Patent Publication Number: US-2021169074-A1

Title: Dispenser and method of use thereof

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application 62/944,748, filed on Dec. 6, 2019, the entire contents of which are hereby incorporated by reference, for any and all purposes. 
    
    
     REFERENCE REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     SEQUENCE LISTING 
     Not applicable. 
     BACKGROUND 
     1. Field of the Invention 
     The present disclosure relates generally to a dispensing device for release of a volatile material and, more particularly, to a dispenser and substrate for the passive emanation of a volatile material that includes a multi-layer substrate supported by a protective enclosure. 
     2. Description of the Background 
     Various volatile material dispensing devices known in the art generally include a reservoir that holds a volatile material, as well as a housing or support structure that retains the reservoir. These devices typically either allow passive diffusion of the volatile material to occur without the aid of a dispensing mechanism, or enhance and/or facilitate the release of the volatile material using a dispensing mechanism. For example, typical dispensing mechanisms used in volatile material dispensing devices include a heating device and/or a fan. Such prior dispensers may often require these mechanisms or other costly materials to ensure constant release of a volatile material over a prolonged period of time; however, these prior dispensers often require electricity and are significantly more expensive to produce. 
     In some instances, dispensers that passively emanate a volatile material may be provided as a sheet or film, and may include a plurality of layers, one of which may be exposed to a surrounding environment and resultantly emanate an amount of volatile material therefrom. However, such prior passive dispensers also have common drawbacks. For one, a user may have to contact the material to be emanated while activating or opening the dispensing device or during use of the dispenser. Further, the release rate of active ingredients from passive dispensers typically decreases with time and the efficacy of a volatile release therefrom decreases over a period of use. 
     What is needed is a dispenser that preferably overcomes one or more of these drawbacks. More particularly, what is needed is a dispenser that passively emanates a volatile material over a prolonged period of time at a constant rate, while not requiring a user to contact the volatile material having active agents, such as insecticides. 
     SUMMARY 
     Embodiments of the current disclosure provide a substrate for dispensing a volatile material. The substrate includes opposing first and second layers with a first configuration and a first pore size. The substrate further includes an intermediate layer between the first and second layers that is of a second configuration. The opposing first and second layers are also liquid and air permeable. 
     In related embodiments, the current disclosure provides a dispenser for the release of a volatile material. The dispenser includes a front face with a plurality of apertures, a rear face, and a substrate with opposing first and second layers and an intermediate layer provided between the first and second layers. The first and second layers are of a first configuration and have a first pore size, respectively. Further, the intermediate layer is of a second configuration, and the opposing first and second layers are liquid and air permeable. 
     According to another aspect of the present disclosure, a system for consistently emitting a volatile material is provided. The system includes a dispenser having at least one aperture, a substrate adapted to fit within the dispenser, and a volatile material. The substrate also includes a first woven layer having a first pore size, a second woven layer having a second pore size, and a third non-woven, fiber layer extending between the first woven layer and the second woven layer. Additionally, the system has a steady state weight loss of the volatile material over a time greater than 30 days. 
     In further embodiments, the volatile material includes an active agent selected from the group consisting of metafluthrin, transfluthrin, tefluthrin, and vaporthrin. The pore size of the first woven layer may be between about 1 millimeters and about 10 millimeters, and the steady state weight loss of the volatile material may be between about one milligram per day and about ten milligrams per day. Further, a weight of the volatile material may be between about one gram and about five grams, and the at least one aperture of the dispenser exposes a portion of the first woven layer. In even further embodiments, the at least one aperture of the dispenser exposes between about 50% and about 99% of a surface area of the first woven layer. 
     In other embodiments, the system has a steady state weight loss of the volatile material over a time greater than 60 days or greater than 70 days. In some embodiments, the first pore size may be different than the second pore size, the dispenser may include a front face and a rear face, and the front face includes the at least one aperture. In one embodiment, the first woven layer, the second woven layer, and the third non-woven fibrous layer are constructed from the same material. Additionally, in another embodiment, the first woven layer and the second woven layer are constructed from a first material, and the third non-woven fibrous layer is constructed from a second material, and the first material and the second material are different. 
     According to another aspect of the present disclosure, another system for consistently emitting a volatile material is provided. The system includes a frame having at least one aperture, a substrate positioned within the frame, and a volatile material. The substrate includes a first woven layer having a plurality of pores, a second woven layer having a plurality of pores, and a third non-woven, fiber layer extending between the first woven layer and the second woven layer. The system provides a steady state weight loss of the volatile material over a time greater than 30 days. 
     In further embodiments, the steady state weight loss of the volatile material is between about 4 mg/day and about 6 mg/day; the volatile material is selected from the group consisting of metafluthrin, transfluthrin, tefluthrin, and vaporthrin; and the volatile material is in an amount between about 2 grams and about 3 grams. In even further embodiments, the system has a steady state weight loss of the volatile material over a time greater than 70 days. In some embodiments, the frame includes a first aperture that exposes a portion of the first woven layer and a second aperture that exposes a portion of the second woven layer. 
     According to yet another aspect of the present disclosure, a method of designing a system for constantly emitting a volatile material is provided. The method includes a step of selecting a minimum time for constant emanation of the volatile material, a step of selecting a minimum emanation rate of the volatile material, a step of calculating a minimum concentration of the volatile material using the minimum time for constant emanation of the volatile material and the minimum emanation rate of the volatile material, a step of selecting a first layer for a substrate based on at least the minimum emanation rate of the volatile material, and a step of selecting a second layer for the substrate based on at least the minimum concentration of the volatile material. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front isometric view of a dispenser, according to a first aspect of the present disclosure; 
         FIG. 2  is a rear isometric view of the dispenser of  FIG. 1 ; 
         FIG. 3  is a rear isometric view of the dispenser of  FIG. 1 , according to a second aspect of the present disclosure; 
         FIG. 4  is a front isometric view of a dispenser, according to another aspect of the present disclosure; 
         FIG. 5  is a front view of a front face of the dispenser of  FIG. 1 ; 
         FIG. 6  is a front isometric view of a dispenser, according to yet another aspect of the present disclosure; 
         FIG. 7  is a front view of the dispenser of  FIG. 6 ; 
         FIG. 8  is a rear view of the dispenser of  FIG. 6 ; 
         FIG. 9  is a side view of a substrate for use with the dispensers of  FIGS. 1 and 6 ; 
         FIG. 10  is a top plan view of a portion of another substrate for use with the dispensers of  FIGS. 1 and 6 ; 
         FIG. 11  is a top plan view of a portion of yet another substrate for use with the dispensers of  FIGS. 1 and 6 ; 
         FIG. 12A  is a top plan view of a portion of the substrate of  FIG. 9  in a first state; 
         FIG. 12B  is a top plan view of a portion of the substrate of  FIG. 9  in a second state; 
         FIG. 13  is a graph illustrating the release or emanation rate of a plurality of active agents of a volatile material from the substrate of  FIG. 9 , according to an aspect of the present disclosure, over a period of time; 
         FIG. 14  is a graph illustrating the wicking rate of various substrates over a period of time; 
         FIG. 15A  is a graph illustrating the release or emanation rate of an active agent of a volatile material from the dispenser of  FIG. 6  having the substrate of  FIG. 9  over a period of time; 
         FIG. 15B  is another graph illustrating the release or emanation rate of an active agent of a volatile material from the dispenser of  FIG. 6  having the substrate of  FIG. 9  over a period of time; 
         FIG. 15C  is another graph illustrating the release or emanation rate of an active agent of a volatile material from the dispenser of  FIG. 6  having the substrate of  FIG. 9  over a period of time; 
         FIG. 16  is a graph illustrating an amount of an active agent within a variety of substrates having varying thickness, after 72 hours; 
         FIG. 17  is a graph illustrating an amount of an active agent within a variety of substrates having varying pore diameters, after 72 hours; 
         FIG. 18  is a graph illustrating an amount of an active agent within a variety of substrates having varying pore diameters, after 72 hours; 
         FIG. 19  is a graph illustrating the release or emanation rate of an active agent of a volatile material from a variety of substrates having varying densities and fiber surface areas; 
         FIG. 20  is a graph illustrating the release or emanation rate of an active agent of a volatile material from a variety of dispensers having varying percentages of the substrate exposed during use thereof; 
         FIG. 21  illustrates a design method for constructing the substrate of  FIG. 9 , according to an aspect of the present disclosure; 
         FIG. 22  is a bracelet that may be used in combination with the substrate of  FIG. 9 , for example; 
         FIG. 23  is a front isometric view of a clip that may be used in combination with the substrate of  FIG. 9 , for example; 
         FIG. 24  is a rear isometric view of the clip of  FIG. 23 ; 
         FIG. 25  is another bracelet that may be used in combination with the substrate of  FIG. 9 , for example; 
         FIG. 26  illustrates a hanger that may be used in combination with the substrate of  FIG. 9 , for example; 
         FIG. 27  illustrates another hanger that may be used in combination with the substrate of  FIG. 9 , for example; 
         FIG. 28  illustrations a mechanism that may be used in combination with the substrate of  FIG. 9 , for example; 
         FIG. 29  illustrates a kit including a cage and pouch that may be used in combination with the substrate of  FIG. 9 , for example; and 
         FIG. 30  illustrates a reservoir that may be used to dose the substrate of  FIG. 9  or the bracelet of  FIG. 25 , for example. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     The following discussion and accompanying figures disclose various embodiments or configurations of a dispensing device and a substrate that may be used in combination with the dispensing device. 
     The term “about,” as used herein, refers to variation in the numerical quantity that may occur, for example, through typical measuring and manufacturing procedures used for volatile dispensers or other articles of manufacture that may include embodiments of the disclosure herein; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of the ingredients used to make the compositions or mixtures or carry out the methods; and the like. Throughout the disclosure, the terms “about” and “approximately” refer to a range of values ±5% of the numeric value that the term precedes. 
     The terms “weight percent,” “wt-%,” “percent by weight,” “% by weight,” and variations thereof, as used herein, refer to the concentration of a substance or component as the weight of that substance or component divided by the total weight, for example, of the composition or of a particular component of the composition, and multiplied by 100. It is understood that, as used herein, “percent,” “%,” and the like may be synonymous with “weight percent” and “wt-%.” 
     The present disclosure is directed to dispensers and substrates for holding volatile materials. While the present disclosure may be embodied in many different forms, several specific embodiments are discussed herein with the understanding that the present disclosure is to be considered only as an exemplification of the principles of the disclosure, and it is not intended to limit the disclosure to the embodiments illustrated. 
     Further, the principles of the present disclosure apply to any volatile material emitted through passive emanation, and although particular examples illustrate the passive emanation of particular volatile materials (e.g., insecticides), it is envisioned that the dispensers and substrates discussed herein can be used with a variety of volatile materials. Examples of volatile materials include, but are not limited to, an insecticide, an insect repellant, an insect attractant, a fragrance, a mold or mildew inhibitor, a cleaner, a disinfectant, an air purifier, an aromatherapy scent, an antiseptic, a positive fragrance volatile material, an air-freshener, a deodorizer, or the like, and combinations thereof. Additives may also be included in the volatile materials, such as, fragrances or preservatives, as will be discussed in further detail herein. 
     Dispensers 
       FIGS. 1 and 2  generally depict a dispensing device  100  for use in the emanation of a volatile material into an ambient environment and, in this particular embodiment, the passive emanation of a volatile material into an ambient environment. In one preferred embodiment, as will be further discussed herein, the dispensing device  100  is used in combination with a multi-layer substrate to emanate a pest control agent, such as a repellant or insecticide, into an ambient environment. 
     Still referencing  FIGS. 1 and 2 , the dispensing device  100  is shown to have to two opposing sides, including a front face  102  (see  FIG. 1 ) and a rear face  104  (see  FIG. 2 ). A central plate  106  extends between the front face  102  and the rear face  104 , and a substrate (not shown) may be positioned between the front face  102  and the rear face  104 , as will be further discussed herein. In these embodiments, the substrate is a reservoir for a volatile material and emanates the volatile material from the dispensing device  100  over a specified period of time. 
     In this embodiment, the central plate  106  is generally rectangular and includes rounded corners  108 . Alternatively, in other embodiments, the dispensing device  100  and the central plate  106  may have different configurations or shapes. For example, the dispensing device  100  may be circular, ovular, triangular, square, rectangular, pentagonal, hexagonal, or any other desired geometric configuration. The central plate  106  may have an aperture  110  centrally disposed on an upper part thereof, as shown in this embodiment. The aperture  110  allows a user to hang the dispensing device  100  prior to or during use thereof. Additional apertures may be positioned around a perimeter of the central plate  106  in alternative embodiments to assist in hanging the dispensing device  100 . 
     With particular reference to  FIG. 1 , the front face  102  extends from the central plate  106  and, in this embodiment, is generally rectangular with rounded corners  112 . Similar to the central plate  106 , the front face  102  may have alternative configurations or shapes in other embodiments. For example, in some embodiments, the front face  102  may be circular, ovular, triangular, square, rectangular, pentagonal, hexagonal, or any other desired geometric configuration. A leg  114  may extend from a bottom end  116  of the front face  102 , which supports the dispensing device  100  and allows the dispensing device  100  to be placed on top of a surface (not shown) prior to or during use thereof. The front face  102  may also include a plurality of apertures  120 , which allow air to enter and exit the dispensing device  100 . As such, during use of the dispensing device  100 , a volatile material may emanate from a substrate within the dispensing device  100  through the apertures  120 . 
     In particular embodiments, the front face  102 , and the apertures  120  thereof, may be altered or tuned to increase or decrease the emanation rate of the volatile material from the dispensing device  100 . Referring now to  FIG. 5 , an illustration of the front face  102  is depicted that shows the front face  102  with a height H and a width W. In some embodiments, the height H may be between about 10 centimeters and about 100 centimeters, or between about 10 cm and about 50 cm, or between about 10 cm and about 30 cm. In these embodiments, the width W may be between about 10 cm and about 100 cm, or between about 10 cm and about 50 cm, or between about 10 cm and about 30 cm. As previously discussed herein, the front face  102  may have alternative configurations and, in some embodiments, may be circular, ovular, triangular, square, rectangular, pentagonal, hexagonal, or any other desired geometric configuration. In these embodiments, the front face  102  may be dimensioned such that the front face  102  has a surface area of between about 100 cm 2  and about 10,000 cm 2 , or between about 100 cm 2  and about 2,500 cm 2 , or between about 100 cm 2  and about 900 cm 2 . 
     In one aspect, as shown in  FIGS. 1 and 5 , the apertures  120  may be circular apertures with varying diameters. For example, with continued reference to  FIGS. 1 and 5 , the circular apertures  120  proximate a center  122  of the front face  102  may have the smallest relative diameter and the diameter of the apertures  120  may increase as the apertures  120  extend outwardly from the center  122  of the front face  102 . In addition, as best shown in  FIG. 5 , the apertures  120  may be organized in a plurality of concentric rings or annular rows that extend outwardly from the center  122  of the front face  102 . Further, in this particular embodiment, the diameter of the apertures  120  within each concentric circle of apertures may be uniform. However, as previously discussed herein, the diameter of the apertures  120  may generally increase as the apertures  120  extend outwardly from the center  122  or, in other words, the diameter of the apertures  120  within the first concentric circle may be the smallest and the diameter of the apertures  120  within the concentric circle farthest from the center  122  may be the largest. 
     In this particular embodiment, the front face  102  includes approximately 13 concentric rings or annular rows of apertures  120 , i.e., annular rows A-M (see  FIG. 5 ). However, in alternative embodiments, the front face  102  may include any number of apertures  120  to produce the desired emanation of the volatile material from the dispensing device  100 . For example, in alternative embodiments, the apertures  120  may be organized into rows or columns to produce a grid configuration. In such embodiments, the front face  102  may include between 1 row and 100 rows and/or between about 1 column and 100 columns. Further, the rows and columns may individually include between 1 and 100 apertures. In other embodiments, the apertures  120  may be organized to depict particular shapes, letters, words, or images. 
     According to another aspect of the present disclosure, the apertures  120  within regions N-Q proximate the corners  112  of the front face  102  may have alternative configurations. For example, as best shown in  FIG. 5 , the apertures  120  proximate the corners  112  of the front face  102  may be in a triangular configuration. Further, the apertures  120  farthest from the corners  112  may have the smallest diameter and the apertures  120  closest to the corners  112  may have the largest diameter, in this embodiment. As such, the diameter of the apertures  120  may generally increase as the apertures  120  extend from the center  122  of the front face  102 , then decrease as the apertures  120  transition between the first pattern (i.e., concentric rings or annular row of apertures) to the second pattern (i.e., triangular pattern of apertures), and then subsequently increase yet again as the apertures  120  extend to the corners  112 . 
     In alternative embodiments, the apertures  120  may be in an inverse configuration, with the apertures  120  farthest from the corners  112  having the largest diameter and the apertures  120  closest to the corners  112  may have the smallest diameter. In yet another embodiment, the front face  102  may not include the apertures  120  within the triangular configuration. Rather, in one embodiment, the front face  112  may only include apertures  120  within concentric rings that extend to the corners  112 , such that the apertures  120  only increase in diameter as they extend outwardly from the center  122  of the front face. 
     In alternative embodiments, the apertures  120  may be circular apertures with a uniform diameter. In other embodiments, the apertures  120  may be organized in alternative configurations, such as rows or columns, or may be arbitrary or randomly placed on the front face  102 . However, in particular embodiments, the apertures  120  may be between about 35% and about 99% of the surface area of the front face  102  of the dispensing device  100 . In alternative embodiments, the apertures  120  may be between about 50% and about 99% of the front face  102 , or between about 75% and about 99% of the front face  102 , or between about 90% and 95% of the front face  102 . For example, with continued reference to  FIG. 5 , the front face  102  may have a total surface area (SA) defined by multiplying the width W by the height H. Further, a portion of the total surface area (SA) of the front face  102  that the apertures  120  extend throughout may be characterized by the total surface area (SA) minus the surface area (SA 1 ), which is devoid of any of the apertures  120 . In this particular embodiment, the surface area (SA 1 ) may be calculated using the radius (r), which is defined as the distance between the center  122  of the front face  102  and an innermost edge defining one of the apertures  120  of the smallest concentric ring or annular row A, and Equation 1 below. 
       SA1=π r   2   (Eq. 1)
 
     Additionally, the total surface area of the substrate exposed to the ambient environment (SA S ) may be approximately equal to the total surface area (SA) minus the surface area (SA 1 ), which is approximately equal to the surface area devoid of any of the apertures  120 . Further, a percentage of the surface area of the substrate that is exposed may be determined by dividing the total surface area of the substrate exposed (SA ES ) by the total surface area of the substrate (SA s ), which in most embodiments, is equal to the total surface area (SA). The formula for determining the percentage of surface area of the substrate that is exposed is shown in Equation 2 below. 
     
       
         
           
             
               
                 
                   
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     The concentric rings of the apertures A-M, as well as the apertures in the quadrants N-Q, may also be characterized by individual radii extending from a center of each aperture. As such, an actual measurement of the surface area that is defined by the apertures  120  may be calculated, or, the surface area devoid of any apertures may be calculated. Turning again to  FIG. 5 , the largest or last concentric ring of apertures M may be characterized by a radius (R), as shown in  FIG. 5 , which is defined by an outermost edge of one of the apertures of the largest concentric ring or annular row M. The radius (R) may also be approximately equal to half the height H of the front face  102  and/or approximately equal to half the width W of the front face  102 . In these embodiments, the percentage of the surface area (SA) having the apertures within the first pattern (i.e., the concentric rings or annular rows of apertures A-M) may be calculated using Equation 3 below, and may be characterized as a first footprint or diffusion area. The percentage of the surface area having the apertures within the second pattern (i.e., regions N-Q) may be calculated using Equation 4 below, and may be characterized as a second footprint or diffusion area having four quadrants. 
       SA with Apertures of First Patten=π R   2 −SA1  (Eq. 3)
 
       SA with Apertures of Second Pattern=SA−π R   2 −SA1  (Eq. 4)
 
     Additionally, the surface area of each quadrant having the alternative configuration, i.e., regions N-Q, may be calculated by dividing the surface area calculated in Equation 3 by 4. 
     The diameter of the apertures  120  may range between about 1 millimeter and about 25 millimeters, or between about 1 mm and about 15 mm, or between about 5 mm and about 10 mm. In alternative embodiments, the apertures  120  may be in alternative configurations. For example, the apertures  120  may be ovular, triangular, square, rectangular, pentagonal, hexagonal, or any other desired geometric shape. In such embodiments, the apertures  120  may have a surface area ranging between about 0.75 mm 2  and about 500 mm 2 , or between about 0.75 mm 2  and about 175 mm 2 , or between about 20 mm 2  and about 75 mm 2 . 
     Further, as previously discussed herein, the diameter of the apertures  120  may generally increase as the apertures  120  extend outwardly from the center  122 , as shown in  FIG. 5  for example. As a result, the emanation rate or release rate of a volatile material from the dispensing device  100  may vary at different locations on the front face  102 . For example, in this embodiment, the emanation rate may generally increase extending outwardly from the center  122  and may have a positive relationship with a size of the apertures  120 . In other words, because concentric ring M includes apertures  120  having larger diameters than the apertures  120  of the concentric ring A, the emanation rate of the volatile material of the dispensing device  100  may be larger through the apertures  120  of the concentric ring M compared to the emanation rate of the volatile material through the apertures  120  of the concentric ring A. By effect, the dispensing device  100  may wick a volatile material from the center  122  and to the corners  112  of the front face  102 . In alternative embodiments, the size of the apertures  120  may be altered and tuned to provide other desired airflows and emanation rates. 
     In some embodiments, the front face  102  may include between about 1 and 7,500 apertures, or between about 1 and 2,000 apertures, or between about 500 and about 1,000 apertures, or between about 700 and about 800 apertures. Still referencing  FIG. 5 , the apertures  120  may also have symmetry across a vertical axis  124  and/or a horizontal axis  126 . Further, as shown in  FIG. 4 , a surface beneath the aperture  120  may be a different color than that of the front face  102 . 
     With reference to  FIG. 2 , the rear face  104  of the dispensing device  100  may be similar to the front face  102  and may include a plurality of apertures  130  that extend outwardly from a center  132 . However, in alternative embodiments, the rear face  104  of the dispensing device  100  may not include the apertures  130 , as shown in  FIG. 3 . In other embodiments, the rear face  104  may be constructed independently from the front face  102  and may include apertures  130  of varying size, number, and pattern. Therefore, the aforementioned disclosure of the front face  102 , and the apertures  120  thereof, equally and independently applies to the rear face  104  and the apertures  130  thereof. For example, in some embodiments, the rear face  104  may independently have a height and width between about 10 centimeters and about 100 centimeters, or between about 10 cm and about 50 cm, or between about 10 cm and about 30 cm. Additionally, the apertures  130  may be circular and may have a diameter between about 1 millimeter and about 25 millimeters, or between about 1 mm and about 15 mm, or between about 5 mm and about 10 mm, for example. Alternatively, the dispensing device  100  may not include the rear face  104  and the central plate  106  may define a rear surface of the dispensing device  100 . 
     The dispensing device  100  may also be characterized by a thickness, which may be a distance measured between the front face  102  and the rear face  104  of the dispensing device  100 . In some embodiments, the thickness of the dispensing device  100  may be between about 0.05 cm to about 10 cm. 
     Further, in this particular embodiment, the rear face  104  also includes a leg  134  that extends from a bottom end  136  of the rear face  104 , which may support the dispensing device  100 . During use, the legs  114 ,  136  allow the dispensing device  100  to sit or be placed on a surface (not shown). 
       FIGS. 6-8  depict another dispensing device or frame  200  for use in the emanation of a volatile material into an ambient environment, according to a second aspect of the present disclosure. Similar to the dispensing device  100 , the dispensing device  200  is used in combination with a multi-layer substrate to emanate a volatile material, such as a pest control agent, a repellant, or insecticide, into an ambient environment. 
     The dispensing device  200  includes two opposing sides, including a front face  202  and a rear face  204 , and a substrate  206  may be positioned between the front face  202  and the rear face  204 . As will be discussed further, the substrate  206  is a reservoir for a volatile material and passively emanates a volatile material from the dispensing device  200  over a specified period of time. 
     As shown in  FIGS. 6 and 7 , the front face  202  includes an aperture  208  which allows airflow through the substrate  206  to provide for passive emanation of a volatile material from the substrate  206 . The rear face  204  of the dispensing device  200  may be similar to the front face  202 , as shown in  FIG. 8 , and may also include an aperture  210  that allows airflow through the substrate  206  to provide for passive emanation of a volatile material from the substrate  206 . Alternatively, the rear face  204  does not include the aperture  210 , and in this embodiment, the rear face  204  is closed and covers the substrate  206 . 
     With continued reference to  FIGS. 6-8 , the apertures  208 ,  210  may be between about 50% and about 99% of the front face  202  or rear face  204 , respectively. In further embodiments, the apertures  208 ,  210  may be between about 75% and about 99%, or between about 90% and 95% of the front face  202  or rear face  204 , respectively. For example, with continued reference to  FIGS. 6-8 , the front face  202  may have a total surface area (SA 2 ) defined by multiplying the width W 2  by the height H 2  and the rear face  204  may have a total surface area (SA 3 ) defined by multiplying the width W 3  by the height H 3 . As such, the apertures  208 ,  210  may expose between about 50% and about 99%, or between about 75% and about 99%, or between about 90% and 95% of the substrate  206  to the ambient environment. Thus, similar to the dispensing device  100 , the front face  202  and the rear face  204 , and the apertures  208 ,  210  thereof, may be sized to increase or decrease the emanation rate of the volatile material from the dispensing device  200 . 
     Referring now to  FIGS. 7 and 8 , the heights H 2 , H 4  and the widths W 2 , W 4  may be similar in dimension to the height H and the width W of the dispensing device  100 . More particularly, the heights H 2 , H 3  and the widths W 2 , W 3  may be individually between about 10 centimeters and about 100 centimeters, or between about 10 cm and about 50 cm, or between about 10 cm and about 30 cm. In these embodiments, the front face  202  and/or the rear face  204  may be dimensioned such that the front face  202 , or the rear face  204 , has a surface area of between about 100 cm 2  and about 10,000 cm 2 , or between about 100 cm 2  and about 2,500 cm 2 , or between about 100 cm 2  and about 900 cm 2 . 
     The front face  202  and the rear face  204 , and the apertures  208 ,  210  thereof, may be altered or tuned to increase or decrease the emanation rate of the volatile material form the dispensing device  200 . With reference to  FIGS. 7 and 8 , the apertures  208 ,  210  may be defined by a height H 3 , H 5  and a width W 3 , W 5 , respectively, and the surface area of the exposed substrate (SA ES ) may be calculated by multiplying the height H 3 , H 5  by the width W 3 , W 5 , in this embodiment. Thus, the percentage of substrate surface area exposed to the ambient environment can be calculate by dividing the surface area of the exposed substrate (SA ES ) by the total surface area of the substrate (SA s ), which in most embodiments, is equal to the total surface area (SA) of the front face  202  or the rear face  204 . The total surface area (SA) of the front face  202  or the rear face  204  can be calculated using the height H 2 , H 4  and width W 2 , W 4  dimensions. In this embodiment, the total surface area (SA) of the front face  202  or the rear face  204  can be calculated by multiplying the height H 2 , H 4  of the front face  202  or rear face  204  by the width W 2 , W 4  thereof. The formula for determining the percentage of surface area of the substrate that is exposed to an ambient environment is shown in Equation 5 below. 
     
       
         
           
             
               
                 
                   
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     Similar to the dispensing device  100 , the front face  202  and the rear face  204 , and the apertures  208 ,  210  thereof, may be altered or tuned to increase or decrease the emanation rate of the volatile material from the dispensing device  200 . As previously noted herein, the apertures  208 ,  210  may be between about between about 35% and about 99% of the surface area of the front face  202  or rear face  204  of the dispensing device  200 . In alternative embodiments, the apertures  208 ,  210  may be between about 50% and about 99% of the front face  202  or rear face  204 ; or between about 75% and about 99% of the front face  202  or rear face  204 ; or between about 90% and 95% of the front face  202  or rear face  204 . As a result, the percentage of the surface area of the substrate exposed (SA ES ) may be between about 50% and about 99%, or between about 75% and about 99%, or between about 90% and about 95%. 
     Substrates 
       FIG. 9  illustrates a portion of a substrate  250  that may be used in combination with the dispensing device  100  or the dispensing device  200 . As will be further discussed herein, the substrate  250  may be constructed from one or more layers and may be a 3-dimensional fabric material used for the passive emanation of an active agent of a volatile material. In one embodiment, the structure of the substrate  250  may include a plurality of woven and non-woven layers that may be layered to produce the substrate  250 . For example, as shown in  FIG. 9 , the substrate  250  may include a first layer  252 , a second layer  254 , and a third layer  256 . However, according to alternative aspects of the present disclosure, the substrate  250  may include additional layers or, alternatively, only a first and second layer, such as only the first layer  252  and the second layer  254 . 
     The configuration of the substrate  250 , and the layers thereof, produces a substrate  250  with a high surface area per projected volume. More particularly, the first layer  252  and/or the third layer  256  may provide an optimal layer for wicking and subsequently emitting a volatile material or active agent using a plurality of pores that allow air to flow through the substrate  250  and the layers thereof; and the second layer  254  may provide an optimal layer for storing a volatile material or active agent over a prolonged period of time. 
     According to aspects of the present disclosure, the physical properties of the layers of the substrate  250  may be optimized to achieve a desired wicking, saturation, and rate of evaporation. More particularly, a thickness, porosity, weave pattern, material, and/or space density of the layers of the substrate  250  may be optimized to achieve a desired wicking, saturation, and rate of evaporation of an active agent from the substrate  250 , for example. Further, a thickness, porosity, weave pattern, material, and/or space density of the layers of the substrate  250  may be optimized to achieve a desired product lifetime or emanation life time, such as a length of time during which the substrate  250  constantly emanates an active agent therefrom. As will be further discussed herein, the substrate  250 , and the properties thereof, may be tuned such that the substrate  250  passively and consistently emanates an active agent, such as transfluthrin, over a period of time, such as one week, ten days, two weeks, three weeks or four weeks, six weeks or eight weeks, most preferably. 
     As discussed above, the substrate  250  may include the first layer  252 , the second layer  254 , and the third layer  256 . Further, in particular embodiments, the first layer  252 , the second layer  254 , and the third layer  256  may have individual properties; however, in some embodiments, the first layer  252 , the second layer  254 , and the third layer  256  may be constructed from the same material, may be interwoven, and may contain continuous fibers therebetween. For example, the first layer  252  and the third layer  256  may be woven layers and the second layer  254  may be a non-woven layer extending therebetween. Further, the fibers of the second layer  254  may connect the fibers of the first layer  252  and the third layer  256 . 
     First Layer of the Substrate 
     The first layer  252  may be formed using one or more materials to provide sufficient wicking, saturation, and rate of evaporation. For example, in particular embodiments, the first layer  252  may be the top layer of the substrate  250  and may be a woven fibrous material constructed from a cotton, polyester, or nylon based material. In these embodiments, the first layer  252  may have a pore size, a weave pattern, a thickness, a porosity, and a density. 
     The pore size of the first layer  252  may range between about 0.5 millimeters and about 20 millimeters, or between about 1 mm and about 10 mm, or between about 1 mm and about 5 mm, or between about 2 mm and about 5 mm, or any pore size between the aforementioned values to provide the desired emanation rate of a volatile material from the substrate  250 , as will be further discussed herein. For example, if a dispensing device  100 ,  200  with a rapid emanation rate is desired, the pore size of the first layer  252  may be substantially higher than a pore size of a first layer  252  of a substrate  250  for a dispensing device  100 ,  200  where a slow emanation rate is desired. 
     Additionally, the pore size of the first layer  252  may be dependent on the construction of the dispensing device  100 ,  200  to be used in combination with the substrate  250 . More particularly, the pore size of the first layer  252  and the total surface area of the substrate  250  that is exposed to the ambient environment, by way of the configuration of the apertures of the dispensing devices  100 ,  200 , each affect the emanation rate of the volatile material or active agent from the substrate  250 . Therefore, when designing the substrate  250 , the first layer  252 , and the properties thereof (i.e., the pore size), may be tuned in combination with the dispensing device to be used therewith. 
     To provide non-limiting examples,  FIG. 10  depicts a substrate  300  having a pore size X 1  of about 3 mm and  FIG. 11  depicts a substrate  320  having a pore size X 2  of about 5 mm, both of which may be utilized for the first layer  252  of the substrate  250  or the third layer  256  of the substrate  250 . Further, in some embodiments, the top layer  252  may also include multiple pore sizes. For example, with reference to  FIG. 11 , the substrate  320  may include a pore size X 2  and a pore size X 3 . 
     As noted above, the weave pattern, thickness, and density of the first layer  252  may also be optimized to produce a desired emanation rate. For example, in the embodiment where the first layer  252  is a woven material, the weave pattern of the first layer  252  may be adjusted to control the rate of wicking. In one preferred embodiment, the optimal weave pattern creates a preferred balance between the release rate of the volatile material therein and an internal surface area, which acts as a reservoir for the volatile material therein. 
     As will be further discussed herein, the first layer  252  may be constructed from textiles produced by Gehring-Tricot Warp Knit Fabrics located in St. Johnsonville, N.Y. and Dolgeville, N.Y., such as the D3® Spacer fabrics. Specific, non-limiting, examples of materials or textiles that may be used to construct the first layer  252  include the following fabrics produced by the Gehring-Tricot Corporation: Gehring Green, SHR 714F, SHR 796F, SHR 918, SHR 891, SHR 896, SHR 701/6, SHR 711/6, SHR 878, SHR 863 SHR 884, SHR 895, SHR 844, SHR 860/1, SHR 724/5, and SHR 702/1. The aforementioned fabrics will be discussed in further detail in the examples herein. 
     Examples of materials that are satisfactory for forming the first layer  252  include textile based materials, such as cotton, polyester, nylon, rayon, or a combination thereof. In further embodiments, the first layer  252  may be formed from a plant-based material, such as hemp fibers. 
     The thickness of the first layer  252  may also be optimized for the particular use for the substrate  250 . As will be further discussed herein, the thickness of the first layer  252  is positively correlated to the release rate; thus, if a higher release rate or emanation rate is desired, a material with a larger thickness may be used for the first layer  252 . In particular embodiments, a thickness of the first layer  252  may range between about 0.1 millimeters and about 6 millimeters, or between about 0.3 mm and about 5 mm, or between about 0.3 and about 3 mm, or between about 1 mm and about 2.5 mm, or between about 1 mm and 2 mm. 
     Second Layer of the Substrate 
     The second layer  254  may also be formed using one or more materials to provide sufficient wicking, saturation, and rate of evaporation. For example, in particular embodiments, the second layer  254  may be an intermediate, spacer layer positioned between the first layer  252  and the third layer  256 . In these embodiments, the second layer  254  may be a fibrous, non-woven material, such as a cotton, polyester, or nylon based material. Further, in these embodiments, the second layer  254  may have a thickness and may be altered to tune the density, thickness, and surface area to volume ratio of the substrate  250 . 
     As noted above, the thickness and density of the second layer  254  may also be optimized to produce a desired emanation rate. More particularly, in certain embodiments, the spacer thickness and the density of the second layer  254  may be varied to control the degree of saturation of the substrate  250  (i.e., the amount of volatile material capable of being stored within the substrate  250 ) and, as a result, the duration of emanation of the volatile material from the substrate  250 . In these embodiments, the second layer  254  may act as a reservoir for the volatile material having the active agent. As such, the density of the second layer  254  may be increased or decreased to control the degree of saturation of the volatile material or active agent. For example, if a higher degree of saturation is desired, the density of the fibers of the second layer  254  can be increased to increase the surface density of the substrate  250 . As will be further discussed herein, the second layer  254  may be altered by increasing or decreasing the fibers therein, such that a surface density of the substrate  250  ranges between about 75 grams per square meter (g/m 2 ) and about 500 grams per square meter, or between about 150 g/m 2  and about 400 g/m 2 , or between about 150 g/m 2  and about 350 g/m 2 , or between about 200 g/m 2  and about 320 g/m 2 , or between about 250 g/m 2  and about 300 g/m 2 , or about 280 g/m 2 . 
     In addition to altering the density of the second layer  254 , the thickness of the second layer  254  may be altered. The thickness of the second layer  254  may be generally defined as the distance between the first layer  252  and the second layer  254 , i.e., the distance through which the fibers of the second layer  254  extend. In particular embodiments, a thickness of the second layer  254  may range between about 0.1 millimeters and about 6 millimeters, or between about 0.5 mm and about 5 mm, or between about 0.5 mm and about 5 mm, or between about 1 mm and about 4 mm, or between about 2 mm and 3 mm, or between about 0.1 mm and about 0.3 mm. 
     Examples of materials, or fibers, which are satisfactory for forming the second layer  254  include textile based materials, such as cotton, polyester, nylon, rayon, or a combination thereof. In further embodiments, the first layer  252  may be formed from a plant-based material, such as hemp fibers. 
     Third Layer of the Substrate 
     The third layer  256  may be formed using one or more materials to provide sufficient wicking, saturation, and rate of evaporation. In particular embodiments, the third layer  256  may be the bottom layer of the substrate  250  and may be a woven fibrous material constructed from a cotton, polyester, or nylon based material. In these embodiments, the third layer  256  may have a pore size, a weave pattern, a thickness, a porosity, and a density. 
     The pore size of the third layer  256  may range between about 0 millimeters and about 20 millimeters, or between about 1 mm and about 10 mm, or between about 1 mm and about 5 mm, or between about 2 mm to about 5 mm, or any pore size between the aforementioned values to provide the desired emanation rate of a volatile material from the substrate  250 , as will be further discussed herein. For example, if a dispensing device  100 ,  200  with a rapid emanation rate is desired, the pore size of the third layer  256  may be substantially higher than a pore size of a third layer  256  of a substrate  250  for a dispensing device  100 ,  200  where a slow emanation rate is desired. Additionally, the pore size of the third layer  256  may be dependent on the construction of the dispensing device  100 ,  200  to be used in combination with the substrate  250 . For example, in one embodiment, the third layer  256  may be proximate the rear face  104  of the dispensing device  100  when placed therein. As such, in these embodiments, the pore size of the third layer  256  may be between about 1 mm and about 5 mm to allow for emanation of an active agent of a volatile material within the substrate  250  when the rear face  104  includes the apertures  130 , such as that shown in  FIG. 2 . However, in an alternative embodiment, the pore size of the third layer  256  may be 0 mm when the rear face  104  does not include the apertures  130 , such as that shown in  FIG. 3 . 
     As noted above, the weave pattern, thickness, and density of the third layer  256  may also be optimized to produce a desired emanation rate. For example, in the embodiment where the third layer  256  is a woven material, the weave pattern of the third layer  256  may be adjusted to control the rate of wicking. 
     As will be further discussed herein, the third layer  256 , similar to the first layer  252 , may be constructed from textiles produced by Gehring-Tricot Warp Knit Fabrics located in St. Johnsonville, N.Y. and Dolgeville, N.Y., such as the D3® Spacer fabrics. Specific, non-limiting, examples of materials or textiles that may be used to construct the first layer  252  include the following fabrics produced by the Gehring-Tricot Corporation: Gehring Green, SHR 714F, SHR 796F, SHR 918, SHR 891, SHR 896, SHR 701/6, SHR 711/6, SHR 878, SHR 863 SHR 884, SHR 895, SHR 844, SHR 860/1, SHR 724/5, and SHR 702/1. The aforementioned fabrics will be discussed in further detail in the examples herein. 
     Generally, examples of materials that are satisfactory for forming the third layer  256  include textile based materials, such as cotton, polyester, nylon, rayon, or a combination thereof. In further embodiments, the third layer  256  may be formed from a plant-based material, such as hemp fibers. 
     The thickness of the third layer  256  may also be optimized for the particular use for the substrate  250 . As will be further discussed herein, the thickness of the third layer  256  is positively correlated to the release rate; thus, if a higher release rate or emanation rate is desired, a material with a larger thickness may be used for the third layer  256 . In particular embodiments, a thickness of the third layer  256  may range between about 0.1 millimeters and about 6 millimeters, or between about 0.3 mm and about 5 mm, or between about 0.3 and about 3 mm, or between about 1 mm and about 2.5 mm, or between about 1 mm and 2 mm. 
     The aforementioned layers of the substrate  250  may also be individually altered to create a substrate having an optimal density, thickness, wicking rate, release or emanation rate, or saturation. 
     In particular embodiments, the layers of the substrate  250 , and the properties thereof, may be altered to provide a substrate  250  having a saturation ranging between about 1 milligram (mg) and about 10,000 mg, or between about 1 mg and about 5,000 mg, or between about 1 mg and about 3,000 mg of volatile material, or between about 50 mg and about 100 mg of volatile material, or between about 1,500 mg and about 2,300 mg of volatile material, or between about 100 mg and about 700 mg, or between about 150 mg and about 400 mg, or between about 150 mg and about 300 mg of volatile material. In related embodiments, the layers of the substrate  250 , and the properties thereof, may be altered to provide a substrate  250  having a saturation ranging between about 0.005 mg/cm 2  and about 55 mg/cm 2 , or between about 0.005 mg/cm 2  and about 30 mg/cm 2 , or between about 0.2 mg/cm 2  and about 0.4 mg/cm 2 , or between about 6.5 mg/cm 2  and about 10 mg/cm 2 , or between about 0.4 mg/cm 2  and about 3 mg/cm 2 , or between about 0.6 mg/cm 2  and about 1.7 mg/cm 2 , or between about 0.6 mg/cm 2  and about 1.3 mg/cm 2 . 
     In some embodiments, the layers of the substrate  250 , and the properties thereof, may be altered to provide a substrate  250  having a thickness ranging between about 0.1 millimeters and about 6 millimeters, or between about 1 and about 4 mm, or between about 1.5 mm and about 3 mm, or between about 1.7 mm and about 2.5 mm, or any thickness between the aforementioned values to provide the desired emanation rate of a volatile material from the substrate  250 , as will be further discussed herein. 
     In further embodiments, the layers of the substrate  250 , and the properties thereof, may be altered to provide a substrate  250  having a surface density ranging between about 75 grams per square meter (g/m 2 ) and about 500 grams per square meter, or between about 150 g/m 2  and about 400 g/m 2 , or between about 150 g/m 2  and about 350 g/m 2 , or between about 200 g/m 2  and about 320 g/m 2 , or between about 250 g/m 2  and about 300 g/m 2 , or about 250 g/m 2 , or about 280 g/m 2 , or any density between the aforementioned values to provide the desired emanation rate of a volatile material from the substrate  250 , as will be further discussed herein. In a preferred embodiment, the substrate  250  has a density ranging between about 40 g/m 2  and 70 g/m 2 . 
     In some embodiments, the substrate  250  may also include a use-up cue that indicates to a user that the dispensing device  100 ,  200  has volatized all or nearly all of the volatile material therefrom. For example, as shown in  FIGS. 12A and 12B , the first layer  252  of the substrate  250  may include a bright colored textile fiber and a dark colored textile fiber, which provide contrast that may be used as a visual cue or dose cue that shows the presence of a volatile material on the substrate  250 . For example, when the substrate  250  does not include a volatile material, bright colored textile fibers  350  provide a visual cue or appearance, as shown in  FIG. 12A , and when the substrate  250  is dosed with a volatile material, the bright colored textile fibers are less apparent, thereby indicating that a volatile material is present thereon or therein, as shown in  FIG. 12B . 
     The dispensing device  100 ,  200  and the substrate  250  therein may include any suitable volatile material. In some embodiments, the volatile material may include an active agent, such as a fragrance, an insecticide, a deodorizer, a fungicide, a bacteriocide, a sanitizer, a pet barrier, or other active volatile or other compound disposed within a carrier liquid, e.g., an oil-based, organic based, and/or water based carrier or solvent, a deodorizing liquid, or the like, and/or combinations thereof. In particular embodiments, the dispensing device  100 ,  200  includes an insect control agent, an insect repellant, or an insecticide. Examples of possible insecticides that may be suitable in the volatile material include pyrethroids such as metafluthrin, transfluthrin, tefluthrin, and vaporthrin, or natural actives (geraniol, etc.) or a blend of these insecticides. 
     Additional examples of an active agent that may be used in the volatile material may include RAID®, Pyrel®, POLIL®, AUTAN®, OUST™ or GLADE®, sold by S. C. Johnson &amp; Son, Inc., of Racine, Wis. The volatile material may also comprise other actives, such as sanitizers, air and/or fabric fresheners, cleaners, odor eliminators, mold or mildew inhibitors, insect repellents, and the like, or others that have aromatherapeutic properties. The volatile material alternatively comprises any fluid know to those skilled in the art that can be dispensed from a container, such as those suitable for dispersal in the form of particles or droplets suspended within a gas and/or propelled by means of a propellant. 
     In some embodiments, the active agent, such as transfluthrin, may be present in the volatile material in an amount between about 5 wt. % and about 95 wt. %, between about 60 wt. % and about 90 wt. %, or between about 70 wt. % and about 85 wt. %, or even more specifically, between about 75 wt. % and about 85 wt. %. In a particular embodiment, the insect control agent may be about 80 wt. % of the volatile material and, in a preferred embodiment, transfluthrin may be about 80 wt. % of the volatile material. 
     The volatile material may also comprise liquids, solids, or vapors. In one aspect, the volatile material may include one or more solvents, such as an organic or aqueous solution, in which the insect control agent may be dissolved. For example, in certain aspects, the active agent may be in a solid state at room temperature (23° C.), and a solvent may be added to the active agent in order to provide and keep the volatile material in a liquid state, thus allowing the volatile material to spread, be coated on, and positioned within the substrate  250 . In further embodiments, the volatile material may include a fragrance. However, in other embodiments, the volatile material may not be mixed with any other components and may consist solely of the active agent. 
     The dispensing device  100 ,  200  can provide delivery of the volatile material from the dispensing device  100 ,  200  at an initial delivery rate that is measured within one hour of exposing the volatile material and the dispensing device  100 ,  200  to the atmosphere. The dispensing device  100 ,  200  can provide delivery of the volatile material across, or from, the first layer  252  at a subsequent delivery rate that is measured at a fixed time after exposing the volatile material and the substrate  250  of the dispensing device  100 ,  200  to the atmosphere. The fixed time can be any length of time over which the vapor-dispensing device is desired to provide delivery of the volatile composition. For example, the fixed time can be six hours, twelve hours, one day, two days, three days, four days, five days, six days, one week, ten days, two weeks, fifteen days, twenty days, three weeks, twenty-five days, four weeks, thirty days, five weeks, forty days, six weeks, forty-five days, seven weeks, fifty days, fifty-five days, eight weeks, ten weeks, twelve weeks, fifteen weeks, twenty weeks, twenty-five weeks, thirty weeks, one year, and the like. More particularly, the dispensing device  100 ,  200  and the substrate  250  and, more particularly, the properties thereof, may be chosen to provide a dispensing device  100 ,  200  that emanates a volatile material over a specified and desired amount of time at a generally constant rate. 
     As described herein, the substrate  250 , or the dispensing devices  100 ,  200 , may be characterized as having a constant emanation rate, or a steady state emanation rate, if the emanation or release of the volatile material or active agent may be graphed or fitted with a linear regression line with a correlation of determination, i.e., an R 2  value, of greater than 0.8, or greater than 0.85, or greater than 0.90, or greater than 0.95, or greater than 0.98. 
     In certain aspects, the particular surface area and formulation concentration of the dispensing device  100 ,  200  may be designed to constantly emanate between about 0.1 mg/day and about 10 mg/day of the active agent or the volatile material, between about 1 mg/day and about 10 mg/day, between about 1 mg/day and about 7 mg/day, between about 1 mg/day and about 5 mg/day of the active agent or the volatile material, or between about 1.5 mg/day and about 4 mg/day of the active agent or the volatile material, or between about 1.5 mg/day and about 2 mg/day of the active agent or the volatile material. In further embodiments, the dispensing device  100 ,  200 , and the substrate  250  therein, may emanate greater than 10 mg/day of the active agent or the volatile material. For example, in some embodiments, the substrate  250  may emanate the active agent or the volatile material at a rate greater than 10 mg/day when the airflow through the substrate  250  is increased. 
     Likewise, as previously discussed herein, the dosage of the substrate  250  and/or the dispensing device  100 ,  200  may be selected based on the desired duration of emanation, e.g., from weeks, months, or seasons. For example, if the dispensing device  100 ,  200  is designed to have an emanation rate of about 2 mg active agent/day then a dispensing device  100 ,  200  designed for use for one month will be dosed with at least 60 mg of an active agent (e.g., transfluthrin). As another example, if the dispensing device  100 ,  200  is designed to have an emanation rate of about 2 mg active agent/day, then a dispensing device  100 ,  200  designed for use for three months (i.e., for a season) will be dosed with at least between about 1,500 and about 2,300 mg of an active agent (e.g., transfluthrin). Hence, initial dosage level of the volatile material and/or the active agent therein may vary from 1 mg to 5 g and may be dependent on the properties of the substrate  250 , a desired emanation rate, and/or a desired emanation lifetime. 
     As discussed above, in some embodiments, the dispensing device  100 ,  200  may be initially dosed with the volatile material and/or the active agent with a predetermined initial dosage. In particular aspects, the initial dosage of the volatile material and/or the active agent therein may range between about 1 mg and about 5 g, between about 20 mg and about 3 g, between about 20 mg and about 1 g, between about 20 mg and about 200 mg, between about 40 mg and about 100 mg, or between about 55 mg and about 70 mg. In other aspects, the initial dosage of the volatile material and/or the active agent therein may range between about 1 mg and about 5 g, between about 1 g and about 3 g, or between about 1.5 g and about 2.3 g. In one example, a dispensing device  100 ,  200  or the substrate  250  may be initially dosed with about 75 mg of an active agent. In another example, the dispensing device  100 ,  200  or the substrate  250  may be initially dosed with between about 3 g and about 4.6 g of a volatile material, which may include approximately between about 1.5 g and 2.3 g of an active agent (e.g., transfluthrin or metofluthrin) and approximately between about 1.5 g and about 2.3 g of a diluting agent (e.g., Exxsol™ D60). In this particular embodiment, the initial dose is delivered per 230 cm 2  of material (e.g., between about 3 g and about 4.6 g of a volatile material per 230 cm 2  of the substrate  250 ). Further, in these embodiments, the inclusion of a diluting agent may promote faster wicking, better distribution, and may inhibit crystallization. 
     After the substrate  250  is dosed with an amount of volatile material, the substrate  250  is placed within the dispensing device  100 ,  200 , which prevents contact between a future user of the dispensing device  100 ,  200  and the active agent. Further, the dispensing device  100 ,  200  and the apertures  120 ,  130 , thereof, promote the appropriate airflow to allow for protective emanation of the volatile material from the dispensing device  100 ,  200 . 
     Although amounts of an initial dosage are outlined above with regard to particular embodiments, it should be understood by one skilled in the art that the initial dosage may vary and may be dependent on a combination of factors, including but not limited to, the surface area of the substrate  250  to which the volatile material is applied, the properties of the one or more layers of the substrate  250  to which the volatile material may be applied (e.g., a thickness of the first layer  252 , the second layer  254 , or the third layer  256 ), a desired delivery rate of the volatile material from the dispensing device  100 ,  200 , a type of material(s) used for the one or more layers of the dispensing device  200  (e.g., a type of material(s) used for the first layer  252 , a type of material(s) used for the second layer  254 , a type of material(s) used for the third layer  256 ), or a type of volatile material(s) used in the dispensing device  100 ,  200 . 
     EXAMPLES 
     The examples herein are intended to illustrate certain embodiments of the dispensing device  100 ,  200  or the substrate  250  to one of ordinary skill in the art and should not be interpreted as limiting in the scope of the disclosure set forth in the claims. The dispensing device  100 ,  200  or the substrate  250  may comprise the following non-limiting examples. 
     In connection with the examples herein, the emanation rates and the amount of active agent, e.g., an amount of transfluthrin, remaining in the substrate of the examples herein were measured by analyzing the weight loss of a particular substrate over time. More particularly, the amount of active agent remaining within a particular substrate may be calculated by first measuring the substrate  250  prior to dosing the substrate  250  with the active agent (or volatile material) and then subtracting that value from the weight of the substrate  250  at any given time after dosing. For example, with reference to Example 1, an initial weight of the substrate  250  was measured, the substrate  250  was dosed with an active agent (i.e., transfluthrin or metofluthrin), and a weight of the substrate  250  was measured multiple times after initial dosage and after emanation of the active agent into the ambient environment. The initial weight of the substrate  250  was then subtracted from a weight of the substrate  250  after initial dosage and this value indicated the remaining active agent within the substrate  250 . Further, after determining the remaining active agent within the substrate  250 , the amount of active agent (or volatile material) emanated to the ambient environment may also be calculated by subtracting the amount of active agent remaining in the substrate  250  from the initial dosage amount of the active agent. All weight measurements can be performed on an analytical scale. Further, the examples herein were conducted in a closed environment, such as a sealed chamber, having a controlled airflow rate. 
     Example 1 
     As discussed herein, characteristics relevant to the dispensing device  100 ,  200  and the substrate  250  may be altered to provide optimal emanation of a volatile material from the dispensing device  100 ,  200 . Additionally, according to an aspect of the present disclosure, the characteristics of the dispensing device  100 ,  200  and the substrate  250  may be altered to provide an optimal, as well as constant, emanation of a volatile material or active agent. 
     To demonstrate the consistent emanation rate of a volatile material from substrates of the present disclosure, a substrate  250  having a surface area of approximately 30 cm 2  was dosed with about 75 mg of two different volatile materials and the emanation rate was measured over a 40 day period. The data collected is depicted in  FIG. 13 . 
     In this example, the substrate  250  includes three layers, such as the first layer  252 , the second layer  254 , and the third layer  256 . Further, in this embodiment, the first layer  252  is a woven material having a honeycomb weave pattern, a pore size of 3 mm and a thickness of 0.3 mm; the second layer  254  is a fibrous material constructed from polyester thread and the substrate  250  has a surface density of about 340 g/m 2 ; and the third layer  256  is a woven material having a honeycomb weave pattern, a pore size of 3 mm and a thickness of 0.3 mm. 
     As shown in  FIG. 13 , a linear release rate was observed when the substrate  250  was dosed with approximately 75 mg of transfluthrin or 75 mg of metofluthrin. When the substrate  250  was dosed with transfluthrin, the substrate  250  constantly emanated the volatile material over a month and, in particular, approximately 36 days at a constant linear rate of about 1.5 mg/day. When the substrate  150  was dosed with metofluthrin, the substrate  250  emanated the volatile material over 20 days at a constant linear rate of about 1.9 mg/day. As a result, embodiments of the substrate  250  may be effectively employed to provide a constant, linear release rate of a volatile material that is long lasting. Further, the degree of volatile material and the characteristics of the substrate  250  (e.g., surface area, porosity, thickness, density, etc.) may be varied dependent on the dosage. For example, the characteristics of the substrate  250  may be altered such that higher dosages (e.g., dosages between about 150 mg and about 800 mg) may be applied to the substrate  250  to provide linear release rates of a volatile material over longer periods of time, such as 3 to 6 months, or even 12 months. 
     As previously discussed herein, the materials used for the substrate  250 , and the layers thereof, may be chosen to optimize the characteristics of the substrate  250 , including the saturation level or emanation rate of the substrate  250 . Optimal materials for the substrate  250 , and the first and third layers  252 ,  256 , are shown in Table 1 below and were provided by Gehring-Tricot Warp Knit Fabrics located in St. Johnsonville, N.Y. and Dolgeville, N.Y., with the exception of the “SCJ 1.0” sample, which is a substrate similar to the substrate described in U.S. patent application Ser. No. 15/164,580, the entire contents of which is incorporated herein by reference. More particularly, based on the desired emanation rate, initial dose of a volatile material, and period of desired emanation, an optimal material for the substrate  250  may be chosen. For example, if a 0.15 mg/hr emanation rate is desired over a 40 day period, SHR 714 F may be chosen for the first layer  252  and/or the third layer  256  of the substrate  250  and the substrate  250  may be dosed with approximately 147 mg of volatile material. 
     Additionally,  FIG. 14  illustrates the wicking rate of each material listed in Table 1 as a function of time, and after approximately 1.2 grams of volatile material was applied to the material. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Saturation Levels of 3-D Meshes 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                 Wicking time 
                 Release 
               
               
                   
                 Saturation 
                 Thickness 
                 (min) 
                 Rate 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Sample ID 
                 (mg) 
                 (mm) 
                 T 25%   
                 T 50%   
                 T 75%   
                 (mg/hr) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 SHR 714 F 
                 147 
                 0.3 
                 11.3 
                 40.9 
                 1033 
                 0.15 
               
               
                 Gehring Green 
                 146 
                 2.35 
                 3.8 
                 17.2 
                 41.4 
                 0.14 
               
               
                 Mesh 
                   
                   
                   
                   
                   
                   
               
               
                 SCJ 1.0 
                 129 
                 2.35 
                 2.2 
                 10.5 
                 26.7 
                 0.13 
               
               
                 SHR 796 F 
                 187 
                 0.3 
                 2.7 
                 9.6 
                 24.2 
                 0.12 
               
               
                 SHF 918 
                 194 
                 1.74 
                 1.5 
                 6.2 
                 17.1 
                 0.12 
               
               
                 SHR 891 
                 241 
                 1.72 
                 2.4 
                 10.5 
                 29.8 
                 0.11 
               
               
                 SHR 896 
                 496 
                 1.76 
                 1.3 
                 5.5 
                 15.4 
                 0.11 
               
               
                 SHR 701/6 
                 310 
                 2 
                 0.7 
                 2.6 
                 7 
                 0.1 
               
               
                 SHR 711/6 
                 221 
                 1.9 
                 2.3 
                 13.5 
                 46 
                 0.09 
               
               
                 SHR 878 
                 717 
                 2.96 
                 1 
                 4.1 
                 11.1 
                 0.09 
               
               
                 SHR 863 
                 292 
                 2.39 
                 6.7 
                 6.4 
                 17.5 
                 0.08 
               
               
                 SHR 884 
                 247 
                 2.58 
                 1.3 
                 4.9 
                 14.3 
                 0.07 
               
               
                 SHR 895 
                 307 
                 1.39 
                 0.4 
                 3.2 
                 12.8 
                 0.07 
               
               
                 SHR 844 
                 270 
                 4.38 
                 1.6 
                 8 
                 24.6 
                 0.06 
               
               
                 SHR 860/1 
                 368 
                 5.14 
                 2.3 
                 12 
                 33.2 
                 0.05 
               
               
                 SHR 724/5 
                 184 
                 1.35 
                 2.7 
                 9.3 
                 27.8 
                 0.04 
               
               
                 SHR 702/1 
                 372 
                 0.3 
                 1.17 
                 4.2 
                 10.8 
                 0.01 
               
               
                   
               
            
           
         
       
     
     Example 2 
     To demonstrate the consistent emanation rate of a volatile material from substrates of the present disclosure used in combination with the dispensing device  200 , and over a period exceeding one month, a substrate  250  was inserted into the dispensing device  200  and the emanation rate of the substrate  250  was measured. In this example, the substrate  250  includes three layers, such as the first layer  252 , the second layer  254 , and the third layer  256 . Further, in this embodiment, the first layer  252  is a woven material having a honeycomb weave pattern, a pore size of 3 mm and a thickness of 0.3 mm; the second layer  254  is a fibrous material constructed from polyester and the substrate  250  has a surface density of about 340 g/m 2 ; and the third layer  256  is a woven material having a honeycomb weave pattern, a pore size of 3 mm and a thickness of 0.3 mm. The substrate  250  was dosed with about 2400 mg of transfluthrin and the concentration of the transfluthrin within the substrate  250  at different locations in a sealed chamber was measured over a period of 75 days. During this trial, the substrate  250  was exposed to an airflow of about 4.8 meters/minute. The data collected is shown in  FIGS. 15A, 15B, and 15C . 
     As shown in  FIGS. 15A-15C , the dispensing device  200  having the substrate  250  constantly emanated a volatile material over a period of 75 days, and emanated the active agent (i.e., transfluthrin) at a constant rate between about 4 mg/day and 6 mg/day.  FIG. 15A  depicts the concentrations of the active agent within the substrate  250  of the dispensing device  200 , wherein the dispensing device  200  was at a first location within a sealed chamber. At this location, the dispensing device  200  (or substrate  250 ) constantly emanated about 4 mg/day for a period greater than 70 days.  FIG. 15B  depicts the concentrations of the active agent within the substrate  250  of the dispensing device  200 , wherein the dispensing device  200  was at a second location within the sealed chamber. At this location, the dispensing device  200  (or substrate  250 ) constantly emanated about 6 mg/day for a period greater than 70 days. Finally,  FIG. 15C  depicts the concentrations of the active agent within the substrate  250  of the dispensing device  200 , wherein the dispensing device  200  was at a third location within the sealed chamber. At this location, the dispensing device  200  (or substrate  250 ) constantly emanated about 4 mg/day for a period greater than 70 days. 
     As shown in  FIGS. 15A-C , the substrates  250  of the present disclosure have the ability to release a volatile material or active agent, such as transfluthrin, over a prolonged period of time. In this particular example, a substrate  250  was designed to emanate a volatile material having transfluthrin as an active agent to repel insects (e.g., mosquitos) over a prolonged period of time without the need to replace or re-dose the substrate  250 . Looking to  FIGS. 15A-15C , the substrate  250  used in this particular example was able to be saturated with about 2400 mg of transfluthrin and released transfluthrin at an emanation rate ranging between about 4 mg/day and 6 mg/day. Additionally, the emanation rate was constant over the 75 day period, as shown by the fitted linear regression lines having high correlation values (i.e., R 2  values) of 0.978, 0.988, and 0.989. Using these linear regression lines, it can be determined that the substrate  250  disclosed herein provide constant emanation of an active agent, such as transfluthrin, over a prolonged period of time greater than about one month, two months, three months, etc. More particularly, using the linear regression lines, the substrate  250  of the present embodiment has the capability of emanating the active agent, transfluthrin, for a period exceeding one year at a constant, linear rate. 
     Example 3 
     Multiple characteristics and dimensions of the substrate  250  were altered to demonstrate the effect the characteristics have on the release or emanation rate of a volatile material from the substrate  250 . 
     First, the thickness of the substrate  250  was varied by varying the thickness of the layers thereof (e.g., second layer  252 ), and the percentage of volatile material (i.e., transfluthrin) remaining in the substrate  250  after 72 hours was measured. The data collected is depicted in  FIG. 16 . 
     Second, the pore diameter of the first layer  252  of the substrate  250  was varied and the percentage of volatile material remaining in the substrate  250  after 72 hours was measured. The data collected is depicted in  FIG. 17 . 
     Third, the pore diameter of the third layer  256  of the substrate  250  was varied and the percentage of volatile material remaining in the substrate  250  after 72 hours was measured. The data collected is depicted in  FIG. 18 . 
     As shown in  FIGS. 16-18 , the release rate of the volatile material from the substrate  250  was positively and linearly correlated to the thickness of the substrate  250 , the pore size of the first layer  252 , and the pore size of the third layer  256  of the substrate  250 . 
     A statistical analysis was also conducted, which is shown in Tables 2 and 3. As shown in Tables 2 and 3, a high correlation value of approximately 0.9 was determined between the thickness and pore size of the first layer  252  and the second layer  254 , and the release rate of the volatile material from the substrate  250 . Further, the F ratio was minimal. 
     
       
         
           
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 Summary of Fit 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 R Square 
                 0.907165 
               
               
                   
                 R Square Adj. 
                 0.851464 
               
               
                   
                 Root Mean Square Error 
                 0.521671 
               
               
                   
                 Observations (or Sum Wgts) 
                 9 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Analysis of Variance 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Source 
                 DF 
                 Sum of Squares 
                 Mean Square 
                 F Ratio 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Model 
                 3 
                 13.296522 
                 4.43217 
                 16.2864 
               
               
                   
                 Error 
                 5 
                 1.360701 
                 0.27214 
                 Prob &gt; F 
               
               
                   
                 C. Total 
                 8 
                 14.657222 
                   
                  0.0052* 
               
               
                   
                   
               
            
           
         
       
     
     Example 4 
     As previously discussed herein, characteristics relevant to the dispensing device  100 ,  200  and the substrate  250  may be altered to provide optimal emanation of a volatile material from the dispensing device  100 ,  200 . According to another aspect of the present disclosure, the surface area/density of the substrate  250  was varied to demonstrate the effect the surface area/density had on the emanation or release rate of a volatile material from the substrate  250 . More particularly, the surface density of a substrate  250  was varied, by altering the layers of the substrate  250 , between about 10 m 2 /bulk m 2  and about 100 m 2 /bulk m 2  and the release or emanation rate from the substrates were measured. The data collected is depicted in  FIG. 19 . Further, as shown in  FIG. 19 , a positive and linear relationship was observed between the surface density of the substrate  250  and the release rate of a volatile material therefrom. The correlation of release rate with density (g/m 2  or GSM) x surface area BET (i.e., actual m 2 /bulk m 2 ) provides directional guidance on a method of selecting commercially available meshes for the substrate  250  to provide and target the desired release rate or emanation rate for a particular application that will use the substrate  250 . 
     With continued reference to  FIG. 19 , g/m 2 *BET is a representation of an amount of surface area available for a given unit of volume, i.e., a low value corresponds to a small amount of surface area corresponding to a given volume of the substrate  250  and a high value corresponds to a large amount of surface area corresponding to a given volume of the substrate  250 . Further, BET refers to the Brunauer-Emmett-Teller theory, which is an analysis technique for measurement of the specific surface area of a material, such as the substrate  250 , and more particularly, the surface area of the fibers (m 2 /g) per mass of sample. The results shown in  FIG. 19  exemplify a linear relationship between the amount of surface area available and the release rate (or emanation rate) of the active agent or volatile material within the substrate  250 . In short, as g/m 2 *BET increases, so does the emanation rate. 
     Example 5 
     As further discussed herein, the percentage of the substrate  250  exposed may alter the emanation of the volatile material from the dispensing device  100 ,  200 . Therefore, according to another aspect of the present disclosure, the percentage of the surface areas of the substrate  250  exposed was varied to demonstrate the effect the percent exposure had on the emanation or release rate of a volatile material from the substrate  250 . More particularly, the percentage of the substrate  250  exposed was varied between about 10% and about 100% and the release rate from the substrates were measured. The data collected is depicted in  FIG. 20 . Further, as shown in  FIG. 20 , a positive and linear relationship was observed between the percent exposure of the surface area of the substrate  250  and the release rate of a volatile material therefrom. 
     Method of Producing the Substrate 
     All of the findings herein can be utilized to optimize the substrate  250  and produce a substrate  250  for constant, passive emanation of a volatile material over a specified period of time. Further, the substrate  250 , and the layers thereof, may be altered or tuned to provide a substrate  250  for particular uses. 
     A design method has been developed to determine the material and characteristics required to achieve the desired emanation rate and product lifetime for the substrate  250 .  FIG. 21  schematically illustrates the design method for constructing the substrate  250 . 
     First, as supported by the non-limiting examples herein, it is understood that the emanation of a volatile material or active agent from the substrate  250  may be modeled using a linear regression line and the concentration of volatile material within the substrate  250  at any given time can be determined using Equation 6: 
         C ( t )= X −ER* t   (Eq. 6)
 
     where the concentration of volatile material or active agent within the substrate  250  is C(t), the initial concentration or dosage of volatile material or active agent is X, and the desired emanation rate or release rate of the volatile material or active agent is ER. 
     Step 1 of the design method involves selecting a minimum, desired product lifetime for the substrate  250 , or minimum, desired product lifetime for the dispensing device  100 ,  200  that will include the substrate  250 . For example, as previously discussed herein, a dispenser having a product lifetime of a week may be desired, or alternatively, a dispenser having a product lifetime of three months may be desired. 
     Step 2 of the design method involves selecting a minimum desired emanation rate (ER) for the substrate  250 , or dispensing device  100 ,  200 . For example, in some embodiments herein, an emanation rate between about 1.4 mg/day and 1.6 mg/day is desired, and in other embodiments, an emanation rate between about 4 mg/day and 6 mg/day is desired. 
     Step 3 in designing the substrate  250 , or dispensing device  100 ,  200 , involves calculating the minimum value for the initial concentration of the volatile material or active agent. The minimum value for the initial concentration of the volatile material or active agent may be calculated using Equation 6, and plugging in the minimum desired product lifetime from Step 1 for t and the minimum desired emanation rate from Step 2 for ER. For example, if a minimum desired product lifetime of three months (i.e., 90 days) and a minimum desired emanation rate of 3.6 mg/day are chosen in Steps 1 and 2, respectively, the minimum value for the initial concentration of the volatile material or active agent will be 324 mg of active agent (e.g., transfluthrin). 
     Step 4 in designing a substrate  250 , or dispensing device  100 ,  200 , involves selecting the first layer  252  and/or third layer  256  for the substrate  250  that will provide the minimum desired emanation rate (ER) determined in Step 2.  FIGS. 17 and 18  provide linear correlations between the pore size and emanation rate or release rate of an active agent (i.e., transfluthrin). Additionally, Table 1 herein provides average emanation or release rates for multiple fabrics produced by Gehring-Tricot Warp Knit Fabrics located in St. Johnsonville, N.Y. and Dolgeville, N.Y., which can be used for the first layer  252  or the third layer  256 . Using this knowledge, a fabric from Table 1 may be chosen for the first layer  252  and/or the third layer  256  to provide the desired emanation rate. For example, if an average emanation rate of 0.15 mg/hr (or 3.6 mg/day) is desired, the fabric SHR 714 F manufactured by Genring-Tricot Corporation may be chosen for the first layer  252  or the third layer  256 , or the fabric SHR 884 may be chosen for the first layer  252  and the third layer  256 . Alternatively, if a fabric other than the fabrics disclosed in Table 1 is desired, Table 1 may provide a basis for comparison, and  FIGS. 17 and 18  may provide the necessary correlating information between a characteristic of the fabrics (e.g., pore size) and their effect on the emanation rate. Therefore, the emanation rates of other fabrics contemplated for the first layer  252  and/or third layer  256  may be approximately estimated using these values and calculations. 
     Step 5 in designing a substrate  250 , or dispensing device  100 ,  200 , involves selecting the second layer  254  for the substrate  250  that will provide the desired saturation capacity for the initial concentration of the volatile material or active agent determined in Step 3. For example, if the minimum value for the initial concentration of the volatile material or active agent was determined to be 324 mg of active agent, such as 324 mg of transfluthrin, a material, thickness, and density of the second layer  254  may be altered, such that the second layer  254  can hold 324 mg of active agent therein. 
     After Steps 1-5, the substrate  250  may be constructed by combining the first layer  252  and/or third layer  256  selected in Step 4 with the second layer  254  selected in Step 5. The first layer  252 , the second layer  254 , and the third layer  256  may be combined using methods know in the art, including glue, adhesive, or the like. In other embodiments, the fibers of the second layer  254  may be interwoven with the fibers of the first layer  252  and/or the fibers of the second layer  256 . In these particular embodiments, the fibers of the first layer  252 , the fibers of the second layer  254 , and the fibers of the third layer  256  are tied together during the weaving process. More particularly, in these embodiments, the layers  252 ,  254 ,  256  may be connected during the weaving process, such that the substrate  250  (and the layers thereof) is fully constructed using a loom. In particular embodiments, the substrate  250  may be constructed using a raschel knitting machine and may be warp knit, such as a double needle bed raschel type spacer knit. 
     This design method may include additional steps not specifically illustrated in  FIG. 21 . In some embodiments, the design method may also include a step to determine the optimal wicking rate for the substrate  250 . For example, a substrate  250  with a high wicking speed may be desired, and in these embodiments, Step 4 of the design method, which involves selecting the first and/or third layer  252 ,  254 , may involve selecting a first and/or third layer  252 ,  254  having the desired wicking speed. To assist in this step, Table 1 discussed herein provides average wicking speeds for multiple fabrics produced by Gehring-Tricot Warp Knit Fabrics located in St. Johnsonville, N.Y. and Dolgeville, N.Y., and  FIG. 14  illustrates these wicking speeds over a period of time. 
     In other embodiments, the design method may also include a step of constructing a dispenser or dispensing device for use with the substrate  250 , such as the dispensing device  100  or the dispensing device  200 . As discussed previously herein, the emanation rate of a volatile material or active agent from the substrate  250  is positively and linearly correlated to the percentage of the surface area of the substrate  250  that is exposed to an ambient environment. More particularly,  FIG. 20  illustrates the positive and linear correlation between the emanation rate of a volatile material from a substrate having an active agent and the percentage of a surface area of a substrate exposed to the ambient environment. Further, the dispensing devices  100 ,  200  disclosed herein include one or more apertures  120 ,  208 ,  210  that expose a portion of the surface area of the substrate  250  enclosed therein, and the number of apertures  120 ,  208 ,  210  and/or the size of the apertures  120 ,  208 ,  210  may be altered to increase or decrease the percentage of the surface area of the substrate  250  that is exposed to an ambient environment. Therefore, in these embodiments, an additional step of the design method may include using the minimum emanation rate for the substrate  250  determined in Step 2, and the selection of the first substrate  252  and the third substrate  256  in Step 4, to determine the percentage of surface area of the substrate  250  that is necessary to provide the desired emanation rate from Step 2. After determining the percentage of surface area of the substrate  250  that needs to be exposed to provide the desired emanation rate, the apertures  120 ,  208 ,  210  of the dispensing devices  100 ,  200  may be tuned to provide the desired emanation rate. It should be understood that this step may also affect Step 4, as a designer may select a particular first layer  252  and/or third layer  256  after determining the percentage of surface area of the substrate  250  that will be exposed to the ambient environment during use of the substrate  250 . 
     Additional Dispensers 
       FIGS. 22-30  illustrate additional dispensing devices that may be used in combination with the substrate  250  disclosed herein. 
       FIG. 22  illustrates a bracelet  400  that may be used in combination with the substrate  250  of  FIG. 9 . In this embodiment, the bracelet  400  includes an outer frame  402  having an interior groove  404  and a recessed surface  406 . A user may position the substrate  250  on the recessed surface  406  and within the groove  404 . Further, the bracelet  400  may include a strap  408 , such as a Velcro® strap. 
       FIGS. 23 and 24  illustrate a dispenser  500  that may be used in combination with the substrate of  FIG. 9 . In this embodiment, the dispenser  500  includes an outer frame  502  and a recessed surface  504 , into which the substrate  250  may be positioned. Additionally, the dispenser  500  may include a clip  506 , which may be used to fix the dispenser onto a user. 
       FIG. 25  illustrates another bracelet  600  that may be used in combination with the substrate  250 . In this embodiment, the bracelet  600  includes an enclosure  602  that includes a plurality of apertures  604  on a front face  606  thereof, as well as a bracelet band  608 . Here, the enclosure  602  may be opened and closed, and the substrate  250  may be inserted or removed from the enclosure  602 . When positioned within the enclosure, the substrate  250  may emanate a volatile material or active agent from the substrate  250  through the apertures  604 . 
       FIGS. 26 and 27  illustrate two hangers  700 ,  800 . In these embodiments, the hangers  700 ,  800  may include a first component  702 ,  802  with a front face  704 ,  804  that can releasably couple with a second component  706 ,  806  having a reservoir or recessed interior  708 ,  808 . Further, the front face  704 ,  804  and a rear face  710 ,  810  may include a plurality of apertures  712 ,  812 . During use, a user may insert the substrate  250  into the recessed interior  708 ,  808  of the second component  706 ,  806  and couple the first component  702 ,  802  to the second component  706 ,  806 , thereby encasing the substrate  250  within the hanger  700 ,  800 . After the substrate  250  is positioned within the hangers  700 ,  800 , the volatile material or active agent may emanate from the substrate  250  and through the apertures  712 ,  812  of the hangers  700 ,  800 . 
       FIG. 28  depicts another dispenser  900  that may be used in combination with the substrate  250  discussed herein. In this embodiment, the dispenser  900  includes a front face  902  coupled to a rear face  904  along a hinge  906 , which allows the dispenser  900  to transition between an open state, as shown in  FIG. 28 , and a closed state (not shown). The front face  902  includes a receptacle  908  and the rear face  904  includes a receptacle  910 . Each receptacle  908 ,  910  may house the substrate  250  therein, and when in the open state, the dispenser  900  allows emanation of a volatile material or active agent from the substrate  250 . 
       FIG. 29  depicts another dispenser  1000  that may be used in combination with the substrate  250 . In this embodiment, similar to the dispenser  900 , the dispenser  1000  includes a front face  1002  and a rear face (not shown) coupled together using a hinge  1004 . Further, the front face  1002  may include a plurality of apertures  1006  which allow air to flow into the dispenser and the passive emanation of a volatile material or active agent from the substrate  250 . In some embodiments, the dispenser  1000  may be provided as a kit and the kit may include a pouch  1008  that encapsulates an amount of volatile material or active agent  1010  therein. In this embodiment, the front face  1002  includes an element (not shown) on an interior surface thereof that is capable of puncturing the pouch  1008  once the dispenser  1000  is closed. Therefore, during use, a user may insert the pouch  1008  into the dispenser  1000  and close the dispenser  1000 , which resultantly punctures the pouch  1008 , thereby releasing the volatile material or active agent  1010  therein. After the pouch  1008  is punctured, the substrate  250  within the dispenser  1000  may wick the volatile material or active agent  1010  and subsequently emanate the volatile material or active agent  1010  therefrom over a period of time. 
       FIG. 30  illustrates a reservoir  1100  that may be used to dose the substrate  250 , or alternatively one or more of the dispensers disclosed herein. For example, the bracelet  600  may be dosed with an amount of volatile material or active agent using the reservoir  1100  by positioning an aperture  1102  on a rear side  1104  of the enclosure  602  of the bracelet  600  over a nozzle  1106 . Next, a user may position the nozzle  1106  within the aperture  1102 , and apply a downward force. The downward force causes the nozzle  1106  to emit an amount of volatile material from the reservoir  1100 , through the nozzle  1106 , and into the enclosure  602 , which houses the substrate  250  therein. As a result, the substrate  250  can be re-dosed using the reservoir  1100 . 
     Variations and modifications of the foregoing are within the scope of the present disclosure. It is understood that the embodiments disclosed and defined herein extend to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present disclosure. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art. 
     As noted previously, it will be appreciated by those skilled in the art that while the invention has been described above in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication were individually incorporated by reference herein. 
     Any of the embodiments described herein may be modified to include any of the structures or methodologies disclosed in connection with different embodiments. 
     INDUSTRIAL APPLICABILITY 
     The aspects of the dispenser, dispensing device, or substrate described herein advantageously combine the features of a dispensing device or protective enclosure and a multi-layer substrate or mesh material to effectively emanate a volatile material or active agent at a desired time of use and over a desired amount of time. Additionally, the aspects of the dispenser or dispensing device provides a mechanism that is both easy to use and inexpensive, as well as a device that is structurally stable and safe. Accordingly, the disclosed dispenser or dispensing device may be used across a broad range of applications. 
     Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention. The exclusive rights to all modifications which come within the scope of the appended claims are reserved.