Abstract:
A method of manufacturing a non-woven material uses a contoured honeycomb drum with an outer microporous surface, more particularly with a contoured outer surface, for the manufacture of contoured non-woven fibrous materials. The method can use spunbonded, melt blown, or electro-static spun techniques for depositing solidifying filaments on the microporous surface such that the non-woven material conforms to the contour of the drum. The drum facilitates continuous production of non-woven articles with three-dimensional shapes such as surgical masks or pleated air filters. Airflow through the drum can be controlled with an internal adjustable manifold with independent valves to obtain non-woven material articles of various configurations and properties. In addition, efficiency can be improved by including turning vanes. Vacuum or pressure can be applied.

Description:
RELATED APPLICATIONS  
       [0001]    This application is related to and claims priority to U.S. patent application Ser. No. 60/170,037 entitled “Method and Apparatus for Controlling Flow in a Drum, filed on Dec. 10, 1999, as well as is related to 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 a honeycomb drum with an outer microporous surface to produce non-woven articles and more particularly, to an internal manifold for controlling flow in the 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]    [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]    [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  46  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.  
         SUMMARY OF THE INVENTION  
         [0007]    present invention relates to a manifold spanning a sector of a drum across at least a portion of a width thereof, the manifold having at least two chambers independently regulatable with respect to at least one of pressure and flow.  
           [0008]    In another embodiment of the present invention, the manifold is an inner tube located inside of a shell, the shell further having at least one plate to prevent airflow from leaking around the inner tube. The inner tube may also include a plurality of ports to provide fluidic communication between the inner tube and the shell. A plurality of gate valves may be provided in communication with the plurality of ports to regulate at least one of pressure in and flow through the manifold.  
           [0009]    The shell may include a frame forming an aperture and optionally include a honeycomb panel mounted within the frame aperture. At least one flow turning vane may be disposed between the inner tube and the frame aperture. The shell may include at least one partition, thereby defining the at least two independently regulatable chambers.  
           [0010]    Another embodiment of the present invention relates to a drum with a generally tubular honeycomb member that has an outer surface forming a contour. The drum also includes the manifold discussed above, which spans a sector of the drum across a portion of a width thereof. The manifold includes at least two chambers independently regulatable with respect to at least one of pressure and flow. A microporous layer may be provided covering at least a portion of the contour on the outer surface of the drum.  
           [0011]    Another embodiment of the present invention relates to a method of independently regulating at least one of pressure and flow spanning a sector of a drum across at least a portion of a width thereof. In one embodiment, the method includes providing a drum with a manifold spanning a sector of the drum across at least a portion of a width thereof. The manifold is subdivided into at least two chambers independently regulatable with respect to at least one of pressure and flow. The method further includes applying a pressure to the manifold to achieve at least one of a desired pressure or flow profile across the sector of the drum. The applied pressure may be negative (i.e., a vacuum) or positive.  
           [0012]    Another embodiment of the present invention relates to a method for manufacturing non-woven articles. In one embodiment, the method includes providing a drum made of a tubular honeycomb member that forms an outer contour. The drum also includes the manifold discussed above, which spans a sector of the drum along at least a portion of a width thereof. The manifold is subdivided into at least two chambers independently regulatable with respect to at least one of pressure and flow. The drum may include a microporous layer covering at least a portion of the outer contour.  
           [0013]    In accordance with the inventions embodied in a manufacturing system, flows can be tailored to suit the particular contoured articles being formed or to normalize flows across the drum to compensate for inherent variability in conventional vacuum systems. 
       
    
    
     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]    [0015]FIG. 1 is a schematic of a spunbonded process for manufacturing non-woven materials;  
         [0016]    [0016]FIG. 2 is a schematic of a melt blown process for manufacturing non-woven materials;  
         [0017]    [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]    [0018]FIG. 3B is a partially exploded side view of the drum illustrating the mounting structure, vacuum apparatus, and V-belt drive groove;  
         [0019]    [0019]FIG. 3C is a partially exploded perspective view of the drum structure;  
         [0020]    [0020]FIG. 4 is a partial cross-sectional view of the drum taken along line  4 - 4  in FIG. 3A illustrating a pleated surface;  
         [0021]    [0021]FIG. 5 is a partial radial view of the drum illustrating the honeycomb mesh;  
         [0022]    [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]    [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]    [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]    [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]    [0027]FIG. 11 is a schematic perspective view of a drum apparatus for the manufacture of non-woven materials;  
         [0028]    [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]    [0029]FIG. 13 is a schematic perspective view of an inner tube and a vacuum shell of the manifold of the current invention;  
         [0030]    [0030]FIG. 14 is a schematic top view of a vacuum frame of the inner tube and vacuum shell depicted in FIG. 13;  
         [0031]    [0031]FIG. 15 is a partial cross-sectional view of the vacuum tube assembly taken along line  15 - 15  in FIG. 14;  
         [0032]    [0032]FIG. 16 is a cross-sectional view of the inner tube and vacuum shell taken along line  16 - 16  in FIG. 15;  
         [0033]    [0033]FIG. 17 is an exploded view of Detail C in FIG. 15;  
         [0034]    [0034]FIG. 18 is a schematic bottom view of an inner tube of the manifold;  
         [0035]    [0035]FIG. 19 is a schematic side view of the inner tube of the manifold;  
         [0036]    [0036]FIG. 20 is a partial cross-sectional view of the inner tube taken along line  20 - 20  in FIG. 19.  
         [0037]    [0037]FIG. 21 is a schematic perspective view of vanes for controlling air flow direction in the manifold;  
         [0038]    [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]    [0039]FIG. 23 is a schematic perspective view of one set of vanes installed in the manifold; and  
         [0040]    [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. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0041]    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.  
         [0042]    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.  
         [0043]    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 outerlayer to form any desired contoured outer surface  102 .  
         [0044]    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.  
         [0045]    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.  
         [0046]    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.  
         [0047]    [0047]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.  
         [0048]    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 .  
         [0049]    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 retardants, stain repellents, colored dyes, and the like, or to change the shape, feel, texture, or appearance of the contoured non-woven material  164 .  
         [0050]    [0050]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.  
         [0051]    [0051]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 pre-formed 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 .  
         [0052]    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.  
         [0053]    [0053]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.  
         [0054]    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.  
         [0055]    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.  
         [0056]    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.  
         [0057]    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.  
         [0058]    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.  
         [0059]    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 .  
         [0060]    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 .  
         [0061]    [0061]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.  
         [0062]    [0062]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.  
         [0063]    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 .  
         [0064]    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 .  
         [0065]    [0065]FIG. 17 is an exploded view of Detail C 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.  
         [0066]    [0066]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 .  
         [0067]    Referring to FIG. 20, shown is a view along cross-section  20 - 20  of the inner tube  202  of FIG. 19. Topped 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 of about 100° to about 110°, although any location can be selected.  
         [0068]    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 .  
         [0069]    [0069]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 .  
         [0070]    [0070]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, only a section of the drum  100  is shown in FIG. 22.  
         [0071]    [0071]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.  
         [0072]    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.  
         [0073]    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. For example, the manifold may be subdivided into greater or fewer than eight compartments and the compartments need not be the same size. Similarly, the number of valves and ports, as well as the configuration and orientation of the valves and ports need not be the same as disclosed herein.  
         [0074]    Accordingly, the invention is to be defined not by the preceding illustrative description, but instead by the following claims.