Patent Publication Number: US-2005125908-A1

Title: Physical and mechanical properties of fabrics by hydroentangling

Description:
RELATED APPLICATIONS  
      This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/529,490, filed Dec. 15, 2003; the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD  
      The subject matter disclosed herein relates generally to fabrics having antipilling properties. More particularly, the present subject matter relates to methods for reducing the pilling tendency and improving abrasion resistance of a pillable fabric through the use of a hydroentanglement process.  
     BACKGROUND ART  
      Cotton and cotton blend woven and knitted fabrics have a great tendency to be subjected to pilling or generate so-called “pills”. Many other staple fibers and blends thereof when formed into woven and knitted fabrics also have a tendency to pill. Pills are small bunches or balls of interlaced fluff caused by small bundles of entangled fibers clinging to the cloth surface by one or more surface fibrils. Pilling is typically preceded by fuzz formation and when the material is subject to physical stimulation such as friction, the fuzz or fluff clumps together and is gathered by the fibrils. This undesirable pilling effect occurs with the lapse of time and wear and the tendency to pill generally lowers the commercial value of the fabrics.  
      Given the undesirable nature of a fabric that is subject to pilling, several industrial means have previously been employed in order to prevent such generation of pills. For example, U.S. Pat. No. 3,975,486 to Sekiguchi et al. is directed to a process for producing an antipilling acrylic fiber wherein the steps of coagulation, stretching and relaxing heat treatment are conducted under particular conditions. Likewise, U.S. Pat. No. 4,205,037 to Fujimatsu is directed to acrylic synthetic fibers highly resistant to pilling and having good dyeability produced by specifying the composition of the acrylic polymer, the condition of the primary stretching step, the internal water content of the water-swollen gel fibers, and the conditions of the steps of the drying-compacting, secondary stretching and relaxing heat treatment. Additionally, U.S. Pat. No. 6,051,034 to Caldwell is directed to a method for reducing pilling of cellulosic towels wherein a composition comprising an acidic agent, and optionally a fabric softener, is applied to a pillable cellulosic towel, preferably to the face yarns of the towel. The towel is then heated for a time and under conditions sufficient to effect a controlled degradation of the cellulosic fibers, thereby reducing pilling.  
      While these prior art antipilling techniques have included various methods of reducing the pilling tendency of a fabric using chemical or other process modifications, the need exists for a simpler and more effective finishing method for producing fabrics that have a lower tendency to pill as well as having improved abrasion resistance.  
      As is well known to those skilled in the art, hydroentanglement or “spun lacing” is a process used for mechanically bonding a web of loose fibers to form fabrics directly from fibers. This class of fabric typically belongs to the nonwovens family of engineered fabrics. In conventional hydroentangling processes, webs of nonwoven fibers are treated with high pressure fluid jets while supported on apertured patterning screens. Typically, the patterning screen is provided on a drum or continuous planar conveyor. The underlying mechanism in hydroentanglement is the subjecting of the fibers to a non-uniform pressure field created by successive banks of fine, closely spaced, high-velocity water jets. The impact of the water jets with the fibers, while they are in contact with their neighboring fibers, displaces and rotates the fibers with respect to their neighbors and entangles these fibers with the neighboring fibers. During these relative displacements, some of the fibers twist around others and/or interlock with the neighboring fibers to form a strong structure due to fiber-to-fiber frictional forces. The final outcome is a highly compressed and uniform fabric composed of entangled fibers that is characterized by relatively high strength, flexibility, and conformability.  
      In the past, various efforts have been directed to improving the dimensional stability and physical properties of woven and knitted fabrics through the finishing step of hydroentanglement. In such applications, warp and filling fibers in fabrics are hydroentangled at crossover points to effect enhancement in fabric cover.  
      For example, U.S. Pat. No. 4,695,500 to Dyer et al. is directed to a loosely constructed knit or woven fabric that is dimensionally stabilized by causing staple length textile fibers to be entangled about the intersections of the yarns comprising the fabric. The stabilized fabric is formed by covering one or both sides of the loosely constructed base fabric with a light web of the staple length fibers, and subjecting the composite material to hydraulic entanglement while supported on a porous forming belt configured to direct and concentrate the staple length fibers at the intersections of the yarns comprising the base fabric.  
      U.S. Pat. No. 5,136,761 to Sternlieb et al. is directed to an apparatus and method for enhancement of woven and knit fabrics through the use of dynamic fluids which entangle and bloom fabric yarns. The process includes a two stage enhancement process wherein top and bottoms sides of the fabric are respectively supported and impacted with a fluid curtain included high pressure jet streams. The controlled process energies and use of the support members having open areas which are aligned in offset relation to the process line produces fabrics having a uniformed finish and improved characteristics including edge fray, drape, stability, abrasion resistance, fabric weight and thickness.  
      U.S. Pat. No. 5,761,778 to Fleissner is directed to a method for hydrodynamic entanglement or needling, preferably for binder-free compaction, of fibers of a fiber web, especially a nonwoven fiber web, composed of natural or synthetic fibers of any type, wherein the fibers of the fiber web are entangled and compacted with one another by a plurality of water streams or jets applied at high pressure, with a large number of the water streams or jets striking the fiber web not only in succession but also several times on alternate sides of the web for optimum twisting of the fibers on the top and bottom on the fiber web.  
      Finally, U.S. Pat. No. 6,557,223 to Greenway et al. is directed to improvements in hydroenhancement efficiency obtained by operating a manifold in relative movement to fabric transported under the manifold so as to deliver a low energy to the fabric per pass in multiple passes on the fabric. This process results in greater enhancement efficiency and reduction in wasted energy, and also improves fabric coverage and reduces fabric shrinkage.  
      While these prior art hydroentanglement finishing processes have been directed to improving dimensional stability and physical properties such as edge fray and drape and abrasion resistance, there remains a need to better reduce the pilling tendency and better improve abrasion resistance of a pillable fabric utilizing a physical finishing method that can be employed based upon specific process parameters for generation of an antipilling fabric.  
     SUMMARY  
      In accordance with one embodiment of the present subject matter, a method for reducing the surface pilling tendency and also improving abrasion resistance of a pillable fabric is disclosed.  
      The method includes the step of providing a pillable fabric, the fabric having a top surface, a bottom surface, and side edges and comprising yarns which intersect at crossover points to define interstitial open areas in the fabric and further comprising fibrils extending from at least one of the top and bottom surfaces thereof. The fabric may comprise a woven fabric or a knitted fabric and the fabric yarns may include cotton, polyester, nylon, or blends thereof. The fabric is supported on a support member wherein the support member may comprise a belt, a drum, or a belt/drum combination and may include a pattern of closely spaced fluid pervious open areas to affect fluid passage therethrough. At least one of the surfaces is exposed to a hydroentanglement process to cause entanglement of the fibrils into the interstitial open areas of the fabric. The hydroentanglement process preferably includes imparting an energy in the range of at least about 4000 to 5000 KJoules/Kg of fabric using pressures of 200 bars or greater and includes the use of banks of one or more high pressure water jet manifolds that apply high pressure water jets to the fabric top and/or bottom surfaces.  
      The method further includes reducing the presence of the fibrils on the at least one fabric surface to an amount wherein the pilling production on the fabric is less than about 20% after 5,000 cycles of abrasion on a Martindale device according to ASTM D4970 testing standard. The fibrils are also reduced to an amount wherein the remaining mass of the fabric is at least about 80% to 90% after 50,000 cycles of abrasion on a Martindale device according to ASTM D4966 testing standard.  
      It is therefore an object of the present subject matter to provide a method for reducing the pilling tendency and improving abrasion resistance of a pillable fabric utilizing a finishing hydrointanglement process that results in the removal or entanglement of pilling-causing fibrils such that the tendency of the fabric to pill is greatly reduced, as gauged by pilling production calculated or remaining mass calculated after a set number of abrasion test cycles.  
      An object of the present subject matter having been stated hereinabove, and which is addressed in whole or in part by the present subject matter, other objects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIGS. 1A and 1B  are plan and side views, respectively, of a typical woven product treated in accordance with the process of the present subject matter;  
       FIGS. 2A-2C  are cross-sectional, top plan, and bottom plan views, respectively, of a typical hydroentangling nozzle provided in accordance with the present subject matter;  
       FIGS. 3A and 3B  are schematic drawings of typical hydroentangling configurations in accordance with the present subject matter;  
       FIG. 4  is a line graph depicting the effect of hydroentangling and washing on fabric sample thickness;  
       FIGS. 5A-5F ;  6 A- 6 F; and  7 A- 7 F are enlarged photographic surface views of control fabric samples and samples treated in accordance with the present subject matter;  
       FIGS. 8A-8C  are line graphs depicting weight loss of fabric samples in relation to the number of abrasion cycles conducted;  FIGS. 9A-9H ;  10 A- 10 H;  11 A- 11 F; and  12 A- 12 H are enlarged photographic surface views of control fabric samples and samples treated in accordance with the present subject matter after undergoing abrasion testing;  
       FIGS. 13A and 13B  are line graphs depicting pilling production of fabric samples in relation to the number of abrasion cycles conducted;  
       FIGS. 14A and 14B  are enlarged photographic surface views showing pilling production of a control fabric sample and a sample treated in accordance with the present subject matter, respectively, after undergoing abrasion testing; and  
       FIGS. 15A-15H ;  16 A- 16 F; and  17 A- 17 D are enlarged photographic surface views of control fabric samples and varying fabric composition samples treated in accordance with the present subject matter. 
    
    
     DETAILED DESCRIPTION  
      The subject matter disclosed herein relates to methods for reducing the pilling tendency and improving abrasion resistance of a pillable fabric through the use of a hydroentanglement process. Hydroentanglement finishing at specified process parameters results in the complete removal or entanglement of surface yarn fibrils into the body of the fabric thereby improving the fabric strength while making the surface more smooth. Since the fibrils are no longer available on the fabric surface, they cannot entangle other fibers to form fluff balls or pills. The present subject matter is directed to the use of a high energy hydroentanglement process that has lead to significantly improved physical and mechanical properties of fabrics.  
      Referring to  FIGS. 1A and 1B , a typical pillable fabric  10  treated by the process of the present subject matter is shown by example as a woven fabric, although it is also envisioned that additional fabrics such as knitted fabrics may be treated in accordance with the present subject matter. Fabric  10  has a top surface TS, a bottom surface BS, and side edges E and comprises an open structure comprising warp yarns  12  extending in the machine direction and fill yarns  14  crossing at right angles to the warp yarns. The yarns are not secured at the intersections and consequently are easily displaced by external forces. Fibrils  16  are hook-like projections extending from yarns  12 ,  14  which extend away from top and bottom surfaces TS, BS of fabric  10  and contribute to the pilling properties of the fabric.  
      Yarns  12 ,  14  of fabric  10  may be selected from cotton, polyester, nylon, and other yarn compositions known to those of skill in the art. Additionally, blends of various fiber types may be used to form the fabric yarns.  
      Referring now to  FIGS. 2A-2C , a typical hydroentangling nozzle assembly  20  provided in accordance with one aspect of the present subject matter is shown in cross-section, top plan view, and bottom plan view, respectively. Hydroentangling nozzles are traditionally made up of two sections: a cylindrical section  22  (capillary part) with a typical diameter of about 120 microns, connected to a slim cone  24  with a side angle extending approximately 18 degrees outwardly from the side of cylindrical section  22 . Hydroentangling water jets are issued from thin-plate strips  26  having 1600-2000 orifices per meter and produce operating pressures ranging from  10  bars to over 1000 bars.  FIG. 2B  depicts a top view of strip  26  wherein cylindrical section  22  of the orifice is shown, and  FIG. 2C  depicts a bottom view of strip  26  wherein cone  24  of the orifice is shown.  
      The amount of energy imparted to the fabric during hydroentanglement can be very significant. Energy calculation is based on Bernoulli equation that ignores viscous losses throughout the system. Having the hydroentangling manifold&#39;s pressure as P 1 , the water jet velocity can be calculated as: 
 
 V   1 ={square root}{square root over (2 P   1 /ρ)}
 
 Where ρ=998.2 kg/m 3  (the density of water at room temperature), P 1  is the pressure in Pa, and V 1  is in m/s. (Note that 1 bar is equal to 10 5  Pa.) 
 
      Rate of energy transferred by the water jet is calculated as follows:  
       E   =       π   8     ⁢           ⁢   ρ   ⁢           ⁢     d   2     ⁢     C   d     ⁢     V   3           
 
 Where d is the diameter of the orifice capillary section in millimeters (assumed in a Hyrdocalculator to be 0.127 mm), C d  is the discharge coefficient, and E is energy rate in J/s. 
 
      Specific energy is calculated based on the following formula:  
         SE   ⁡     [     J     kg   fabric       ]       =     E   M         
 
 Where M is the mass flow rate of the fabric in Kg/s and is calculated as follows 
          M=Samplewidth[m]×Basisweight[kg/m 2 ]×Beltspeed[m/s]       

      Therefore, SE will be obtained in Joules per kg of fabric.  
      With reference to  FIGS. 3A and 3B , pilling tendency reduction and abrasion resistance enhancement of fabric  10  is accomplished by entanglement and intertwining of fibrils on the surfaces of fabric  10  by hydroentangling finishing systems  30  and  40  wherein fabric  10  is supported by support members such as a drum  32  or an endless belt  34  or a combination thereof and impacted with a curtain of water jets under controlled process energies. Support members  32 ,  34  may include a pattern of closely spaced fluid pervious open areas to affect fluid passage therethrough and are designed to process fabric  10  through the system at a controlled rate.  
      Since knitted fabric has a tendency to shrink during exposure to water processes, it is further envisioned by the present subject matter that the side edges of the knitted fabric may be restrained during the hydroentanglement process in order to reduce the potential for shrinkage during processing (not shown). The restraining of the fabric edges may be accomplished by clamps along the conveyor system or by other mechanisms known to those of skill in the art.  
      Hydroentanglement system  30  further includes preferably two banks  36 A,  36 B of one or more high pressure water jet manifolds  38  oriented in a perpendicular direction relative to movement of fabric  10 . Manifolds  38  may typically be spaced several inches apart and include a plurality of closely aligned and spaced nozzles  20 . Hydroentanglement system  40  also preferably includes two banks  46 A,  46 B of one or more high pressure water jet manifolds  38 . It is envisioned that banks  36 A,  36 B ( FIG. 3A ) with manifolds  38  may be arranged along support members  32  of system  30  in order to impart pilling reduction enhancement to both surfaces TS, BS of fabric  10  with one pass direction. Banks  46 A,  46 B with manifolds  38  may be arranged along support members  32 ,  34  of system  40  ( FIG. 3B ) to impart the same effects. For example, as shown in  FIGS. 3A and 3B , hydroentanglement systems  30  and  40  may comprise one bank  36 B,  46 B of three manifolds  38  that impart pilling reduction enhancement to fabric top surface TS and another bank  36 A,  46 A of two manifolds  38  that impart pilling reduction enhancement to fabric bottom surface BS.  
      Each manifold  38  may comprise approximately 1600 to 2000 fluid nozzle orifices  20  per meter, wherein each nozzle  20  has an orifice diameter of approximately 80-300 microns, preferable 120 microns. Water pressure in each manifold  36  may be between 10 bars and 1000 bars depending on the amount of nozzle orifices  20  present and the size of the particular orifices. For optimum results in pilling reduction and abrasion resistance, it has been discovered that hydroentanglement systems  30  and  40  should each impart an energy in the range of at least about 4000 to 5000 KJoules/Kg of fabric using pressures of 200 bars or greater during processing of fabric  10 .  
     EXAMPLES  
     Test Methods and Standards Reporting  
      Experiments were conducted on sample fabrics using hydroentanglement system  40  (see  FIG. 3B ) in order to determine the effect on mechanical properties (pilling, abrasion, etc.) and hand improvement of a finished textile utilizing the finishing concept of the present subject matter. Different settings of the hydroentanglement process were tested for physical properties with the results presented below.  
      The samples exposed to hydroentangling were subjected to the hydroentangling process as described hereinabove. The hydroentangling process system comprised one bank of three (3) water jet manifolds that enhanced the top surface (face) of the fabric and one bank of two (2) water jet manifolds that enhanced the bottom surface (back) of the fabric. The manifold pressures of the systems were as shown in Table 1.  
               TABLE 1                          Water Jet Pressures                             Manifold Position   Beam Pressure (bar)                                         Manifold 1 - Face pre-wet   60           Manifold 2 - Face entangling   150           Manifold 3 - Face entangling   200           Manifold 4 - Back entangling   150           Manifold 5 - Back entangling   200                      
 
      The determination of the resistance to the formation of pills, abrasion resistance, and other related surface changes on textile fabrics is governed by testing standards ASTM D4966 for abrasion resistance and ASTM D4970 for pilling. The testing procedures utilize the Martindale tester and is generally applicable to all types of fabrics.  
      In general, under the ASTM D4966 test, abrasion resistance is measured by subjecting the specimen to rubbing motion in the form of a geometric figure under known conditions of pressure and abrasive action. Resistance to abrasion is evaluated by the determination of mass loss as the difference between the masses before and after abrasion (expressed as a percentage of the before abrasion mass) and an end point when a hole appears in the fabric sample.  
      In general, under the ASTM D4970 test, resistance to pill formation testing involves mounting the fabric on the Martindale tester wherein the face of the test specimen is rubbed against the face of the same mounted fabric in a geometric pattern. The test specimen is compared with visual standards of actual fabrics or photographs of fabrics showing a range of pilling resistance in order to gauge the degree of fabric pilling or surface appearance change. The observed resistance to pilling is reported using an arbitrary scale from 5 (no pilling) to 1 (very severe pilling) as described in more detail hereinbelow.  
     Example I  
     The Effect of the Tightness Factor  
      Referring to  FIGS. 5-14 , experiments were first run on a single type of fiber composition at various fiber tightness factors. Due to its vast usage in the garment industry, the sample textile fabric chosen consisted of a single jersey structure knitted on a circular knitting machine (gauge 18) incorporating yarns of 100% cotton (Ne 18/1 cp ringspun; 35 Tex). Three tightness factor fabrics  15  were used and various samples were either washed or not washed and were broken down into groups including no hydroentangling passes, one hydroentangling pass, and two hydroentangling passes. The samples were identified as shown in Table 2.  
               TABLE 2                          Descriptions of Sample Set                                             Surface       # of           Sample   Tightness   Mass   Thickness   Hydroentangling       ID   factor   (g/m 2 )   (mm)   Passes   Wash/Dry               C16.00   16.00   183   0.597   0   No       NH       C16.00   16.00   183   0.597   1   No       1P       C16.00   16.00   183   0.597   1   Yes       1P W       C16.67   16.67   188   0.610   0   No       NH       C16.67   16.67   188   0.610   1   No       1P       C16.67   16.67   188   0.610   1   Yes       1P W       C17.56   17.56   199   0.648   0   No       NH       C17.56   17.56   199   0.648   1   No       1P       C17.56   17.56   199   0.648   2   No       2P       C17.56   17.56   199   0.648   1   Yes       1P W                  
 
 Effect on Thickness 
 
       FIG. 4  graphically depicts the effect of hydroentangling and washing on the thickness of the various samples. The non-hydroentangled/non-washed samples had the greatest sample thicknesses ranging from approximately 0.6 mm to 0.65 mm, while the hydroentangled/non-washed samples had the lowest sample thicknesses ranging from approximately 0.56 mm to 0.58 mm. Washing of the hydroentangled samples generally increased sample thickness slightly.  
      Effect on Surface Properties  
      As shown pictorially in  FIGS. 5-7 , in all three sets of fabrics, more loose surface fibers (fibrils) are found in the non-hydroentangled fabrics, as the structure is more loose in general. Surface fibrils in the hydroentangled fabrics are more compact and are entangled into the interstices between the yarns or  15  cut from the fabric surface altogether, thus allowing the fabric structures to be more apparent in the hydroentangled fabrics due to the absence of multiple loose surface fibers.  
       FIGS. 5A, 5  C, and  5  E show the  16  tightness factor non-hydroentangled fabric at magnifications of 35×, 100×, and 300×, respectively.  FIGS. 5B, 5D , and  5 F show the  16  tightness factor one-pass hydroentangled fabric at magnifications of 35×, 100×, and 300×, respectively.  
       FIGS. 6A, 6C , and  6 E show the  16 . 67  tightness factor non-hydroentangled fabric at magnifications of 35×, 100×, and 300×, respectively.  FIGS. 6B, 6D , and  6 F show the 16.67 tightness factor one-pass hydroentangled fabric at magnifications of 35×, 100×, and 300×, respectively.  
       FIGS. 7A, 7C , and  7 E show the 17.56 tightness factor non-hydroentangled fabric at magnifications of 35×, 100×, and 300×, respectively.  FIGS. 7B, 7D , and  7 F show the 17.56 tightness factor one-pass hydroentangled fabric at magnifications of 35×, 100×, and 300×, respectively.  
      Effect on Abrasion Resistance (Mass Loss)  
      With reference for  FIGS. 8A-8C , three fabric samples of three (3) different tightness factors showed increases in abrasion resistance when subjected to hydroentanglement, indicated by the significantly lower weight reduction (i.e., more remaining mass) after exposure to up to 70,000 cycles on the Martindale tester. Higher abrasion resistance in hydroentangled samples vs. non-hydroentangled samples was shown by reduced mass loss and longer cycles needed to make the first hole in the fabrics.  
      Specifically,  FIG. 8A  depicts abrasion testing on fabric samples with a 16 tightness factor. The non-hydroentangled sample (NH) showed a steep decline in remaining mass reaching around 75% remaining mass when a hole developed in the fabric after approximately 35,000 cycles. The one-pass non-washed hydroentangled sample (1P) showed a remaining mass of approximately 87% when a hole developed in the fabric after approximately 50,000 cycles. The one-pass washed hydroentangled sample (1PW) showed a gradual decline in remaining mass reaching around 82% when a hole developed in the fabric after approximately 70,000 cycles.  
       FIG. 8B  depicts abrasion testing on fabric samples with a 16.67 tightness factor. The non-hydroentangled sample (NH) showed a steep decline in remaining mass reaching around 73% remaining mass when a hole developed in the fabric after approximately 36,000 cycles. The one-pass non-washed hydroentangled sample (1P) showed a remaining mass of approximately 91% when a hole developed in the fabric after approximately 50,000 cycles. The one-pass washed hydroentangled sample (1PW) showed a gradual decline in remaining mass reaching around 83% when a hole developed in the fabric after approximately 52,000 cycles.  
       FIG. 8C  depicts abrasion testing on fabric samples with a 17.56 tightness factor. The non-hydroentangled sample (NH) showed a steep decline in remaining mass reaching around 78% remaining mass when a hole developed in the fabric after approximately 36,000 cycles. The one-pass non-washed hydroentangled sample (1P) showed a remaining mass of approximately 83% when a hole developed in the fabric after approximately 52,000 cycles. The two-pass non-washed hydroentangled sample (2P) showed a remaining mass of approximately 83% when a hole developed in the fabric after approximately 48,000 cycles. As shown pictorially in  FIGS. 9-12 , representing two (2) types of tightness factor fabrics being hydroentangled and non-hydroentangled, as the abrasion cycles increased, fibers in both series of fabrics were cut and fibrillated. However, while the cut ends of the fibers in the non-hydroentangled fabrics are protruded from the surface and can lead to generation of pilling, the cut ends of the fibers in the hydroentangled fabrics remained entangled into the fabric interstices so as to not contribute to pilling tendency.  
      Specifically,  FIGS. 9A-9H  show the fabric surface of the 16 tightness factor non-hydroentangled fabric at magnifications of 35× and 100× at abrasion cycles of 0, 2000, 20000, and 35000.  
       FIGS. 10A-10H  show the fabric surface of the  16  tightness factor one-pass hydroentangled fabric at magnifications of 35× and 100× at abrasion cycles of 0, 2000, 20000, and 35000.  
       FIGS. 11A-11F  show the fabric surface of the 17.56 tightness factor non-hydroentangled fabric at magnifications of 35× and 100× at abrasion cycles of 0, 20000, and 35000.  
       FIGS. 12A-12H  show the fabric surface of the 17.56 tightness factor one-pass hydroentangled fabric at magnifications of 35× and 100× at abrasion cycles of 0, 2000, 30000, and 60000.  
      The markedly improved abrasion resistance of fabric samples exposed to the hydroentangling process of the present invention can be attributed to the entanglement or removal of the surface fibrils. This effect leads to a smoother fabric surface and a reduction in mass loss of the fabric during abrasion testing.  
      Effect on Pilling  
      Tests were conducted to determine the resistance of the fabric samples to form pills on the fabric surface. The Martindale tester was used to run through approximately 6000 cycles, wherein the samples were intermittingly inspected and a standard pilling rating was assigned to the samples according to the rating scale shown in Table 3.  
               TABLE 3                          Pilling Rating Scale                     Rating   Surface Evaluation               5   No pilling       4   Slight pilling       3   Moderate pilling       2   Severe pilling       1   Very severe pilling                  
 
      With reference to  FIGS. 13A and 13B , the pilling tendency of the fabrics (16 tightness factor in  FIG. 13A and 17 . 56  tightness factor in  FIG. 13B ) were greatly reduced after hydroentanglement, and even more so after washing and/or multiple passes through the hydroentanglement process. The non-hydroentangled fabrics samples (NH) showed very severe pilling after only approximately 150 cycles, while the hydroentangled fabrics (1P) displayed only slight pilling even after 5000 cycles. The two-pass (2P) hydroentanglement fabric sample (see  FIG. 13B ) showed no pilling until approximately 2000 cycles, when it began showing slight pilling.  
       FIGS. 14A and 14B  pictorially display the pilling effect after 5000 cycles on the Martindale device.  FIG. 14A  shows a cotton knitted non-hydroentangled fabric sample after 5000 cycles. The sample displayed very significant pilling (see also  FIGS. 13A and 13B ), due to the presence of surface fibrils.  FIG. 14B  shows a cotton knitted hydroentangled fabric sample after 5000 cycles. The sample displayed only slight pilling, hardly noticeable to the viewer (see also  FIGS. 13A and 13B ).  
      As shown in  FIGS. 13A, 13B  and  14 A,  14 B, the pilling behavior is strongly improved in fabric samples exposed to the hydroentangling process of the present subject matter. Similar to the markedly improved abrasion resistance, the pilling resistance of the hydroentangled fabrics can be attributed to the specific energy ranges of the present subject matter which cause a lack of fibrils at the surface of the fabric either through entanglement of the fibrils into the fabric interstices or perhaps removal of the fibrils altogether. The smooth, fibril-less fabric surface results in a fabric which has great abrasion resistance and a tendency not to produce pills.  
     Example II  
     The Effect of Fiber Composition and Hydroentangling Parameters  
      Referring now to  FIGS. 15-17 , experiments were additionally run on fabrics of various compositions and at varying hydroentangling processing parameters. The textile fabric structure comprised a single jersey construction with a 17.5 tightness factor. The fabric compositions were formed as shown in Table 4 and the samples and hydroentangling parameters (for those samples that were hydroentangled) were identified as shown in Table 5.  
               TABLE 4                          Fabric Compositions                                 Fiber   Tightness factor   Surface Mass(g/m 2 )                       100% cotton   17.5   229           50/50 Cotton/polyester   17.5   216           100% Polyester   17.5   199                      
 
                     TABLE 5                          Descriptions of Sample Set and Hydroentangling Parameters                                                                                 Belt   Number           Sample   Pressure   Pressure   Pressure   Pressure   Pressure   Belt type   speed   of       ID   #1(bar)   #2(bar)   #3(bar)   #4(bar)   #5(bar)   Mesh/inch   (m/min)   Passes   Fiber               1a   60   150   200   150   200   100   10   1   Cotton       1b   60   150   200   150   200   100   10   2   Cotton       1c   60   150   200   150   200   100   10   3   Cotton       2a   60   150   200   150   200   100   10   1   Co/Poly       3a   60   150   200   150   200   100   10   1   Polyester       4a   60   150   200   150   200   100   50   1   Cotton                    
 Effect on 100% Cotton Fabrics 
 
       FIGS. 15A-15H  pictorially display the surface structure of a variety of the 100% cotton jersey fabric samples.  
      Specifically,  FIGS. 15A and 15B  show the surface image of a non-washed, non-hydroentangled 100% cotton jersey fabric at 35× and 100× magnification, respectively, and  FIGS. 15C and 15D  show the surface image of a washed, non-hydroentangled 100% cotton jersey fabric at 35× and 100× magnification, respectively. While the washed sample showed some fibrillation of the fibers, neither of these non-hydroentangled fabric samples showed substantial changes in the loose surface fibers as the structure in general remained in a loose state.  
       FIGS. 15E and 15F  show the surface image of a non-washed, one-pass hydroentangled 100% cotton jersey fabric (sample 1a) at 35× and 100× magnification, respectively, and  FIGS. 15G and 15H  show the surface image of a non-washed, two-pass hydroentangled 100% cotton jersey fabric (sample 1b) at 35× and 100× magnification, respectively. Each of these samples showed extensive fibrillation of the cotton fibers and entanglement of the surface fibers into the fabric interstice structure or removal of the surface fibers altogether. The two-pass hydroentangled fabric sample showed even more fibrillation of the fibers over the one-pass hydroentangled sample, along with additional flattening of the structure.  
      Effect on 50/50 Cotton/Polyester Fabrics  
       FIGS. 16A-16F  pictorially display the surface structure of a variety of the 50/50 cotton/polyester jersey fabric samples.  
      Specifically,  FIGS. 16A and 16B  show the surface image of a washed, non-hydroentangled 50/50 cotton/polyester jersey fabric at 35× and 100× magnification, respectively. While some fibers were fibrillated, the fabric sample showed no substantial changes in the loose surface fibers.  
       FIGS. 16C and 16D  show the surface image of a non-washed, one-pass hydroentangled 50/50 cotton/polyester jersey fabric (sample 2a, non-washed) at 35× and 100× magnification, respectively, and  FIGS. 16E and 16F  show the surface image of a washed, one-pass hydroentangled 50/50 cotton/polyester jersey fabric (sample 2a, washed) at 35× and 100× magnification, respectively. Each of these samples showed extensive fibrillation of the cotton fibers and entanglement of the surface fibers into the fabric interstice structure or removal of the surface fibers altogether.  
      Effect on 100% Polyester Fabrics  
       FIGS. 17A-17D  pictorially display the surface structure of a variety of the 100% polyester jersey fabric samples.  
      Specifically,  FIGS. 17A and 17B  show the surface image of a washed, non-hydroentangled 100% polyester jersey fabric at 35× and 100× magnification, respectively. The fabric sample showed no substantial changes in the loose surface fibers.  
       FIGS. 17C and 17D  show the surface image of a washed, one-pass hydroentangled 100% polyester jersey fabric (sample 3a, washed) at 35× and 100× magnification, respectively. The sample showed extensive entanglement of the surface fibers into the fabric interstice structure or removal of the surface fibers altogether.  
      The present subject matter reflects a use of specific ranges of hydroentanglement energies to produce a fabric containing unexpectedly and surprisingly advantageous properties of reduced surface pilling and improved abrasion resistance.  
      It will be understood that various details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation, as the invention is defined by the claims as set forth hereinafter.