Abstract:
A thermoplastic binder applied in the vicinity of the roots of a pile surface structure, typically before stitching, is raised above its melting point but below the critical exposure temperature that can adversely affect the properties of the material forming the pile elements. While at this elevated temperature the pile surface structure is mechanically flexed, as by repeatedly bending the backing with the pile loops thereon into and out of its plane. This flexing action assists the molten (but not freely flowing) binder to propagate into the roots of the pile elements and into the interstices between the fibers forming the same.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a divisional of co-pending application Ser. No. 09/727,207, originally filed on Nov. 30, 2000, in the name of Dimitri Peter Zafiroglu. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a method for bonding of stitched carpets.  
         [0004]     2. Description of the Prior Art  
         [0005]     Published application WO 00/52246, the PCT counterpart of co-pending application U.S. application Ser. No. 09/260,749, filed Mar. 2, 1999 and assigned to the assignee of the present invention, discloses a stitched pile surface structure having a thermoplastic binder disposed in the vicinity of the roots of the pile elements. To be most effective the binder material should penetrate into the roots of the pile elements and into the interstices between the filaments forming the same.  
         [0006]     Disposing the binder material in these locations requires some care, as the operating temperature window for binder processing is, in most cases, relatively narrow. On one hand the binder must have a melting temperature that is sufficiently high so that the binder remains set when exposed to the expected maximum end-use temperatures for a pile surface structure, typically in the vicinity of eighty degrees Centigrade (80° C.). On the other hand, processing the binder at too high a temperature may negatively affect the material from which the pile elements are made. For example, in the case of nylon pile elements, temperatures in excess of approximately one hundred twenty degrees Centigrade (120° C.) may adversely affect certain properties of the nylon material forming the pile elements.  
         [0007]     Accordingly, it is not simply a matter of raising the temperature of the binder to an extent that the binder freely flows into the desired locations in the pile surface structure.  
         [0008]     In view of the narrow temperature operating window it is imperative that physical pressure be exerted while the thermoplastic binder is molten but not freely flowing, to help the binder propagate into the desired bond areas.  
         [0009]     It should be noted that care must also be exercised when applying pressure to the pile surface structure.  
         [0010]     Applying nip pressure, by pressing from above and below with pressure rolls, is a mechanical expedient occasionally used in the industry to apply pressure to a pile structure. However, nip pressure may have the undesirable side effect of “matting”, or “crushing”, the pile.  
         [0011]     Accordingly, in view of the foregoing it is believed desirable to provide a process, which utilizes a binder material with a relatively low melting point so that the binder can be processed at a temperatures under the critical temperatures that adversely affect the pile material. The process should, at the same time, be practiced in a physical environment in which pressure may be brought to bear on the pile to cause the thermoplastic binder to propagate without crushing of the pile. It is believed to be of further advantage to achieve this result while the pile surface structure is subjected to usual industry finishing processes, such as scouring, dyeing and drying.  
       SUMMARY OF THE INVENTION  
       [0012]     In accordance with the present invention a thermoplastic binder is applied in the vicinity of the roots of a pile surface structure, typically before stitching. The binder material is raised above its melting point but below the critical exposure temperature that can adversely affect the properties of the material forming the pile elements. While at this elevated temperature the pile surface structure is mechanically flexed, as by repeatedly bending the backing with the pile loops thereon into and out of its plane. This flexing action assists the molten (but not freely flowing) binder to propagate into the roots of the pile elements and into the interstices between the fibers forming the same. In the preferred implementation the process is practiced using conventional dyeing systems wherein the temperature is customarily raised and flexing customarily employed to promote dye propagation and dye setting. The process may also be practiced in equipment, which flexes the heated pile structure over small-diameter rolls or bars.  
         [0013]     Optionally, the pile structure may be scoured before the flexing step, and/or, subjected to a final heating step without flexing. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The invention will be more fully understood from the following detailed description, taken in connection with the accompanying drawings which form a part of this application, and in which:  
         [0015]      FIG. 1  is stylized view of a finished pile surface structure manufactured in accordance with the process of the present invention;  
         [0016]      FIGS. 2A through 2E  are stylized block diagrammatic views illustrating various embodiments of the process of the present invention;  
         [0017]      FIGS. 3A through 3H  are stylized views illustrating the unfinished pile surface structure at reference point R along the process wherein each unfinished pile surface structure has a thermoplastic binder present in the vicinity of the root portions thereof;  
         [0018]      FIGS. 4 and 5  are stylized diagrammatic views illustrating apparatus for mechanically flexing the pile surface structure into and out of the plane of the backing at a temperature greater than the melting point of the binder. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     Throughout the following detailed description similar reference numerals refer to similar elements in all figures of the drawings.  
         [0020]     With reference to  FIG. 1  shown is a stylized diagrammatic view of a portion of a finished, stitched pile surface structure generally indicated by the reference character  10  manufactured in accordance with the process of the present invention.  
         [0021]     The pile surface structure  10  includes a backing  14  having an upper surface  14 S and a lower surface  14 L thereon. An array of pile yarn elements  16  is stitched to the upper surface  14 S of the backing  14 .  
         [0022]     The pile yarn elements  16  are formed using a stitching apparatus of the type having a sinker bar carrying an array of sinker fingers. Details of a suitable stitching apparatus are set forth in published application WO 00/52246, the PCT counterpart of co-pending application U.S. application Ser. No. 09/260,749, filed Mar. 2, 1999 and assigned to the assignee of the present invention.  
         [0023]     Briefly summarized, the stitching apparatus used to form the pile surface structure includes a transversely extending sinker bar from which extends a plurality of sinker fingers. The sinker fingers project forwardly past a needle plane defined by the reciprocating operation of an array of stitching needles. The backing  14  is conveyed through the stitching apparatus so that successive transversely extending regions of the backing  14  are advanced into the needle plane. Stitching threads from adjacent thread-carrying guide bars are successively looped around respective spaced locations on a length of yarn dispensed from a yarn guide bar.  
         [0024]     As successive transverse regions of the backing  14  move into the needle plane pairs of adjacent first and second needles are actuated and raised through the backing to positions above the sinker fingers. In the raised positions the adjacent needles respectively successively engage the looped stitching threads and draw these stitching threads toward the backing  14 . These actions draw the length of dispensed yarn to the surface  14 S of the backing  14 .  
         [0025]     As the adjacent needles draw the threads downwardly toward the backing  14  the dispensed length of yarn becomes trained over the surface of the sinker finger, thereby forming a laid-in pile yarn element  16  overlying above the first surface  14 S of the backing  14 . Continued downward movement of each needle through the backing  14  forms an underlap portion  20 U of a chain stitch  20 . The underlap  20 U of the stitch  20  secures the pile yarn element  16  against the first surface  14 S. Each stitch  20  also includes an interlockable looped overlap portion  20 L that lies against the bottom surface  14 B of the backing  14 . Sequential overlap portions  20 L typically interlock with each other, chain-fashion, longitudinally along the bottom surface  14 B of the pile surface structure  10 .  
         [0026]     In a loop pile embodiment illustrated in  FIG. 1  the pile element  16  has the form of an inverted loop  16 L that overlies the top surface  14 S of the backing between a first generally U-shaped root portion  16 R- 1  located in a first longitudinally extending stitch line and a second generally U-shaped root portion  16 R- 2  located in a second longitudinally extending stitch line. The root portions  16 R- 1 ,  16 R- 2  are each held against the top surface  14 S of the backing  14  by the underlap portion  20 U of one of the stitches  20 . The underlaps  20 U constrict the pile yarn to form distended regions  16 D in the vicinity of each underlap  20 U.  
         [0027]     As is illustrated by the dot-dash lines in  FIG. 1  the pile element  16  may also be implemented in a cut pile form. The cut pile is produced by cutting the loop  16 L of the pile element near the apex of the loop, resulting in the formation of a pair of cut pile elements. Each cut pile element has one generally U-shaped root portion, e.g. root  16 R- 1 , in the vicinity of each underlap  20 U of the stitching thread. Two substantially erect branches  16 B- 1 ,  16 B- 2  extend from the U-shaped root portion  16 R- 1 . Expressed alternatively, a loop pile yarn element may be considered as the pile structure defined by the integral jointure of one branch of a cut pile element lying in a first stitch line to a branch emanating from a cut pile element disposed in an adjacent stitch line.  
         [0028]     A binder material assists in securing the pile element  16  to the upper surface  14 S of the backing  14 . In  FIG. 1  the binder material in its final solidified condition is illustrated by the hatched shading  24 S. As seen from  FIG. 1  the major portion of the final solidified binder material  24 S is concentrated above the backing  14  in the vicinity of the U-shaped root portions of the pile elements  16 , primarily surrounding the underlaps  20 U holding the pile element  16  to the top surface  14 S of the backing  14 .  
         [0029]     More particularly, the final solidified binder material  24 S is concentrated: 
        (a) in the distended regions  16 D of the pile element formed by the constricting underlaps  20 U:     (b) in the constricted portion of the roots  16 R- 1 ,  16 R- 2  near the underlaps  20 U;     (c) in the thread forming the underlaps  20 U;     (d) in the space between distended regions  16 D;     (e) in the space between distended regions  16 D and the first surface  14 S of the backing  14 ; and     (f) near the upper surface  14 S of the backing  14  adjacent to the roots  16 R- 1 ,  16 R- 2  of the pile elements  16 . 
 
 It is noted that some final solidified binder material  24 S may be incidentally present in regions of the backing spaced from the roots. 
       
 
         [0036]     Substantially all of the filaments of the pile yarn and the interstices therebetween in the distended regions  16 D of the root portions of substantially all of the pile elements  16  have set binder material  24 S present thereon. At least the upper two-thirds of each pile yarn element  16  remains substantially free of binder material.  
         [0037]      FIGS. 2A through 2E  are stylized block diagrammatic views illustrating various embodiments of the process of the present invention.  
         [0038]     The initial step in accordance with the present invention is the application of a thermoplastic binder material having a predetermined melting point in the vicinity of the root portion of the loops. This binder application is generally indicated throughout these  FIGS. 2A-2E  by the reference character  26 . The particular mode of application depends upon the particular physical form taken by the binder material.  
         [0039]     Whatever its physical form, in the preferred instance the binder material is an amorphous binder. Typically, the melting point of the amorphous thermoplastic binder lies in the range from about eighty-five to about one hundred degrees Centigrade (85-100° C.). An amorphous thermoplastic binder tends to flow more readily than a thermoplastic binder in the form of film or strands.  
         [0040]     As will be developed the amorphous thermoplastic binder is most preferably in the physical form of a powder having particles with sizes in the range from about one (1) to about five hundred (500) microns. A suitable amorphous thermoplastic binder material useful for the purpose here described is that available from EMS Corporation, Ems Switzerland, as Griltex 1500A P-1 powder.  
         [0041]     The most preferred technique of binder application is to apply an amorphous binder material to the surface  14 S of the backing  14  in the form of a dry powder. The binder powder is scattered from a dispenser  28  onto the upper surface  14 S of the advancing backing  14 . Suitable for use as the dispenser is a scattering device manufactured and sold by the Herbert Meyer Company, Roetz, Germany.  
         [0042]     It lies within the contemplation of the present invention to mix with the binder powder a small percentage of a secondary thermoplastic adhesive powder. Preferably the secondary thermoplastic adhesive powder also has particle sizes in the range from about one (1) to about five hundred (500) microns and a melting point in the range from about five (5) to about twenty (20) degrees Centigrade ° C. below the melting point of the primary binder powder. The secondary thermoplastic adhesive powder is on the order from about five percent (5%) to about twenty percent (20%) of the weight of the primary binder. A suitable thermoplastic material useful for the secondary thermoplastic adhesive powder is that available from EMS Corporation, Ems Switzerland, as Griltex 1531A.  
         [0043]     After the primary binder powder (or the mixture of the primary binder powder and the secondary thermoplastic adhesive powder) is applied the backing is heated to a predetermined temperature. This heating step is generally indicated by the reference character  30 . Any suitable heating device may be used to implement the heating step, such as an oven, a radiant heater or a hot gas heater. The predetermined temperature to which the backing  14  is heated is dependent upon whether the binder powder alone or the powder mixture is applied to the surface  14 S. If only a primary binder powder is applied to the surface  14 S, the backing  14  is heated to a temperature slightly (on the order if a few degrees) greater than the melting point of the primary binder powder, thus melting the primary powder binder and attaching the same to the backing  14 . After solidifying downstream of the heating device a layer of the primary powder binder (indicated by the reference character  24 L in  FIG. 3A ) is attached over the surface  14 S of the backing  14 .  
         [0044]     If a mixture of a primary binder powder and a secondary thermoplastic adhesive powder is applied to the surface  14 S, the backing  14  is heated to a temperature slightly greater than the melting point of the secondary thermoplastic adhesive powder but less than the melting point of the primary binder. Heating to this temperature melts the secondary thermoplastic adhesive powder. When solidified after leaving the heating device a layer of the primary powder binder supported in an adhesive matrix (indicated by the reference character  24 L′ in  FIG. 3B ) is attached over the surface  14 S of the backing  14 .  
         [0045]     The backing  14  with the binder material  24 L,  24 L′ applied to the surface  14 S thereof is next stitched, as indicated by the reference character  32 , using a stitching apparatus such as the one described above. In the stitching apparatus the pile elements  16  are formed on the backing  14  in the manner above discussed. Accordingly, as illustrated in  FIG. 3A  or  3 B, at the reference point R at the outlet of the stitching apparatus the upper surface  14 S of the backing  14  has an array of pile elements  16  formed thereover. The root portions  16 R of the pile elements  16  are attached to the backing  14  by the underlaps  20 U of the stitches  20 . The surface  14 S of the backing has a layer  24 L,  24 L′, as the case may be, of binder disposed thereon.  
         [0046]     In accordance with the present invention, after formation, the pile surface structure  10  is mechanically flexed into and out of the plane of its backing  14  at a temperature greater than the melting point of the binder. This mechanical flexing at the elevated temperature is indicated by the reference character  34 . The term “mechanically flexing” (or a similar term) of the pile surface structure  10  into and out of the plane of its backing  14  is meant to denote repeatedly folding and counter-folding the backing in such a way that portions of the pile surface and portions of the backing are alternatively brought toward and away from each other.  
         [0047]     The elevated temperature causes the binder material to melt. The flexing action imposes mechanical forces on the then-molten binder causing it to flow and to penetrate into the root portions of the pile loops in the vicinity of the stitching thread underlaps holding the same to the backing and into the interstices between the filaments forming the pile loops.  
         [0048]     In one embodiment of the invention the temperature at which the flexing occurs is maintained by immersing the pile surface structure  10  in a liquid having a temperature greater than the melting point of the binder. An example of a suitable apparatus  40  in which the immersion and flexing occurs is illustrated in diagrammatic form in  FIG. 4 . The apparatus  40 , generally similar to a standard Beck dye bath apparatus, includes an enclosure  42  having a pair of agitating rotors  44  rotationally mounted therein. The rotors  44  may be any suitable configuration to effect the action to be described. In  FIG. 4  the rotors  44  are each substantially diamond-shaped in cross section.  
         [0049]     In operation, a length of pile surface structure  10  is formed into an endless loop that is trained over the rotors  44 . Preferably, the lower surface  14 L of the backing  14  engages against the rotors  44  to avoid crushing of the pile elements  16  on the upper surface  14 S of the backing. Portions of the pile surface structure  10  are folded and counter-folded upon themselves both upstream and downstream of each rotor. Some folding of the pile surface structure, such as that indicated by the reference character  46 F, causes the pile elements on portions of the pile surface structure  10  to be brought toward each other while portions of the backing are simultaneously brought away from each other. Alternatively, counter-folding, such as that indicated by the reference character  46 C, brings portions of the backing toward each other while pile elements on the opposite surface of the backing are brought away from each other.  
         [0050]     The folded and counter-folded portions of the pile structure are submerged in the liquid  48  disposed in the lower portion of the enclosure  42 . The liquid  48  is maintained at the desired temperature sufficient to melt the binder material. As the rotors  44  rotate in the directions indicated by the reference arrows  50 , the pile surface structure  10  is drawn from the liquid bath  48  and is continuously flexed as the backing  14  of the pile structure  10  folds and unfolds into and out of the liquid bath  48 . Each progressive reversal of direction in the backing  14 , both within the bath  48  as well as over the rotors  44 , flexes the backing  14  into and out of its plane. This mechanical flexing action creates pressure in the pile elements  16  and causes the then-molten binder to flow into the root portion of the pile loops and into the interstices of filaments forming the pile elements. The pile surface structure  10  is subjected to the treatment described for a suitable period of time, e.g., in the range from about several minutes to several hours.  
         [0051]     As may be appreciated, a standard Beck dye chamber may be used to effect suitable mechanical flexing action in the elevated temperature liquid.  
         [0052]     In another embodiment of the invention the temperature at which the flexing occurs is maintained by passing steam or a heated gas having a temperature greater than the melting point of the binder over the pile surface structure  10 . An example of a suitable apparatus  54  for this purpose is illustrated in stylized diagrammatic form in  FIG. 5 . The apparatus  54 , generally similar to a standard vertical steamer apparatus, includes an enclosure  56  having entrance port  56 P and exit port  56 P′ defined in the walls thereof. Roller elements  58  and/or fixed abutments  60  (if desired) are mounted within the enclosure  56 . The rollers  58  and the abutments  60  may be any suitable configuration to effect the action to be described. For example, as suggested in  FIG. 5 , the rollers  58  (which may be implemented as rotatably mounted bars) may be circular while the abutments  60  may be pyramidal in cross section.  
         [0053]     In operation, a length of pile surface structure  10  is threaded over the rollers  58  and the abutments  60 . The pile surface structure  10  is drawn through the enclosure  56  by the action of a pair of nip rolls  62  disposed in a convenient location, such as adjacent to the exit port  56 P′. Preferably, those rollers  58  which interface against the pile elements  16  (i.e., the lower rollers  58  in  FIG. 5 ) have pins  58 P which penetrate into the upper surface  14 S of the backing  14 , to avoid crushing of the pile elements  16 . The other rollers engage the bottom surface  14 B of the backing  14 . The nip roll  62  may also be provided with pins  62 P, if desired.  
         [0054]     The pile surface structure  10  is drawn into and through the enclosure  56  by the action of the nip rolls  62 , as indicated by the reference arrows  64 . The pile surface structure  10  is thus conveyed, in serpentine fashion, over and under the rollers  58  and/or the abutments  60  mounted within the enclosure  56 . At the same time the pile surface structure  10  within the enclosure  56  is subjected to a flow of steam or hot gas (such as hot air) introduced into the enclosure, as from suitable jets  66  provided for that purpose. The temperature of the steam or hot gas is sufficient to melt the binder material on the pile surface structure  10 .  
         [0055]     Each reversal of direction of the pile surface structure over or under the rollers  58  and/or the abutments  60  folds and counterfolds the backing  14  of the pile surface structure into and out of its plane (as again indicated by the reference characters  46 F,  46 C), similar to the mechanical flexing action discussed in connection with  FIG. 4 . This mechanical flexing action creates pressure in the pile elements  16  and causes the binder to flow into the root portion of the pile loops and into the interstices of filaments forming the pile elements. The rollers  58  and/or the rounded tip of the abutments  60  have a relatively small radius that increases the flexing of the backing and therefore the pressure exerted on the binder.  
         [0056]     Yet further, a second pairs of nip rolls  68  (with pins  68 P) may be mounted within the enclosure  56 . These nip rolls  68  serve to force a length of the pile surface structure  10  into a U-shaped region defined between plates  70  and thus, further flexing the pile structure  10 .  
         [0057]     Prior to mechanically flexing the pile surface structure  10  may be scoured in a vat of heated liquid to remove substantially all oil and finish from the pile loops. This action is indicated diagrammatically in  FIG. 2A  by the reference character  36 . The scouring may be effected by passing the pile surface structure  10  through using a heated liquid disposed within a suitable enclosure. The scouring liquid should preferably contain a detergent and, optionally, a surfactant. Of course, if the pile surface structure  10  is flexed using the heated liquid apparatus of  FIG. 4 , scouring may be performed simultaneously with the flexing, and a separate scouring step may not be required.  
         [0058]     After the flexing action is completed, especially if the flexing is carried in the presence of the heated liquid or steam, the pile surface structure is dried, as indicated by step  38 . Any suitable dryer apparatus may be used. A suitable time-temperature profile would dry the pile surface structure at a temperature of at least one hundred ten degrees Centigrade (110° C.) for at least two (2) minutes, to improve plastic flow and adhesion during drying.  
         [0059]     The finished pile surface structure ( FIG. 1 ) is collected from the outlet of the drying step  38  on a suitable take-up mechanism (not shown).  
         [0060]      FIG. 2A  also illustrates an alternative manner  26  in which the binder is applied to the surface  14 S of the backing  14 . In this alternative manner the primary binder powder is applied in the form of a slurry comprising the primary binder powder dispersed in a liquid vehicle. Water containing a surfactant forms a suitable liquid vehicle. The slurry may be applied by spraying using a suitable spray apparatus  28 ′. Alternatively, the slurry may be applied by padding onto the surface  14 S of the backing  14 .  
         [0061]     In another alternative embodiment, as diagrammatically illustrated in  FIG. 2B , the binder may be applied to the backing  14  in a melt-blown dry state using a melt-spinning device  28 ″. Melt-blown materials are also amorphous and flow well. Compressed gas attenuates spun filaments of a molten polymer into a web-like structure. Melt-blowing produces a layer  24 L″ of amorphous binder material onto the surface  14 S of the backing  14 , as is illustrated by the diagrammatic view shown in  FIG. 3C .  
         [0062]     After application of the binder the backing  14  is conveyed directly (i.e., without heating) to be stitched, where the pile surface structure  10  is formed in the manner described. The remaining steps of the method may be implemented as described in connection with  FIG. 2A .  
         [0063]      FIG. 2C  illustrates yet another alternative manner  26  in which the binder is applied to the surface  14 S of the backing  14 . In this embodiment the primary binder powder is again applied in the form of a slurry dispensed from a suitable spray apparatus  28 ′. The slurry comprises the primary binder powder dispersed in a liquid vehicle (e.g., water). However, the liquid vehicle has a soluble adhesive dissolved therein. The soluble adhesive has a setting point in the range from five (5) to twenty (20) degrees Centigrade ° C below the melting point of the binder. A surfactant may be required in the liquid vehicle. A suitable soluble adhesive is that available from Philchem Corporation, Greer, S.C. as L1000 textile sizing.  
         [0064]     The slurry may alternatively be applied by padding onto the surface  14 S of the backing  14 .  
         [0065]     After application of the slurry the backing  14  is again heated, as indicated by block  30 . In the heating device the surface of the backing  14  is heated to a temperature that is above the evaporation temperature of the vehicle, above the setting temperature of the soluble adhesive, and below the melting temperature of the powder binder. As a result a layer of binder supported in a matrix of adhesive is disposed over the surface of the backing. The layer is similar to the layer  24 L′ shown in the diagrammatic view of  FIG. 3B .  
         [0066]     In accordance with this embodiment of the invention, after stitching the pile surface structure  10  is soaked, as indicated at reference character  39 , to dissolve and remove the adhesive matrix. Scouring may also be performed with the soaking, if desired.  
         [0067]     After soaking the pile surface structure  10  is flexed into and out of the plane of the backing, as discussed in connection with block  32  in  FIG. 2A . The pile surface structure may thereafter be dried, as indicated by the block  38 .  
         [0068]      FIG. 2D  diagrammatically indicates additional techniques by which the binder material may be initially applied in the vicinity of the root portion of the loops of the pile surface structure. For example, a strand  25  of binder material may be laid-in the pile surface structure with the pile yarn. The binder strand  25  may be supplied from a suitable beams or bobbins (shown diagrammatically at  74  in  FIG. 2D ).  
         [0069]     As illustrated in  FIG. 3D  the binder strand  25  may be laid-in above the root portion  16 R of the pile element  16  and is held in place by the thread underlaps  20 U. Alternatively or additionally, the strand  25  of binder material may be laid-in with the pile yarn so that the binder strand  25  lies below the root portion  16 R ( FIG. 3E ). Yet further, the binder strand  25  may be transversely inserted to lie beneath the root portions  16 R of the pile elements using a weft-insertion apparatus. The resulting pile surface structure is illustrated in  FIG. 3F .  
         [0070]     The binder material may alternatively or additionally be introduced into the pile surface structure as part of a composite stitching thread  25 T. In this case the composite thread  25 T originates from a suitable beam or creel of bobbins (shown diagrammatically at  76  in  FIG. 2D ). The resulting pile structure is illustrated in  FIG. 3G .  
         [0071]     The remaining steps of the method diagrammatically illustrated in  FIG. 2D  may be implemented as described in connection with  FIG. 2A .  
         [0072]      FIG. 2E  illustrates yet another alternative manner in which the binder material may be initially applied to the pile surface structure. In this embodiment the pile surface structure is fabricated using a backing  14 ′ of a type an open structure adapted to permit a liquid slurry to penetrate therethrough.  
         [0073]     After stitching  32  (and scouring  36 , if desired) a slurry similar to that described in connection with  FIG. 2A  is applied to the bottom surface of the pile surface structure, as illustrated by the block  26 . The liquid penetrates through the backing  14 ′ to reach the vicinity of the root portion  16 R of the loops  16 L. The resulting pile surface structure, wherein the liquid binder permeates the structure as indicated by the waved lines  24 L 3 , is illustrated in  FIG. 3H .  
         [0074]     The resulting pile surface structure is thereafter flexed as indicated at the block  34  and optionally dried, as indicated at the block  38 , both in the manner described earlier in connection with  FIG. 2A .  
         [0075]     Those skilled in the art, having the benefit of the teachings of the present invention, as hereinabove set forth, may effect numerous modifications thereto. It should be understood that all such modifications lie within the contemplation of the present invention as defined by the appended claims.