Patent Publication Number: US-2002013112-A1

Title: Multi-drum manufacturing system for nonwoven materials

Description:
RELATED APPLICATIONS  
     [0001] This application is related to and claims priority to U.S. patent application Serial No. 60/212,562 entitled “Multi-Drum Manufacturing System for Nonwoven Materials,” filed on Jun. 20, 2000, U.S. patent application Serial No. 60/286,802 entitled “Method and Apparatus for Bonding a Non-Woven Web,” filed on Apr. 25, 2001, and U.S. patent application Ser. No. 09/733,147 entitled “Method and Apparatus for Controlling Flow in a Drum” filed on Dec. 8, 2000, which in turn claims priority to U.S. patent application Serial No. 60/170,037 entitled “Method and Apparatus for Controlling Flow in a Drum, filed on Dec. 10, 1999, International Patent Application No. PCT/US99/27294 entitled “Method and Apparatus for Manufacturing Non-Woven Articles” filed on Nov. 17, 1999, which in turn claims priority to U.S. patent application Ser. No. 09/193,582, filed Nov. 17, 1998, now U.S. Pat. No. 6,146,580 and U.S. Provisional patent application Serial No. 60/149,270, filed Aug. 17, 1999, all the disclosures of which are incorporated herein by reference in their entirety. 
    
    
     
       FIELD OF THE INVENTION  
       [0002] This invention relates to a method of using non-woven fiber sources to produce a multi-layered web, and more particularly, forming the multi-layered web from nonwoven webs, where each web is formed independently on a separate drum.  
       BACKGROUND OF THE INVENTION  
       [0003] Non-woven materials are used in applications that require articles to be air permeable. Some applications of non-woven articles are surgical masks and filter membranes. Since many applications that use non-woven material entail disposable articles, the non-woven articles should be easily manufacturable and low cost. Some methods of manufacturing non-woven materials are spunbonded and melt blown processes, and electro-spinning of nano-fibers.  
       [0004]FIG. 1 illustrates the spunbonded process  10  for manufacturing non-woven materials. Thermoplastic fiber forming polymer  12  is placed in an extruder  14  and passed through a linear or circular spinneret  16 . The extruded liquid polymer streams  18  are rapidly cooled and attenuated by air and/or mechanical drafting rollers  20  to form desired diameter solidifying filaments  22 . The solidifying filaments  22  are then laid down on a first conveyor belt  24  to form a web  26 . The web  26  is then bonded by rollers  28  to form a spunbonded web  30 . The spunbonded web  30  is then transferred by a second conveyer belt  32  and then to a windup  34 . The spunbonded process is an integrated one step process which begins with a polymer resin and ends with a finished fabric.  
       [0005]FIG. 2 illustrates the melt blown process  40  for manufacturing non-woven materials. Thermoplastic forming polymer  42  is placed in an extruder  44  and is then passed through a linear die  46  containing about twenty to forty small orifices  48  per inch of die width. Convergent streams of hot air  50  rapidly attenuate the extruded liquid polymer streams  52  to form solidifying filaments  54 . The solidifying filaments  54  subsequently get blown by high velocity air  56  onto a take-up screen  58 , thus forming a melt blown web  60 . The web is then transferred to a windup  62 . U.S. Pat. No. 4,380,570 entitled “Apparatus and Process for Melt-Blowing a Fiberforming Thermoplastic Polymer and Product Produced Thereby” describes the melt blown process and is incorporated herein by reference in its entirety.  
       [0006] While non-woven materials can be manufactured by either the spunbonded or melt blown process, there are difficulties associated with each process. For example, the newly manufactured non-woven material (e.g. melt blown web  60 ) tends to stick to the take-up screen  58 . Further, the processes produce sheet material. Accordingly, to manufacture non-woven materials into three-dimensional shapes, e.g. surgical masks and pleated filters, some form of post-processing is required.  
       [0007] In addition, non-woven processes for the production of spunbond and meltblown materials may use travelling belt collectors or drums upon which to form the non-woven materials or “webs.” Normally, a single drum or belt is used for this purpose. There has been some progress in the design of “multi-beam” equipment, where a traveling belt is used as a collector, and multiple spinnerettes are positioned over the belt in order to produce multi-layered webs of spunbond and meltblown materials.  
       [0008] The spinnerettes can be shifted to a variety of positions in order to produce composite webs of different structure, such as a layered spunbond/meltblown/spunbond (SMS) web. These layered webs can then be bonded or otherwise treated in a “post laydown” period to consolidate the layers.  
       [0009] Certain advantages can be achieved by use of this system. For example, one continuous belt acts as a transport system as well as a laydown area or collector for the meltblown or spunbond fibers. There are a number of disadvantages, however. For example, each layer must be collected on top of the last deposited layer of the web. Therefore, each time a layer of the web is collected on the belt, it blocks or changes the “air flow profile” on the collector, so as to present a less desirable collecting surface for the next layer of the web. Each subsequent layer of the web therefore is generally less uniform and of poorer overall quality.  
       SUMMARY OF THE INVENTION  
       [0010] The present invention employs at least two drums, where each drum is made of a generally tubular honeycomb member having an outer collection surface for forming a non-woven web thereon. A non-woven fiber source applies solidifying filaments to each drum. A web transport system is provided for forming a multi-layered web.  
       [0011] In another embodiment of the present invention, a through-air bonding apparatus may be placed in proximity to at least one of the drums to add structural integrity to the non-woven web being formed on the drum.  
       [0012] In yet another embodiment of the present invention, one of the drums may have a contoured outer collection surface to form a contoured non-woven web. Optionally, filler material can be added in the contours to be incorporated into the multi-layered web.  
       [0013] Another embodiment of the present invention relates to a method of producing a multi-layer web. In one embodiment, the method includes providing at least two drums, each drum having a generally tubular honeycomb member with an outer collection surface for forming a non-woven web thereon. A non-woven fiber source applies solidifying filaments to each drum. A web transport system is provided for forming the multi-layered web. The method includes supplying non-woven fibers from the non-woven fiber sources to the corresponding drums, forming independently non-woven webs on each of outer collection surface of the drums, and forming the multi-layer web on the web transport system. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0014] The above and further advantages of this invention may be better understood by referring to the following description, taken in conjunction with the accompanying drawings, in which:  
     [0015]FIG. 1 is a schematic of a spunbonded process for manufacturing non-woven materials;  
     [0016]FIG. 2 is a schematic of a melt blown process for manufacturing non-woven materials;  
     [0017]FIG. 3A is a perspective view of an embodiment of the drum of the current invention, illustrating a contoured honeycomb tube with an outer microporous surface;  
     [0018]FIG. 3B is a partially exploded side view of the drum illustrating a mounting structure, vacuum apparatus, and V-belt drive groove;  
     [0019]FIG. 3C is a partially exploded perspective view of the drum structure;  
     [0020]FIG. 4 is a partial cross-sectional view of the drum taken along line  4 - 4  in FIG. 3A illustrating a pleated surface of the drum;  
     [0021]FIG. 5 is a partial radial view of the drum illustrating the honeycomb mesh;  
     [0022]FIG. 6 is a cross-sectional view of the drum taken along line  6 - 6  in FIG. 3A illustrating a contoured outer surface having a three dimensional surface;  
     [0023]FIG. 7 is a schematic of a process of the current invention for the manufacture of non-woven materials that substantially match the contoured outer surface of the drum;  
     [0024]FIG. 8 is a schematic of a process of the current invention for the post processing of non-woven materials after a three dimensional contour has been formed;  
     [0025]FIG. 9 is a schematic perspective view illustrating a first material and a second material bridging a three dimensional contour;  
     [0026] FIGS.  10 A- 10 C are schematic perspective views illustrating three embodiments of three dimensional shapes that can be formed in a non-woven material by a process of the current invention;  
     [0027]FIG. 11 is a schematic perspective view of a drum apparatus for the manufacture of non-woven materials;  
     [0028]FIG. 12 is a schematic perspective view of an outer drum sector and an inner vacuum tube assembly or manifold of the current invention;  
     [0029]FIG. 13 is a schematic perspective view of an inner tube and a vacuum shell of the manifold of the current invention;  
     [0030]FIG. 14 is a schematic top view of a vacuum frame of the inner tube and vacuum shell depicted in FIG. 13;  
     [0031]FIG. 15 is a partial cross-sectional view of the vacuum tube assembly taken along line  15 - 15  in FIG. 14;  
     [0032]FIG. 16 is a cross-sectional view of the inner tube and vacuum shell taken along line  16 - 16  in FIG. 15;  
     [0033]FIG. 17 is an exploded view of Detail  17  in FIG. 15;  
     [0034]FIG. 18 is a schematic bottom view of an inner tube of the manifold;  
     [0035]FIG. 19 is a schematic side view of the inner tube of the manifold;  
     [0036]FIG. 20 is a partial cross-sectional view of the inner tube taken along line  20 - 20  in FIG. 19;  
     [0037]FIG. 21 is a schematic perspective view of vanes for controlling air flow direction in the manifold;  
     [0038]FIG. 22 is a schematic side view of the shell and inner tube showing the orientation of the vanes for controlling air flow direction in the manifold;  
     [0039]FIG. 23 is a schematic perspective view of one set of vanes installed in the manifold;  
     [0040]FIG. 24 is a schematic exploded view of the inner tube, the vacuum shell, the vanes, the frame, the brackets, and the honeycomb of the manifold;  
     [0041]FIG. 25 is a perspective view of a drum and a through-air bonding apparatus for the manufacture of non-woven materials;  
     [0042]FIG. 26 is a front view of a drum and bonding manifold of the current invention;  
     [0043]FIG. 27 is a side view of a drum and through-air bonding system of current invention; FIG. 28 is a side view of a portion of the drum surface and manifold of the current invention;  
     [0044]FIG. 29 is a side view of a portion of a contoured drum surface and manifold of the current invention;  
     [0045]FIG. 30 is a table showing typical ranges of process parameters for the current invention;  
     [0046]FIG. 31 is a schematic diagram illustrating an apparatus for forming a multi-layered web; and  
     [0047]FIG. 32 is a schematic diagram illustrating another apparatus for forming a multi-layered web. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0048] Referring to FIG. 3A, shown is a drum  100  having a contoured outer surface  102  which may take many different shapes and forms. As shown, the drum  100  is made of a tubular honeycomb member  104  that is surrounded by a microporous layer  106 . The microporous layer  106  is tack welded to the tubular honeycomb member  104  and may be finely electroetched stainless steel having numerous holes on the order of about 0.010 inches (0.25 mm) in diameter, at a spacing such that the microporous layer  106  is uniformly about fifty percent open. A frame  108  rotatably supports the drum  100 . The material for the tubular honeycomb member  104  can be, but is not limited to, stainless steel.  
     [0049] Referring to FIG. 3B, the drum  100  is supported by the frame  108  or frames, so that the drum  100  can be rotated as the solidifying filaments are continuously applied by spunbonded or melt blown processes or by electro-spinning of nano-fibers. FIG. 3B also shows an internal pipe  70  with a vacuum port  72  and a bearing surface  74 . The pipe  70  is located in the center of the drum  100 . The pipe  70  also has a slot  73  that is in communication with the vacuum port  72  to draw a negative pressure  75  through a sector of the drum  100  to conform the solidifying filaments to the contour. See FIG. 7. Also shown is V-belt drive  76  which can be used to rotate the drum  100  by any conventional source known to those skilled in the art, such as a variable speed motor.  
     [0050] Referring to FIG. 3C, the drum  100  includes inner support bars  78  which are located throughout the drum  100 . The inner support bars  78  provide stiffness to the drum  100  and allow a negative pressure  75  or positive pressure  79  to be provided to a portion of the drum  100 , as shown in FIG. 7. FIG. 3C also shows that the drum  100  includes a plurality of panels  80  that can attached to the drum  100  by a variety of means (e.g., fasteners or clips). The panels  80  can be made of honeycomb with a microporous outer layer to form any desired contoured outer surface  102 .  
     [0051] Referring to FIG. 4, shown is a partial cross-sectional view of one embodiment of the drum  100  of the present invention. The drum  100  has a contoured outer surface  102  that has the shape of alternating peaks  110  and valleys  112 . The contoured outer surface  102  is covered by the microporous layer  106 . As will be further shown, the contoured outer surface  102  with alternating peaks  110  and valleys  112  can be used to form pleated-shaped non-woven articles useful as particulate air filters.  
     [0052] Referring to FIG. 5, shown is a partial radial view of a portion of the drum  100  illustrating a rectangular mesh  114  of tubular honeycomb member  104 . The mesh  114  consists of alternating multiple rows of mesh holes  116 , where each row is offset from the previous row. Each mesh hole has a length  118  and width  120 . In one embodiment the mesh hole length  118  is about 0.5 inches (1.3 cm) and the width  120  is about 0.25 inches (0.64 cm). By using a rectangular mesh  114 , the honeycomb member  104  can be readily formed into a circular contour.  
     [0053] Referring to FIG. 6, shown is another partial cross-sectional view of the drum  100  illustrating a three dimensional form  122  that is attached (e.g., tack-welded) to the drum  100 . The three-dimensional form  122  also has honeycomb construction and can be formed by, but not limited to, electrical discharge machining. The three-dimensional form  122  is also covered by the microporous layer  106 . As will be further shown, the three-dimensional form  122  can be used to make, for example, a surgical mask shaped article.  
     [0054]FIG. 7 shows one process for manufacturing contoured non-woven articles. Thermoplastic forming polymer  150  is placed in an extruder  152  and passed through a linear die  154  containing about twenty to forty or more small orifices  156  per inch of die  154  width. Convergent streams of hot air  158  rapidly attenuate the extruded liquid polymer  160  to form solidifying filaments  162 . The solidifying filaments  162  subsequently get blown by high velocity air  163  onto the contoured outer surface  102  of drum  100 . Note that the method illustrated in FIG. 7 for generating the solidifying filaments  162  is a melt blown process, but a spunbonded process, or any other method for generating the solidifying filaments  162  can be used, such as electro-spinning of nano-fibers using an electrostatic spun technique. Melt blown process equipment is available from Biax Fiberfilm Corporation located in Wisconsin.  
     [0055] The drum  100 , which is rotating, has a contoured outer surface  102 , which can have a combination of shapes, for example, alternating peaks  110  and valleys  112  or a series of three dimensional forms  122 . Once the solidifying filaments  162  are deposited on the drum  100 , a vacuum or negative pressure  75  can be applied to a portion of the drum  100  to conform the solidifying filaments  162  to the contoured outer surface  102 , to prepare closely matching contoured non-woven materials  164 .  
     [0056] After the contoured non-woven materials  164  are formed, the rotating drum  100  rotates to a point where the contoured non-woven materials  164  are removed from the drum  100 . Positive pressure  79  can optionally be applied through a portion of the drum  100  to facilitate removing the contoured non-woven materials  164  from the drum  100 . Once off the drum  100 , the contoured non-woven material  164  can be post processed in a variety of post processing operations, for example by application of a spray  165 . The treatment can consist of adding various supplements such as flame retardents, stain repellents, colored dyes, and the like, or to change the shape, feel, texture, or appearance of the contoured non-woven material  164 .  
     [0057]FIG. 8 is an expanded view of additional optional post processing performed on the contoured non-woven material  164 . In addition to the treatment operations discussed above, a first material  171  may be added to the contoured non-woven material  164  in order to achieve desired properties in a final product  168 . The first material  171  may be a non-woven material or any other material, based on properties required in the final product  168 . For example, some materials that can be used for the first material  171  are absorbent substances or charcoal or other filter materials known to those skilled in the art. The first material  171  may be selected based on desired material properties such as pore size, fiber diameter and length, basis weight, and density.  
     [0058]FIG. 8 shows a process step  180  for adding the first material  171  to the contoured non-woven material  164 . The process  180  for adding the first material  171  to the contoured non-woven material  164  may be a spunbonded process or a melt blown process for non-woven materials. Alternatively, loose fill or preformed sheet goods, with or without an adhesive treatment, can be deposited on the non-woven material  164 . If the first material  171  is a material other than a non-woven material, a person skilled in the art can choose the appropriate method for manufacturing the desired material. An additional process  172  can add a second different material  173  on top of the first material  171 . The same considerations used to select the first material  171  can be used to select the second material  173 .  
     [0059] A covering material  182  from a source  181  may be placed over the contoured non-woven material  164 . The covering material  182  captures or retains the first material  171  and the optional second material  173  within the contoured non-woven material  164 . Some materials that may be used for the covering material  182  are organic fibers, inorganic fibers, and polymers, which can be in the form of woven or non-woven sheet goods, films, and the like, and which may or may not be porous. The covering material  182  may be adhered or bonded to the contoured non-woven material  164  by a variety of processes  184  known to those skilled in the art, such as a pair of rollers, a heated die, etc. to seal and/or laminate the layers. Additional layers of materials and coverings may be applied, as desired.  
     [0060]FIG. 9 illustrates the presence of the first material  171  and the second material  173  in the valleys of a pleated contoured non-woven material  164 . The first material  171  and the second material  173  effectively bridge  174  the peaks  110  in the pleated material  164 . The bridge  174  may be made up of just the first material  171 , a combination of the first material  171  and the second material  173 , or a plurality of different desired materials. The bridge  174  may bridge or partially or fully fill any three dimensional contour.  
     [0061] The process of FIG. 8 results in a wide variety of articles which can be used in a variety of applications. One embodiment resulting from the process of FIG. 8 consists of a non-woven material  164 , where the first material  171  added is a carbon filtration material and a covering material is applied overall. Another embodiment consists of a non-woven material  164 , where the material added results in a varying gradient filter article. The varying gradient filter article has multiple filter layers. Each layer can have its own filter pore size. Each layer in the varying gradient filter article can trap different particle sizes. In addition, another embodiment of the process of FIG. 8 consists of a non-woven material  164 , where the first material  171  added can be a high loft material, so that the resultant article can be used for absorption of oil or other liquid. Other materials can be selected by a person skilled in the art, based on the particular application and performance sought.  
     [0062] FIGS.  10 A- 10 C show additional three dimensional contours which can be manufactured by the process, such as half tube  175 , multinodal  176 , and pyramidal or frustoconical  177  contours. Other contours, both regular and irregular, will be apparent to those skilled in the art based on the teachings herein.  
     [0063] Referring back to FIG. 7, after any post processing has been completed, the contoured non-woven material  164  may pass through a cutter  166 , to cut the contoured non-woven material  164  into the desired article or final product  168 . The cutter  166  may be a die, water jet, laser, or any other apparatus capable of trimming to the desired contour. Any waste  170  after the cutting operation can either be disposed of or recycled. Accordingly, non-woven contoured articles such as wipes, filters, face masks, sorbent products, insulation, clothing, and the like can be rapidly produced from polypropylene, polyester, or other materials in a continuous process at low cost.  
     [0064] While an open, apertured inner tube  70 , such as that depicted in FIG. 3B, may be used in a variety of applications with good results, it may be desirable to better control the pressure and/or flow across the drum  100  by using an internal manifold with adjustable features and low losses. Accordingly, the amount of suction or pressure applied to the material deposited on the drum can be tailored for the particular material, density, contour, etc.  
     [0065] Referring to FIG. 11, shown is an embodiment of an apparatus  130  for the manufacture of non-woven articles. The apparatus  130  includes a rotatable honeycomb drum  100 . The drum  100  can have a contoured surface, as discussed hereinabove, and have an adjustable manifold disposed therein.  
     [0066] Referring to FIG. 12, shown is an embodiment of a manifold tube assembly  200  for controlling flow in the drum  100 , solely a portion of which is depicted. The tube assembly  200  includes an inner tube  202  and a vacuum shell  206 . Either vacuum or pressure may be applied to the drum  100 . The tube assembly  200  defines an air flow path inside the drum  100 . The air flow path passes through a honeycomb panel  216 , past a partition top  208 , along a channel formed between the inner tube  202  and the vacuum shell  206 , through port  215 , and inner tube  202 . See FIG. 16. Air may flow into or out of the manifold  200  and the drum  100  along the flow path defined above, depending on whether vacuum or pressure is applied to the inner tube  202 .  
     [0067] Referring to FIG. 13, shown is a perspective view of an embodiment of the inner tube  202  and vacuum shell  206  of the manifold  200 . The inner tube  202  passes through the vacuum shell  206 . The vacuum shell  206  has a partitioned bottom  203  to direct air through a plurality of ports  215  of inner tube  202  to allow air to pass into or out of the inner tube  202 . See FIG. 18. The vacuum shell  216  includes a vacuum plate  205  at each end sealed to the inner tube  202  to prevent air from leaking around the inner tube  202 . A honeycomb panel  216  can be mounted within vacuum frame  211 , as shown in FIG. 24, to provide a uniform distribution of air flow through the vacuum shell  206 .  
     [0068]FIG. 13 shows the vacuum shell  206  is split into left and right halves by a center ring partition  201  and along its longitudinal axis by top partition  208  and bottom partition  203 . FIG. 15 shows each side or half can be balanced for airflow via a plurality of gate valves  210 , which can be adjusted independently to uncover, partially cover, or fully cover the ports  215 . The double tube arrangement (inner tube  202  within vacuum shell  206 ) is used to provide tailored airflow without the use of a plurality of separate pipes. The double tube configuration of the manifold  200  also provides an efficient method for redirecting airflow from a radial to an axial direction.  
     [0069]FIG. 14 shows a view of the inner tube  202  and vacuum shell  206  viewed through the vacuum frame  211 . This view illustrates the center ring  201  for dividing the air flow at a midpoint of the inner tube  202  and the drum  100 . Two additional rings  201 ′,  201 ″ are depicted, which further subdivide the vacuum frame opening into eighths.  
     [0070] Referring to FIG. 15, shown is a partial cross-sectional view of the inner tube taken along line  15 - 15  in FIG. 14. FIG. 15 illustrates one embodiment for controlling the flow of air in the drum. Gates  210  can be moved over ports  215  to modify the flow of air into or out of inner tube  202 . In one embodiment, the gates  210  are slotted and can be attached to the inner tube  202  by screws  213 .  
     [0071] Referring to FIG. 16, shown is a partial cross-sectional view of the inner tube  202  and vacuum shell  206  along line  16 - 16  in FIG. 15. FIG. 16 illustrates the flow path of air drawn through the drum  100  and into the manifold  200 . For descriptive purposes only, a vacuum flow through the drum is described, but the path can be reversed to apply a pressure to the drum to facilitate removing a non-woven article formed thereon. Air is drawn through the outer drum honeycomb assembly (not shown), through the honeycomb panel  216 , into an annular channel formed between the vacuum shell  206  and the inner tube  202 , and then into the inner tube  202  through ports  215 . FIG. 16 also shows once the air is in the inner tube  202 , air is drawn out of the inner tube through one or more openings at the ends of the inner tube  202 .  
     [0072]FIG. 17 is an exploded view of Detail  17  in FIG. 15 to illustrate the relationship between the ports  215 , gates  210 , and screws  213 . As may be readily understood, by subdividing the vacuum tube assembly into a plurality of zones, with airflow paths independently controllable using the gates  210 , vacuum or pressure applied to various zones of the drum passing thereover can be tailored to achieve a desired result.  
     [0073]FIG. 18 is a bottom view of the inner tube  202  showing the ports  215  in the inner tube  202  which allow air to pass into or out of the inner tube  202 . This embodiment employs sixteen ports  215 . FIG. 19 is a side view of inner tube  202 .  
     [0074] Referring to FIG. 20, shown is a view along cross-section  20 - 20  of the inner tube  202  of FIG. 19. Tapped holes for the gate screws  213  may be located for convenient access to facilitate adjustment of the gates  210 . In this embodiment, they may be located at an angle a of about 100° to about 110°, although any location can be selected.  
     [0075] Referring back to FIG. 13, the vacuum shell  206  is split into left and right halves by a center ring portion  201  and along its longitudinal axis by top partition  208  and bottom partition  203 . FIG. 13 shows an embodiment where the vacuum shell  206  is divided by similar rings  201 ′,  201 ″ which are parallel to the outer ring, further subdividing the shell  206  into multiple compartments. In this embodiment, there are eight compartments so formed. Each compartment can be balanced for airflow volume via a separate gate valve  210  which can be adjusted to uncover, partially cover, or fully cover two ports  215 . In addition, the efficiency of airflow in each compartment can be enhanced and losses reduced by using optional flow turning vanes  217 .  
     [0076]FIG. 21 shows a perspective view of the flow turning vanes  217  used in each compartment. Rails  227  are connected to leading edges of the flow turning vanes  217  to hold the flow turning vanes  217  together. The flow turning vanes  217  are then placed on the top partition  208  as best seen in FIG. 23. Once the flow turning vanes are placed on the top partition  208 , the downstream edges of the flow turning vanes  227  are suspended in the annular channel between the inner tube  202  and the vacuum shell  206 . By altering the distance between the downstream edges the airflow speed may be altered over the entire surface covered by the vanes  217 .  
     [0077]FIG. 22 is a side view of the inner tube  202  and the vacuum shell  206  which shows the position of the flow turning vanes  217  in the annular channel between the inner tube  202  and the vacuum shell  206 . FIG. 22 also shows the relationship between the manifold  200  and the drum  100 . Note that only a section of the drum  100  is shown in FIG. 22.  
     [0078]FIG. 23 is a perspective view of two sets of the vanes  217  installed in two of the compartments of the manifold  200  and FIG. 24 is an exploded view. Vanes  217  can be used in all, some, or none of the compartments and can be of similar or different number and configuration, depending on the particular application and desired results. In the assembly, the flow turning vanes  217  and rails  227  are placed on the top partition  208 . Then the frame  211  is mounted to the vacuum shell  206 . Brackets  218  are then screwed on to the vacuum shell  206  to constrain the frame  211 . Screws  222  to attach the frame  211  to the vacuum shell  206  run through holes  220  in the brackets  218 . Finally, an optional honeycomb panel  216  is placed inside the frame  211 . The height of the honeycomb  216  relative to the turning vanes  217  can be adjusted.  
     [0079] The double arrangement of the inner tube  202  within the vacuum shell  206 , coupled with the flow turning vanes  217  and gate valves  210 , are used to provide tailored air flow on the honeycomb panel  216  and, accordingly, through the drum  100 , in both machine direction and cross direction. The double arrangement of the inner tube  202  within the vacuum shell  206 , coupled with the turning vanes  217 , also provides a method for redirecting airflow from a radial to an axial direction efficiently.  
     [0080] The following detailed description relates to a method and apparatus for use with a honeycomb drum and a through-air bonding apparatus for forming non-woven articles. The method and apparatus provide a hot air flow through non-woven articles being formed on the drum which bonds the non-woven articles internally, without the use of compression rollers or heated calender rollers.  
     [0081] Referring to FIG. 25, shown is an embodiment of an apparatus  600  for the manufacture of non-woven articles. The apparatus  600  includes a rotatable honeycomb drum  502 . The drum  502  can have a contoured outer surface, as discussed above. In addition, the apparatus  600  also includes a through-air bonding apparatus  504 .  
     [0082] The apparatus  600  includes a drum control unit  506  to control the movement of the drum  502  and a hot air control unit  508  to control the temperature, pressure, and volume of air to be used to internally bond and consolidate non-woven articles formed on the drum  502 . Air is supplied from an air source to the hot air control unit  508  and then conveyed to the through-air bonding system  504  through one or more pipes  510 . In one embodiment, unheated air can be supplied to the through-air bonding apparatus  504 . The air can be heated by one or more heaters  512  attached to the through-air bonding apparatus  504 . Heated air is then fed to a manifold  514  in the through-air bonding apparatus  504 .  
     [0083] Referring to FIG. 26, shown is an embodiment of the drum  502  and manifold  514  of the through-air bonding apparatus  504 . The air is fed from pipes  510  to heaters  512  to heat the air. Heated air is fed by pipes  516  to the manifold  514 . The manifold  514  generally include a flow control honeycomb structure  518  to provide a uniform distribution of the heated air to the drum  502 . The manifold  514  also includes a centrally located internal manifold compartment bulkhead  519  and optionally can include further bulkheads, turning vanes, etc. to provide a more uniform or tailored distribution of heated air. The controlled distribution of heated air results in predetermined consolidation of non-woven materials formed on the drum  502 . Using a tailored distribution of heated air to achieve predetermined consolidation of non-woven materials can be important in forming non-woven materials with three-dimensional shapes. Heated air exits the manifold  514  through manifold aperture  520 . As disclosed in the above-referenced patents, a vacuum can be drawn through the drum  502 . The heated air exiting the aperture  520  can be drawn through the non-woven material and the drum  502  and out through the center of the drum through air duct  522 .  
     [0084] Referring back to FIG. 25, the air duct  522  is used to return the air back to the air source. The apparatus of FIG. 25 also includes an aperture height adjustment  524  to adjust the height or standoff of the aperture  520  relative to the drum  502 .  
     [0085]FIG. 27 shows one embodiment of the drum  502  and through-air bonding apparatus  504  which uses a spun bond method for creating a non-woven web; however, melt blown, electro spinning of nano-fibers, or other methods of making a non-woven webs known to those skilled in the art can be used.  
     [0086] A spinneret  526  generates a series of solidifying filaments or fibers  528  which form a non-woven web  530  on drum  502 . Note that a belt can be used in place of the drum  502 . The drum  502  then moves the non-woven web  530  past a separation panel  532  and passes the non-woven web  530  under the through-air bonding apparatus  504 . The separation panel  532  isolates the newly formed non-woven web  530  from hot air until the non-woven web  530  is positioned under the through-air bonding apparatus  504 .  
     [0087] Prior to applying hot air, the non-woven fibers  528  from the spunbound process which form the non-woven web  530  and can easily be pulled apart. At this point the non-woven web  530  does not have enough structural integrity to be passed from the drum  502  to a web transfer roll  536 . A through-air bonding process applies hot air from the through-air bonding apparatus  504  to the non-woven web  530  to achieve an internally bonded, consolidated non-woven material  534 .  
     [0088] After the hot air passes through the non-woven material  530 , the hot air is drawn into the drum  502  through a vacuum or hot air collection system  538  in the drum  502 . The hot air then passes to air ducts  522  which return the air back to the air source.  
     [0089] The amount of bonding provided to the non-woven material can be adjusted by changing the temperature of the air, the distance of the aperture  520  supplying the air relative to the drum  502 , the velocity of the air, and the volume of air. The amount of bonding can be set to achieve a desired material property in the non-woven material. Some material properties that can be affected by the amount of bonding are the softness and drape of the non-woven material. The drape of the non-woven material is the ability of a non-woven material to fold onto itself and conform to the shape of an article it covers.  
     [0090] In addition, the amount of bonding applied to the non-woven material  530  can be set to provide enough structural integrity to eliminate the need for compression rollers and heated calender rollers used in the prior art to provide structural integrity to the non-woven web  530 . By eliminating the use of compression rollers and heated calender rollers, the resulting internally bonded non-woven material  534  has more loft than if the heated calender rolls and compression rollers were used. However, if one desires to have certain non-woven material properties associated with the use of calender rolls, such as strength or compaction, a calender roll may be added downstream from the through-air bonding apparatus  504 .  
     [0091] After passing under the through-air bonding apparatus  504 , the bonded non-woven material  534  is transferred to a web transfer roll  536 . Then the bonded non-woven material  534  can be post-processed as discussed above.  
     [0092] Referring to FIG. 28, shown is an embodiment of the manifold  514  and drum  502 . FIG. 28 shows dimension D, which represents the height of the aperture  520  in the manifold  514  relative to the drum  502 . The height D can be adjusted by the height adjustment mechanism  524  shown in FIG. 25, using twin screws. By adjusting the height D, the amount of bonding of the non-woven material  530  can be modified to achieve a desire material property in the bonded non-woven material  534 .  
     [0093]FIG. 29 illustrates an embodiment of the drum  502  and the through-air bonding apparatus  504  where the drum  502  has three-dimensional contours. The three-dimensional contours on the drum  502  allow a non-woven article with a three-dimensional shape to be formed using the methods described above. By using through-air bonding, this allows bonded non-woven materials  534  with three-dimensional shapes to be bonded without the use of compression rollers or heated calender rolls. Bonding non-woven materials with three-dimensional shapes without the use of compression rollers or heated calender rolls allows the non-woven material to maintain its three-dimensional shape.  
     [0094]FIG. 30 is a table showing typical ranges of process parameters in accordance with the current invention.  
     [0095] A multi-drum system may be employed to improve multi-layered web uniformity and the overall quality of the non-woven product by presenting a single optimal collection surface for each independent web layer being produced. In FIG. 31, a first drum  702  is shown collecting solidifying fibers  704  from a spunbond spinneret  706 . A vacuum port  708  on the drum  702  may be “air flow balanced” as previously described and, by design, presents an optimum condition to the fibers for formation of the spunbond layer of the web  710 . Each subsequent drum similarly provides an optimum condition for producing one or more additional spunbond and/or meltblown layers. FIG. 31 also shows drum  712  collecting solidifying fibers  714  from spunbond spinneret  716  to form a second spunbond layer  718 . Spunbond layers  710  and  718  may be passed through respective nip rollers  719 . In addition, also shown in FIG. 31 is drum  720  collecting solidifying fibers  722  from a melt blown source  724  to form meltblown layer  726 . Each web layer is then independently distributed to the transport system  728  for incorporation and consolidation into the multi-layered web  730 . In one embodiment, the transport system  728  can be a travelling belt. The multi-layered web  730  can be calendared with calendar rolls  732 , if desired.  
     [0096] Optionally, other roll goods may be distributed into the multi-layered web  730 , such as a thin polymer film  734 , shown in FIG. 31. Similarly, other optional processes may be incorporated “in line,” such as bonding or finishing, shown as post processing apparatus  735 . In the embodiment shown in FIG. 31, the multi-layer web  730  is made from spunbond layers  710  and  718 , meltblown layer  726 , and film layer  734 .  
     [0097] Through-air bonding of the web can be advantageously employed on one or more of the drums in order to provide bonding, strength, and integrity to the various layers of the web. As previously described, heated air  736  is applied, through a manifold  738 , over a wide area of the web, in order to cause a softening and/or slight melting of the individual fibers. The fibers are fused together at the points where they touch or contact each other, causing a permanent bond joint. If desired, the fibers may be specially manufactured to improve the bonding conditions. This may include the use of bicomponent fibers, such as a polypropylene material core sheathed with polyester material, or a “side-by-side” configuration of polypropylene and polyester fibers. This technique takes advantage of the lower melting point of the second component fiber, enhancing the bond condition.  
     [0098] Multi-zone thru-air ovens may be used for highloft bonding of the web at low speeds. Heated air is applied to the spunbond layer of the web, as it is newly formed on the surface of a drum. The spunbond layer is thereby provided with enough structural integrity to be unwound from the drum, for post processing, or for introduction of the spunbond layer into a multi-layered web structure. In this manner, the web can be processed at very high speeds utilizing through-air bonding on a drum collector. For a description of thermal bonding methods, refer to web page entitled “Thermal bonding processes,” found at address http://www.nonwovens.com/facts/technology/bonding/thermal.htm, the disclosure of which is incorporated herein in its entirety by reference.  
     [0099] In the “stacked drum” configuration shown in FIG. 32, other processes are shown being accommodated. In this embodiment, a meltblown process is combined with a spunbond process and a 3-D meltblown process, in accordance with the description hereinabove. The meltblown process uses meltblown fiber source  740  to provide meltblown fibers  742  to form a meltblown web  744  on drum  746 . The spunbond process uses spunbond fiber source  748  to provide spunbond fibers  750  to form spunbond web  752  on drum  754 . Manifold  755  can be used to supply heated air  757  to cause a softening or slight melting of the fibers. The 3-D meltblown process uses meltblown fiber source  756  to provide meltblown fibers  758  to form contoured meltblown web  760  on contoured drum  762 . Further, an optional dispenser  764  distributes materials  766  such as cellulose, carbon, filtration, superabsorbent, or other materials into the 3-D shapes to produce a filled layered web. Superabsorbent materials are also known as superabsorbent particles or SAP. Superabsorbent materials are disclosed in U.S. Pat. No. 5,064,653, the contents of which are incorporated by reference in its entirety. Typical superabsorbent materials include sodium and aluminum salts of starch grafted copolymers of acrylates and acrylamides and combinations thereof, as well as polyacrylate salts. A film layer, impervious to the flow of liquids therethrough, may optionally be added, as desired. Subsequent finishing operations may include bonding with bonding rolls  768  or other treatment of the web to further consolidate or process the multi-layered material.  
     [0100] Many different combinations and permutations of the configurations of the embodiments described above are possible. For example, multiple sources of non-woven fibers could be applied to either different circumferential or axial locations on a drum. In addition, a belt may be used in place of a drum.  
     [0101] Variations, modifications, and other implementations of what is described herein will occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the invention is to be defined not by the preceding illustrative description, but instead by the following claims.