics desired or required in the finished nonwoven textile fabric.

The total number of binder areas or lines per inch of nonwoven fabric, as measured in the machine direction along the long axis may be as few as about 4 or. it may U be as many as about 30. Within the more commercial aspects of the present invention, however, a total number of binder lines of from about 8 per inch to about 24 per inch has been found preferable.

The widths or thicknesses of these binder areas will depend upon many factors such as, for example, the properties desired in the ultimate nonwoven textile fabric, the number of binder areas per inch, the thickness and weight of the fabric, the length and other characteristics of the fibers used, the nature of the binder, and so forth. Widths of lines of from about 0.006 inch to about 0.100 inch have been found satisfactory, with the preferred commercial range extending from about 0.010 inch to about 0.050 inch.

The particular type of binder used may be selected from a large group of binders now known in the industry for such purpose. A non-migratory binder, however, such as viscose or regenerated cellulose is preferred inasmuch as it yields sharp and clear boundaries of binder with the unbonded fabric areas. Other types of binders may be used, such as polyvinyl chloride, polyvinyl acetate, copolymers thereof, polyvinyl acrylate, polyethyl acrylate, polymethyl methacrylate, polyvinyl butyral, cellulose, acetate, ethyl cellulose, and any one or a combination of resins, many of them being preferably applied from a solvent system.

It is not essential that the binding of the fibers of the nonwoven fabrics be accomplished by the addition of separate binder materials. The use of solvents, heat and/ or pressure may be employed to bind the fibers in the desired pattern areas. This, of course, is particularly advantageously employed when thermoplastic fibers are used, such as cellulose acetate, Vinyon (vinyl chloridevinyl acetate copolymer), or other fibers preferably having low melting or fusing temperatures. Other fibers, such as polyamide nylon 66 (hexamethylene-diamineadipic acid), having higher melting points, may be used when such higher temperatures are not objectionable.

Figures 1, 2 and 3 illustrate the fibrous nonwoven textile fabric 70, after it has been processed by the methods of the present invention. It is immediately noted that the unbonded fabric areas 73 are relatively highly puffed and distended whereas the binder areas or

lines

71 and 72; have remained relatively smooth and are not puffed or distended. Binder areas or

lines

71 and 72 are illustrated as meeting in intersections '74.

Further study of these figures reveals that the areas or

lines

71 and 72 have acted as a resist to the puffing or distending action of the methods of the present invention and have remained relatively smooth and basically unchanged with merely a small decrease in their dimensions. With regard to the unbonded fabric areas 73 which separate the

binder areas

71 and 72, however, it is to be noted that the puffs therein are very regularly and sharply defined, usually coming to relatively distinct four-sided pyramidal peaks 75 Well above the plane of the nonwoven fabric.

These distinct four-sided pyramidal peaks 75 are relatively soft but possess considerable resilience and will spring back to their original peaked positions after being depressed. Not having any binder thereon which is exposed to the touch, they have a soft and full hand. This, of course, leads to another advantage inasmuch as the underside of the fabric contains the binder areas and is relatively harder and firmer and forms an eX- cellent base for stability purposes.

The width of the nonwoven textile fabric 70, as measured in the cross direction along the cross axis, has remained substantially the same, many fabrics decreasing in width by less than The length of the non- Woven fabric 70, as measured in the long direction along the long or machine axis, has also remained substantially the same, many fabrics again decreasing by less than 10%. Under more severe processing conditions by the apparatus to be described more fully hereinafter,

6 decreases in width and in length of up to 30% or more have been obtained, whereby that amount of additional elasticity and stretch may be created in the nonwoven textile fabric.

The appearance of the nonwoven textile fabric 70 is particularly striking. The visual effect is somewhat similar to an embossed waffle print with distinct diamonds or lozenges rising from the plane of the fabric and extending in regularly spaced lines, just as if the fabric had been mechanically embossed or engraved. The binder areas or lines which resisted the embossing action are static and substantially unchanged. The unbonded fabric areas are reproduced in raised or has relief to yield a unique and striking surface interest to the nonwoven textile fabric.

The principlm of the present invention are applicable to the type of nonwoven fabric illustrated in US. Patent 2,862,251 and it is to be appreciated that. the rearranged, bundled nonwoven fabric disclosed in that patent may be bonded by any of the herein-described binder patterns.

One form of apparatus suitable for carrying out the preferred methods of the present invention is diagrammatically set forth in Figures 4 and 5. A nonwoven fabric is delivered from a suitable source such as a supply roll (not shown) to a steaming or moistening device 102 which may be used to increase the moisture content of the nonwoven fabric 100 to a desired amount. For many nonwoven fabrics, particularly the lighter weight varieties, the normal natural regain moisture is occasionally hardly sufiicient and some additional moisture is required. For other nonwoven fabrics, particularly the heavier weight varieties, the addition of small amounts of moisture, up to about 25% or even 50% or more by weight, based on the weight of the dry nonwoven fabric, has been found advantageous.

The nonwoven fabric 100 is then passed around a directional guide roll 104 rotating on a shaft 165 and then is placed on the periphery of a widthwise-prepleating noll 106 which is shown in detail in Figure 5 and is of a type generally known in the textile industry. The prepleating roll 106 is formed of rotatable disks or plates 108 mounted on an arcuate shaft 110. The curvature of the arcuate plate 110 is such that the disks 108 are individually inclined to each other with relatively wide spaces between the plates at one side 112 of the periphery of roll 106 and relatively narrow spaces between the plates at the other side 114 of the periphery of roll 1%. Spacing elements 116 are provided to control the accurate spacing, inclination and positioning of the disks Hi3.

Consideration of Figures 4 and 5 will make it apparent that the nonwoven fabric 100, when placed on the enterin g peripheral side 112 of the prepleating roll 106 will be relatively flat and will be positioned on the outermost edges of the disks 108. As the disks 108 rotate, however, and as the nonwoven fabric 100 advances on the periphery of the prepleating roll 106, the spaces between the piates 10$ narrows and the nonwoven fabric 100 begins to become pinched or pleated between the plates 108. The space between the plates 108 narrows and the extent of the pleating action increases until the fabric 100 reaches the discharge side 114 of the periphery of the prepleating roll 106.

The prepleated fabric is then advanced over a rotatable directional guide roll 120 mounted on a shaft 122. The roll 120 is provided with circumferential gnooves adapted to continue the widthwise pinching or pleating action on the fabric. The roll 1.20 is broken out at 124 to indicate that it has a metallic core 126 (such as steel or aluminum) and is preferably faced with a more resilient material 128 such as synthetic or natural rubber, or the like, to provide for a desired frictional or tractional grip on the fabric being advanced.

The fabric is then directed between the nip of two pleating rolls 132 and 134 which are rotatably mounted on

shafts

136 and 138. These

rolls

132 and 134 are provided with circumferential grooves which are finer than the peripheral grooves of the preceding rolls of the apparatus and thus the pinching or pleating of the fabric in a widthwise direction is continued with the pinches or pleats becoming progressively finer and finer. The

rolls

132 and 134 are broken open at 142 and 144, respectively, to indicate that again they preferably have aluminum or

steel cores

146 and 148, respectively, and that they are preferably faced with natural or synthetic rubber or the like to provide for a desired frictional or tractional bite on the fabric being advanced.

The fabric is then directed to and placed on the periphery of a pressure roll 160 which is rotatably mounted on a shaft 162 driven by a source of power (not shown). The pressure roll-160 is provided with peripheral grooves which are even finer than the peripheral grooves of the preceding rolls of the apparatus and the pinching or pleating action thus becomes very-fine. The pressure roll 160 is broken away at 164 ct indicate that it preferably has a steel or aluminum core 166 and a face 168 of a more resilient material such as a synthetic or natural rubber, or the like. In appearance, the pressure roll 160 may be described as a series of relatively thin plates mounted on a rotatable shaft and separated from each other by spacing elements or washers, whereby the peripheral grooves are formed.

As the fabric progresses around the periphery of the pressure roll 160, it goes under a pre-pressing roll 161 which is formed with peripheral grooves 163 which fit into the peripheral grooves of the pressure roll 160. The pre-pressing roll 161 serves to press the fabric into the peripheral grooves of the pressure roll 160 and to prepare it for the compacting operation. As the fabric passes from under the pre-pressing roll 161 and continues to advance around the periphery of the pressure roll 166, it slides under a pressure plate or shoe 170, the lower surface 172 of which is provided with lengthwise comb-like teeth 174 extending in the direction of the movement of the nonwoven fabric. The lower surface 172 of the pressure shoe 170 is so formed and positioned that it lies in close proximity with the periphery of the pressure roll 160 with the teeth of the pressure plate 170 fitting into the grooves of the pressure shoe 176. The teeth 174 on the lower surface 172 of the pressure shoe 170 are relatively short and almost nonexistent at the point where the fabric first passes under the forward or leading edge of the pressure shoe 170 and there is relatively little, if any, pressure on the nonwoven fabric at that point. However, the teeth 174 of the pressure shoe 170 increases in length as they advance and the arcuate nature of the lower surface 172 of the pressure shoe 170 is such that increasing pressure is applied to the advancing nonwoven fabric as it advances under the pressure shoe 170.

The pre-pressing roll 161 is mounted upon a forwardly extending portion of the pressure shoe 170 and is capable of being positioned and adjusted simultaneously therewith by means to be described more fully hereinafter. Any suitable form of pressure-applying means, such as a pneumatic device or a simple springor weight-loaded mechanism (not shown), may be used to apply the proper pressure to the pre-pressing roll 161 and the pressure shoe 175) to be applied against the pressure roll 160.

The coaction of the moving grooved peripheral surface of the pressure roll 160 and the stationary toothed surface of the pressure shoe 170 is such that a dragging action is imposed on the nonwoven fabric pressed between these surfaces. The dragging action is exerted in the long direction of the nonwoven fabric and the mechanical working and compacting is in that direction.

The pressure shoe 170 is mounted on an angularly positioned arm 176 which is so adjustably mounted on the frame 178 of the fabric treating apparatus so that the position and clearance of the pressure shoe 170 and the pre-pressing roller 161 can be very precisely controlled with respect to the periphery of the pressure roll 160. A lock nut 175 fitting pivotal-1y within a slotted opening 177 is one simple form for providing the desired adjustability. This is an important adjustment and regulates the extent of the mechanical working or other deformation of the fabric. A stop 179 is provided to limit the downward movement of the arm 176 and to prevent the grooved lower surface 174 of the pressure shoe 170 from actually contacting the pressure roll 160.

As the fabric is discharged from the trailing end of the pressure shoe 170, it comes into contact with a peripherally grooved compacting roll 180 which is rotatably mounted on a shaft 182 for rotation in the same counterclockwise direction as pressure roll 160, as indicated by the directional arrows. The net effect is a sharp reversal in direction of the fabric past the trailing edge of the pressure shoe 170. Additionally, the peripheral linear speedof the surface of the compacting roll 180 is less than the peripheral linear speed of the surface of the pressure roll 160. As a result, the fabric tends to be overfed from the faster moving pressure roll to the slower moving compacting roll 180 and to be pinched and shortened as it is transferred from the pressure roll 160 to the compacting roll 180. This time, however, the pinching or pleating of the fabric is in its lengthwise or long direction. The resulting nonwoven fabric 1% is shown magnified at 192, as it is delivered from the compacting roll 1%. The compacting roll 180 is broken away at 184 to indicate that it may be made of all steel.

The compacting roll 180 may be adjusted peripherally with respect to the surface of the pressure roll 160 so that its spatial relationship with respect to the pressure shoe may be adjusted and controlled. As shown, the compacting roll may be adjusted from a full position (180) to the outlined position (1841), or other desired positions, as required.

The pressure roll 16!) travels at a peripheral linear speed which ranges preferably from about 1.1 times to about 7 or more times the peripheral linear speed of the compacting roll 180. The particular speed ratio selected for a particular application will depend, of course, upon the degree of puffing or distending desired in the long direction.

If this linear speed ratio is maintained constant, the resulting nonwoven fabric will be puffed and distended in the unbonded fabric areas generally uniformly to substantially the same degree. If the linear speed ratio is changed, such as by being alternated periodically between a 1:1 linear speed ratio and, let us say, a 3:1 linear speed ratio, a surprising striped effect is obtained. The fabric areas processed during the 1:1 linear speed period will not be puffed or distended and a smooth unchanged stripe will cross the fabric. The fabric areas processed during the 321 linear speed period, however, will be puffed and distended and an embossed stripe will cross the fabric at that time. Alternation of the linear speed ratios can be varied as desired, whereby unusual surface effects are obtained.

Instead of abruptly changing the linear speed ratio, such change may be made gradually in a uniform fashion or otherwise to provide other interesting effects. For example, gradually changing the linear speed ratios from 1.221 to 3:1 will result in a pleasing waved effect in the nonwoven fabric, wherein the height of the wave, as created by the degree of pufiing and distending, gradually varies from shallow waves to deep waves, and vice versa. Many other variations are possible whereby enhanced surface interest is created.

It is also to be noted that the surface characteristics of the pressure roll 160 and the compacting roll 180 may be different. The rubber or more yielding and resilient surface 168 of the pressure roll 160 is softer and possesses a higher coefficient of friction than the steel or less yielding and resilient surface 184 of the compacting roll 180. This facilitates the overfeed of the nonwoven fabric past the pressure shoe 170 without any slippage and provides for a better fabric control.

If desired, the difference in surface characteristics and the necessary control over the advancing fabric may be obtained by roughening or otherwise treating the surfaces of the rolls to obtain preferred coefficients of friction. Knurling, etching or engraving, for example, may be employed to change the surface characteristics mechanically. The depth and extent of such mechanical change will vary naturally depending primarily upon the nonwoven fabric being processed and the composition of rolls being used. Differences in coefficients of friction may also be obtained by using rolls of basically different compositions. Such rolls may be made, for example, of leather, composition, compressed paper, other metals than steel, and various combinations thereof.

Heating of the processing rolls, and particularly the pressure roll 160 and the compacting roll 180, has been found to be advantageous in many instances. The temperatures to which these rolls may be heated will depend primarily upon the nature, properties and characteristics of the fibers in the fabrics being treated, the percentage of moisture in the fabrics, and the bonding materials used to stabilize and strengthen the fabric structure. Under normal conditions, such as when a viscose rayon web which has been bonded with viscose or regenerated cel lulose is processed, elevated temperatures of from about 120 F. to about 300 F. have been found beneficial. With other or more heat resistant fibers, such as polyamide nylon 66 (hexamethylene-diamine-adipic acid), operating temperatures may be safely increased to 400 F. With other or less heat resistant fibers, such as Vinyon fibers (vinyl chloride-vinyl acetate), the safe operating temperatures must be lowered to below about 200 F.

Although the present invention has been described with particular reference to a preferred embodiment of apparatus, as illustrated in Figures 4 and 5, and to preferred fabrics, such as nonwoven fabrics, it is to be appreciated that other forms of apparatus and fabrics are also utilizable, provided such apparatus is capable of mechanically working the selected fabric to puff or distend it in the desired unbonded areas.

For example, another form of apparatus basically capable of accomplishing the desired objects of the present invention is illustrated and described in United States Patent 2,765,514, issued October 9, 1956 to R. R. Walton. The basic principles of the operation of such apparatus such as the roll surface characteristics, the ratio of peripheral linear speeds of the rolls, etc., are substantially as described hereinbefore. Additional operating details and more specific description of the structure involved is to be found in the patent itself. Additional moisture may be supplied to the nonwoven fabric, as desired or re quired, and other features of the patented apparatus may be employed.

Still another form of apparatus suitable for carrying out the methods of the present invention is illustrated in Figure 6. Two closely spaced rotatable rolls 200 and 202 are shown, rotating in the directions indicated by the respective arrows. These

rolls

200 and 202 are preferably made of a relatively firm or rigid material, such as aluminum, steel or natural and synthetic rubber and may be of the same material or different materials, as desired. The rolls 2% and 202 are preferably rotated at approximately the same peripheral linear speeds. A fabric 204, such as a fiat nonwoven fabric, is delivered along a table or feed plate ass into the nip of the opposed spaced

rolls

200 and 202 and is discharged with considerable pressure on the far side of the nip against one of a pair of knife or buckling

elements

208 and 210. The position of these

knives

208 and 210 is adjustable and their tapered points may be so adjusted as to lie in actual pressing contact with the rotating periphery of the

rolls

200 and 202 and to butt against the fabric being delivered from between the nip of the rolls. The angle of the

knife blades

208 and 210 is adjustable with respect to the periphery of the

rolls

200 and 202 and may be controlled as desired. The knife-butting action causes the fabric to become puffed and distended, controlled, of course, by the resisting action offered by the pattern of binder areas.

The fabric is then led between a pair of spaced

angle brackets

212 and 214. As shown in Figure 6, the lower angle bracket 214 is relatively fixed with respect to the apparatus generally. The upper angle bracket 212, however, is pivetally mounted, as at 216, and is capable of pivotal movement from a closed lower position 212 (shown in full) to an upper open position 212 (shown in outline) due to the force of the fabric F as it piles up and is stuffed against its inner surface. It is apparent that the angle bracket 212 will remain in its lower closed position until sufficient force is exerted 'by the accumulating fabric to force it open to permit the escape of some fabric. A weight 218 (or an equivalent fluid pressure or spring-loaded device) may be used to control and adjust the force required to force the angle bracket open to permit the escape of the fabric. Examination of the final product indicates that it is puffed and distended in the unbonded fabric portions and still relatively smooth and level in the binder areas.

Figure 7 is a photomacrograph, approximately 10X, of a typical nonwoven textile fabric prepared by the processes of the present invention. The starting material was a 'Masslinn nonwoven fabric very similar in pattern design to the nonwoven fabric illustrated in Figure 1. This photornacrograph was taken eighteen months after the fabric had been processed and stored under continuous pressure in a letter file. The durability and permanency of the diamond-shaped unbonded fabric areas is to be noted.

The degree of permanence of the puffed and distended eifect may be even further enhanced by treating the non woven fabric with from about 3% by weight to about 50% and preferably from about 5% to about 30% of an uncured thermosetting resin, either before or after processing, and then curing the thermosetting resin after processing. Typical of such thermosetting resins are the amino resins such as urea-formaldehyde, ethylene ureaformaldehyde, and melamine-formaldehyde; the phenolic resins such as phenol-formaldehyde, phenol-furfural and resorcinol-formaldehyde; etc. When cured, these resins set the nonwoven fabrics in a permanent finish, resistant to washing, laundering and dry cleaning.

A somewhat similar effect is obtained by including thermoplastic fibrous or other materials in the nonwoven fabrics and then activating their potentially adhesive properties by solvents, heat and/or pressure after they have processed to render the surface interest more permanent. Under normal circumstances, as little as 3% by weight of the thermoplastic material has been found to exert an effect and up to by weight may be used, if desired.

The invention will be further illustrated in greater detail by the following specific examples. It should be understood, however, that although these examples may describe in particular detail some of the more specific features of the invention, they are given primarily for purposes of illustration and the invention in its broader aspects is not to be construed as limited thereto.

Example I lines per inch for each set of binder lines, as measured in the machine direction; the thickness of each binder line is about 0.024 inch; each set of binder lines is approximately 64 to the long axis; the size of each diamond meaesures slightly under /2 inch, as measured in the cross direction of the nonwoven fabric and slightly under inch, as measured in the long direction of the fabric. The binder material is viscose or regenerated cellulose and the migration of the binder into the unbonded fabric areas is very small. The surface coverage of the binder is about 22% of the total surface of the nonwoven textile fabric. The binder comprises about 8% of the weight of the nonwoven textile fabric.

A length of this nonwoven textile fabric (30" wide) is processed through the apparatus of Figures 4 and 5 with a fabric discharge from the compacting roll of about 26 yards per minute (linear speed ratio approximately 1.421). The resulting nonwoven textile fabric is highly puffed and distended in the diamond-shaped unbonded fabric areas whereas the diamond outlines constituted of viscose binder material have remained smooth and relatively unchanged. This, of course, is due to the resistance offered by the viscose binder to the puffing and distending action which takes place during the mechanical working of the nonwoven fabric.

Each diamond-shaped unbonded fabric area is distinctly defined in the form of four-sided pyramidal peaks which rise above the plane of the nonwoven fabric containing the diamond-outlined viscose binder material. Storage under pressure of the processed nonwoven textile fabric for over eighteen months causes the peaks of the diamond-shaped unbonded fabric areas to become depressed and to lose some of their distinctness and sharpness. Nevertheless, the processed nonwoven textile fabric still possesses its fullness and softness and characteritic three dimensional appearance after such eighteen months storage under pressure.

The resulting nonwoven textile fabric is useful as a dinner napkin and is considerably softer, thicker, bulkier and more textile like than paper products.

Example II The procedures set forth in Example I are carried out substantially as set forth therein except that a blend of 50% by weight of staple cotton fibers and 50% by weight of viscose rayon, 2 inch staple 1 /2 denier, is used. The surface coverage of the binder areas is about 24%. The results are comparable to those of Example I, except that the luster of the nonwoven textile fabric is not as bright.

Example 111 The procedures set forth in Example I are carried out substantially as set forth therein except that only one set of lines is engraved in the print roll applying the binder material. The percentage of binder is only about 4% of the weight of the nonwoven textile fabric and the surface coverage is reduced to about 13%. The puffed or distended unbonded fabric areas combine with the binder lines to yield a twill or ribbed effect.

Example IV Example V The procedures set forth in Example IV are carried out substantially as set forth therein except that only one set of binder lines at 45 to the long axis is used. The

binder add-on is about 6% 'by'weight and'the surface coverage of the binder areas is about 15%. The nonwoven textile'fabric has a 45 twill or ribbed'effect due to the puffed or distended unbonded fabric areas extending out from the lower binder areas.

Examples VI and VII The procedures of Example I are followed substantially as set forth therein except that the viscose binder is replaced with (VI) polyvinyl acetate and (VII) polyvinyl chloride, respectively. These binder materials migrate more than the viscose binder and the surface coverages are about (VI) 31% and (VII) 35%, respectively.

Example VIII The procedures of Example I are followed substantially as set forth therein except that the speed of the rolls is increased but keeping the same linear speed ratio of the pressure roll and the compacting roll. The fabric discharge is capable of being increased to 75 yards per minute without difficulty and without loss of the desirable properties and characteristics of the processed nonwoven fabric.

Example IX The procedures of Example I are followed substantially as set forth therein except that the moisture content of the starting nonwoven fabric is increased to 25% by weight as based on the weight of the dry starting nonwoven fabric. The surface interest effects are obtained with excellent durability and permanence characteristics.

Example X The procedures of Example I are followed substantially as set forth therein except that the linear speed ratios are alternated periodically as abruptly as possible between 1:1 and 1.5 :1. A striped pattern effect of smooth stripes and puffed stripes is obtained extending across the width of the nonwoven fabric. The alternating effect of the stripes creates considerable additional pattern and surface interest.

Example XI The procedures of Example I are followed substantially as set forth therein except that the linear speed ratios are alternated gradually between 1.211 and 1.511. A gentle wave effect is obtained wherein the small puffed areas gradually build up into large puffed areas and then down to small puffed areas, and so forth. The visual effect is marked.

Example XII The procedures of Example I are followed substantially as set forth therein except that the starting fabric has a thermosetting resin incorporated in it prior to processing. The composition of the thermosetting resin mix (by weight) is as follows:

6% cyanamid resin EU (ethylene urea formaldehyde,

50% solids) 7% cyanarnid resin MW (modified melamine formaldehyde, solids) 3 /2% magnesium chloride catalyst (M-gCl Approximately 3% by weight of solids, based on the weight of the dry nonwoven starting fabric, is deposited. Curing takes place at about 300 F. for 2 minutes. The resulting material, after processing, possesses a permanent diamond puffed effect which is retained after washing or laundering.

Although several specific examples of the inventive concept have been described, the same should not be construed as limited thereby nor to the specific substances or constructions mentioned therein but to include various other equivalent substances and constructions as set forth in the claims appended hereto. It is understood 13 that any suitable changes, modifications and variations may be made without departing from the spirit and scope of the invention.

What is claimed is:

1. An embossed bonded fibrous textile fabric having surface interest and a soft and full hand comprising fibers bonded in a predetermined pattern of spaced binder areas extending across said textile fabric at an angle to the long axis thereof in bonding relationship with the fibers passing therethrough, said binder areas covering less than about 35% of the surface of the textile fabric and being relatively smooth and separated by unbonded fabric areas which are relatively highly distended and possess resilience, whereby a durable embossed appearance is created in the textile fabric.

2. An embossed bonded fibrous nonwoven textile fabric having surface interest and a soft and full hand comprising a web of overlapping intersecting fibers bonded in a predetermined pattern of spaced binder areas extending across said nonwoven textile fabric at an angle to the long axis thereof in bonding relationship with the fibers passing therethrough, said binder areas covering less than about 35% of the surface of the nonwoven textile fabric and being relatively smooth and separated by unbonded fabric areas which are relatively highly distended and possess resilience, whereby a durable embossed appearance is created in the nonwoven textile fabric.

3. An embossed bonded fibrous nonwoven textile fabric having surface interest and a soft and full hand comprising a web of overlapping intersecting fibers bonded in a predetermined pattern of spaced binder areas extending substantially continuously across said nonwoven textile fabric at an angle to the long axis thereof in bonding relationship with the fibers passing therethrough, said binder areas covering less than about 35% of the surface of the textile fabric and being relatively smooth and separated by unbonded fabric areas which are relatively highly distended and possess resilience, whereby a durable embossed appearance is created in the nonwoven textile fabric.

4. An embossed bonded fibrous nonwoven textile fabric having surface interest and a soft and full hand comprising a web of overlapping intersecting fibers bonded in a predetermined pattern of a plurality of sets of spaced binder areas extending across said nonwoven textile fabric at an angle to each other and to the long axis of the nonwoven textile fabric to form polygonalshaped unbonded fabric areas therebetween, said binder areas being in bonding relationship with the fibers passing therethrough, said plurality of sets of binder areas covering less than about 35 of the surface of the textile fabric and being relatively smooth and separated by unbonded fabric areas which are relatively highly distended and possess resilience, whereby durable polygonal-shaped embossed areas are created in the nonwoven textile fabric.

5. An embossed bonded fibrous nonwoven textile fabric having surface interest and a soft and full band comprising a web of overlapping intersecting fibers bonded in a predetermined pattern of spaced binder areas extending across said non-woven textile fabric at an angle to the long axis thereof in bonding relationship with the fibers passing therethrough, said binder areas covering less than about 35% of the surface of the nonwoven textile fabric and being relatively smooth and generally spaced binder areas extending across said nonwoven teii tile fabric at an angle to the lon axis thereof and covering less than about 35% of the surface of the textile fabric, said binder areas being in bonding relationship with the fibers passing therethrough and being separated by unbonded fabric areas; and then treating said bonded web to decrease the width and length thereof up to 30% to distend the unbonded areas between said binder areas while leaving the binder areassmooth, said distended unbonded areas having resilience whereby a durable embossed appearance is created in the nonwoven textile fabric.

7. A method of forming an embossed bonded fibrous nonwoven textile fabric having surface interest and a soft and full hand which comprises: bonding a web of overlapping intersecting fibers in a predetermined pattern of spaced binder areas extending across said nonwoven textile fabric at an angle to the long axis thereof and covering less than about 35% of the surface of the textile fabric, said binder areas being in bonding relationship with the fibers passing therethrough and being separated by unbonded fabric areas; and then mechanically compacting said bonded web to decrease the width and length thereof up to 30% to distend the unbonded areas between said binder areas while leaving the binder areas smooth, whereby an embossed appearance is created in the nonwoven textile fabric. I

8. A method of forming an embossed. bonded fibrous nonwoven textile fabric having surface interest and a soft and full hand which comprises: bonding a web of overlapping intersecting fibers in a predetermined pattern of spaced binder areas extending across said nonwoven textile fabric at an angle to the long axis thereof and covering less than about 35% of the surface of the textile fabric, said binder areas being in bonding relationship with the fibers passing therethrough and being separated by unbonded fabric areas; widthwise pleating and lengthwise compacting said bonded web to decrease the width and length thereof up to 30% to distend the unbonded areas between said binder areas while leaving the binder areas smooth, whereby an embossed appearance is created in the nonwoven textile fabric.

9. A method of forming an embossed bonded fibrous nonwoven textile fabric having surface interest and a soft and full hand which comprises: bonding a web of overlapping intersecting fibers in a predetermined pattern of spaced binder areas extending across said nonwoven textile fabric at an angle to the long axis thereof and covering less than about 35% of the surface of the textile fabric, said binder areas being in bonding relationship with the fibers passing therethrough and being separated by unbonded fabric areas; moistening the bonded web; and mechanically compacting the same to decrease the width and length thereof up to 30% to distend the unbonded areas between said binder areas while leaving the binder areas smooth, whereby an embossed appearance is created in the nonwoven textile fabric.

10. An embossed bonded fibrous textile fabric having surface interest and a soft and full hand comprising fibers bonded in a predetermined pattern of spaced binder areas extending across said textile fabric at an angle to the long axis thereof in bonding relationship with the fibers passing therethrough, said binder areas covering from about 10% up to about 35% of the surface of the textile fabric and being relatively smooth and separated by unbonded fabric areas which are relatively highly distended and possess resilience, whereby a durable embossed appearance is created in the textile fabric.

11. An embossed bonded fibrous nonwoven textile fabric having surface interest and a soft and full hand comprising a web of overlapping intersecting fibers bonded in a predetermined pattern of a plurality of sets of spaced binder areas extending across said nonwoven textile fabric at an angle to each other and to the long axis of the nonwoven textile fabric to form polygonal-shaped unbonded fabric areas therebetween, said binder areas being in bonding relationship with the fibers passing therethrough, said plurality of sets of binder areas covering from about up to about 35% of the surface of the textile fabric and being relatively smooth and separated by unbonded fabric areas which are relativelyhighly distended and possess resilience, whereby durable polygonal-shaped embossed areas are created in the nonwoven textile fabric.

12. An embossed bonded fibrous textile fabric having surface interest and a soft and full hand comprising fibers bonded in a predetermined pattern of spaced binder areas extending across said textile fabric at an angle to the long axis thereof in bonding relationship with the fibers passing therethrough, said binder areas covering from about 10% up to about 35% of the surface of the textile fabric and being relatively smooth and separated by unbonded fabric areas which are relatively highly distended and possess resilience, and said binder areas containing binderin an amount of from about 1% to 35% by Weight of the weight of said textile fabric, whereby a durable embossed appearance is created in the textile fabric.

13. An embossed bonded fibrous nonwoven textile fabric having surface interest and a soft and full hand comprising a web of overlapping intersecting fibers bonded in a predetermined pattern of a plurality of sets of spaced binder areas extending across said nonwoven textile fabric at an angle to each other and to the long axis of the nonwoven textile fabric to form polygonalshaped unbonded fabric areas therebetween, said binder areas being in bonding relationship With the fibers passing therethrough, said plurality of sets of binder areas covering from about 10% up to about 35 of the surface of the textile fabric and being relatively smooth and separated by unbonded fabric areas which are relatively highly distended and possess resilience, said binder areas containing binder in an amount of from about 1% to by weight of the Weight of said textile fabric, whereby durable polygonal-shaped embossed areas are created in the nonwoven textile fabric.

14. An embossed bonded fibrous nonwoven textile fabric as defined in claim 13 wherein the embossed polygonal-shaped unbonded fabric areas are quadrilaterals.

15. Au embossed bonded fibrous nonwoven textile fabric as defined in claim 13 wherein the embossed polygonal-shaped unbonded fabric areas are diamond-shaped.

16. An embossed bonded fibrous nonwoven textile fabric as defined in claim 13 wherein the embossed polygonal-shaped unbonded fabric areas are rectangularshaped.

17. An embossed bonded fibrous nonwoven textile fabric as defined in claim 13 wherein the embossed polygonal-shaped unbonded fabric areas are square-shaped.

18. An embossed bonded fibrous nonwoven textile fabric as defined in claim 13 wherein the embossed polygonal-shaped unbonded fabric areas are triangularshaped.

Claims

11. AN EMBOSSED BONDED FIBROUS NONWOVEN TEXTILE FABRIC HAVING SURFACE INTEREST AND A SOFT AND FULL HAND COMPRISING A WEB OF OVERLAPPING INTERSECTING FIBERS BONDED IN A PREDETERMINED PATTERN OF A PLURALITY OF SETS OF SPACED BINDER AREAS EXTENDING ACROSS SAID NONWOVEN TEXTILE FABTIC AT AN ANGLE TO EACH OTHER AND TO THE LONG AXIS OF THE NONWOVEN TEXTILE FABRIC TO FORM POLYGONAL-SHAPED UNBONDED FABRIC AREAS THEREBETWEEN, SAID BINDER AREAS BEING IN BONDING RELATIONSHIP WITH THE FIBERS PASSING THERETHROUGH, SAID PLURALITY OF SETS OF BINDER AREAS COVERING FROM ABOUT 10% UP TO ABOUT 35% OF THE SURFACE OF THE TEXTILE FABRIC AND BEING RELATIVELY SMOOTH AND SEPARATED BY UNBONDED FABRIC AREAS WHICH ARE RELATIVELY HIGHLY DISTENDED AND POSSES RESILIENCE, WHEREBY DURABLE POLYGONAL-SHAPED EMBOSSED AREAS ARE CREATED IN THE NONWOVEN TEXTILE FABRIC.