Abstract:
A device and method for applying adhesive to materials, such as elastic strands or flat substrates, used in the production of nonwoven products. Generally, a nozzle is provided and includes a liquid discharge orifice configured to discharge a bead of liquid adhesive. First and second pattern air discharge orifices are associated with the first liquid discharge orifice to vacillate or oscillate the adhesive bead. First and second cleaning and stabilizing air discharge orifices are also associated with the first liquid discharge orifice. These latter air discharge orifices keep airborne contaminants away from the associated liquid discharge orifice and also stabilize the oscillation of the adhesive bead in a single plane. Another embodiment includes walls to separate adjacent sets of air discharge orifices.

Description:
[0001]    This application is continuation-in-part application of application Ser. No. 09/805,085 filed on Mar. 13, 2001 (pending) which claims the priority of Japanese Patent Application No. 2000-117263 filed Mar. 14, 2000, the disclosures of which are hereby fully incorporated by reference herein.  
         FIELD OF THE INVENTION  
         [0002]    The present invention pertains to a device and a method for applying adhesive filaments to materials such as strands and flat substrates.  
         BACKGROUND OF THE INVENTION  
         [0003]    The structure of a disposable diaper is disclosed, for example, in Japanese Patent Kokai No. 11[1999]-285,510. In the structure of this disposable diaper an elastic strand(s) is provided at various locations including at the bending section and free ends of a sheet so as to form a barrier. In the process of producing disposable diapers with this kind of structure, the disposable diapers are produced through steps such as applying an adhesive to elastic strand material being fed continuously, then bonding the elastic strand material to a base or substrate material which forms the main part of the diaper and which is also fed continuously, and finally in a subsequent step cutting the resulting product into individual diapers.  
           [0004]    Not only in the production of the aforesaid disposable diapers but also in the process of producing, for example, disposable surgical gowns to be used in operating rooms, elastic strand material and nonwoven or woven fabrics are bonded together with an adhesive. Also, in a process of this kind, the materials to be coated with the adhesive are not always elastic members, there are cases where strand materials with no stretching properties are coated with the adhesive and bonded to a substrate. Accordingly, the term “strand material” or similar terms as used in the present specification are meant to also include both elastic materials such as elastic yarn and nonelastic material.  
           [0005]    Furthermore, the cross-sectional shape of the strand material is not only circular but includes various shapes such as elliptic, square, and rectangular, and the thickness also ranges from the order of hundredths of a millimeter to the order of several millimeters. Thus, there are no particular limitations with regard to the shape and thickness of the strand material. As the adhesive to be used, a hot-melt adhesive is used in many cases, but other types of adhesive can be used as well.  
           [0006]    A conventional device and method for applying an adhesive to strand material in the process of producing the aforesaid disposable diapers or other products will now be explained with reference to FIGS.  9 - 12 . FIG. 9 shows a front view of the conventional coating device. FIG. 10 shows a vertical sectional view of the conventional coating device. FIG.  11  shows an expanded view of the leading end portion of FIG. 10. FIG. 12 shows an enlarged view of encircled portion D of FIG. 9.  
           [0007]    In FIGS.  9 - 12 , coating device  51  includes a valve mechanism  65  which is opened and closed by operating air  80 . A gun body  52  forms the coating device  51 ; a cylinder block  53  is attached with a plurality of bolts  54  to the top of the gun body  52 , and a piston  55  moves up and down and is located inside the cylinder block  53 . A valve stem  56  is fastened to the piston  55  and is extended into a liquid chamber  59  through a seal block  57 . A seal member  58  is provided in the gun body  52 , and includes a valve ball  60  at the leading end.  
           [0008]    Furthermore, a valve seat member  62  that has an outlet  62   a  is attached with a plurality of bolts  63  to the lower part of the gun body  52 . A screw  62   b  is provided in the lower outer diameter section of the valve seat member  62 . The valve ball  60  is at the leading end of the valve stem  56  and the valve seat member  62  forms the valve mechanism  65 . A spring  75  is placed between the large-diameter section at the leading end of the valve stem  56  and the underside of the seal block  57 , and closes the valve mechanism  65  by forcing the valve stem  56  downward at all times.  
           [0009]    A nozzle member  66  has a flange section  66   a . A cap nut  67  is provided with a small-diameter section  67   a  to be engaged with the flange section  66   a  of the nozzle member  62  and a screw section  67   b  to be engaged with the screw  62   b  of the valve seat member  62 . The nozzle member  66  is attached to the lower end of the valve seat member  62  by engaging the small-diameter section  67   a  of the cap nut  67  with the flange section  66   a , and attaching the screw section  67   b  of the cap nut  67  over the screw  62   b.    
           [0010]    Moreover, a flat section  66   b  is formed in the nozzle member  66 , and a nozzle plate  68  is fastened with a plurality of bolts  69  to the flat section  66   b . A through-hole  66   c  communicates with the outlet  62  of the valve seat member  62 . A horizontally long groove  66   d  extends in the horizontal direction in communication with the through-hole  66   c  and opens to the flat section  66   b , and three branched nozzle grooves  66   e  communicate with the horizontal groove  66   d  in the nozzle member  66 . The horizontal groove  66   d  and the nozzle grooves  66   e  are combined in such a way that the nozzle plate  68  covers the open section of the grooves. The nozzle groove  66   e  is open at the lower end and a nozzle hole  70  couples with the nozzle plate  68 .  
           [0011]    The lower ends of the nozzle member  66  and the nozzle plate  68  have exactly the same shape, and are formed like teeth of a comb stretching to below the nozzle hole  70 . An inverted V-shape groove  61  with its lower end slightly spreading is formed with the nozzle hole  70  at the center. This groove  61  plays a role as a guide for the strand material  14  to be coated with the adhesive. An example of the conventional coating device shown in the figures is a device wherein three nozzle holes  70  are formed so as to apply three strands  14  simultaneously by one coating device  51 . The device is not limited to this and may have one nozzle hole or many more nozzle holes to enable the coating of one or more strands.  
           [0012]    To return to the explanation of the gun body  52 , the gun body  52  is provided with an air through-hole  52   a  for feeding operating air  80  to the underside of the piston  55 , and an adhesive through-hole  52   b  for feeding an adhesive  81  to the liquid chamber  59 . The gun body  52  is fastened with a plurality of bolts  72  to a manifold  71 . The manifold  71  is provided with an air feed hole  71  a that communicates with the air through-hole  52   a  of the gun body  52 , and an adhesive feed hole  71  b that communicates with the adhesive through-hole  52   b . An operating air feed device  73  is connected with the air feed hole  71  a of the manifold  71  via a tubular path such as a hose, and an adhesive feed device  74  is connected with the adhesive feed hole  71  b of the manifold  71  via a tubular path such as a hose.  
           [0013]    In the coating device thus constructed, the adhesive  81  fed from the adhesive feed device  74  is stored in the liquid chamber  59  through the adhesive feed hole  71  b of the manifold  71  and the adhesive through-hole  52  of the gun body  52 . If operating air  80  is fed from the operating air feed device  73  to the underside of the piston  55 , the piston  55  and valve stem  56  operate upward against the force of the spring  75 , and the valve mechanism  65  is opened.  
           [0014]    While the valve mechanism  65  is open, the adhesive  81  in the liquid chamber  59  is extruded from the nozzle hole  70  via through-hole  66   c  of the nozzle member  66  and the horizontally long groove  66   d  from the outlet  62   a  of the valve seat member  62 , and applied to the surface of strand material  14 . In this case, the nozzle hole  70 , the topmost part of the inverted V-shape grooves  61  of the nozzle member  66  and nozzle plate  68  are in contact with the strand material  14 . The strand material  14  is coated with the adhesive  81  and adhered to the substrate in a not-illustrated device in a later step. If the feeding of operating air  80  is stopped and the air pressure on the underside of the piston  55  is released, the valve mechanism  65  closes by the force of the spring  75 , and the extrusion of adhesive  81  from the nozzle hole  70  stops. The adhesive can be applied intermittently by the opening and closing operations of the valve mechanism  65 .  
           [0015]    In another known device, the adhesive is dispensed in a spiral pattern towards the strand material. One or multiple strands can be used and the adhesive can be dispensed from one or multiple nozzles. The spiral pattern of adhesive wraps completely around the strand material while the strand material is still separate from the substrate. The operating characteristics of this system such as adhesive pressure, air pressure, distance from the dispenser nozzle to the strand material can all be varied to control the extent of the wrap around and to control the amount of adhesive captured by the strand material. It is well known to those of ordinary skill in the field that the strand material can capture substantially all of the spiral adhesive or some portion of the spiral adhesive can pass by the strand material to contact the substrate. This known device is described in U.S. Pat. No. 4,842,666 and as shown in “Adhesive and Powder Application Systems for the Nonwoven Industry”, Nordson Corporation, October 1992, both of which are incorporated herein by reference.  
           [0016]    The first aforementioned adhesive coating device is known to have the following problems. If the thickness or shape of the strand material changes, the size of the inverted V-shape groove also must be changed, and this leads to troublesome operation and extra time. Furthermore, since the strand material is coated with the adhesive in constant contact with the nozzle hole and inverted V-shape groove while being transferred at high speed (usually 70-400 m/minute), stress develops in the strand material. As a result, the strand material can be severed, or the grooves of the nozzle member can wear during lengthy operation and become larger than the diameter of the strand material. In some cases the adhesive drips from the strand material onto the substrate.  
           [0017]    Furthermore, although the adhesive is applied sufficiently to the area facing the nozzle hole of the strand material, the adhesive is not applied sufficiently to the opposite underside, and this can result in poor adhesion. Moreover, because fiber products are being transferred at high speed, the operating environment is such that fine fibrous dust is more easily formed by friction between the fiber products and mechanical devices. This fine airborne dust adheres readily to the nozzle hole sections, and this adhered dust piles up over time, solidifies, and destabilizes the coating process. In an extreme case, the extrusion of the adhesive becomes obstructed and the strand material can be severed.  
           [0018]    Yet another problem has been that, when applying the adhesive intermittently by controlling the opening and closing of the valve mechanism, the adhesive remaining downstream from the valve mechanism is inevitably drawn out by the strand material even after the valve mechanism is closed, and a poor final coating results.  
           [0019]    In the second known device mentioned above, the spiral pattern is sometimes difficult to control across the length of the strand material. This can lead to uneven or nonuniform application of the spiral bead of adhesive to the strand material.  
         SUMMARY OF INVENTION  
         [0020]    The invention of the present application was developed in view of the above-mentioned problems, and is aimed at providing a device and a method for applying an adhesive to material such as strand material, which requires no change in the device even if the thickness or shape of the strand material is changed, by installing the coating device in noncontact with the strand material. The present invention can achieve good all-around attachment of the adhesive, and moreover can carry out high-quality application of the adhesive with clean nozzles without any adhesion of dust and while maintaining a more uniform back and forth or vacillating adhesive bead pattern.  
           [0021]    The present invention generally provides a nozzle for dispensing a liquid adhesive to materials, such as strand materials or flat substrates, used in the manufacture of nonwoven products. The nozzle includes a nozzle body having a liquid supply passage and a first liquid discharge orifice in fluid communication with the liquid supply passage. The first liquid discharge orifice extends along a first axis and is configured to discharge a first bead of the liquid adhesive. First and second pattern air discharge orifices in the nozzle body are associated with the first liquid discharge orifice. In addition, first and second cleaning and stabilizing air discharge orifices in the nozzle body are also associated with first liquid discharge orifice. The first and second pattern air discharge orifices and the first and second cleaning and stabilizing air discharge orifices are arranged around the first liquid discharge orifice at 90° alternating positions. That is, the first and second pattern discharge orifices are arranged 180° apart on opposite sides of the first liquid discharge orifice and the first and second cleaning and stabilizing air discharge orifices are arranged 180° apart on opposite sides of the first liquid discharge orifice at positions 90° from the first and second pattern air discharge orifices.  
           [0022]    The two sets of air discharge orifices have different advantageous functions each in association with the corresponding liquid discharge orifice. The pattern air discharge orifices vacillate the first bead of adhesive back and forth in a vacillating plane containing the first and second pattern air discharge orifices. The first and second cleaning and stabilizing air discharge orifices emit jets of air in a direction parallel to the first axis to clear airborne contaminants, such as dust, away from the first liquid discharge orifice and to stabilize the first bead of adhesive in the vacillation plane. Thus, not only do the cleaning and stabilizing air discharge orifices clean the nozzle of contaminants, such as dust which may clog the liquid discharge orifice, they also help maintain the vacillating adhesive bead in a single plane, which is generally a plane perpendicular to the machine direction of the material. This ensures a more uniform adhesive bead pattern and, therefore, more accurate and consistent bead placement.  
           [0023]    More specifically, the nozzle may comprise more than one liquid discharge orifice and associated sets of pattern air discharge orifices and cleaning and stabilizing air discharge orifices, depending on the application needs. Further, the nozzle is advantageously coupled to an on/off dispensing module including a valve mechanism for selectively allowing and preventing the flow of adhesive from the liquid discharge orifice or orifices. The first and second pattern air discharge orifices preferably converge toward the axis defining the associated liquid discharge orifice, while the first and second cleaning and stabilizing air discharge orifices are preferably parallel to the axis of the associated liquid discharge orifice. In addition, the liquid discharge orifice preferably opens on the apex of a projecting nozzle portion, while the first and second pattern air discharge orifices preferably open on the base of the projecting nozzle portion. The first and second cleaning and stabilizing air discharge orifices open on the apex as well, directly adjacent the associated liquid discharge orifice.  
           [0024]    A method of applying an adhesive bead in accordance with the invention comprises moving a strand of material in a linear direction and positioning the liquid discharge orifice of the nozzle spaced apart from the strand of material. An adhesive bead is extruded from the liquid discharge orifice toward the strand of material and first and second pattern air jets are discharged from the nozzle to vacillate the adhesive bead back and forth in a vacillation plane while the vacillating adhesive bead attaches to the strand of material. Cleaning and stabilizing air jets are discharged from the first and second cleaning and stabilizing air jet orifices to clear airborne contaminants away from the liquid discharge orifice and to stabilize the vacillating bead of adhesive in the vacillation plane. In another aspect of the method, the first and second cleaning and stabilizing air jets are preferably directed at a lower pressure than the first and second pattern air jets. In addition, the first and second cleaning and stabilizing air jets may be discharged intermittently or continuously, while the first and second pattern air jets are preferably directed in a continuous manner to produce the vacillating pattern. The cleaning and stabilizing air jets may be continued after the adhesive bead extrusion has stopped to continue to clear away airborne contaminants from the liquid discharge orifice.  
           [0025]    In another embodiment of the invention, a nozzle is provided for dispensing a plurality of liquid filaments, such as adhesive filaments, in which a wall is provided between adjacent liquid and process air discharge outlets. This helps prevent adjacent process air streams from interfering with each other and further promotes adhesive filament uniformity and accuracy. More specifically, the nozzle includes a body having liquid and process air supply passages, a tip portion, first and second liquid discharge outlets on the tip portion and first and second pluralities of process air outlets on the tip portion. A first wall projects from the tip portion and includes an end positioned beyond the liquid and process air outlets and positioned between the first and second pluralities of process air outlets to separate the process air streams respectively discharged from the first and second pluralities of process air outlets. In the preferred embodiment, at least two of the process air outlets associated with the respective liquid discharge outlets communicate with the process air passages which are configured to generally converge with the associated liquid discharge outlet. Even more preferably, the axes of the process air discharge passages associated with the respective liquid discharge passage cross the axis of the associated liquid discharge passage at a location proximate the end of the first wall. This helps ensure the separation of adjacent process air stream patterns. It should be understood that the axes of the process air discharge passages may not directly intersect with the axis of the associated liquid discharge passage, as this will depend on the desired filament pattern. In the preferred embodiment, the nozzle has multiple sets of process air and liquid discharge passages with a wall preferably extending between each set, for separation purposes, and a wall extending from the tip portion of the nozzle at each end of the nozzle.  
           [0026]    These and other objects, advantages and features of the invention will become more readily apparent to those of ordinary skill in the art upon review of the following detailed description taken in conjunction with the accompanying drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0027]    [0027]FIG. 1 is a front view of a coating device according to the present invention.  
         [0028]    [0028]FIG. 2 is a vertical sectional view of a coating device according to the present invention.  
         [0029]    [0029]FIG. 3 is a diagram of the nozzle block seen from side A in FIG. 2.  
         [0030]    [0030]FIG. 4 is a diagram of the nozzle block seen from side B in FIG. 2.  
         [0031]    [0031]FIG. 5 is a sectional view along C-C of FIG. 3.  
         [0032]    [0032]FIG. 6 is a base view of the nozzle block.  
         [0033]    [0033]FIG. 7 is a schematic diagram which shows the manner of the adhesive being applied.  
         [0034]    [0034]FIG. 8 is a schematic diagram which shows the manner of the adhesive being applied.  
         [0035]    [0035]FIG. 9 is a front view of a conventional coating device.  
         [0036]    [0036]FIG. 10 is a vertical sectional view of a conventional coating device.  
         [0037]    [0037]FIG. 11 is an expanded view of the leading end part of FIG. 10.  
         [0038]    [0038]FIG. 12 is an expanded view of part D of FIG. 9.  
         [0039]    [0039]FIG. 13 is a rear elevational view of a liquid filament dispensing nozzle constructed in accordance with an alternative embodiment of the invention.  
         [0040]    [0040]FIG. 14 is a bottom view of the nozzle shown in FIG. 13.  
         [0041]    [0041]FIG. 15 is a front elevational view of the nozzle shown in FIG. 13.  
         [0042]    [0042]FIG. 16 is a cross sectional view taken along line  16 - 16  of FIG. 15. 
     
    
     DETAILED DESCRIPTION  
       [0043]    The preferred embodiment of carrying out the present invention will now be described. First, an adhesive fed from a well-known adhesive feed device is extruded as a continuous bead from an adhesive discharge nozzle installed above a long strand of material traveling at high speed in noncontact with said material, by opening the valve mechanism of a coating device. Pattern air is jetted from two pattern air jet nozzles provided on both sides of the adhesive discharge nozzle onto the continuous adhesive beads extruded from the adhesive discharge nozzle, the pattern air comes into contact with the adhesive beads and causes the adhesive beads to begin an oscillating or vacillating motion. In this disclosure, the terms oscillating and vacillating are synonymous. This vacillating motion swings in the form of a wave centered around the adhesive discharge nozzle in the direction of the pattern air jet nozzles.  
         [0044]    The oscillated adhesive beads are deposited on the surface of the strand material so as to straddle the traveling strand in the crossing direction. Accordingly, the position of the pattern air jet nozzles relative to the adhesive discharge nozzle must be located in the direction of crossing the traveling strand material. The adhesive thus deposited on the surface of the strand material begins a fluid movement as a viscous liquid after the deposition, and makes its way around the strand material by drooping to the underside. The bead also flattens out, so that the adhesive is applied all around the strand material so as to enwrap it.  
         [0045]    The above operations are performed while jetting cleaning air intermittently or continuously from the cleaning air jets provided adjacent to the front side and rear side of the adhesive discharge nozzle, thereby enabling continuous operation. In other words, the problem of airborne fibrous particles adhering to the nozzle holes, piling up and solidifying with the passage of time is avoided. This can prevent destabilizing the coating process and obstructing the extrusion of the adhesive. Furthermore, when the cleaning air is jetted continuously, irregular swings of the adhesive can be prevented, and a rectifying or stabilizing effect such as to make the bead-form adhesive swing regularly in the right and left directions is achieved.  
         [0046]    It is desirable to adjust the discharge pressure of the cleaning air to a pressure lower than the discharge pressure of the pattern air during the extrusion of the adhesive. However, the discharge pressure of the cleaning air can be raised while the valve mechanism is closed, i.e., the extrusion of the adhesive is stopped, and thereby the adhesion of dust is prevented more effectively.  
         [0047]    The present invention will now be described in concrete terms with the use of figures which show an actual example of the present invention. Here, the present actual example uses a structure for applying an adhesive to three strand materials simultaneously with one coating device, but the present invention is not limited to this example.  
         [0048]    In FIGS. 1 and 2, the coating device  1  has a structure with a valve mechanism  15  which is opened and closed by operating air  30 . Specifically, a gun body  2  forms the coating device  1 , and a cylinder  2   a  is formed in the upper part of the gun body  2  and a piston  5  moves up and down and is located inside the cylinder  2   a  . A piston cover  3  is attached with a plurality of bolts  4  to the top of the gun body  2 . A spring  25  forces the piston  5  downward at all times.  
         [0049]    A valve stem  6  is fastened to the piston  5 , and the valve stem  6  extends into a liquid chamber  9  through seal members  7  and  8  provided in a small-diameter section in the gun body  2 . An adapter  12  is attached with a plurality of bolts  13  to the lower part of the gun body  2 . A valve seat part  12   a  leading to the liquid chamber  9  and an adhesive through-hole  12   b  downstream from the valve seat part  12   a  are formed inside the adapter  12 . The adhesive through-hole  12   b  is open to a flat section  12   c  of the adapter  12 , with its lower part bent in an L-shape. The valve stem  6  and valve seat part  12   a  of the adapter  12  comprise the valve mechanism  15 . The valve mechanism  15  is kept closed at all times by the force of the spring  25 .  
         [0050]    A nozzle block  10 , and a nozzle holding plate  11  are stacked and attached with a plurality of bolts  19  to the flat section  12   c  of the adapter  12 . The configuration of the nozzle block  10  is shown in detail in FIGS.  3 - 6 . The nozzle block  10  is provided with attaching holes  10   a  for the bolts  19 . A triangular groove  10   b  for an adhesive  31  is formed on side A, and three pipe-shaped nozzle members  16  communicating with the triangular groove  10   b  are provided so as to open to the triangular groove  10   b  by fixing a neck part  16   b  firmly in the nozzle block  10  by means such as pressure insertion, brazing, or welding. Furthermore, the nozzle member  16  opens its leading end as an adhesive discharge nozzle or orifice  16   a  to a protrusion  10   c  that protrudes on the underside of the nozzle block  10 . The adhesive through-hole  12   b  of the adapter  12  opens to the top of the triangular groove  10   b.    
         [0051]    A through-hole  10   d  for pattern air  32  extends through the nozzle block  10 . The through-holes  10   d  communicate with a pattern air groove  10   e  on side B of the nozzle block  10 . The pattern air groove  10   e  communicates with pattern air jet nozzles or orifices  10   f  which open to both sides of each adhesive discharge nozzle or orifice  16   a  on the underside of the nozzle block  10 . The pattern air nozzles  10   f  may be bored in the vertical direction, but good results can be obtained if they are bored so as to adjust the angle {circle over (-)} to the adhesive discharge nozzle  16   a  in the range of 10-20 degrees. Furthermore, a through-hole  10   g  for cleaning air  33  extends through the nozzle block  10 . The through-holes  10  communicate with a cleaning air groove  10   h  on side B of the nozzle block  10 . The cleaning air groove  10   h  further communicates with cleaning and stabilizing air jet orifices  10   i  which are open in a crescent shape in front and behind the nozzle member  16 .  
         [0052]    The nozzle block  10  is stacked with the nozzle holding plate  11  and attached to the flat part  12   c  of the adapter  12 . The triangular groove  10   b  provided on side A of the nozzle block  12  forms a space that is closed by the flat part  12   c  of the adapter  12 , and functions as a path for the adhesive  31 . The pattern air groove  10   e  and cleaning air groove  10   h  provided on side B form grooves closed by the nozzle holding plate  11 , and function as a pattern air path and a cleaning air path, respectively.  
         [0053]    An operating air through-hole  2   b  communicates with the cylinder  2   a  below the piston  5  and an adhesive through-hole  2   c  communicates with the liquid chamber  9 . The gun body  2  is fastened together with the adapter  12  with a plurality of bolts  22  to a manifold  21 . Furthermore, the adapter  12  is provided with a horizontally long groove  12   d  for pattern air  32  and a horizontally long groove  12   e  for cleaning air  33  on the side meeting the manifold  21 . The horizontally long groove  12   d  is provided with two pattern air through-holes  12   f  that communicate with two through-holes  10   d  of the nozzle block  10 . The horizontally long groove  12   e  is provided with two cleaning air through-holes  12   g  that communicate with two through-holes  10   g  of the nozzle block  10 , though only one air through-hole is shown for each in FIG. 2.  
         [0054]    The manifold  21  is provided with an operating air feed hole  21   a  that communicates with the operating air through-hole  2   b  and an adhesive feed hole  21   b  that communicates with the adhesive through-hole  2   c . A pattern air feed hole  21   c  communicates with the horizontally long groove  12   d  and a cleaning air feed hole  21   d  communicates with the horizontally long groove  12   e  provided in the adapter  12 . The operating air feed hole  21   a , pattern air feed hole  21   c , and cleaning air feed hole  21   d  are connected via a tubular path such as a hose to an air feed control device  23  equipped with the function to regulate the pressure, flow rate, and temperature of the air and the function of on and off control, these functions working independently for each amount of air. The adhesive feed hold  21   b  is connected via a tubular path such as a hose to an adhesive feed device  24  equipped again with the function to control pressure, flow rate, etc.  
         [0055]    The action of the coating device  1  thus constructed will be explained below. First, the adhesive  31  fed from the adhesive feed device  24  is stored in the liquid chamber  9 , after passing through the adhesive feed hole  21   b  of the manifold  21 , and the adhesive through-hole  2   c  of the gun body  2 . If the operating air  30  fed from the air feed control device  23  is fed into the cylinder  2   a  below the piston  5  via the operating air feed hole  21  a of the manifold  21  and the operating air through-hole  2   b  of the gun body  2 , the piston  5  and valve stem  6  move upward against the force of the spring  25 , and the valve mechanism  15  is opened.  
         [0056]    The adhesive  31  in the liquid chamber  9  is extruded in the form of continuous beads from the adhesive discharge nozzles  16   a  of the nozzle member  16  through the adhesive through-hole  12   b  of the adapter  12  and the triangular groove  10   b  of the nozzle block  10 , while the valve mechanism  15  is open. Pattern air  32  fed from the air feed control device  23  is jetted from the pattern air jet nozzles  10   f  through the pattern air feed hole  21   c  of the manifold  21 , the pattern air through-hole  12   f  of the adapter  12 , and the through-holes  10   d  and pattern air groove  10   e  of the nozzle block  10 . The bead-form adhesive  31  begins a swing motion from side to side in a vacillation plane under the influence of the pattern air  32  as shown in FIG. 7.  
         [0057]    The adhesive  31  is swung in the direction of crossing for the moving strand material  14  which is the material to be coated. The adhesive is applied to the surface of the strand material  14  so as to straddle the strand material  14  which is continuously transferred in noncontact below the adhesive discharge nozzle  16   a . The adhesive  31  is deposited on the surface of the strand material  14  and begins a fluid movement as a viscous liquid after deposition, and makes its way to the underside of the strand material  14  and also flattens out to form a film, so that the adhesive is applied all around the strand material  14  so as to enwrap it as shown in FIG. 8. The strand material  14  coated with the adhesive is bonded further downstream with a substrate  28  on a roll  29 .  
         [0058]    These operations are performed while jetting cleaning air  33  from the cleaning and stabilizing air jet orifices  10   i  in crescent shaped orifices provided adjacent to the front side and rear side of the adhesive discharge nozzle  16   a . The cleaning air  33  fed from the air feed control device  23  is jetted from the cleaning and stabilizing air jet orifices  10   i  through the cleaning air feed hole  21   d  of the manifold  21 , the cleaning air through-hole  12   g  of the adapter  12 , and the through-holes  10   g  and the cleaning air groove  10   h  of the nozzle block  10 .  
         [0059]    The jetting of cleaning air  33  prevents fine fibrous dust floating in the air from sticking around the adhesive discharge nozzles  16   a , and enables stable application of the adhesive for long periods of time. This cleaning air jetting may be continuous or intermittent. If the cleaning air is jetted continuously, a rectifying effect such as to make the bead-form adhesive swing regularly in the right and left directions by preventing irregular swings of the adhesive is also achieved. Furthermore, it is desirable to adjust the discharge pressure of the cleaning air to a pressure lower than the discharge pressure of the pattern air. The discharge pressure of the cleaning air can be raised while the valve mechanism is closed, i.e., the extrusion of the adhesive is stopped, and thereby the adhesion of dust is prevented more effectively. Moreover, according to test results, it is desirable to adjust the distance H from the leading end of the adhesive discharge nozzle  16   a  to the strand material  14  to 5-20 millimeters.  
         [0060]    To stop the discharge of the adhesive, the operating air  30  being fed to the underside of the piston  5  is released by the operation of the air feed control device  23 , then the piston  5  and the valve stem  6  move downward by the force of the spring  25 , and the valve mechanism  15  closes and the dis-charge of the adhesive stops. Thus, the open and shut operation of the valve mechanism  15  can achieve intermittent application of the adhesive.  
       TEST EXAMPLE  
       [0061]    Many tests of applying an adhesive to a strand material were repeated under the following conditions, and good results were obtained in all the tests. The conditions were as follows:  
         [0062]    (1) strand material used as the substrate: strand elastic, thickness 560 denier (diameter about 0.28 mm), traveling speed 150-170 m/minute.  
         [0063]    (2) Type of adhesive used: product No. H-6830 from Nitta Findley Co., Ltd. and product No. HE-1 from Japan N. S. C. Co., Ltd., both being rubber-based hot-melt adhesives.  
         [0064]    (3) Melting temperature of adhesive upon heating: 150° C. for H-6830 and 160° C. for HE-1.  
         [0065]    (4) Distance from the leading end of the adhesive discharge nozzle to the workpiece: 5-20 mm.  
         [0066]    (5) Diameter of the adhesive discharge nozzle: 0.6 mm.  
         [0067]    (6) Discharge pressure of the adhesive: 7-14 kg/cm 2 .  
         [0068]    (7) Diameter of pattern air jet nozzle: two diameters, 0.46 mm and 0.50 mm.  
         [0069]    (8) Pressure of pattern air: 0.3-1.0 kg/cm 2 .  
         [0070]    (9) Area of cleaning air jet: approximately equal to the opening area of the pattern air jet nozzle.  
         [0071]    (10) Pressure of cleaning air: 0.1-0.8 kg/cm 2 , continuous and intermittent jetting.  
         [0072]    According to the device and method of the present invention of applying an adhesive to strand materials, the coating device is placed in noncontact with the strand materials, as described above, and thereby a device and a method for applying an adhesive to strand materials is provided. The generation of stretching stress in the strand materials or the severing of these materials as sometimes seen in contact application according to one known conventional technique can be avoided. No change is required in the device even if the thickness and shape of the strand material is changed. The all-around attachment of the adhesive is good. Moreover, high-quality coating of the adhesive can be achieved with clean nozzles with no adhesion of dust and with accurate, uniform placement of the adhesive.  
         [0073]    FIGS.  13 - 16  illustrate another alternative embodiment of the invention in the form of a nozzle  50 . Nozzle  50  includes a body  52  having a tip portion  54  for dispensing multiple liquid filaments which, in this illustrative case, may be comprised of four adhesive filaments. Liquid enters nozzle body  52  through a liquid supply passage  56  which is a coat hanger shaped slot. Process air enters body  52  through respective process air passages  58   a ,  58   b  which also communicate with a slot  59  and slot  81  via grooves  87 . Referring to FIG. 14, four separate liquid discharge outlets  60  are provided and with respect to each outlet  60 , four air discharge outlets  62 ,  64 ,  66 ,  68  are provided in a generally diamond-shaped pattern as discussed with respect to the first embodiment. However, it will be understood that different numbers of process air discharge outlets as well as different configurations thereof may be substituted for the illustrative examples shown in this embodiment depending on the desired effect on the discharged filament. Liquid distribution passages  70  respectively communicate between slot  56  and respective liquid discharge passages  72  and each liquid discharge passage  72  communicates with an outlet  60  as discussed above. Four air discharge passages  74 ,  76 ,  78 ,  80  are provided as discussed with respect to the first embodiment. As shown in FIG. 16, process air discharge passages  78 ,  80  receive pressurized process air from slot  81  and a bore  85  communicating with each other by way of three holes  83 . Nozzle body  52  further includes two fastener holes  90 ,  92  for holding nozzle  50  to a suitable dispensing unit (not shown).  
         [0074]    In accordance with this embodiment of the invention, a plurality of walls  100  respectively extend from tip portion  54  beyond the respective liquid and air discharge outlets. More preferably, when using process air which is directed generally toward a discharged liquid filament in a converging manner, walls  100  have a length such that the ends  100   a  thereof extend to a location proximate a point at which axes  84 ,  86  of process air discharge passages  76 ,  74  cross axis  82  of liquid discharge passage  72 . As illustrated in this non-limiting example, walls  100  extend between adjacent sets of air and liquid discharge passages, and additional walls extend from tip portion  54  at opposite ends of nozzle body  52 . This helps achieve the most advantageous separation of isolation of discharged process air streams.  
         [0075]    While the present invention has been illustrated by a description of a preferred embodiments and while these embodiments have been described in some detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The various features of the invention may be used alone or in numerous combinations depending on the needs and preferences of the user. This has been a description of the present invention, along with the preferred methods of practicing the present invention as currently known.