Abstract:
The present invention is directed to tamper-evident mesh material, methods of manufacture therefor, and tamper-evident bags manufactured therefrom. The tamper-evident mesh material of the present invention may be used, for example, in the manufacture of a variety of tamper-evident security bags for use in applications where it is desirable to detect any traces or evidence of tampering with or of unauthorized access to the contents of the bag.

Description:
PRIORITY CLAIM 
       [0001]    To the fullest extent permitted by law, the present non-provisional patent application claims priority to, and the full benefit of, U.S. Provisional Patent Application No. 62/326,683, filed on Apr. 22, 2016, and entitled “Tamper-Evident Mesh Material and Methods of Manufacture Therefor”. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to tamper-evident material and, more specifically, to tamper-evident mesh material, methods of manufacture therefor, and tamper-evident bags manufactured therefrom. 
       BACKGROUND OF THE INVENTION 
       [0003]    Tamper-evident security bags manufactured from woven or nonwoven fabrics are known. Such security bags, however, suffer a shortcoming in that the strands of the woven or nonwoven fabric may be displaced, without detection, and thereby allow the unauthorized access to the contents of the bag. 
         [0004]    Therefore, a need exists for a tamper-evident mesh material for use in the manufacture of tamper-evident security bags, in which the displacement of any strands of the mesh material can be detected, the presence of which indicates that the bag and the contents thereof had been tampered with or otherwise accessed without authorization. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is directed to tamper-evident mesh material, methods of manufacture therefor, and tamper-evident bags manufactured therefrom. The tamper-evident mesh material of the present invention may be used, for example, in the manufacture of a variety of tamper-evident security bags for use in applications where it is desirable to detect any traces or evidence of tampering with, or of unauthorized access to, the contents of the bag. Examples of such tamper-evident security bags include currency bags or transaction bags. 
         [0006]    The tamper-evident mesh material of the present invention is formed from a pigmented nonwoven mesh fabric comprising a contrast layer disposed thereover. The nonwoven mesh fabric comprises a first plurality of strands and a second plurality of strands, wherein the first plurality of strands is oriented in a direction different from the second plurality of strands, and the first plurality of strands is disposed over and bonded to the second plurality of strands at a plurality of crossover points, i.e., points where overlying strands of the first plurality of strands cross over and contact underlying strands of the second plurality of strands. Each strand of the first and second plurality of strands is pigmented. At least one surface of each strand of the first and second plurality of strands is covered with a contrast layer that is visually distinct from the pigmentation of each of the strands. The contrast layer may be, for example, a metal layer, a printed layer or a coating. Specifically, the contrast layer may be disposed over, for example, the front surface of each strand of the first and second plurality of strands to conceal the pigmentation of those front surfaces; however, sections on the front surface of the underlying strands of the second plurality of strands over which the overlying strands of the first plurality of strands are bonded (namely, at the plurality of crossover points) do not include the contrast layer, as those sections were shielded during application of the contrast layer by sections of the overlying strands of the first plurality of strands bonded thereover. Breakage of the bond, and thus disruption of the contrast layer, at a crossover point of an overlying strand and an underlying strand of the respective first and second plurality of strands (via displacement of either the overlying or underlying strand) exposes the pigmented section of the underlying strand at that particular crossover point, i.e., the pigmented section on the front surface of the underlying strand to which the overlying strand had been previously bonded. In a tamper-evident security bag formed from the tamper-evident mesh material of the present invention, the visibility of that pigmented section on that underlying strand would serve as an indicator that the bag and the contents thereof had been tampered with or otherwise accessed without authorization. 
         [0007]    In one embodiment of the present invention, the tamper-evident mesh material is formed from a metalized, pigmented nonwoven mesh fabric. The nonwoven mesh fabric comprises a first plurality of strands and a second plurality of strands, wherein each strand of the first and second plurality of strands is pigmented, and wherein the first plurality of strands is oriented in a direction different from the second plurality of strands. The first plurality of strands is disposed over and thermally bonded to the second plurality of strands at a plurality of crossover points, i.e., where the first plurality of strands crosses over and contacts the second plurality of strands. At least one surface of each strand of the first and second plurality of strands is metalized. Specifically, a metal layer is disposed over, for example, the front surface of each strand of the first and second plurality of strands to conceal the pigmentation of those front surfaces; however, sections on the front surface of the strands of the second plurality of strands over which the strands of the first plurality of strands are thermally bonded (namely, at the plurality of crossover points) are not metalized, as those sections on the front surface of those strands of the second plurality of strands were shielded during the metallization process by sections of strands of the first plurality of strands thermally bonded thereover. Breakage of the thermal bond, and thus disruption of the metal layer, at a crossover point of an overlying strand and an underlying strand, respectively, of the first and second plurality of strands (via displacement of either the overlying or underlying strand) exposes the pigmented, non-metalized section of the underlying strand at that particular crossover point, i.e., the pigmented section on the front surface of that underlying strand over which the overlying strand had been previously thermally bonded. In a tamper-evident security bag formed from the tamper-evident mesh material of the present invention, the visibility of that pigmented, non-metalized section on that underlying strand would serve as an indicator that the bag and the contents thereof had been tampered with or otherwise accessed without authorization. 
         [0008]    In another embodiment of the present invention, in which the tamper-evident mesh material is formed from a metalized, pigmented nonwoven mesh fabric, the nonwoven mesh fabric thereof comprises a plurality of pigmented strands oriented in a first direction (first direction (or FD) strands) disposed over a plurality of pigmented strands oriented in a second direction (second direction (or SD) strands). The FD strands are thermally bonded to the SD strands at a plurality of crossover points, i.e., where the FD strands cross over and contact the underlying SD strands. 
         [0009]    The front surface of the nonwoven mesh fabric is metalized to conceal the pigmentation of the nonwoven mesh fabric, and, more precisely, to conceal the pigmentation of the front surfaces of the FD and SD strands thereof. Specifically, a metal layer extends over the entire front surface of each FD strand, and over the front surface of each SD strand except for those sections on the front surface of each SD strand over which the FD strands are thermally bonded (namely, at the plurality of crossover points). Breakage of the thermal bond, and thus disruption of the metal layer, at a crossover point of the metalized FD and SD strands (via displacement of those metalized FD or SD strands) exposes the pigmented, non-metalized section of the SD strand at that particular crossover point, i.e., the pigmented section on the front surface of the SD strand over which the FD strand had been previously thermally bonded. In a tamper-evident security bag formed from the afore-described tamper-evident mesh material, the visibility of this pigmented, non-metalized section of the SD strand would serve as an indicator that the bag and the contents thereof had been tampered with or otherwise accessed without authorization. 
         [0010]    The tamper-evident mesh material of the present invention may be used in the manufacture of a tamper-evident security bag, pouch or other packaging, including a bag having one side formed from film and the other side formed from the tamper-evident mesh material of the present invention, or a bag having film sides with one or more windows formed from the tamper-evident mesh material of the present invention, or a bag in which both sides are formed from the tamper-evident mesh material of the present invention. 
         [0011]    These and other features and advantages of the present invention will become apparent to those of ordinary skill in the art after reading the following Detailed Description of the Invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various embodiments of the present invention and, together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the embodiments of the invention. 
           [0013]      FIG. 1  is a plan view of a tamper-evident mesh material according to an embodiment of the present invention, showing no displacement of the FD and SD strands thereof. 
           [0014]      FIG. 2  is a plan view of the tamper-evident mesh material of  FIG. 1 , showing a magnified view of the displacement of certain of the FD and SD strands thereof. 
           [0015]      FIG. 3  is a cross-sectional perspective view of a portion of either a FD or SD strand of the tamper-evident mesh material of  FIG. 1 . 
           [0016]      FIG. 4  is a cross-sectional perspective view of portions of FD and SD strands of the tamper-evident mesh material of  FIG. 1 , showing no displacement of the FD and SD strands. 
           [0017]      FIG. 5  is a cross-sectional perspective view of the portions of FD and SD strands of the tamper-evident mesh material of  FIG. 4 , showing displacement of the FD and SD strands. 
           [0018]      FIG. 6  is a perspective view of a tamper-evident security bag manufactured from the tamper-evident mesh material of  FIG. 1 . 
           [0019]      FIG. 7  is a perspective view of a tamper-evident security bag manufactured from the tamper-evident mesh material of  FIG. 1 . 
           [0020]      FIG. 8  is a perspective view of a tamper-evident security bag manufactured from the tamper-evident mesh material of  FIG. 1 . 
           [0021]      FIG. 9  is a cross-sectional perspective view of portions of FD and SD strands of a tamper-evident mesh material according to an embodiment of the present invention, showing no displacement of the FD and SD strands. 
           [0022]      FIG. 10  is a cross-sectional perspective view of the portions of FD and SD strands of the tamper-evident mesh material of  FIG. 9 , showing displacement of the FD and SD strands. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    For simplicity and illustrative purposes, the principles of the present invention are described by referring to various exemplary embodiments thereof, and which embodiments may be depicted in  FIGS. 1-10 . The present invention is not limited to the particular examples, embodiments or methods described herein or otherwise depicted in the Figures, as these may vary. Additionally, the terminology used herein is used for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. Specific methods and materials are described, although other methods and materials similar or equivalent to those described herein may be used in the practice of the present invention. Moreover, although certain methods may be described with reference to certain steps that are presented herein in a certain order, in many instances, these steps may be performed in any order as would be appreciated by one of ordinary skill in the art, and thus the methods are not limited to the particular arrangement of steps disclosed herein. 
         [0024]    Referring now to  FIGS. 1-5 , in one embodiment of the present invention, tamper-evident mesh material  10  is formed from a metalized, pigmented nonwoven mesh fabric  20 . Mesh fabric  20  comprises a plurality of pigmented strands oriented in a first direction (first direction (or FD) strands  22 ) disposed over a plurality of pigmented strands oriented in a second direction (second direction (or SD) strands  24 ). FD strands  22  may be, for example, a plurality of pigmented strands generally oriented in the cross machine direction (cross machine direction (or CD) strands), and SD strands  24  may be, for example, a plurality of pigmented strands generally oriented in the machine direction (machine direction (or MD) strands), or vice versa. FD strands  22  are thermally bonded (e.g., via calendaring, through-air, infrared or ultrasonic) (or, alternatively, chemically bonded (e.g., via solvents or binders)) to SD strands  24  at substantially each of crossover points  23 , i.e., at substantially each point where the FD strands  22  cross over and contact the underlying SD strands  24 . (As used herein, the term “substantially”, when made with reference to thermal bonding at “each of crossover points  23 ”, is intended to allow for conventional levels of bonding imperfections and defects in otherwise uniformly oriented and bonded nonwoven fabrics.). 
         [0025]    A metal layer  30 , applied via a metallization process (described below), is disposed over at least the front surface  20   a  of mesh fabric  20 ; that is, at least front surface  20   a  of mesh fabric  20  is metalized to conceal the pigmentation of mesh fabric  20 , and, more precisely, to conceal the pigmentation of the front surfaces  22   a ,  24   a , respectively, of FD and SD strands  22 ,  24  (see,  FIGS. 1, 3, 4 ). Specifically, metal layer  30  extends over the entire front surface  22   a  of each FD strand  22 , and over the front surface  24   a  of each SD strand  24  except for sections  24   b  on the front surface  24   a  of each SD strand  24  over which FD strands  22  are thermally bonded (namely, at substantially each of crossover points  23 ) (see,  FIGS. 3, 4 ). Stated differently, the front surface  22   a  of each FD strand  22  is metalized, and the front surface  24   a  of each SD strand  24  is also metalized; however, the sections  24   b  on the front surface  24   a  of each SD strand  24  over which FD strands  22  are thermally bonded (namely, at substantially each of crossover points  23 ) are not metalized, as those sections  24   b  were shielded during the metallization process by the sections  22   b  of FD strands  22  thermally bonded thereover (see,  FIGS. 1, 4 ). Consequently, breakage of the thermal bond, and thus disruption of metal layer  30 , at a crossover point  23  of the metalized FD and SD strands  22 ,  24  (via displacement of those metalized FD or SD strands  22 ,  24 ) exposes the pigmented, non-metalized section  24   b  of the SD strand  24  at that particular crossover point  23 , i.e., the pigmented section  24   b  on the front surface  24   a  of the SD strand  24  over which the FD strand  22  had been previously thermally bonded (see,  FIGS. 2, 5 ). In a tamper-evident security bag formed from the afore-described tamper-evident mesh material, where the metalized front surface  20   a  of mesh fabric  20  forms, at least in part, an exterior face of the security bag, the visibility of this pigmented, non-metalized section  24   b  of SD strand  24  would serve as an indicator that the bag and the contents thereof had been tampered with or otherwise accessed without authorization. 
         [0026]    Mesh fabric  20  may be formed from any colored or pigmented polyolefin (including, without limitation, polyethylene) or other suitable polymers, and more preferably from a cross-laminated nonwoven pigmented polyolefin fabric, including, without limitation, any such nonwoven pigmented fabric designated under the trademark CLAF® and available from JX Nippon ANCI, Inc. (including, without limitation, JX28 or other pigmented CLAF® fabrics (see, www.claf.com/english/claf/properties/pdf/claf_grade.pdf)). Red-pigmented JX28 fabric comprises FD strands (more specifically, CD strands) that are about 350 microns wide, and SD strands (more specifically, MD strands) that are about 907 microns wide. As such, if material  10  were formed from a metallized, red-pigmented JX28 fabric, displacing a CD or MD strand thereof, and breaking the thermal bond at a crossover point of the CD and MD strands, would reveal a red-pigmented, non-metalized section of the MD strand measuring about 350 microns by about 907 microns at that particular crossover point. 
         [0027]    Metallization of mesh fabric  20  may be achieved through a variety of metallization techniques and processes, including for example: (a) vacuum metallization (the process of evaporating a metal, such as aluminum or other selected metals, in a vacuum chamber, which evaporated metal then bonds to the desired substrate (here, mesh fabric  20 ), applying a uniform metalized layer thereover (mesh fabric  20  would be unwound and rewound within the chamber during application of metal layer  30  via the metallization process)), with such vacuum metallization processes available through Printpack, Inc. (www.printpack.com) and Polyplex Corporation Limited (www.polyplex.com); and, (b) sputter-coating technologies, such as those available through Eastman Chemical Company (www.eastman.com) and Vacuum Depositing Inc. (www.vdi-llc.com), which may be used to apply an array of metals to the substrate (here, mesh fabric  20 ), including stainless steel, titanium, aluminum, gold, copper, silver, and other metal or metal oxide alloys. Additionally, slit die coating, foam coating, or gravure printing, may be used to apply metallic or non-metallic coatings to mesh fabric  20 , such that each section  24   b  of each SD strand  24  (over which FD strands  22  are thermally bonded) remains uncoated or unprinted. 
         [0028]    Referring now to  FIGS. 2, 5 and 6-8 , the tamper-evident mesh material of the present invention may used in the manufacture of a tamper-evident security bag, pouch or other packaging, including a bag  100  having one side  110  formed from film and the other side  120  formed from the tamper-evident mesh material  10  of the present invention (see,  FIG. 6 ), or a bag  200  having film sides  210 ,  212  with one or more windows  220  formed from the tamper-evident mesh material  10  of the present invention (see,  FIG. 7 ), or a bag  300  having both sides  310 ,  312  formed from the tamper-evident mesh material of the present invention (see,  FIG. 8 ). In each of bags  100 ,  200 ,  300 , the metalized front surface  20   a  of mesh fabric  20  forms, at least in part, an exterior face of the bag. Breakage of the thermal bond, and thus disruption of metal layer  30 , at a crossover point  23  of an overlying FD strand  22  and an underlying SD strand  24  of mesh fabric  20  (via displacement of those FD and SD strands  22 ,  24 ) exposes the pigmented, non-metalized section  24   b  of the underlying SD strand  24  at that particular crossover point  23 , i.e., the pigmented section  24   b  on the front surface  24   a  of the underlying SD strand  24  over which the overlying FD strand  22  had been previously thermally bonded (see,  FIGS. 2, 5 ). Visibility of this pigmented, non-metalized section  24   b  of the underlying SD strand  24  would serve as an indicator that the bag ( 100 ,  200 , or  300 ) and the contents thereof had been tampered with or otherwise accessed without authorization. Bags  100 ,  200 ,  300  may be manufactured in accordance with any generally known and accepted bag manufacturing methods and practices, including, for example, side-sealed bag and tube bag manufacturing methods and practices. Tamper-evident tapes seals or other sealing strips may be incorporated into the mouth or opening of each such tamper-evident security bag, pouch or other packaging, including bags  100 ,  200 ,  300 , also in accordance with generally known and accepted manufacturing methods and practices. Ink or dye packs may be used in conjunction with a tamper-evident security bag manufactured from material  10 , with such inks or dyes having the ability to pass through material  10  upon tampering with or unauthorized access to the bag or the contents thereof. 
         [0029]    Referring now to  FIGS. 9 and 10 , in a further embodiment of the present invention, tamper-evident mesh material  10  may comprise a printed layer or coating applied over front surface  20   a  of pigmented mesh fabric  20 , instead of metal layer  30 . The printed layer or coating (print/coating  50 ) may be an acrylic or urethane ink or coating, or other ink or coating suited for the application contemplated herein. Similar to the “metalized” embodiment described hereinabove, in this print/coating embodiment, pigmented nonwoven mesh fabric  20  comprises FD strands  22  disposed over and thermally bonded to SD strands  24  at substantially each of crossover points  23 , i.e., at substantially each point where the FD strands  24  cross over and contact the underlying SD strands  24 . Here as well, FD strands  22  may be, for example, a plurality of pigmented strands generally oriented in the cross machine direction (cross machine direction (or CD) strands), and SD strands  24  may be, for example, a plurality of pigmented strands generally oriented in the machine direction (machine direction (or MID) strands), or vice versa. A print/coating layer  50  is disposed over front surface  20   a  of mesh fabric  20  to conceal the pigmentation thereof, and, more precisely, to conceal the pigmentation of front surfaces  22   a ,  24   a , respectively, of FD and SD strands  22 ,  24 . Specifically, the print/coating layer  50  extends over the entire front surface  22   a  of each FD strand  22 , and over front surface  24   a  of each SD strand  24  except for those sections  24   b  on the front surface  24   a  of each SD strand  24  over which FD strands  22  are thermally bonded (namely, at substantially each of crossover points  23 ). Stated differently, front surface  22   a  of each FD strand  22  includes the print/coating layer  50 , and front surface  24   a  of each SD strand  24  also includes the print/coating layer  50 ; however, the sections  24   b  on the front surface  24   a  of each SD strand  24  over which FD strands  22  are thermally bonded do not include the print/coating layer  50 , as those sections  24   b  were shielded during the printing/coating process by sections  22   b  of FD strands  22  thermally bonded thereover. Consequently, breakage of the thermal bond, and thus disruption of the print/coating layer  50 , at a crossover point  23  of the FD and SD strands  22 ,  24  (via displacement of those FD or SD strands  22 ,  24 ) exposes the pigmented, unprinted/uncoated section  24   b  of the SD strand  24  at that particular crossover point  23 , i.e., the pigmented section  24   b  on the front surface  24   a  of the SD strand  24  over which the FD strand  22  had been previously thermally bonded. In a tamper-evident security bag formed from the tamper-evident mesh material of this “print/coating” embodiment, where the print/coating layer  50  of the front surface  20   a  of the mesh fabric  20  forms, at least in part, an exterior face of the security bag, the visibility of this pigmented, unprinted/uncoated section  24   b  of the SD strand  24  would serve as an indicator that the bag and the contents thereof had been tampered with or otherwise accessed without authorization. 
         [0030]    In yet a further embodiment of the present invention, the tamper-evident mesh material of the present invention is formed from a metalized, pigmented nonwoven mesh fabric, wherein the nonwoven mesh fabric comprises three or more pluralities of strands, each such plurality of strands oriented in a direction different from the other plurality(ies) of strands, with a first such plurality of strands thermally bonded over a second such plurality of strands at a plurality of crossover points (and with any such further plurality(ies) of strands thermally bonded, in succession, thereunder). Each of the strands of each plurality of strands are metalized. Specifically, through a metallization process, a metal layer is disposed over, for example, the front surface of each strand in each plurality of strands to conceal the pigmentation of those front surfaces; however, sections on the front surfaces of those strands over which other strands are thermally bonded (namely, at the plurality of crossover points) are not metalized, as those sections on the front surfaces of those strands were shielded during the metallization process by sections of the other strands thermally bonded thereover. Breakage of the thermal bond, and thus disruption of the metal layer, at a crossover point of an overlying and an underlying metalized strand (via displacement of those metalized strands) exposes the pigmented, non-metalized section of the underlying strand at that particular crossover point, i.e., the pigmented section on the front surface of the underlying strand over which the overlying strand had been previously thermally bonded. In a tamper-evident security bag formed from the tamper-evident mesh material of this further embodiment, the visibility of that pigmented, non-metalized section on that strand would serve as an indicator that the bag and the contents thereof had been tampered with or otherwise accessed without authorization. It is contemplated that, in this further embodiment, a print/coated layer may be used instead of the metal layer. 
         [0031]    It is contemplated herein that both the front and back surfaces of mesh fabric  20 , and thus the front and back surfaces of FD and SD strands  22 ,  24 , may comprise the metal layer, print layer or coating described hereinabove, thus concealing the pigmentation of all surfaces of mesh fabric  20  with the exception of those surface sections of FD and SD strands  22 ,  24  thermally bonded to each other at substantially each of the crossover points  23  thereof. Accordingly, breakage of the thermal bond (and thus disruption of the metal layer, print layer or coating, as applicable) at a crossover point  23  of the FD and SD strands  22 ,  24 , would expose the pigmented (non-metalized, unprinted, or uncoated, as applicable) surface sections of each of FD and SD strands  22 ,  24  at that particular crossover point  23 , i.e., the pigmented sections on the back and the front surfaces, respectively, of FD and SD strands  22 ,  24 , where FD and SD strands  22 ,  24  had been previously thermally bonded to each other. In a tamper-evident security bag formed from such a tamper-evident mesh material, the visibility of this pigmented section of SD strand  24  would serve as an indicator that the bag and the contents thereof had been tampered with or otherwise accessed without authorization. 
         [0032]    It is further contemplated herein that mesh fabric  20  may also be formed from a spunbonded fabric, another type of nonwoven fabric, characterized by fine fibers or strands, a relatively random orientation of such strands, and a plurality of crossover points between or among the strands thereof. Accordingly, similar to the above-described embodiments, if mesh fabric  20  were formed from a pigmented spunbonded fabric having a metal (or print or coated) layer disposed over at least one surface thereof, breaking the thermal bond(s), and thus disrupting the metal (or print or coated) layer, at one or more crossover points between or among the strands (by displacing or shifting one or more such strands, or by stretching the fabric to so displace or shift one or more such strands), would expose the pigmented, non-metalized (or unprinted or uncoated) surface(s) of the one or more strands at the corresponding crossover point(s). In addition to the foregoing, mesh fabric  20  may also be formed from other pigmented nonwoven fabrics, including, for example, carded web fabrics and meltblown fabrics. 
         [0033]    While the invention has been described with reference to certain exemplary embodiments thereof, those skilled in the art may make various modifications to the described embodiments of the invention without departing from the scope of the invention. The terms and descriptions used herein are set forth by way of illustration only and not meant as limitations. Although the invention has been described and disclosed in various terms and certain embodiments, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved, especially as they fall within the breadth and scope of the claims here appended. Those skilled in the art will recognize that these and other variations are possible within the scope of the invention as defined in the following claims and their equivalents.