Patent Publication Number: US-10786020-B2

Title: Method and system for placing pre-cut nose wires in a facemask manufacturing process

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to the field of protective facemasks, and more specifically to a method and system for placing nose wires in the manufacturing of such facemasks. 
     FAMILY OF RELATED APPLICATIONS 
     The present application is related by subject matter to the following concurrently filed PCT applications (all of which designate the US): 
     a. International Application No.: PCT/US2015/055858; entitled “Method and System for Splicing Nose Wire in a Facemask Manufacturing Process”. 
     b. International Application No.: PCT/US2015/055861; entitled “Method and System for Splicing Nose Wire in a Facemask Manufacturing Process”. 
     c. International Application No.: PCT/US2015/055863; entitled “Method and System for Introducing a Reserve Nose Wire in a Facemask Production Line”. 
     d. International Application No.: PCT/US2015/055865; entitled “Method and System for Cutting and Placing Nose Wires in a Facemask Manufacturing Process”. 
     e. International Application No.: PCT/US2015/055867; entitled “Method and System for Placing Nose Wires in a Facemask Manufacturing Process”. 
     f. International Application No.: PCT/US2015/055871; entitled “Method and System for Placing Nose Wires in a Facemask Manufacturing Process”. 
     g. International Application No.: PCT/US2015/055876; entitled “Method and System for Wrapping and Preparing Facemasks for Packaging in a Facemask Manufacturing Line”. 
     h. International Application No.: PCT/US2015/055878; entitled “Method and System for Automated Stacking and Loading Wrapped Facemasks into a Carton in a Facemask Manufacturing Line”. 
     i. International Application No.: PCT/US2015/055882; entitled “Method and System for Automated Stacking and Loading of Wrapped Facemasks into a Carton in a Facemask Manufacturing Line”. 
     The above cited applications are incorporated herein by reference for all purposes. Any combination of the features and aspects of the subject matter described in the cited applications may be combined with embodiments of the present application to yield still further embodiments of the present invention. 
     BACKGROUND OF THE INVENTION 
     Various configurations of disposable filtering facemasks or respirators are known and may be referred to by various names, including “facemasks”, “respirators”, “filtering face respirators”, and so forth. For purposes of this disclosure, such devices are referred to generically as “facemasks.” 
     The ability to supply aid workers, rescue personnel, and the general populace with protective facemasks during times of natural disasters or other catastrophic events is crucial. For example, in the event of a pandemic, the use of facemasks that offer filtered breathing is a key aspect of the response and recovery to such event. For this reason, governments and other municipalities generally maintain a ready stockpile of the facemasks for immediate emergency use. However, the facemasks have a defined shelf life, and the stockpile must be continuously monitored for expiration and replenishing. This is an extremely expensive undertaking. 
     Recently, investigation has been initiated into whether or not it would be feasible to mass produce facemasks on an “as needed” basis during pandemics or other disasters instead of relying on stockpiles. For example, in 2013, the Biomedical Advanced Research and Development Authority (BARDA) within the Office of the Assistant Secretary for Preparedness and Response in the U.S. Department of Health and Human Services estimated that up to 100 million facemasks would be needed during a pandemic situation in the U.S., and proposed research into whether this demand could be met by mass production of from 1.5 to 2 million facemasks per day to avoid stockpiling. This translates to about 1,500 masks/minute. Current facemask production lines are capable of producing only about 100 masks/minute due to technology and equipment restraints, which falls far short of the estimated goal. Accordingly, advancements in the manufacturing and production processes will be needed if the goal of “on demand” facemasks during a pandemic is to become a reality. 
     The various configurations of filtration facemasks include a flexible, malleable metal piece, known as “nose wire”, along the edge of the upper filtration panel to help conform the facemask to the user&#39;s nose and retain the facemask in place during use, as is well known. The nose wire may have a varying length and width between different sizes and mask configurations, but is generally cut from a spool in a continuous in-line process and laid onto a running carrier nonwoven web (which may include a plurality of nonwoven layers) along an edge that becomes a top edge of the finished mask. The edge is subsequently sealed with a binder material, which also encapsulates and permanently holds the nose wire in place at the top edge. 
     The process steps of conveying the supply of continuous wire, cutting the wire into individual nose wires, and placing the nose wires from the cutter takes time and specialized equipment. In addition, the splicing of a reserve wire onto the continuously running wire generally requires a stoppage of the production line. For mass production of facemasks in an in-line manufacturing process at the throughputs mentioned above, it would be desirable to eliminate the cutting step altogether, as well as the necessity to splice a reserve wire when the running wire is depleted. 
     The present invention addresses this need and provides a method and associated system for high speed cutting and placement of nose wires on the running carrier web in an in-line manufacturing process of facemasks. 
     SUMMARY OF THE INVENTION 
     Objects and advantages of the invention will be set forth in the following description, or may be obvious from the description, or may be learned through practice of the invention. 
     In accordance with aspects of the invention, a method is provided for placing nose wires in a facemask production line. The nose wires are pre-cut into a desired length and are supplied to a dispenser in the production line. With the dispenser, the nose wires are metered and deposited onto a running carrier web that is conveyed past the dispenser at a defined spacing and orientation. For example, the individual nose wires may be deposited along an edge of the carrier web that corresponds to the edge of an upper panel of the finished facemasks. The carrier web with nose wires deposited thereon are then conveyed to a folding station wherein a binder web is folded over an edge of the carrier web such that the nose wires are encapsulated between the binder web and the carrier web. 
     In a particular embodiment, the pre-cut nose wires are supplied in loose, unattached form to a hopper or accumulator that is operationally configured with the dispenser. The hopper may include any manner of mechanical means therein to orient the nose wires, which may then drop through a chute or other guide to the dispenser. 
     The dispenser may be variously configured for the purpose of isolating a single nose wire from the supply of nose wires and then depositing the single nose wire in a rotary or linear manner onto the carrier web. The present inventive method is not limited to any particular type of dispenser or dispensing method. 
     In an alternate embodiment, the pre-cut nose wires may be aligned for dispensing in a cartridge or other package that mates with the dispenser. The cartridge may include an internal biasing device, such as spring, that moves the nose wires towards the dispenser as the nose wires are depleted. Alternatively, the dispenser may have a rack or tray in which the cartridge is loaded, wherein the rack or tray has a biasing mechanism to advance the nose wires. 
     In still another embodiment, the pre-cut nose wires are supplied in a strip form, and are aligned and attached along longitudinal edges in the strip form, for example with an adhesive. For example, the nose wires may be configured similarly to strips of individual staples that are supplied to a staple gun, wherein the dispenser functions like the head of the staple gun with a punch that separates the leading nose wire from the strip for each dispense cycle and deposits the nose wire onto the underlying carrier web. 
     In may be preferred in certain embodiments that an adhesive is pre-applied to a surface of the nose wires that contacts the carrier web. This adhesive has sufficient tack to ensure that the nose wires remain attached to the carrier web at the desired spacing and orientation. 
     The present invention also encompasses various system embodiments for for placing pre-cut nose wires in a facemask production line in accordance with the present methods, as described and supported herein. 
     Other features and aspects of the present invention are discussed in greater detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, which makes reference to the appended figures in which: 
         FIG. 1  is a perspective view of a conventional respiratory facemask worn by a user, the facemask incorporating a nose wire to conform the facemask to the user&#39;s face; 
         FIG. 2  is a top view of the conventional facemask of  FIG. 1  is a folded state; 
         FIG. 3  is a cross-sectional view of the facemask of  FIG. 2  taken along the lines indicated in  FIG. 2 ; 
         FIG. 4  is a top view of a web having a plurality of facemask panels defined therein, with a nose wire incorporated in edges of alternating panels in the web; 
         FIG. 5  is a schematic depiction of a facemask production line related to cutting and placement of nose wires on a web; 
         FIG. 6  is a schematic representation of an embodiment for placement of individual, pre-cut nose wires on a carrier in accordance with aspects of the invention; 
         FIG. 7  is a schematic representation of another embodiment for placement of individual, pre-cut nose wires on a carrier web in accordance with aspects of the invention; 
         FIG. 8  is a schematic representation of yet a different embodiment for placement of individual, pre-cut nose wires on a carrier web in accordance with aspects of the invention. 
     
    
    
     DETAILED DESCRIPTION OF REPRESENTATIVE EMBODIMENTS 
     Reference now will be made in detail to various embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
     As mentioned, the present methods relates to cutting and placement of individual nose wires in a facemask production line. The downstream facemask production steps are not limiting aspects of the invention and, thus, will not be explained in great detail herein. 
     Also, the present disclosure refers to or implies conveyance or transport of certain components of the facemasks through the production line. It should be readily appreciated that any manner and combination of article conveyors (e.g., rotary and linear conveyors), article placers (e.g. vacuum puck placers), and transfer devices are well known in the article conveying industry and can be used for the purposes described herein. It is not necessary for an understanding and appreciation of the present methods to provide a detailed explanation of these well-known devices and system. 
     Various styles and configurations of facemasks that incorporate a nose wire are well known, including flat pleated facemasks, and the present methods may have utility in the production lines for these conventional masks. For illustrative purposes only, aspects of the present method are described herein with reference to a particular type of respirator facemask often referred to in the art as a “duckbill” mask, as illustrated in  FIG. 1 . 
     Referring to  FIGS. 1-3 , a representative facemask  11  (e.g., a “duckbill” facemask) is illustrated on the face of wearer  12 . The mask  11  includes filter body  14  that is secured to the wearer  12  by means of resilient and elastic straps or securing members  16  and  18 . The filter body  14  includes an upper portion  20  and a lower portion  22 , both of which have complimentary trapezoidal shapes and are preferably bonded together such as by heat and/or ultrasonic sealing along three sides. Bonding in this manner adds important structural integrity to mask  11 . 
     The fourth side of the mask  11  is open and includes a top edge  24  and a bottom edge  38 , which cooperate with each other to define the periphery of the mask  11  that contacts the wearer&#39;s face. The top edge  24  is arranged to receive an elongated malleable member  26  ( FIGS. 2 and 3 ) in the form of a flat metal ribbon or wire (referred to herein as a “nose wire”). The nose wire  26  is provided so that top edge  24  of mask  11  can be configured to closely fit the contours of the nose and cheeks of wearer  12 . The nose wire  26  is typically constructed from an aluminum strip with a rectangular cross-section. With the exception of having the nose wire  26  located along top edge  24  of the upper portion  20  of the mask  11 , the upper and lower portions  20  and  22  may be identical. 
     As shown in  FIG. 1 , the duckbill mask  11  has the general shape of a cup or cone when placed on the face of wearer  12  and thus provides “off-the-face” benefits of a molded-cone style mask while still being easy for wearer  12  to carry mask  11  in a pocket prior to use. “Off-the-face” style masks provide a larger breathing chamber as compared to soft, pleated masks which contact a substantial portion of the wearer&#39;s face. Therefore, “off-the-face” masks permit cooler and easier breathing. 
     Blow-by associated with normal breathing of wearer  12  is substantially eliminated by properly selecting the dimension and location of the nose wire  26  with respect to top edge of  24 . The nose wire  26  is preferably positioned in the center of top edge  24  and has a length in the range of fifty percent (50%) to seventy percent (70%) of the total length of the top edge  24 . 
     As illustrated in cross-sectional view of  FIG. 3 , the upper and lower portions  20  and  22  may include multiple layers and each have an outer mask layer  30  and inner mask layer  32 . Located between outer and inner mask layers  30 ,  32  is one or more intermediate layer  34  that comprises the filter media for the mask  11 . This layer is typically constructed from a melt-blown polypropylene, extruded polycarbonate, melt-blown polyester, or a melt-blown urethane. 
     The top edge  24  of the mask  11  is faced with an edge binder  36  that extends across the open end of mask  11  and covers the nose wire  26 . Similarly, the bottom edge  38  is encompassed by an edge binder  40 . Edge binders  36  and  40  are folded over and bonded to the respective edges  24 ,  30  after placement of the nose wire  26  along the top edge  24 . The edge binders  36 ,  40  may be constructed from a spun-laced polyester material. 
       FIG. 4  illustrates the layout of the generally trapezoidal shape for cutting the layers forming the upper body portions  20 . A similar layout would be produced for the lower body portion  22 , which is then brought into alignment with and bonded to the upper body portion  20  in the facemask manufacturing line. More precisely, the layouts of  FIG. 4  represent the outline of cutters which ultimately cut layers  30  and  32  for the upper portion  20  from respective flat sheets of material, with the layouts arranged in an alternating pattern on the flat sheets of material between edges  50 ,  52  representing the open side of mask  11  formed by top edge  24  and bottom edge  38 . The arrangement of the layouts is such that a continuous piece of scrap may be formed as the material is fed through the cutter (not shown) utilized in making mask  11 .  FIG. 4  illustrates placement of cut nose wires  26  on the portions of the continuous web corresponding to the top edge  24  prior to folding and bonding of the edge binders  36 ,  40  along the edges  24 ,  38 . 
       FIG. 5  depicts portions of a production line  106  for facemasks that incorporate a nose wire  26  ( FIG. 4 ). A running wire  101  is supplied in continuous strip form from a source, such as a driven roll  104 , to a cutting station  108 . Suitable cutting stations  108  are known and used in conventional production lines. The station  108  typically includes a set of feed rollers  110  that define a driven nip, wherein one of the feed rollers is driven and the other may be an idler roll. The running wire  101  is fed to a cutter roller  112  configured opposite to an anvil  114  (which may be a stationary or rotary anvil), wherein the cuter roller  112  is driven at a rate so as to cut the running wire  101  into individual nose wires  102  having a defined length. Downstream of the cutter roller  112 , a pair of delivery rollers  116  transports the individual nose wires  102  from the cutting station  108  onto a carrier web  118 . Referring to  FIG. 4 , this carrier web  118  may be the continuous multi-layer web that defines the upper body portion  20  wherein the individual nose wires  26  are deposited along the edge of the carrier web  118  corresponding to the top edge  24 . 
     After placement of the individual nose wires  102  in position on the carrier web  118 , the binder web  120  is introduced to the production line along both edges of the carrier web  118  (only one binder web  120  is depicted in  FIG. 5 .). The combination of carrier web  118 , nose wire  26 , and binder webs  120  pass through a folding station  122  wherein the binder webs  118  are folded around the respective running edges  50 ,  52  of the carrier web  118  ( FIG. 4 ). The components then pass through a bonding station  124  wherein the binder webs  120  are thermally bonded to the carrier web  118 , thereby producing the edge configurations  24 ,  38  depicted in  FIG. 3  with respective binders  36 ,  40 . The nose wire  26  is held in position relative to the top edge  24  by the binder  36 . 
     From the bonding station  124 , the continuous combination of carrier web  118  with nose wires  26  under the binder  36  is conveyed to further downstream processing stations  126  wherein the individual facemasks are cut, bonded, head straps are applied, and so forth. 
     Referring to  FIGS. 6 through 8 , as mentioned, an objective of the present method is to eliminate the cutting station  108  from the production line  106 . In this regard, a method  100  is provided wherein the nose wires  102  are pre-cut into a desired length and are supplied in this form to a dispenser  132  in the production line. With this dispenser  132 , the nose wires  102  are metered and deposited at a defined spacing and orientation onto the running carrier web  118  that is conveyed past the dispenser  132 . For example, the individual nose wires  102  may be deposited along an edge of the carrier web  118  that corresponds to the edge  24  of an upper panel  20  of the finished facemasks. It should be appreciated that an additional dispenser  132  may be operationally disposed opposite to (and upstream or downstream) of the illustrated dispenser  132  in  FIG. 6  for placing the nose wires on the opposite nested upper body portions  20  in the web depicted in  FIG. 4 . For the sake of ease of understanding only one such dispenser  132  is illustrated and described herein. 
     The particular type and operation of the dispenser  132  can vary within the scope and spirit of the invention. For example, the dispenser  132  may utilize a rotary wheel that receives an individual nose wire  102  within a slot at a first position, and rotates to a second position wherein the nose wire  102  falls from (or is ejected from) the slot onto the underlying web. In an alternate embodiment, the dispenser  132  may use a linear slide mechanism that engages an individual nose wire  102  and pushes the wire to a slot where the nose wire  102  falls (or is ejected) onto the carrier web  118 . The present methods  100  are not limited to use of any particular dispenser. 
     Referring to  FIG. 6 , the pre-cut nose wires  102  may be supplied in loose, unattached form to a hopper or accumulator  134  that is operationally configured with the dispenser  132 . A chute  136  may be an integral component of the hopper  134  or may be a separate component installed between the hopper  134  and dispenser  132 . The hopper  134  and chute  136  may include any manner of mechanical means to orient the nose wires  102 , which may then drop through a chute  136  (or other guide means) to the dispenser  132 . Once deposited by the dispenser  132  onto the carrier web  118 , the nose wires  102  and web  118  are conveyed to the folding station  122  and combined with the binder web  120 , as discussed above with reference to  FIG. 5 . 
     Referring to  FIG. 7 , in another embodiment of the method  100 , the pre-cut nose wires  102  are supplied in a strip form  138 . The wires  102  may be aligned and attached along longitudinal edges in the strip form  138 , for example with an adhesive. With this arrangement, the nose wires  102  may be configured similar to strips of individual staples that are supplied to a conventional staple gun. The dispenser  132  functions like the head of a staple gun with a punch member that separates the leading nose wire  102  from the strip  138  for each dispense cycle and deposits the individual nose wire  102  onto the underlying carrier web  118 . 
     In an alternate embodiment of the method  100  depicted in  FIG. 8 , the pre-cut nose wires  102  may be aligned for dispensing in a cartridge  140  or other package that mates with the dispenser  132 . The nose wires  102  may be attached within the cartridge  140 , for example with an adhesive, or may be loose within the cartridge  140 . The cartridge  140  may include an internal biasing device, such as spring  142 , that moves the nose wires  102  towards the dispenser  132  as the nose wires  102  are depleted. Alternatively, the dispenser  132  may have a rack or tray in which the cartridge is loaded, wherein the rack or tray has a biasing mechanism to advance the nose wires. 
     In may be desired that an adhesive is pre-applied to a surface of the nose wires  102  that contacts the carrier web  118 . This adhesive should have sufficient tack to ensure that the nose wires  102  remain attached to the carrier web  118  at the desired spacing and orientation. 
     In an alternate embodiment depicted in  FIGS. 7 and 8 , an adhesive applicator  135  is used to apply an adhesive onto the surface of the carrier web  118  along the edge that will contain the nose wires  102  to further aid in holding the nose wires in the desired spacing and orientation on the web  118 . 
     Referring to  FIGS. 7 and 8 , a controller  144  may be configured with the dispenser  132  to ensure that the dispenser  132  cycles at a rate needed to provide the proper spacing of nose wires  102  along the edge of the carrier web  118 . A speed sensor  146  may be located adjacent to the carrier web  118  and in communication with the controller  144 , wherein the cycle rate of the dispenser  132  is timed with actual speed of the carrier web  118 . 
     As mentioned, the present invention also encompasses various system embodiments for placing precut nose wires onto a web in a facemask production line in accordance with the present methods. Aspects of such systems are illustrated in the figures, and described and supported above. 
     The material particularly shown and described above is not meant to be limiting, but instead serves to show and teach various exemplary implementations of the present subject matter. As set forth in the attached claims, the scope of the present invention includes both combinations and sub-combinations of various features discussed herein, along with such variations and modifications as would occur to a person of skill in the art.