MXPA01003172A - A fabric - Google Patents

Abstract

The present invention desirably provides a fabric including a synthetic fiber structure first zone, a synthetic fiber structure secondzone, and a short fiber third zone. The first zone may include a spunbond web layer and a meltblown web layer. The synthetic fiber structure second zone may be positioned proximate to the synthetic fiber structure first zone and the short fiber third zone may be positioned substantially between the first and second zones. Desirably, the first and second zones are entwined.

Description

A FABRIC FIELD OF THE INVENTION The present invention relates generally to entangled hydraulically nonwoven composite fabrics, and more specifically to fabrics having at least three layers and containing a continuous filament and a fibrous component, and to a process for making the same.

BACKGROUND OF THE INVENTION Hydraulically entangled non-woven fabrics have many applications, such as for tea bags, surgical gowns, covers, cover supply, food service and industrial cleaning cloths. One type of the hydraulically entangled nonwoven fabric may include two layers bonded with spinning and crimps having a cellulose fiber layer in the form of a sandwich. This fabric is primarily nded to be used as a washable clothing material.

Although this fabric has advantages in applications such as clothing material, it has disadvantages in applications that require resistance to abrasion, such as, for example, industrial cleaning cloths.

Consequently, the use of this fabric as an industrial cleaning cloth results in excessive lparticles and a relatively low cloth durability. Another disadvantage is that the manufacture of such a fabric requires a joining step after hydroentanglement. This extra step can increase the cost of the fabric, and therefore reduce your desire as an industrial cleaning cloth.

Therefore, there is a need for a non-woven fabric having at least three layers which have improved abrasion resistance and which do not require an additional bond after hydroentanglement.

DEFINITIONS As used herein, the term "comprises" refers to a part or parts of a whole, but does not exclude other parts. That is, the term "comprises" is an open language that requires the presence of the recited structure or element or its equivalent, but does not exclude the presence of other elements or structures. The term "includes" has the same meaning and is rchangeable with the terms "includes" and "has".

The term "machine direction" as used herein refers to the direction of travel of the forming surface on which the fibers are deposited during the formation of a material.

The term "cross machine direction" as used herein refers to the direction in the same plane which is perpendicular to the machine direction.

As used herein, the term "zones" refers to a region or area set as distinct from the surrounding or adjacent parts.

As used herein, the term "synthetic fiber structure" refers to a fiber structure created from man-made materials such as petroleum distillates or modified or regenerated cellulosic materials. In most cases, synthetic fiber structures generally have a fiber length greater than about 0.01 meters. Examples of a synthetic fiber structure include non-woven fabrics having petroleum distillate fibers, or semisynthetic regenerated cellulosic fiber structures, such as the products sold under the trade designation RAYON®.

As used herein, the term "non-woven fabric" refers to a fabric having a structure of individual fibers which are rleaved to form a matrix, but not in a repetitive and identifiable manner. Non-woven fabrics have been formed, in the past, as a variety of processes known to those skilled in the art, such as, for example, meltblowing, spinning bonding, wet forming and various weaving processes. carded and united.

As used herein, the term "spunbonded fabric" refers to a fabric formed by extruding a molten thermoplastic material such as filaments from a plurality of thin capillary bases, usually circular with the diameter of the extruded filaments then being rapidly reduced, for example, by pulling fluid or other well-known spinning mechanisms. The production of non-woven fabrics bonded with yarn is illustrated in the patents such as that of Appel et al., United States of America No. 4,340,563.

As used herein, the term "meltblown fabric" means a fabric having fibers formed by extruding a molten thermoplastic material through a plurality of thin, usually circular, capillary vessels, such as fibers melted into a stream of liquid. gas (for example air) at high speed which attenuates the fibers of the molten thermoplastic material to reduce its diameters. The melt-blown fibers are then carried by the high velocity gas stream and deposited on a collecting surface to form a randomly discarded fiber fabric. The meltblowing process is well known and is described in several patents and publications, including the report of Naval Research Laboratory number 4364, "Manufacturing of Superfine Organic Fibers" of V.A. Went E.L. Boone and C.D. Fluharty; the report of Naval Research Laboratory No. 5265, "An Improved Device for the Formation of Superfine Thermoplastic Fibers" by K.D. Lawrence, R.T. Lukas Y J.A. Young; and U.S. Patent No. 3,849,241, issued November 19, 1974 to Buntin et al., which are incorporated herein by reference.

As used herein, the term "short fiber" refers to any fiber that has a length of approximately less than 0.01 meters.

As used herein, the term "basic fiber" refers to a fiber cut from a filament. Any type of filament material can be used to form basic fibers. For example, cotton, rayon, wool, nylon, polypropylene and polyethylene terephthalate can be used. The example lengths of the basic fibers can be from about 4 centimeters to about 20 centimeters.

As used herein, the term "filaments" refers to a fiber that has a large aspect ratio.

As used herein, the term "non-crimped" refers to a non-crimped synthetic fiber as measured in accordance with ASTM test procedure D-3937-94 and is defined as less than two crimps per fiber.

As used herein, the term "cellulose" refers to a higher polymer of natural carbohydrate (polysaccharide) having the chemical formula (C5H10O5) and consisting of anhydroglucose units linked by an oxygen bond to form long molecular chains which are essentially linear. The natural sources of the cellulose include the desiduos and coniferous trees, the cotton, the flax, the pasture esparto, the bencetócigo, the straw, the jute, the hemp and the bagaso.

As used herein, the term "pulp" refers to the cellulose produced by such treatments such as, for example, thermal, chemical and / or mechanical treatments.

As used herein, the term "thermoplastic material" refers to a higher polymer that softens when exposed to heat and that returns to its original condition when cooled to room temperature. The natural substances that exhibit this behavior are crude rubber and a number of waxes. Other exemplary thermoplastic materials include styrene polymers and copolymers, acrylics, polyethylenes, polypropylene, vinyls and nylons.

As used herein, the term "thermoplastic material" refers to any material which does not fall within the definition of "thermoplastic material" given above.

As used herein, the term "Taber abrasion" refers to values determined in accordance essentially with the test procedure ASTM D-3884-92 and reported as described herein.

As used herein, the term "tension in the machine direction" (hereinafter "MDT") the force applied in the machine direction to break a sample in essentially in accordance with the TAPPI test procedure can be mentioned. T-494 om-88 and that can be reported as grams-force.

As used herein, the term "tension in the transverse direction" (hereinafter referred to as "CDT") is the force applied in the direction transverse to the rupture of a sample in essentially in accordance with the TAPPI test procedure. t-494 om-88 and can be reported as grams / force.

As used herein, the term "basis weight" (hereinafter referred to as "BW") is the weight per unit area of a sample calculated in accordance with ASTM test procedure D-3776-96 Option C, and can be reported as grams-force per square meter.

As used herein, the term "measured length" is the sample length typically reported in centimeters, measured between the attachment points. As an example, a fabric sample is stapled tightly in a pair of handles. The initial distance between the handles, usually 7.6 or 10.2 centimeters, is the measured length of the sample.

As used herein, the term "stretch percent" refers to the values determined as described herein.

As used herein, the term "trap tear" refers to values determined in general in accordance with the TAPPI test procedure T-494 om-88 as described herein.

SYNTHESIS OF THE INVENTION The problems and needs described above are examined by the present invention, which desirably provides a fabric including a first synthetic fiber structure zone, a second synthetic fiber structure zone, and a third short fiber zone. The first zone may include a layer of cloth bonded with yarn and a layer of melt blown cloth. The second synthetic fiber structure zone can be placed close to the first synthetic fiber structure zone and the third short fiber zone can be placed essentially between the first and second zones. Desirably, at least a portion of the first and second zones may be intertwined with the third zone.

In addition, the third short fiber zone may include pulp fibers, basic fibers, particles, and combinations of one or more of the foregoing. In addition, the second zone may include a layer of spunbonded fabric and a layer of meltblown fabric. In addition, the first and second zones can be pre-joined before being interlaced.

In another embodiment, the third short fiber zone may include a plurality of layers of cellulosic material. The second synthetic fiber structure zone can be placed close to the first synthetic fiber structure zone and the third short fiber zone can be placed essentially between the first and second zones. Desirably, at least a portion of the first and second zones may be intertwined with the third zone.

In addition, the third short fiber zone may include three layers of cellulosic material. In addition, the third short fiber zone may include pulp and basic fibers or particles.

In addition, the first or second zone may include a layer of spunbonded fabric and a layer of meltblown fabric.

A further embodiment of the present invention can relate to a process for producing a fabric. The process may include the steps of providing a first synthetic fiber structure zone, providing a second synthetic fiber structure zone, and providing a third short fiber zone. The third zone can be placed essentially between the first and second zones. Desirably, the first and second zones can be hydroentangled.

Additionally, the third short fiber zone may include pulp fibers, basic fibers or pulp fibers and basic fibers. In addition, the second zone may include a layer of spunbonded fabric and a layer of meltblown fabric.

In a further embodiment the fabric can have a Taber abrasion value of not less than about three essentially in accordance with the ASTM test procedure D-3884-92.

In addition, the third short fiber layer may include the pulp fibers, the basic fibers, the pulp and basic fibers, and the particles. Desirably, the first layer is a layer of non-woven fabric, and more desirably, the non-woven fabric layer is a layer of spunbonded fabric. In addition, the first and second layers can be pre-bound before being interlaced.

Another embodiment of the present invention may be a fabric having a short fiber and a basis weight of less than about 6 percent after five washing and drying cycles.

In yet another additional embodiment, the first zone may include non-crimped fibers.

In yet another additional embodiment, the fabric may include a first structure zone of prebonded synthetic fiber.

DESCRIPTION OF THE DRAWINGS Figure 1 is a top plan view of a web of the present invention.

Figure 2 is an enlarged cross-section of an embodiment of the fabric having three zones.

Figure 3 is an enlarged cross-section of another embodiment of the fabric having five layers.

Figure 4 is an illustration of an example process for making a hydraulically entangled composite fabric.

Figure 5 is a schematic illustration of an embodiment of a process for making a hydraulically entangled composite fabric that includes three layers.

Figure 6 is a schematic illustration of a second embodiment of a process for making a hydraulically entangled composite fabric that includes four layers.

Figure 7 is a schematic illustration of a third embodiment of a process for making a hydraulically entangled composite fabric that includes four layers.

Figure 8 is a schematic illustration of a fourth embodiment of a process for making a hydraulically entangled composite fabric that includes five layers.

Figure 9 is a plan view of an exemplary joining pattern.

Figure 10 is a plan view of an exemplary joining pattern.

Figure 11 is a plan view of an exemplary joining pattern.

DETAILED DESCRIPTION OF THE INVENTION Referring to Figures 1 and 2, a fabric 10 may include three zones, namely, a first synthetic fiber structure zone 20, a second synthetic fiber structure zone 40, and a third short fiber zone 60. Even when each zone 20, 40 and 60 constitutes a distinct layer, these zones 20, 40 and 60 may themselves include a plurality of layers. Desirably, the first zone 20 and the second zone 40 are non-woven fabrics, and more desirably, they are fabrics bonded with yarn.

These zones 20 and 40 provide strength, durability and abrasion prevention to the fabric 10. The third short fiber zone 60 can be basic fibers or wood pulp, or a mixture of both.

The third zone 60 provides absorbency and softness to the fabric 10. Although three distinct layers are present in the fabric 10, some intermingling occurs between the different zones 20, 40 and 60.

The zones or layers of first and second synthetic fiber and 40 may have a basis weight of from about 12 to about 50 grams per square meter (hereinafter referred to as "gsm"). In addition, synthetic fiber layers 20 and 40 may have a basis weight of from about 20 grams per square meter to about 27 grams per square meter. The third zone or short fiber layer 60 can have a basis weight of from about 28 grams per square meter to about 165 grams per square meter. In addition, the short fiber layer 60 can have a basis weight of from about 80 grams per square meter to about 131 grams per square meter. In addition, the short fiber layer 60 can have a basis weight of from about 90 grams per square meter to about 125 grams per square meter.

Alternatively, the layers of synthetic fiber 20 and 40 can vary from about 10 about 70 percent by weight of the weight of the total fabric 10, and correspondingly, the short fiber layer 60 can vary from about 90 to about 30 percent by weight of the weight of the total 10 fabric.

In addition, the synthetic fiber layers 20 and 40 can vary from about 29 about 33 percent by weight of the weight of the total fabric 10, and correspondingly, the short fiber layer 60 can vary from about 71 about 77 percent. by weight of the weight of the total fabric 10. In addition, the total basis weight of the fabric 10 can vary from about 52 grams per square meter to about 250 grams per square meter. In addition, the total basis weight of the fabric 10 can vary from about 90 grams per square meter to about 175 grams per square meter.The synthetic fiber layers 20 and 40 may include combinations of other materials, such as short fibers, long fibers, synthetic fibers, natural fibers, particles, binders and fillers. In addition, the short fiber zone 60 may include combinations of other materials, such as the long fibers generally having a length greater than 0.01 meters, the synthetic fibers, the natural fibers, the particles, the binders and the fillers.

As shown in Figure 3, an alternate embodiment of the present invention is a fabric 100 which may include three zones, namely, a first synthetic fiber structure zone 120, a second synthetic fiber structure zone 140, and a third short fiber zone 160. In this desired embodiment, zones 120, 140 may include non-woven fabrics, and specifically, further include, respectively, a first layer of spunbonded cloth 124 and a first meltblown cloth layer. , and a second layer of fabric bonded with yarn 144 and a second layer of melt blown fabric 148. Layers 124 and 144 provide resistance, durability and abrasion protection to the fabric 100 while the layers 128 148 help to avoid fluff of the entrapment material of the third zone 160, and therefore to prevent the material from detaching from the fabric 100. Even when the third zone of short fiber is illustrated as a single layer 164, t It can also be two, three or more different layers of short fiber material. The short fiber layer 164 can be basic fibers or wood pulp, or a combination of both. The third layer 164 provides absorbency and softness to the fabric 100. Although five distinct layers 124, 128, 144, 148, 164 are present in the fabric 100, some intermingling may occur between the different layers 124, 128, 144, 148 and 164 The fabric layers bonded with first and second yarn 124 and 144 can have a basis weight of from about 12 grams per square meter to about 34 grams per square meter.

In addition, the yarn bonded fabric layers 124 and 144 can have a basis weight of from about 14 grams per square meter to about 27 grams per square meter. The short fiber layer 164 can have a basis weight of from about 28 grams per square meter to about 165 grams per square meter. In addition, the short fiber layer 164 can have a basis weight of from about 90 grams per square meter to about 113 grams per square meter. In addition, first and second melt blown fabric layers 128 and 148 can have a basis weight of from about 2 grams per square meter to about 34 grams per square meter. In addition, the meltblown fabric layers 128 and 148 can have a basis weight of from about 7 grams per square meter to about 20 grams per square meter.

Alternatively, the layers of synthetic fiber structure, namely layers 124, 128, 144, and 148, may vary from about 13 to about 71 percent by weight of total fabric weight 100, and correspondingly, the layer of short fiber 164 may vary from about 87 to about 29 percent by weight of total fabric weight 100. In addition, layers 124, 128, 144 and 148 may vary from about 15 about 66 percent by weight of weight of total fabric 100 and correspondingly, short fiber layer 164 may vary from about 85 to about 34 percent by weight of total fabric weight 100. In addition, layers 124, 128, 144 and 148 may vary from about from 30 to about 45 percent by weight of the total fabric 100, and correspondingly, the short fiber layer 164 can vary from about 70 to about 55 percent by weight of the total fabric weight 100.

In addition, the present invention contemplates varying the percent by weight between the layers bonded with spinning and meltblowing., 128, 144 and 148 in the zone 120 and 140 of the fabric 100. The layers joined with yarn 124 and 144 can vary from about 83 to about 57 percent by weight of the area 120 and 140 of weight, and correspondingly , meltblown fabric layers 128 and 148 can vary from about 17 to about 43 percent by weight of zone 120 and 140 of weight. In addition, layers 124 and 144 may vary from about 75 to about 67 percent by weight of zone 120 and 140 by weight and accordingly, the meltblown fabric layers 128 and 148 may vary from about 25 to 150. about 33 percent by weight of areas 120 and 140 of weight. Also the total basis weight of the fabric 100 can vary from about 60 grams per square meter to about 250 grams per square meter. In addition, the total basis weight of the fabric 100 can vary from about 90 grams per square meter to about 150 grams per square meter.

The synthetic fiber structure zones 120 and 140 may include combinations of other materials, such as short fibers, long fibers, synthetic fibers, natural fibers, particles, binders and fillers. In addition, the short fiber zone 160 may include combinations of other materials, such as. the long fibers generally having a length greater than 0.01 meters, synthetic fiber, natural fibers, particles, binders and fillers.

Both fabrics 10 and 100 can be used in various applications, but can be particularly useful as washable industrial cleaning cloths, cover supply materials, and garment materials. Further, even though these particular combinations of short fiber, spunbonded and meltblown layers have been described for fabrics 10 and 100, it should be understood that other combinations of layers may be used as described in more detail herein. onwards .

An embodiment of the process for producing either the fabric 10 or the 100 is illustrated in Figure 4. The process 200 may include a hydroentanglement and fabric forming apparatus 204 and a drying apparatus 242. The apparatus 204 includes a box of 20 head 212 for providing a short fiber material such as the cellulosic material 218, the supply rolls 228, 230, a foraminous fabric 234, a multiple unit 236, and a vacuum apparatus 238.

The cellulosic material 218 can be of several wood pulps or without wood. The appropriate cellulosic material may include soft wood krafs from the north or south, southern pines, red cedar, hemlock, eucalyptus, black spruce and mixtures thereof. Exemplary commercially available cellulosic fibers suitable for the present invention include those available from Kimberly-Clark Corporation of Dallas, Texas, under the trade designation Longlac-19 (LL19) - Longlac-19 is a soft wood kraft pulp of the North fully bleached (approximately 95 percent by weight of spruce) with a trace amount of fully bleached northern hardwood (mainly poplar) the average fiber length of Longlac-19 is approximately 1.07 millimeters. Desirably, the appropriate cellulosic materials will be either 100 percent Longlac-19 or a mixture of 50 percent by weight of Longlac-19 and 50 percent by weight of kraft of southern softwood. The cellulose fibers can be modified by such treatments such as, for example, chemical and / or mechanical thermal treatments. It is contemplated that the synthetic and / or reconstituted cellulose fibers may be used and / or mixed with other cellulose fibers of the fibrous cellulosic material. The fibrous cellulosic materials may also be composite materials containing cellulosic fibers and one or more non-cellulosic fibers. In addition, particles such as superabsorbents, elastic fibers, splittable fibers, monocomponent filaments, or filaments of plurality of components can be incorporated into cellulosic materials. In addition, basic fibers, thermoplastic materials, or latex can be added to increase abrasion resistance. A description of a fibrous cellulosic composite can be found in, for example, U.S. Patent 5,284,703.

The cellulosic material 218 can have a basis weight of from about 28 grams per square meter to about 165 grams per square meter. In addition, the cellulosic material 218 can have a basis weight of from about 80 grams per square meter to about 131 grams per square meter.

The pulp fibers used for the cellulosic material 218 may not be refined or may be struck at various degrees of refinement. Small amounts of wet strength resins and / or resin binders can be added to improve abrasion resistance and firmness. Useful binders and wet strength resins include, for example, the KIMENE 557 H resin available from Hercules Chemical Company and the PAREZ 631 resin available from American Syanamid, Inc. the cross-launch agents and / or the entangling agents may also be added to the pulp fibers. The debonding agents can be added to the pulp mixture to reduce the degree of bonding of the paper whether an open or loose nonwoven fibrous web is desired. An exemplary binder agent is available from Quaker Chemical Company, of Conshohocken, Pennsykvania, under the trade designation QUACKER 2008..

The supply rolls 228 and 230 can supply the synthetic fiber structure zones 224 and 226 to the apparatus 204. The material can be a yarn-bonded fabric, such as a yarn-bonded fabric manufactured by Kimberly-Clark Corporation, or a composite of a meltblown / meltbond fabric, as previously described for the fabric 100.

Referring to Figure 4, the synthetic fiber structure zones 224 and 226 can be formed by known continuous filament nonwoven shrinking processes, such as, for example, known melt / spinning or solvent spinning processes, and passing directly without first being stored in the supply rolls 228 or 230. The continuous filament nonwoven substrate 226 is preferably a non-woven fabric of fused filaments / continuous yarns formed by the spinning process. Spunbond filaments may be formed from any melt-spinnable polymer, copolymers or mixtures thereof. For example, the spunbonded filaments can be formed of polyolefins, polyamides, polyesters, polyurethanes, block copolymers AB and ABA 'wherein A and A' are thermoplastic end blocks and B is an elastomeric middle block, and the copolymers of ethylene and at least one vinyl monomer such as, for example, vinyl acetates, unsaturated aliphatic monocarboxylic acids, and the esters of such monocarboxylic acids. The polymers can incorporate additional materials such as, for example, pigments, antioxidants, flow promoters, stabilizers and the like.

The filaments can be formed of bicomponent or multi-component materials, desirably in a sheath / core arrangement, which can prevent ripple.

Desirably, the filaments of the present invention are not crimped to increase the abrasive resistance of the outer layers.

If the filaments are formed of a polyolefin, the nonwoven substrate 226 can have a basis weight of from about 12 grams per square meter to about 34 grams per square meter. More particularly, the nonwoven substrate 226 can have a basis weight of from about 10 grams per square meter to about 35 grams per square meter.

One feature for improving the abrasion resistance of the nonwoven continuous filament substrate 226 is that it has a total bond area of less than about 30 percent and a higher uniform bond density of about 155,000 joints per square meter. . Having a joint area of less than 30 percent allows the hydroentanglement with the cellulosic material while having a bonding density greater than about 155,000 joints per square meter which helps the union of the loose fibers, thus improving the abrasion resistance. For example, the continuous nonwoven filament substrate 226 may have a total bond area of from about 2 percent to about 30 percent (as determined by conventional optical microscopic methods) and a bonding density from about 387,000 to about of 775,000 bolt joints per square meter.

Such a combination of the total bonding area and the bonding density can be achieved by joining the continuous filament substrate 226 with a pin bonding pattern having more than about 155,000 joints per square meter which provides a surface area of total union of less than about 30 percent when it makes contact with a smooth anvil roller. Desirably, the bonding pattern can have a pin bonding density of from about 387,000 to about 542,000 bolt joints per square meter and a total bonding surface area of from about 10 percent to about 25 percent when it does contact with a smooth anvil roller. A Example joint pattern is shown in Figure 9. That joint pattern has a bolt density of about 474,000 bolts per square meter. Each joint pattern has a bolt density of around 474,000 bolts per square meter. Each bolt defines a square joining surface that has sides which are around 0.00064 meters in length. When the bolts make contact with a smooth anvil roller they create a total joint surface area of about 15.7 percent. Substrates of high basis weight generally have a binding area which approximates that value. Substrates of lower base weight generally have a lower binding area. Figure 10 is another exemplary joining pattern. The pattern of Figure 10 has a bolt density of about 431,000 bolts per square meter. Each pin defines a joining surface that has 2 parallel sides of about 0.00089 meters long (and about 0.00051 meters apart) and 2 opposite convex sides each having a radius of about 0.00019 meters. When the bolts contact a smooth anvil roller they create a total joint surface area of about 17.2 percent. Figure 11 is a joining pattern which can be used. The pattern of Figure 11 has a bolt density of about 160,000 bolts per square meter. Each pin defines a square joining surface that has sides which are around 0.0011 meters in length. When the bolts make contact with a smooth anvil roller they create a total joint surface area of about 16.5 percent.

Although the bolt joint produced by the thermal bonding rolls is described above, the present invention contemplates any form of bonding which avoids loose filaments with a minimum overall bond area. For example, thermal bonding and / or latex impregnation can be used to provide the desired filament tie with a minimum bond area. In addition, thermal bonding can include the use of meltable / meltable thermoplastic fibers. Alternatively and / or additionally, a resin, a latex or an adhesive may be applied to the non-woven continuous filament fabric by, for example, spraying or printing, and drying to provide the desired bond.

Perforated fabric 234 can be formed in a variety of sizes and configurations including a single-planar mesh having a size of about four wires per centimeter (hereafter can be abbreviated as "cm") by about four wires per centimeter to about 50 wires per centimeter. Also, the perforated fabric 234 can be constructed of a polyester material. Several example forming fabrics are manufactured by Albany Engineer Fabric Wire under the trade designations 14c, 16c 20c, 103-AM, 12C, 90BH, and FT-14. The properties of these seven fabrics are shown below in table 1.

TABLE 1 PROPERTIES OF THE FABRIC The manifold unit 236 includes three manifolds 236 a-c, capable of producing column jets even when other numbers of manifolds may be used. Each manifold 236 a-c may contain a row of holes where the holes may be spaced by about 16 holes per centimeter. Each orifice is around 0.15 millimeters in diameter. The multiple 236 a-c can be obtained from Valmet Honeycomb Incorporated, Biddeford, Maine.

According to the present invention illustrated in Figure 4, a short fiber suspension such as the pulp, supplied by the head box 212 through a channel 214 is deposited on a forming fabric 216. The suspension can be diluted to any consistency that is typical in conventional papermaking processes. As an example, the suspension may contain from about 0.1 to about 1.5 percent by weight pulp fibers. Removal of water from the suspension forms a uniform zone or layer of cellulosic material 218. The cellulosic material 218 is then placeable between two synthetic fiber structure zones or layers 224 and 226, which are unwound from the supply rolls 228 and 228. 230 respectively, thus forming a structure 232.

After forming the structure 232 it is placed on the perforated fabric 234 for the hydroentanglement. Hydroentanglement processes are known in the art, and as an example, U.S. Patent No. 3,485,706 issued to Evans discloses a suitable hydroentanglement process which is incorporated herein by reference. The treatment of the structure 232 with fluid jets, typically water, from the manifold unit 236 entangles the layers of the structure 232. The water leaving the orifice of the manifold unit 236 varies from about 7,000,000 pascals around 34,000,000 pascals Alternatively, the water can be from about 11,000,000 to around 12,000,000 pascals. The perforated fabric 234 and the forming fabric 216 can move about 0.91 meters per minute to about 610 meters per minute. In the upper ranges of the pressures described, it is contemplated that the composite fabrics can be processed at higher speeds. Alternatively, the webs 234 and the web 216 can be moved from about 0.91 meters per minute to about 16.4 meters per minute. The fluid jets entangle and further interweave the synthetic fiber structure zones 224 and 226 together with the cellulosic or short fiber material layer 218, which are supported by the perforated fabric 234. A vacuum apparatus 238 is placed directly below of the perforated fabric 234 in the manifold unit 236 removes the fluid from the hydroentangled fabric 240.

Although Figure 4 illustrates only the hydroentanglement on one side of the structure 232 to form the fabric 240, it is desired to hydroentangle both sides. As an example, U.S. Patent No. 5,587,225, issued to Griesbach et al., Describes such a process and is incorporated herein by reference. The second side of the fabric 240 can be hydroentangled at similar process conditions as those of the first side previously described.

If desired, dyeing can be done online, such as with pulp reducer dyeing, which can also be used to apply softeners or a vacuum suture applicator 260; such as the apparatus and process described in U.S. Patent Nos. 5,486,381 issued to Cleveland et al. and 5,578,124 issued to Cleveland and others which are incorporated herein by reference. In addition, the colored zones 224 and 226 may be used in conjunction with in-line dyeing or be excluded from in-line dyeing.

After in-line dyeing, the hydraulically entangled fabric 240 can be transferred by a differential speed pickup roller 254 to the drying apparatus 242. A desirable drying apparatus is a conventional rotary air drying drum. Alternatively, conventional vacuum collection and transfer fabrics can be used. If desired, the fabric 240 can be creped wet before being transferred to the drying operation. The drying apparatus 242 may be an outer rotating cylinder 244 with the perforations 246 in combination with an outer cover 248 for receiving the hot air blown through the perforations 246. A continuous drying band 250 carries the fabric 240 over the top of the cylinder 244. The forced heated air through the perforations 246 in the outer cylinder 244 removes the water from the fabric 240. The temperature of the forced air can vary from about 200 ° around 500 ° F. Other useful continuous drying methods and apparatuses may be used, for example, those methods and apparatuses described in U.S. Patent Nos. 2,666,369 and 3,821,068, which are incorporated herein by reference. It is contemplated that compressive drying operations can be used to dry the fabric 240 as well. In addition, other exemplary drying apparatuses and methods can be used, such as infrared radiation, Yankee driers, steam cans, vacuum dewatering, microwaves and ultrasonic energy.

A desirable feature of the present invention is to produce a fabric in layers or three zones without additional bonding after hydroentanglement. Although the inventors do not wish to rely on a particular theory of operation, it is believed that the high strength of the synthetic fiber structure zones, which can be thermally or chemically pre-crimped prior to hydroentanglement, allows a high-pressure, hydroentanglement to be rigorous. Stringent hydroentanglement results in a superior bond between the various zones, which avoids the need for subsequent bonding procedures.

It may be desirable to use finishing steps and / or subsequent treatment processes to impart selected properties to the dried composite fabric 252. As an example, the fabric 252 may be lightly or heavily pressed by the calendering rolls, may be creped and brushed to provide a uniform exterior appearance and / or certain tactile properties. Alternatively and / or additionally, subsequent chemical treatments, such as adhesives or dyes may be added to the fabric 252. It is contemplated that the composite fabric 252 may be saturated or impregnated with latexes, emulsions, flame retardants and / or binding agents. . As an example, the composite fabric 252 can be treated with a heat-activated binding agent.

In an aspect of the invention, the fabric 240 may contain various materials, such as activated carbon, clays, starches and superabsorbent materials. As an example, these materials can be added to the suspension of the cellulosic material 218. These materials can also be deposited directly on the synthetic fiber structure zones or on the layer of the cellulosic material 218 before the fluid jet treatments, incorporating them in the fabric 240 by the action of the fluid jets. Alternatively and / or additionally, these materials can be added to the composite fabric after the fluid jet treatments. If the superabsorbent materials are added to the suspension of the fibrous material or the layer of the fibrous material before the water jet treatments, it is desired that the superabsorbents are those which remain inactive during the wet formation and / or the treatment steps. with water jet and can be activated later, such as those described in U.S. Patent No. 3,563,241 issued to Evans et al., which is incorporated herein by reference. The superabsorbents, such as those described in the patent of the United States of America No. ,328,759 issued to McCormack et al. And incorporated herein by reference, may be added to the composite fabric after the water jet treatments and immediately before drying. Figures 5-8 schematically illustrate various methods of hydroentanglement of fabric creation. The following processes can use the same equipment as described for process 200, except where noted otherwise. As an example, each multiple unit hereinafter desirably described includes three multiples as previously described for process 200. Although most of the components, such as head boxes, and perforating and forming fabrics are not shown , these processes are easily reproducible by a person with ordinary skill in the art in light of the present description. In addition, although more than one layer of short fiber may be described hereinafter, the overall ratio of the short fiber content to the synthetic fiber content is almost the same as previously described for the 10 and 100 fabrics. Forming and perforating fabrics of the processes described hereinafter are desirably operated at from about 0.91 meters per minute to about 16.4 meters per minute, even though the higher speeds are contemplated depending on the fluid pressure of the multiple units. . In addition, all subsequent hydroentangling operations and modifications, such as drying and etching, described for process 200 can be used for the following processes as well.

Referring to Figure 5, a hydroentanglement process 300 may include the hydroentanglement of a first layer of synthetic fiber structure 310, a second layer of synthetic fiber structure 320, and a third short fiber layer 330. These layers 310, 320 and 330 can be combined to form a compound and then passed through a manifold unit 340 and hydroentangled with a fluid ranging from about 11,000,000 pascals to about 12,000,000 pascals. After one side of the compound has been hydroentangled, the layers 310, 320 and 330 can be passed through a roller 335, thereby exposing a second side of the compound to the multiple unit 350. The second side can be hydroentangled with a fluid varying from around 11,000,000 Pascals around 12,000,000 Pascals. Alternatively to the processing of layers 310, 320, and 330 continuously, these layers can be processed in loading steps, as previously described for process 200. This process 300 can produce a fabric having two zones or layers of structure. synthetic fiber 310 and 320 having a zone or layer of short fiber 330 in the form of a sandwich.

Referring to Figure 6, a hydroentanglement process 400 may include hydroentanglement a first layer of synthetic fiber structure 410, a second layer of synthetic fiber structure 420, a third layer of short fiber 430, and a fourth layer of short fiber 440. Layers 420 and 440 can be passed through a manifold unit 480 and hydroentangled with a fluid at about 9,100,000 pascals. In addition, layers 410 and 430 can be passed through a manifold unit 460 and hydroentangled with a fluid at about 9,100,000 pascals. Then the hydroentangled layers 410 and 430 can be passed through a roller 435 to place the layer 430 on one side of the layer 440. Next, the layers 410, 420, 430 and 440 can be passed through a manifold unit 470, hydroentanglement these layers 410, 420, 430 and 440 with a fluid ranging from about 11,000,000 pascals to 12,000,000 pascals. This process 400 can form a fabric having the synthetic fiber zones or layers 410 and 420 having two short fiber layers 430 and 440 in sandwich form, which form a single short fiber zone. Although this process 400 has been described using three multiple units 460, 470 and 480 to continuously process the layers 410, 420, 430 and 440, it should be understood that alternatively, these layers can be processed in loading stages.

Referring to Figure 7, a hydroentanglement process 500 may include hydroentanglement a first layer of synthetic fiber structure 510, a second layer of synthetic fiber structure 520, a third layer of short fiber 530, a fourth layer of short fiber 540 , layers 510 and 530 can be passed through a manifold unit 550 and hydroentangled with fluid at about 9,100,000 pascals. Then, the hydroentangled layers 510, 530 can be passed through a roller 535 to place the layer 530 on the side of the layer 540. Then, the layers 510, 520, 530 and 540 can be passed through a manifold unit 560, hydroentanglement by both these layers 510, 520, 530 and 540 with a fluid varying from about 11,000,000 Pascals around 12,000,000 Pascals. This process 500 can form a fabric having two synthetic fiber structure layers or layers 510 and 520 having two short fiber layers 530 and 540, which form a short fiber zone. Although this process 500 has been described using two multiple units 550 and 560 to continuously process the layers 510, 520, 530 and 540, it should be understood that, alternatively, these layers can be processed in loading stages.

Referring to Figure 8, a hydroentanglement process 600 may include hydroentanglement a first layer of synthetic fiber structure 610, a second layer of synthetic fiber structure 620, a third layer of short fiber 630, a fourth layer of short fiber 640 and a fifth layer of short fiber layer 650. Layers 620 and 640 can be passed through a manifold unit 670 and can be hydroentangled with a fluid at about 9,100,000 pascals.

In addition the layers 610 and 630 can be passed through a manifold unit 660 and can be hydroentangled with a fluid of about 9,100,000 pascals. Then, the hydroentangled layers 610 and 630 can be passed through a roller 635, reversing these layers 610 and 630. A fifth short fiber layer 650 can be deposited on the fourth layer 640. The inverted layers 630 and 610 are combined with the layers 620, 640 and 650. After the layers 610, 620, 630, 640 and 650 can be passed through a manifold 680, hydroentangle these layers 610, 620, 630, 640 and 650 with a fluid varying from about 11,000,000 from Pascals to around 12,000,000 Pascals. This process 600 can form a fabric having two zones or layers of synthetic fiber structure 610 and 620 having in sandwich form three layers of short fiber 630, 640 and 650 which can form a single short fiber zone. Although this process 600 has been described using three multiple units 660, 670 and 680 to continuously process layers 610, 620, 630, 640 and 650, it should be understood that alternatively, these layers can be processed in loading stages.

TESTS The tests were carried out on fabrics produced by the present invention. One test measured the abrasion resistance, which was carried out on a TABER abrasion tester manufactured by Taber Industries of North Tanawanda, New York.

The samples were tested either dry and / or wet. The dry samples were tested at ambient conditions and the wet samples were saturated with water, dried with blotting paper and tested immediately.

Table 2 (appended to the end of the description) describes the data of the fabrics having three layers, namely joined with spin-pulp-linked with spinning, produced by the process 200 previously described. Each data point in table 2 represents the mean of four samples.

The test procedure included running each sample for 50 cycles with the wheel operating at around 72 revolutions per minute. The wheel was a wheel of H-18 stone material and was not used against weights. After testing four samples, the wheels on the TABER abrasion tester were changed with a clean wheel. Striped samples were rated on a scale of 1 to 5 with 5 being essentially un-scratched by comparison to standardized photos. Referring to Table 2, most of the samples tested had a Taber resistance of 3 or more, thus illustrating the substantial durability.

In addition, several other samples were taken and washed to prove their durability. These samples were washed according to ASTM d-2724-87 for washing and drying procedures except that about 0.25 liters of CLOROX® bleach was added to the wash cycles. In addition, the samples were washed at about 54 ° C for about 8 minutes, and then dried for about 30 minutes. Each sample is shown in table 3.

As shown in Table 3, the greatest weight loss after five washing and drying cycles is at least about 6 percent of the original sample weight. Therefore, these samples are illustrative of the durability of the three-ply fabric.

Table 4 shows the data of the fabrics having four layers, namely in spun-bonded-spun-bonded, produced by process 400 as previously described. The TABER abrasion test was carried out in essentially the same way as for the three-ply fabric samples.

TABLE 4 As previously described, it is believed that the high strength of the pre-assembled synthetic fiber structure zones allows for a rigorous hydroentanglement. Several tests were carried out on an example fiber zone which in this experiment were two layers joined with spinning. Tests included trap tearing, tension module and Taber abrasion. Each data point shown in Tables 5-7 represents the mean of four samples. Tensile tension and tear module tests were carried out using wet and dry samples. The wet samples were saturated with purified water and the excess was dried with blotting paper before being caught in the apparatus. Conversely, the dry samples were not saturated with water, but were conditioned for approximately 12 hours at 23 ° C at a relative humidity of 50 percent before the test.

The trap tear test measures the firmness of a material by measuring the resistance of the material to the propagation of the tear under a constant extension cup of around 30 centimeters per minute. For the following data shown, the material is cut into trapezoidal-sized samples that have parallel sides of 7.6 centimeters and 15 centimeters. This trapezoidal cutting procedure is deviated from the TAPPI method T494 om-88. After cutting about 1.6 centimeters around the middle of about 7.6 centimeters on each side, the non-parallel sides of the trapezoidal shaped sample were grabbed. The pull caused a tear to propagate in the sample perpendicular to the load. The test was carried out using a SINTEC 2S voltage tester manufactured by Sintec Corporation of 1.001 Sheldon Drive, Cary, North Carolina 27513.

The tensile strength and stretch test measures the firmness of a material by pulling at a constant extension rate ranging from about 290 millimeters per minute to about 310 millimeters per minute until the material breaks. This test was carried out using a SINTECH 2S tension tester manufactured by Sintech Corporation of 1,001 Sheldon Drive, Cary, North Carolina 27513. The test procedure included in securing a sample at any end in the transverse direction with 10.16 centimeter handles. and stretching at a rate of 25.40 centimeters per minute until the sample breaks. Each sample had a length in the machine direction of about 15.24 centimeters and a width in the transverse direction of about 2.54 centimeters. This test procedure obtained data in relation to the tension module and the stretch percent. The percent stretch was expressed as a percentage of the measured length at the peak load.

Resistance to tension and tearing of the trap were reported in units of gram-force, which can be abbreviated as "gf" the results of the aforementioned tests of the two zones of synthetic fibers packed in the direction of the machine are shown in table 5.

Base weight Tension Tension - Tension - Tension - Resistance (gsm) Dry MD MD Dry MD Wet MD Wet to tearing (9t> (% stretch) (9f) (% of trap-stretch) Wet MD (G () 55 4 3769 44 3562 41 3992 The results of the tests mentioned above in the transverse direction are shown in table 6.

TABLE 6 Base Weight Voltage - Voltage - Voltage - Voltage - Resistance (gsm) Dry CD CD Dry CD Wet CD Wet to tearing of tg. ) (% stretch) (9c! (% trap - stretch) Wet CD (G,) 55.4 1908 5644 1836 54 2585 Table 7 shows the Taber abrasion data wet and dry. The tests were carried out essentially the same for the three layers of fabric as previously written.

TABLE 7 It is believed that these strength properties of the layers bonded with spinning as shown in Tables 5, 6 and 7 result in a fabric having improved abrasion resistance as shown in Tables 2 and 4.

Although the present invention has been described in connection with certain preferred embodiments, it should be understood that the subject matter encompassed by the present invention should not be limited to those specific embodiments. On the contrary, it is intended that the subject matter of the invention include all those alternatives and equivalents as they may be included within the speed and scope within the following claims.

TABLE 2 BASE WEIGHT APPROXIMATE SPEED ABRASION JET CHIP (gsm) FABRIC FASTENED FLOAT PRESSURE PRESSURE MESSER (m / min) 1st- PAST? A- PASSED (kPa) (kPa) UNITED WITH TOTAL WET PULP NOMINAL YARN (BOTH LAYERS) 1st-SIDE 2 * »- SIDE 1st- 56 131 190 6. 6 9700 9700 3.4 4.3 56 131 187 6.6 11000 11000 3.4 3.4 56 131 182 6.6 12000 12000 4.7 3.9 40 110 150 6.2 12000 7000 5.0 1.0 40 '110 150 6.2 12000 7700 4.5 1.0 40 110 150 6.2 12000 8400 5.0 1.0 40 110 150 6.2 12000 9100 4.0 2.0 40 110 150 6.2 12000 9800 4.5 2.0 40 110 150 6.2 12000 10000 4.0 2.5 40 110 150 6.2 12000 11000 4.5 3.0 40 110 150 6.2 12000 12000 4.5 4.5 57 125 184 7.3 7000 12000 4.3 4.7 3.7 57 125 182 7.3 8400 12000 4.3 4.3 4.7 57 125 183 7.3 9000 12000 4.7 5.0 4.3 57 125 177 7.3 11000 12000 4.3 5.0 4.3 57 125 173 7.3 13000 12000 5.0 5.0 4.0 57 125 181 7 3 12000 12000 4.0 4.0 57 125 186 7 3 7000 12000 3.5 3.0 57 125 182 7 3 8400 12000 3.5 3.0 57 125 182 7 3 9800 12000 3.5 4.0 57 125 176 7 3 11000 12000 3.0 3.5 57 125 174 7 3 13000 12000 3.0 4.0 57 125 193 7.3 7000 8400 5.0 5.0 3.0 TABLE 2 CONTINUATION BASE WEIGHT APPROXIMATE SPEED ABRASION JET CHIP (gsm) FABRIC FABRIC BREAKER PRESSURE PRESSURE MILL • (m / min) I ra. PAST 2nd. PASS (kPa) (kPa) UNIDO cm PULP TOTAL DRY HUMID DRY NOMINAL (BOTH LAYERS) lér. SIDE 2o. 1st SIDE SIDE 2nd. SIDE 57 125 185 7.3 7000 9800 5.0 4.7 3.3 3.0 57 125 189 7.3 7000 11000 4.3 5.0 3.0 3.3 57 125 182 7.3 7000 13000 3.7 4.7 3.0 3.3 57 125 179 7.3 7000 14000 3.3 4.7 3.0 3.0 57 125 1 91 7.3 7000 8400 2.0 3.0 ' 57 125 189 7.3 7000 9800 3.0 3.0 57 57 185 185 7.3 7000 11000 3.0 3.0 57 125 1 83 7.3 7000 13000 4.0 4.0 57 * 125 181 7.3 7000 14000 4.0 4.0 57 125 182 7.3 9800 9800 3.0 4.0 57 57 176 176 7.3 9800 11000 3.5 5.0 57 125 1 77 7.3 9800 13000 4.0 4.5 57 125 181 7.3 9800 14000 4.0 3.5 57 125 1 88 7.0 9800 8400 2.0 4.0 57 57 1 92 7.0 9800 9800 3.0 3.5 57 125 1 89 7.0 9800 11000 3.5 4.0 57 125 1 92 7.0 9800 13000 4.0 4.0 57 125 181 7.0 9800 14000 4.0 4.0 57 125 1 68 9.1 12000 12000 4.7 3.3 3.0 3.7 57 125 174 9.1 12000 12000 4.0 4.3 3.0 3.0 57 125 1 77 16.4 Í2000 12000 4.3 4.7 3.0 3.0 57 100 14 1 13.4 12000 12000 4.3 4.7 3.0 3.0 57 75 125 9.1 12000 12000 4.7 5.0 3.0 3.0

Claims (20)

1. A fabric comprising: a first synthetic fiber structure zone wherein the first zone comprises a layer of spin-knitted fabric and a meltblown fabric layer; a second synthetic fiber structure zone positioned close to the first synthetic fiber structure zone; a third short fiber zone positioned essentially between the first and second zones wherein at least a portion of the first and second zones are intertwined with the third zone.

2. The fabric as claimed in clause 1 characterized in that the third short fiber zone comprises pulp fibers.

3. The fabric as claimed in clause 1 characterized in that the third short fiber zone comprises basic fibers.

4. The fabric as claimed in clause 1 characterized in that the third short fiber zone comprises pulp fibers and basic fibers.

5. The fabric as claimed in clause 1 characterized in that the second zone comprises a layer of spunbond fabric and a meltblown fabric layer.

6. The fabric as claimed in clause 1 characterized in that the third zone comprises particles.

7. The fabric as claimed in clause 1 characterized in that the first and second synthetic fiber structure zones are pre-assembled before being interlaced.

8. A fabric comprising: a first synthetic fiber structure zone; a second synthetic fiber structure zone positioned near the first synthetic fiber structure zone; Y a third short fiber zone further comprising a plurality of layers of cellulosic material and placed essentially between the first and second zones wherein at least a portion of the first and second zones are intertwined with the third zone.

9. A process for producing a fabric, comprising the steps of: providing a first structure zone of pre-assembled synthetic fiber; provide a second synthetic fiber structure zone; providing a third short fiber zone positioned essentially between the first and second zones; hydroentangle the first zone; hydroentangle the second zone;

10. The process as claimed in clause 9 characterized in that the third short fiber zone comprises pulp fibers.

11. A fabric comprising: a first layer of synthetic fiber structure; a second layer of synthetic fiber structure; a third layer of short fiber positioned essentially between the first and second layers wherein at least a part of the first and second parts is interlocked with the third layer and the fabric has a Taber abrasion value of not less than about three in number. essentially in accordance with the test procedure ASTM D-3884-92.

12. The fabric as claimed in clause 11 characterized in that the third layer of short fiber comprises pulp fibers.

13. The fabric as claimed in the clause 11 characterized in that the third layer of short fiber comprises basic fibers.

14. The fabric as claimed in clause 11 characterized in that the third layer of short fiber comprises pulp fibers and basic fibers.

15. The fabric as claimed in clause 11 characterized in that the first layer is a layer of non-woven fabric.

16. The fabric as claimed in clause 11 characterized in that the third short fiber layer comprises particles.

17. The fabric as claimed in the clause 11 characterized in that the first and second layers are pre-assembled before being interlaced.

18. A fabric having a short fiber layer and a basis weight of less than about 6 percent after five washing and drying cycles.

19. A fabric comprising: a first synthetic fiber structure zone further comprising non-crimped fibers; a second synthetic fiber structure zone positioned near the first synthetic fiber structure zone; Y a third short fiber zone positioned essentially between the first and second zones wherein a part of the first and second zones is interlocked with the third zone.

20. A fabric, comprising: a first structure zone of pre-assembled synthetic fiber; a second synthetic fiber structure zone positioned near the first synthetic fiber structure zone; Y a third short fiber zone positioned essentially between the first and second zones wherein at least a portion of the first and second zones are intertwined with the third zone. SUMMARY The present invention desirably provides a fabric that includes a first synthetic fiber structure zone, a second synthetic fiber structure zone, a third short fiber zone. The first zone may include a layer of spin-knitted fabric and a meltblown fabric layer. The second synthetic fiber structure zone may be positioned close to the first synthetic fiber structure zone and the third short fiber zone may be located essentially between the first and second zones. Desirably, the first and second zones are interlocked.