Substrate for emitting volatile material, method of operating dispenser consistently emitting volatile material, method of manufacturing substrate for emitting volatile material, and method of manufacturing system consistently emitting volatile material

Abstract

To provide 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.SOLUTION: A system for consistently emitting a volatile material includes a dispenser having at least one aperture, a substrate adapted to fit in the dispenser. The substrate includes a first woven layer having a first pore size, a second woven layer having a second pore size, a third, non-woven layer that extends between the first woven layer and the second woven layer, and a volatile material. The system has a steady state weight loss of the volatile material over a time greater than 30 days.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure generally relates to dispenser devices for releasing volatile substances, and more particularly to dispensers and substrates for passive emission of volatile substances, including a multilayer substrate supported by a protective housing.

Background Art

[0002] Various volatile substance dispensing devices known in the art generally include a reservoir for holding a volatile substance and a housing or support structure for holding the reservoir. These devices typically either allow for passive diffusion of the volatile material without the aid of a dispensing mechanism or use a dispensing mechanism to enhance and / or facilitate the release of the volatile material. For example, typical dispensing mechanisms used in volatile substance dispensing devices include heating devices and / or fans. Such prior dispensers often require these mechanisms or other expensive materials to ensure a constant release of the volatile material over a long period of time. However, these prior dispensers often require power and have significantly high manufacturing costs.

[0003] In some examples, dispensers that passively emit volatile materials may be provided as sheets or films and may include multiple layers, one of which is exposed to the surrounding environment and, as a result, can emit an amount of volatile material therefrom. However, such prior passive dispensers also have common drawbacks. For one, the user may have to come into contact with the material being emitted while activating or opening the dispenser or during use of the dispenser. Additionally, the release rate of the active ingredient from passive dispensers typically decreases over time, and the efficacy of the volatile emission therefrom decreases during the period of use.

[0004] What is needed is, preferably, a dispenser that overcomes one or more of these drawbacks. More particularly, what is needed is a dispenser that does not require the user to be in contact with the volatile substance having an active agent such as an insecticide, while passively emitting the volatile substance at a constant rate over a long period of time. SUMMARY OF THE INVENTION

[0005] Embodiments of the present disclosure provide a substrate for dispensing a volatile material. The substrate includes opposing first and second layers having a first configuration and a first pore size. The substrate further includes an intermediate layer having a second configuration between the first layer and the second layer. The opposing first and second layers are also liquid and air permeable.

[0006] In related embodiments, the present disclosure provides a dispenser for releasing a volatile material. The dispenser includes a substrate having a front, a back, and opposing first and second layers having a plurality of openings, and an intermediate layer provided between the first and second layers. The first layer and the second layer each have a first configuration and a first pore size. Further, the intermediate layer has a second configuration, and the opposing first and second layers are liquid and air permeable.

[0007] According to another aspect of the present disclosure, a system for stably releasing a volatile substance is provided. The system includes a dispenser having at least one opening, a substrate adapted to fit within the dispenser, and a volatile substance. The substrate also includes a first woven fabric layer having a first pore size, a second woven fabric layer having a second pore size, and a third non-woven, fibrous layer extending between the first woven fabric layer and the second woven fabric layer. Further, the system has a steady-state weight loss of the volatile material over a time period exceeding 30 days.

[0008] In a further embodiment, the volatile material comprises an active agent selected from the group consisting of metofluthrin, transfluthrin, tefluthrin, and vaporthrin. The pore size of the first fabric layer may be between about 1 millimeter and about 10 millimeters, and the steady weight loss of the volatile material may be between about 1 milligram per day and about 10 milligrams per day. Further, the weight of the volatile material may be between about 1 gram and about 5 grams, and at least one opening of the dispenser exposes a portion of the first fabric layer. In a further embodiment, at least one opening of the dispenser exposes between about 50% and about 99% of the surface area of the first fabric layer.

[0009] In other embodiments, the system has a steady weight loss of the volatile material over a time period longer than 60 days or longer than 70 days. In some embodiments, the first pore size may be different from the second pore size, and the dispenser may include a front and a back, the front including at least one opening. Further, in another embodiment, the first fabric layer and the second fabric layer are constructed from a first material, the third non-woven fiber layer is constructed from a second material, and the first material and the second material are different.

[0010] According to another aspect of the present disclosure, another system for stably releasing a volatile substance is provided. The system includes a frame having at least one opening, a substrate disposed within the frame, and a volatile substance. The substrate includes a first fabric layer having a plurality of pores, a second fabric layer having a plurality of pores, and a third non-woven fiber layer extending between the first fabric layer and the second fabric layer. The system provides a steady weight loss of the volatile material over a time period longer than 30 days.

[0011] In a further embodiment, the steady weight loss of the volatile substance is between about 4 mg / day and about 6 mg / day; the volatile substance is selected from the group consisting of metofluthrin, transfluthrin, tefluthrin, and vaporthrin; and the volatile substance is in an amount between about 2 g and about 3 g. In a further embodiment, the system has a steady-state weight loss of the volatile material over a time period exceeding 70 days. In some embodiments, the frame includes a first opening that exposes a portion of the first fabric layer and a second opening that exposes a portion of the second fabric layer.

[0012] According to yet another aspect of the present disclosure, a method of designing a system for continuously emitting a volatile substance is provided. The method includes selecting a minimum time for the continuous emission of the volatile substance, selecting a minimum emission rate of the volatile substance, calculating a minimum concentration of the volatile substance using the minimum time for the continuous emission of the volatile substance and the minimum emission rate of the volatile substance, selecting a first layer for the substrate based at least on the minimum emission rate of the volatile substance, and selecting a second layer for the substrate based at least on the minimum concentration of the volatile substance.

Brief Description of the Drawings

[0013]

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DETAILED DESCRIPTION OF THE INVENTION

[0014] The following discussion and the accompanying figures disclose various embodiments or configurations of a dispensing device and a base material that can be used in combination with the dispensing device.

[0015] As used herein, the term "about" refers to numerical variations that can arise, for example, from typical measurements and manufacturing procedures used in volatile dispensers or other manufactured articles that may include embodiments of the present disclosure; from inadvertent errors in these procedures; from differences in the manufacture, source, or purity of the components used in the manufacture of a composition or mixture or the execution of a method. Throughout the present disclosure, the term "about" refers to a range of values that are ±5% of the value of the numerical term that it precedes.

[0016] As used herein, "weight percent," "wt-%," "percent by weight," "weight %," and variations thereof refer to the concentration of a substance or component as the weight of that substance or component divided by, and multiplied by 100 with, the total weight of the composition or a particular component of the composition. It is understood that when used herein, "percent," "%," etc. may be synonymous with "weight %" and "wt-%."

[0017] The present disclosure is directed to dispensers for holding volatile substances and substrates. Although the present disclosure may be embodied in many different forms, it should be considered only as an exemplification of the principles of the present disclosure, and it is not intended to limit the present disclosure to the illustrated embodiments. With this understanding, some specific embodiments are discussed herein.

[0018] Furthermore, the principles of the present disclosure apply to any volatile material released by passive emission, and specific examples illustrate the passive emission of specific volatile materials (e.g., insecticides), but it is contemplated that the dispensers and substrates discussed herein can be used with a variety of volatile materials. Examples of volatile substances include, but are not limited to, insecticides, insect repellents, insect attractants, fragrances, mold or mold inhibitors, cleaners, disinfectants, air fresheners, aromatherapy scents, preservatives, positive fragrance volatiles, deodorizers, and combinations thereof. Also, as will be described in more detail herein, additives may be included in the volatile material, e.g., a fragrance or a preservative.

[0019] Dispenser Figures 1 and 2 generally show a dispenser device 100 for the emission of volatile substances into the surrounding environment and, in this particular embodiment, for the passive emission of volatile substances into the surrounding environment. In one preferred embodiment, as further discussed herein, the dispenser device 100 is used in combination with a multilayer substrate to emit a pest control agent, such as a repellent or insecticide, into the surrounding environment.

[0020] Still referring to FIGS. 1 and 2, the dispensing device 100 is shown as having two opposing sides including a front face 102 (see FIG. 1) and a back face 104 (see FIG. 2). A central plate 106 extends between the front face 102 and the back face 104, and a substrate (not shown) can be disposed between the front face 102 and the back face 104 as further discussed herein. In these embodiments, the substrate is a reservoir for the volatile material and emits the volatile material from the dispensing device 100 over a predetermined period of time.

[0021] 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, oval, triangular, square, rectangular, pentagonal, hexagonal, or any other desired geometric configuration. The central plate 106 may have an opening 110 centrally disposed at its top, as shown in this embodiment. The opening 110 allows a user to hang the dispensing device 100 before or during its use. Additional openings may be disposed around the central plate 106 to assist in hanging the dispensing device 100 in alternative embodiments.

[0022] Referring specifically to FIG. 1, the front face 102 extends from the central plate 106 and is generally rectangular in this embodiment, having rounded corners 112. Similar to the central plate 106, the front face 102 may have an alternative configuration or shape in other embodiments. For example, in some embodiments, the front face 102 may be circular, oval, triangular, square, rectangular, pentagonal, hexagonal, or any other desired geometric configuration. The legs 114 may extend from the bottom end 116 of the front face 102, which supports the dispensing device 100 and enables the dispensing device 100 to be placed on a surface (not shown) before or during its use. The front face 102 may also include a plurality of openings 120 that allow air to enter and exit the dispensing device 100. Thus, during use of the dispensing device 100, volatile materials may dissipate from the substrate within the dispensing device 100 through the openings 120.

[0023] In certain embodiments, the front face 102, and its openings 120, may be modified or adjusted to increase or decrease the rate of dissipation of volatile materials from the dispensing device 100. Referring now to FIG. 5, a drawing is depicted showing the front face 102 having 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 discussed previously herein, the front face 102 may have an alternative configuration and, in some embodiments, may be circular, oval, triangular, square, rectangular, pentagonal, hexagonal, or any other desired geometric configuration. In these embodiments, the front face 102 is 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 2It may be dimensioned to have a surface area therebetween.

[0024] In one aspect, as shown in FIGS. 1 and 5, the opening 120 may be a circular opening having various diameters. For example, continuing to refer to FIGS. 1 and 5, the circular opening 120 proximate to the center 122 of the front face 102 may have the smallest relative diameter, and the diameter of the opening 120 may increase as the opening 120 extends outward from the center 122 of the front face 102. Further, as best shown in FIG. 5, the opening 120 may be formed of a plurality of concentric rings or annular rows extending outward from the center 122 of the front face 102. Further, in this particular embodiment, the diameter of the opening 120 within each concentric circle of the opening may be uniform. However, as discussed earlier herein, the diameter of the opening 120 may generally increase as the opening 120 extends outward from the center 122, in other words, the diameter of the opening 120 within the first concentric circle may be the smallest, and the diameter of the opening 120 within the concentric circle furthest from the center 122 may be the largest.

[0025] In this particular embodiment, the front face 102 includes approximately 13 concentric circles or annular rows of the opening 120, namely, annular rows A - M (see FIG. 5). However, in an alternative embodiment, the front face 102 may include any number of openings 120 to cause a desired divergence of the volatile material from the dispensing device 100. For example, in an alternative embodiment, the openings 120 may be arranged in rows or columns to form a grid configuration. In such an embodiment, 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 each include between 1 and 100 openings. In other embodiments, the openings 120 may be arranged to depict a particular shape, character, word, or image.

[0026] According to another aspect of the present disclosure, the opening 120 in the region N - Q adjacent to the corner 112 of the front face 102 may have an alternative configuration. For example, as best shown in FIG. 5, the opening 120 adjacent to the corner 112 of the front face 102 may be of a triangular configuration. Further, in the present embodiment, the opening 120 farthest from the corner 112 may have the smallest diameter, and the opening 120 closest to the corner 112 may have the largest diameter. Thus, the diameter of the opening 120 generally increases as the opening 120 extends from the center 122 of the front face 102, and then decreases as the opening 120 transitions from the first pattern (i.e., the concentric or annular row of openings) to the second pattern (i.e., the triangular pattern of openings), and may then further increase as the opening 120 extends towards the corner 112.

[0027] In an alternative embodiment, the opening 120 may be of a reverse configuration, where the opening 120 farthest from the corner 112 has the largest diameter and the opening 120 closest to the corner 112 has the smallest diameter. In yet another embodiment, the front face 102 may not include the opening 120 within the triangular configuration. Rather, in one embodiment, the front face 112 may include only the concentric openings 120 that extend to the corner 112 such that the diameter of the opening 120 only increases as it extends outward from the center 122 of the front face.

[0028] In an alternative embodiment, the opening 120 may be a circular opening having a uniform diameter. In other embodiments, the openings 120 may be arranged in an alternative configuration such as a row or column, or may be arbitrarily or randomly arranged on the front face 102. However, in certain embodiments, the opening 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 opening 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 about 95% of the front face 102. For example, continuing to refer 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 over which the opening 120 extends may be characterized by subtracting the surface area (SA1) lacking any of the openings 120 from the total surface area (SA). In this particular embodiment, the surface area (SA1) may be defined as the radius (r) between the center 122 of the front face 102 and the innermost edge defining one of the openings 120 of the smallest concentric ring or annular row A, and may be calculated using Equation 1 below.

[0029] [Number]

[0030] Furthermore, the total surface area (SAs) of the substrate exposed to the surrounding environment may be approximately equal to the total surface area (SA) minus the surface area (SA1), which is approximately the same as the surface area lacking any of the openings 120. Further, the ratio of the surface area of the exposed substrate may be determined by dividing the total surface area (SA ES ) of the exposed substrate by the total surface area (SA s ) of the substrate, and in most embodiments, is equal to the total surface area (SA). The equation for determining the ratio of the surface area of the exposed substrate is shown in Equation 2 below.

[0031] [Number]

[0032] The concentric circles of openings A - M and the openings of quarter - circles N - Q may be characterized by individual radii extending from the center of each opening. In this way, an actual measurement of the surface area defined by opening 120 may be calculated, or the surface area excluding any opening may be calculated. Looking again at FIG. 5, the largest or final concentric - circular ring of opening M may be characterized by a radius (R) defined by the outermost edge of one of the openings of the largest concentric circle or circular row M, as shown in FIG. 5. The radius (R) may be approximately equal to half of the height H of the front face 102 and / or approximately equal to half of the width W of the front face 102. In these embodiments, the ratio (SA) of the surface area having the openings of the first pattern (i.e., the concentric circles or circular rows of openings A - M) may be calculated using Equation 3 below and may be characterized as a first footprint or spread area. The ratio of the surface area having the openings 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 spread area having four quarter - circles.

[0033]

Number

[0034]

Number

[0035] Furthermore, the surface area of each quadrant having an alternative configuration, i.e., regions N - Q, may be calculated by dividing the surface area calculated by Equation 3 by 4.

[0036] The diameter of the opening 120 may be between about 1 millimeter and about 25 millimeters, or between about 1 mm and about 15 mm, or between about 5 millimeters and about 10 millimeters. In alternative embodiments, the opening 120 may be of an alternative configuration. For example, the opening 120 may be oval, triangular, square, rectangular, pentagonal, hexagonal, or any other desired geometric shape. In such embodiments, the opening 120 is about 0.75 mm 2 and about 500 mm 2 therebetween, or about 0.75 mm 2 and about 175 mm 2 therebetween, or about 20 mm 2 and about 75 mm 2 and may have a surface area in the range therebetween.

[0037] Furthermore, as previously described herein, the diameter of the opening 120 may generally increase as the opening 120 extends outward from the center 122, as shown, for example, in FIG. 5. As a result, the rate of divergence or release of the volatile substance from the dispensing device 100 may vary at different positions on the front face 102. For example, in the present embodiment, the rate of divergence may increase generally outward from the central portion 122 and may have a positive relationship with the size of the opening 120. In other words, since the concentric circle M includes an opening 120 having a larger diameter than the opening 120 of the concentric circle A, the rate of divergence of the volatile material of the dispensing device 100 may be greater through the opening 120 of the concentric circle M as compared to the rate of divergence of the volatile material through the opening 120 of the concentric circle A. By that effect, the dispensing device 100 may wick the volatile material from the center 122 to the corner 112 of the front face 102. In alternative embodiments, the size of the opening 120 may be changed and adjusted to provide other desired airflows and rates of divergence.

[0038] In some embodiments, the front face 102 may include openings between about 1 and 7,500, or between about 1 and 2,000, or between about 500 and about 1,000, or between about 700 and about 800. Still referring to FIG. 5, the opening 120 may also have symmetry across the vertical axis 124 and / or the horizontal axis 126. Further, as shown in FIG. 4, the surface below the opening 120 may be a color different from the color of the front face 102.

[0039] Referring to FIG. 2, the back face 104 of the dispensing device 100 may be similar to the front face 102 and may include a plurality of openings 130 extending outward from the center 132. However, in an alternative embodiment, the back face 104 of the dispensing device 100 may not include the opening 130 as shown in FIG. 3. In other embodiments, the back face 104 may be constructed independently of the front face 102 and may include openings 130 of various sizes, numbers, and patterns. Thus, the foregoing disclosure regarding the front face 102 and its opening 120 applies equally and independently to the back face 104 and its opening 130. For example, in some embodiments, the back face 104 may independently have a height and width between about 10 centimeters and about 100 centimeters, or between about 10 centimeters and about 50 centimeters, or between about 10 centimeters and about 30 centimeters. Further, the opening 130 may be circular and may have a diameter, for example, between about 1 millimeter and about 25 millimeters, or between about 1 millimeter and about 15 millimeters, or between about 5 millimeters and about 10 millimeters. Alternatively, the dispensing device 100 may not include the back face 104, and the central plate 106 may define the back of the dispensing device 100.

[0040] The dispensing device 100 may also be characterized by its thickness. The thickness may be the distance measured between the front face 102 and the back face 104 of the dispensing device 100. In some embodiments, the thickness of the dispensing device 100 may be between about 0.05 cm and about 10 cm.

[0041] Further, in this particular embodiment, the back surface 104 also includes legs 134 extending from the bottom end 136 of the back surface 104, which may support the dispensing device 100. In use, the legs 114, 136 allow the dispensing device 100 to sit or be placed on a surface (not shown).

[0042] Figures 6 - 8 show another dispensing device or frame 200 for use in the dispersion of volatile materials into the surrounding 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 disperse volatile substances such as pest repellents, deterrents, or insecticides into the surrounding environment.

[0043] The dispenser device 200 includes two opposing sides including a front face 202 and a back face 204, and the substrate 206 may be disposed between the front face 202 and the back face 204. As will be further described, the substrate 206 is a reservoir for the volatile material and passively disperses the volatile material from the dispensing device 200 over a predetermined period.

[0044] The dispensing device 200 includes two opposing sides including a front face 202 and a back face 204, and the substrate 206 may be disposed between the front face 202 and the back face 204. As will be further discussed, the substrate 206 is a reservoir for the volatile material and passively disperses the volatile material from the dispensing device 200 over a predetermined period.

[0045] As shown in FIGS. 6 and 7, the front face 202 includes an opening 208 that allows an air flow through the substrate 206 to provide passive dispersion of the volatile material from the substrate 206. The back 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 opening 210 that permits an air flow through the substrate 206 to provide passive dispersion of the volatile material from the substrate 206. Alternatively, the back face 204 does not include the opening 210, and in this embodiment, the back face 204 is closed and covers the substrate 206.

[0046] Continuing to refer to FIGS. 6-8, the openings 208, 210 may be between about 50% and about 99% of the front 202 or the back 204, respectively. In further embodiments, the openings 208, 210 may be between about 75% and about 99%, or between about 90% and about 95% of the front 202 or the back 204, respectively. For example, continuing to refer to FIGS. 6-8, the front 202 may have a total surface area (SA2) defined by multiplying the width W2 by the height H2, and the back 204 may have a total surface area (SA3) defined by multiplying the width W3 by the height H3. Thus, the openings 208, 210 may expose about 50% to about 99%, or about 75% to about 99%, or about 90% to about 95% of the substrate 206 to the surrounding environment. Thus, similar to the dispensing device 100, the front 202 and the back 204, and their openings 208, 210 may be sized to increase or decrease the rate of emission of volatile substances from the dispensing device 200.

[0047] Referring now to FIGS. 7 and 8, the heights H2, H4 and the widths W2, W4 may be of dimensions similar to the height H and width W of the dispensing device 100. More specifically, the heights H2, H3 and the widths W2, W3 may each be about 10 centimeters to about 100 centimeters, or about 10 centimeters to about 50 centimeters, or about 10 centimeters to about 30 centimeters. In these embodiments, the front 202, and / or the back 204 may be dimensioned to have a surface area 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 of surface area.

[0048] The front face 202 and the back face 204, as well as their openings 208, 210, may be modified or adjusted to increase or decrease the rate of divergence of the volatile material forming the dispensing device 200. Referring to FIGS. 7 and 8, the openings 208, 210 may be defined by heights H3, H5 and widths W3, W5 respectively, and the surface area (SA ES ) of the exposed substrate can, in this embodiment, be calculated by multiplying the height H3, H5 by the width W3, W5. Thus, the proportion of the substrate surface area exposed to the ambient environment can be calculated by dividing the surface area (SA ES ) of the exposed substrate by the total surface area (SAs) of the substrate, which in most embodiments is the same as the total surface area (SA) of the front face 202 or the back face 204. The total surface area (SA) of the front face 202 or the back face 204 can be calculated using the dimensions of the height H2, H4 and the width W2, W4. In this embodiment, the total surface area (SA) of the front face 202 or the back face 204 can be calculated by multiplying the height H2, H4 of the front face 202 or the back face 204 by its width W2, W4. The formula for obtaining the proportion of the surface area of the substrate that is exposed to the ambient environment is shown in Equation 5 below.

[0049]

Number

[0050] Similar to the dispensing device 100, the front face 202 and the back face 204, as well as their openings 208, 210, may be modified or adjusted to increase or decrease the rate of divergence of the volatile substance from the dispensing device 200. As previously described herein, the openings 208, 210 may be between about 35% and about 99% of the surface area of the front face 202 or the back face 204 of the dispensing device 200. In alternative embodiments, the openings 208, 210 may be between about 50% and about 99% of the front face 202 or the back face 204, or between about 75% and about 99% of the front face 202 or the back face 204, or between about 90% and about 95% of the front face 202 or the back face 204. As a result, the proportion of the surface area of the exposed substrate (SA ES) may be between about 50% and about 99% or less, or between about 75% and about 99%, or between about 90% and about 95%.

[0051] Substrate Figure 9 shows a portion of a substrate 250 that can be used in combination with dispensing device 100 or dispensing device 200. As further described herein, substrate 250 may be composed of one or more layers and may be a three-dimensional fabric material used for passive dissipation of an activator of a volatile material. In one embodiment, the structure of substrate 250 may include a plurality of woven and non-woven layers that can be laminated to manufacture substrate 250. For example, as shown in Figure 9, substrate 250 may include a first layer 252, a second layer 254, and a third layer 256. However, according to an alternative aspect of the present disclosure, substrate 250 may include only the first and second layers, such as additional layers or alternatively only the first layer 252 and the second layer 254.

[0052] Substrate 250 and its layer configuration produce a substrate 250 having a high surface area per projected volume. More specifically, the first layer 252 and / or the third layer 256 may provide an optimal layer for wicking and subsequently releasing a volatile material or activator using a plurality of pores that allow air to flow through substrate 250 and its layers, and the second layer 254 may provide an optimal layer for storing the volatile material or activator over a long period of time.

[0053] According to aspects of the present disclosure, the physical properties of the layer of substrate 250 may be optimized to achieve a desired wicking, saturation, and evaporation rate. More specifically, the thickness, porosity, weave pattern, material, and / or spatial density of the layer of substrate 250 may be optimized to achieve, for example, the desired wicking, saturation, and evaporation rates of the active agent from substrate 250. Further, the thickness, porosity, weave pattern, material, and / or spatial density of the layer of substrate 250 may be optimized to achieve a desired product life or dissipation life time, such as the length of time that substrate 250 continuously dissipates the active agent therefrom. As further discussed herein, substrate 250, and its properties, may most preferably be adjusted such that substrate 250 passively and consistently dissipates an active agent, such as transfluthrin, over a period of, for example, one week, ten days, two weeks, three weeks, or four weeks, six weeks, or eight weeks.

[0054] As described above, substrate 250 may include a first layer 252, a second layer 254, and a third layer 256. Further, in certain embodiments, the first layer 252, the second layer 254, and the third layer 256 may have individual properties, but in some embodiments, the first layer 252, the second layer 254, and the third layer 256 may be composed of the same material, may be woven, and may include continuous fibers therebetween. For example, the first layer 252 and the third layer 256 may be fabric layers, and the second layer 254 may be a nonwoven 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.

[0055] First layer of the substrate The first layer 252 may be formed using one or more materials to provide sufficient wicking, saturation, and evaporation rates. For example, in certain embodiments, the first layer 252 may be the top layer of 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, weave pattern, thickness, porosity, and density.

[0056] The pore size of the first layer 252 may be between about 0.5 millimeter and about 20 millimeters, or between about 1 millimeter and about 10 millimeters, or between about 2 millimeters and about 5 millimeters, or any pore size between the aforementioned values, in order to provide a desired rate of divergence of volatile materials from the substrate 250, as further described herein. For example, if dispensing devices 100, 200 having a rapid rate of divergence are desired, the pore size of the first layer 252 may be substantially larger than the pore size of the first layer 252 of the substrate 250 for dispensing devices 100, 200 for which a slow rate of divergence is desired.

[0057] Furthermore, the pore size of the first layer 252 may depend on the structure of the dispensing devices 100, 200 used in combination with the substrate 250. More specifically, the pore size of the first layer 252 and the total surface area of the substrate 250 exposed to the ambient environment by the configuration of the openings of the dispensing devices 100, 200 each affect the rate of divergence of volatile materials or active agents from the substrate 250. Thus, when designing the substrate 250, the first layer 252, and its properties (i.e., pore size), can be adjusted in combination with the dispensing device used therefor.

[0058] To provide a non-limiting example, FIG. 10 depicts a substrate 300 having a pore size X1 of about 3 mm, and FIG. 11 depicts a substrate 320 having a pore size X2 of about 5 mm, both of which can be utilized in the first layer 252 of the substrate 250 or the third layer 256 of the substrate 250. Furthermore, in some embodiments, the top layer 252 may also include a plurality of pore sizes. For example, referring to FIG. 11, the substrate 320 may include a pore size X2 and a pore size X3.

[0059] As described above, the weave pattern, thickness, and density of the first layer 252 may also be optimized to produce a desired rate of divergence. For example, in embodiments 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 divergence. In one preferred embodiment, the optimal weave pattern creates a preferred balance between the rate of release of the volatile material therein and the internal surface area that functions as a reservoir for the volatile material therein.

[0060] As further discussed herein, the first layer 252 may be constructed from a textile produced by a knitting warp knit fabric such as D3® spacer fabric, located in Johnsonville, New York and Dortchville, New York. Specific, non-limiting examples of materials or textiles that may be used to construct the first layer 252 include the following fabrics manufactured by 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 foregoing fabrics are described in more detail in the examples herein.

[0061] Examples of satisfactory materials for forming the first layer 252 include fabric - based materials such as cotton, polyester, nylon, rayon, or combinations thereof. In further embodiments, the first layer 252 may be formed from plant - based materials such as hemp fibers.

[0062] The thickness of the first layer 252 can also be optimized according to the specific use of the substrate 250. As further described herein, the thickness of the first layer 252 has a positive correlation with the release rate, and thus, if a higher release rate or divergence rate is desired, a material having a greater thickness may be used for the first layer 252. In certain embodiments, the thickness of the first layer 252 may be in the range between about 0.1 millimeter and about 6 millimeters, or between about 0.3 millimeter and about 5 millimeters, or between about 0.3 millimeter and about 3 millimeters, or between about 1 millimeter and about 2.5 millimeters, or between about 1 millimeter and 2 millimeters.

[0063] Second layer of the substrate The second layer 254 may also be formed using one or more materials to provide sufficient wicking, saturation, and evaporation rates. For example, in certain embodiments, the second layer 254 may be an intermediate, spacer layer disposed between the first layer 252 and the third layer 256. In these embodiments, the second layer 254 may be a fibrous nonwoven 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 varied to adjust the surface area ratio of the substrate 250 with respect to density, thickness, and volume.

[0064] As described above, the thickness and density of the second layer 254 may also be optimized to produce a desired rate of divergence. More specifically, in certain embodiments, the thickness of the spacer and the density of the second layer 254 may be varied to control the saturation of the substrate 250 (i.e., the amount of volatile material storable within the substrate 250) and, as a result, the duration of the divergence of the volatile material from the substrate 250. In these embodiments, the second layer 254 may function as a reservoir for the volatile substance having the activator. Thus, the density of the second layer 254 may be increased or decreased to control the degree of saturation of the volatile substance or the activator. For example, if a higher 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 further described herein, the second layer 254 has a surface density of about 75 grams per square meter (g / m 2 ) between about 500 grams per square meter, or about 150 g / m 2 and about 400 g / m 2 between, or about 150 g / m 2 and about 350 g / m 2 between, or about 200 g / m 2 and about 320 g / m 2 between, or about 250 g / m 2 and about 300 g / m 2 between, or about 280 g / m 2 and can be changed by increasing or decreasing the fibers therein so as to be between.

[0065] In addition to changing the density of the second layer 254, the thickness of the second layer 254 may be changed. The thickness of the second layer 254 may generally be defined as the distance between the first layer 252 and the second layer 254, i.e., the distance over which the fibers of the second layer 254 extend. In certain embodiments, the thickness of the second layer 254 is between about 0.1 millimeter and about 6 millimeters, or between about 0.5 millimeter and about 5 millimeters, or between about 1 millimeter and about 4 millimeters, or between about 2 millimeters and about 3 millimeters, or between about 0.1 millimeter and about 0.3 millimeter.

[0066] Examples of suitable materials, or fibers, for forming the second layer 254 include fabric-based materials such as cotton, polyester, nylon, rayon, or combinations thereof. In further embodiments, the first layer 252 may be formed from a plant-based material such as hemp fibers.

[0067] Third layer of the substrate The third layer 256 may be formed using one or more materials to provide sufficient wicking, saturation, and evaporation rates. In certain 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 pore size, fabric pattern, thickness, porosity, and density.

[0068] The pore size of the third layer 256 may be between about 0 millimeters and about 20 millimeters, or between about 1 millimeter and about 10 millimeters, or between about 2 millimeters and about 5 millimeters, or any pore size between said values, to provide a desired rate of divergence of volatile materials from the substrate 250, as further described herein. For example, if dispensing devices 100, 200 with a rapid rate of divergence are desired, the pore size of the third layer 256 may be substantially larger than the pore size of the third layer 256 of the substrate 250 of dispensing devices 100, 200 where a slow rate of divergence is desired. Further, the pore size of the third layer 256 may depend on the structure of the dispensing devices 100, 200 used in combination with the substrate 250. For example, in one embodiment, the third layer 256 may be proximate to the back surface 104 of the dispensing device 100 when disposed thereon. Thus, in these embodiments, the pore size of the third layer 256 may be between about 1 mm and about 5 mm to allow for the divergence of the active agent of the volatile material within the substrate 250 when the back surface 104 includes an opening 130 as shown in FIG. 2. However, in an alternative embodiment, when the back surface 104 does not include an opening 130, as shown in FIG. 3, the pore size of the third layer 256 may be 0 mm.

[0069] As described above, the weave pattern, thickness, and density of the third layer 256 may also be optimized to produce a desired rate of divergence. For example, in embodiments 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 divergence.

[0070] As further discussed herein, a third layer 256, similar to the first layer 252, may be composed of a textile produced by a Gehring-tricot warp knit fabric located in Johnsonville, New York and Dolgeville, New York, such as D3® spacer fabric. Specific, non-limiting examples of materials or textiles that may be used to construct the first layer 252 include the following fabrics manufactured by 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 foregoing fabrics are further described in the examples herein.

[0071] Generally, examples of satisfactory materials for forming the third layer 256 include fabric-based materials such as cotton, polyester, nylon, rayon, or combinations thereof. In further embodiments, the third layer 256 may be formed from a plant-based material such as hemp fiber.

[0072] The thickness of the third layer 256 may also be optimized for a particular application with respect to the substrate 250. As further explained herein, the thickness of the third layer 256 has a positive correlation with the release rate, and thus, if a higher release rate or divergence rate is desired, a material having a greater thickness may be used for the third layer 256. In certain embodiments, the thickness of the third layer 256 may range between about 0.1 millimeter and about 6 millimeters, or between about 0.3 millimeter and about 5 millimeters, or between about 0.3 millimeter and about 3 millimeters, or between about 1 millimeter and about 2.5 millimeters, or between about 1 millimeter and about 2 millimeters.

[0073] The aforementioned layer of the substrate 250 can also be individually modified to create a substrate having an optimal density, thickness, wicking rate, release or divergence rate, or saturation.

[0074] In certain embodiments, the layer of the substrate 250, and its properties, are volatile substances 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, or volatile substances between about 50 mg and about 100 mg or between about 1,500 mg and about 2,300 mg, 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, or the layer of the substrate 250, and its properties, may be modified to provide a substrate 250 having a saturation of volatile substances 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 to provide a substrate 250 having a saturation within this range.

[0075] In some embodiments, the layer of substrate 250, and its properties, as further discussed herein, can be modified to provide a desired rate of divergence of volatile materials from substrate 250 to have a thickness between about 0.1 millimeter and about 6 millimeters, or between about 1 millimeter and about 4 millimeters, or between about 1.5 millimeters and about 3 millimeters, or between about 1.7 millimeters and about 2.5 millimeters, or any thickness between the aforementioned values.

[0076] In further embodiments, the layer of substrate 250, and its properties, as further described herein, can be modified to provide a desired rate of divergence of volatile substances from substrate 250 to have a surface density 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 between about 250 g / m 2 , or about 280 g / m 2 or any density range between the aforementioned values. In a preferred embodiment, substrate 250 has a density in the range of about 40 g / m 2 to 70 g / m 2 .

[0077] In some embodiments, the substrate 250 may include an end-of-use cue indicating to the user that the dispensing devices 100, 200 have volatilized all or substantially 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 light-colored textile fibers and dark-colored textile fibers, which provide a contrast that can be used as a visual cue or dosage cue indicating the presence of the volatile material on the substrate 250. For example, when the substrate 250 does not contain the volatile material, the light-colored textile fibers 350 provide a visual clue or appearance as shown in FIG. 12A, and when the substrate 250 is sprayed with the volatile material, the light-colored textile fibers are less obvious, thereby indicating the presence of the volatile material there as shown in FIG. 12B.

[0078] The dispensing devices 100, 200 and the substrate 250 therein may include any suitable volatile material. In some embodiments, the volatile material is an agent such as a fragrance, an insecticide, a deodorant, a bactericide, 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, etc., and / or combinations thereof. In certain embodiments, the dispensing devices 100, 200 include an insect control agent, an insect repellent, or an insecticide. Examples of insecticides that may be suitable for the volatile substance include pyrethroids such as metofluthrin, transfluthrin, tefluthrin, and vaporothrin, or natural active agents (such as geraniol), or blends of these insecticides.

[0079] Additional examples of active agents that can be used in volatile materials include RAID®, Pyrel®, POLIL®, AUTAN®, OUST™ or GLADE® sold by S.C. Johnson & Son, Inc. of Racine, Wisconsin. The volatile material can also consist of other active agents, such as disinfectants, air and / or fabric fresheners, cleaners, odor removers, mold or mildew inhibitors, insect repellents, etc., or other things with aromatherapy properties. Alternatively, the volatile material can consist of any fluid known to those skilled in the art that is dispensed from a container, such as one suitable for being dispersed in the form of particles or droplets floating in a gas and / or propelled by a propellant.

[0080] In some embodiments, an 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 more specifically between about 75 wt% and about 85 wt%. In certain embodiments, 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.

[0081] Also, the volatile material may be composed of a liquid, solid, or vapor. In one aspect, the volatile material may include one or more solvents, such as an organic solution or an aqueous solution in which the insect control agent can dissolve. For example, in one aspect, the active agent may be in a solid state at room temperature (23 °C), and a solvent may be added to the active agent to provide and maintain the volatile material in a liquid state, so that the volatile material can spread and be coated on and positioned within the substrate 250. In a further embodiment, the volatile material may include a fragrance. However, in other embodiments, the volatile material may not be mixed with other components and may consist only of the active agent.

[0082] Dispensing devices 100, 200 can provide the release of volatile materials from the dispensing devices 100, 200 at an initial release rate measured within 1 hour after exposing the volatile materials and the dispensing devices 100, 200 to the atmosphere. The dispensing devices 100, 200 can provide the release of volatile materials across the first layer 252, or from the first layer 252, at a subsequent release rate measured at a fixed time after exposing the volatile materials of the dispensing devices 100, 200 and the substrate 250 to the atmosphere. The fixed time can be any length of time for which it is desired for the vapor dispensing device to provide the release of the volatile composition. For example, the fixed time can be 6 hours, 12 hours, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 10 days, 2 weeks, 15 days, 20 days, 3 weeks, 25 days, 4 weeks, 30 days, 5 weeks, 40 days, 6 weeks, 45 days, 7 weeks, 50 days, 55 days, 8 weeks, 10 weeks, 12 weeks, 15 weeks, 20 weeks, 25 weeks, 30 weeks, 1 year, etc. More specifically, the dispensing devices 100, 200 and the substrate 250, and more specifically, their characteristics, may be selected to provide dispensing devices 100, 200 that generally emit volatile materials at a desired time at a constant rate.

[0083] As described herein, the substrate 250, or the dispensing devices 100, 200, may be characterized as having a constant divergence rate, or a steady divergence rate, if the divergence or release of the volatile material or active agent can be graphed or fitted with a linear regression line having an R 2 value of 0.8 or greater, or 0.85 or greater, or 0.90 or greater, or 0.95 or greater, or 0.98 or greater.

[0084] In certain embodiments, the specific surface area and dispensing concentration of the dispensing devices 100, 200 are constantly an active agent or volatile material between about 0.1 mg / day and about 10 mg / day, 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, or an active agent or volatile material between about 1.5 mg / day and about 4 mg / day, or an active agent or volatile material between about 1.5 mg / day and about 2 mg / day. In further embodiments, the dispensing devices 100, 200, and the substrate 250 therein may emit an active agent or volatile material exceeding 10 mg / day. For example, in some embodiments, the substrate 250 may emit the active agent or volatile material at a rate exceeding 10 mg / day when the airflow through the substrate 250 increases.

[0085] Similarly, as discussed earlier herein, the dosage of the substrate 250 and / or the dispensing devices 100, 200 can be selected based on the desired emission period, for example, from weeks, months, or seasons. For example, if the dispensing devices 100, 200 are designed to have an emission rate of about 2 mg of active agent / day, the dispensing devices 100, 200 designed for use over a one-month period will be dosed with at least 60 mg of active agent (e.g., transfluthrin). As another example, if the dispensing devices 100, 200 are designed to have an emission rate of about 2 mg of active agent / day, the dispensing devices 100, 200 designed for use over a three-month period (i.e., one season) will be dosed with at least about 1,500 to about 2,300 mg of active agent (e.g., transfluthrin). Thus, the initial dosing level of the volatile material and / or the active agent therein may vary from 1 mg to 5 g and can depend on the properties of the substrate 250, the desired emission rate, and / or the desired emission lifetime.

[0086] As described above, in some embodiments, the dispensing devices 100, 200 may be initially dosed with a volatile material and / or an active agent at a predetermined initial dosage. In certain aspects, the initial dosage of the volatile material and / or active agent therein may be 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, the dispensing devices 100, 200 or the substrate 250 may be initially dosed with about 75 mg of the active agent. In another example, the dispensing devices 100, 200 or the substrate 250 may be initially dosed with about 3 g to about 4.6 g of the volatile substance, which may include about 1.5 g to about 2.3 g of the active agent (e.g., transfluthrin or metofluthrin) and about 1.5 g to about 2.3 g of the diluent (e.g., Exxsol TM D60). In this particular embodiment, the initial dosage is released per 230 cm 2 of the material (e.g., about 3 g to about 4.6 g of the volatile material per 230 cm 2 of the substrate 250). Further, in these embodiments, including a diluent can promote faster wicking, better distribution, and can suppress crystallization.

[0087] After dosing the substrate 250 with the amount of the volatile material, the substrate 250 can be placed within the dispensing devices 100, 200 to prevent contact between future users of the dispensing devices 100, 200 and the active agent. Further, the dispensing devices 100, 200 and their openings 120, 130 facilitate an appropriate airflow to enable a protective dispersion of the volatile material from the dispensing devices 100, 200.

[0088] The amount of the initial dosage is outlined above with respect to certain embodiments, but the initial dosage may vary and may depend on, but is not limited to, elements such as the surface area of the substrate 250 to which the volatile material is applied, the properties of one or more layers of the substrate 250 to which the volatile material can be applied (e.g., the thickness of the first layer 252, the second layer 254, or the third layer 256), the desired release rate of the volatile material from the dispensing devices 100, 200, the type of material used for one or more layers of the dispensing device 200 (e.g., the type of material used for the first layer 252, the type of material used for the second layer 254, the type of material used for the third layer 256), or the combination of volatile material(s) used in the dispensing devices 100, 200, as would be understood by those skilled in the art.

Examples

[0089] The examples in this specification are intended to illustrate certain embodiments of the dispensing devices 100, 200 or the substrate 250 to those skilled in the art and should not be construed as limiting the scope of the disclosure defined in the claims. The dispensing devices 100, 200 or the substrate 250 may be composed of the following non-limiting examples.

[0090] In connection with the examples of this specification, the emission rate of the examples of this specification and the amount of the active agent remaining in the substrate, such as transfluthrin, were measured by analyzing the weight loss of a specific substrate over time. More specifically, the amount of the active agent remaining in a specific substrate can be calculated by first measuring the substrate 250 before dosing the substrate 250 with the active agent (or volatile substance) and subtracting that value from the weight of the substrate 250 at any time after dosing. For example, referring to Example 1, the initial weight of the substrate 250 was measured, the substrate 250 was dosed with the active agent (i.e., transfluthrin or metofluthrin), and the weight of the substrate 250 was measured multiple times after the initial dose and after the active agent had dissipated into the surrounding environment. Then, the initial weight was subtracted from the weight of the substrate 250 after the initial dose, and this value indicated the active agent remaining in the substrate 250. Further, after determining the remaining active agent in the substrate 250, the amount of the active agent (or volatile substance) dissipated into the surrounding environment can also be calculated by subtracting the amount of the active agent remaining in the substrate 250 from the initial dose of the active agent. All weight measurements can be performed with an analytical balance. Further, the examples of this specification were carried out in a closed environment such as a sealed chamber having a controlled air flow rate.

[0091] Example 1 As discussed herein, the characteristics associated with the dispensing devices 100, 200 and the substrate 250 may be varied to provide optimal emission of the volatile material from the dispensing devices 100, 200. Further, according to one aspect of the present disclosure, the characteristics of the dispensing devices 100, 200 and the substrate 250 may be varied to provide optimal and consistent emission of the volatile material or active agent.

[0092] To demonstrate a consistent emission rate of the volatile material from the substrate of the present disclosure, two different volatile materials of about 75 mg were dosed onto a substrate 250 having a surface area of about 30 cm 2 and the emission rate was measured over 40 days. The data collected is depicted in FIG. 13.

[0093] In this example, the substrate 250 includes three layers such as a first layer 252, a second layer 254, and a third layer 256. Further, in this embodiment, the first layer 252 is a woven material having a honeycomb weave pattern, having a pore size of 3 mm and a thickness of 0.3 mm, the second layer 254 is a fibrous material composed of polyester yarns, 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, having a pore size of 3 mm and a thickness of 0.3 mm.

[0094] As shown in FIG. 13, when about 75 mg of transfluthrin or 75 mg of metofluthrin was administered to the substrate 250, a linear release rate was observed. When the substrate 250 was dosed with transfluthrin, the substrate 250 constantly emitted the volatile substance at a constant linear rate of about 1.5 mg / day for 1 month, particularly for about 36 days. When the substrate 150 was dosed with metofluthrin, the substrate 250 emitted the volatile substance at a constant linear rate of about 1.9 mg / day for about 20 days. As a result, the embodiment of the substrate 250 can be effectively employed to provide a constant linear release rate of the volatile substance that persists over a long period. Further, the degree of the volatile material and the properties of the substrate 250 (e.g., surface area, porosity, thickness, density, etc.) can be varied depending on the dosage. For example, a higher dosage (e.g., a dosage between about 150 mg and about 800 mg) can be applied to the substrate 250 to vary the properties of the substrate 250 so as to provide a linear release rate of the volatile material over a longer period such as 3 to 6 months, or 12 months.

[0095] As already described in this specification, the substrate 250 and the materials used in its layers can be selected to optimize the properties of the substrate 250, including the saturation level or the release rate of the substrate 250. The optimal materials for the substrate 250 and the first and third layers 252, 256 are shown in Table 1 below and are provided by Guilford - Tricot Warp Knit Fabrics located in Johnsonville, New York and Dolgeville, New York, and the "SCJ 1.0" sample, which is a substrate similar to the substrate described in U.S. Patent Application No. 15 / 164,580, the entire content of which is incorporated herein by reference, is excluded. More specifically, the optimal material for the substrate 250 can be selected based on the desired release rate, the initial dosage of the volatile material, and the desired period of release. For example, if a release rate of 0.15 mg / hr is desired over 40 days, SHR714 F may be selected for the first layer 252 and / or the third layer 256 of the substrate 250, and approximately 147 mg of the volatile material may be administered to the substrate 250.

[0096] Furthermore, Figure 14 shows the wicking rate of each material described in Table 1 as a function of time, after approximately 1.2 grams of the volatile material has been applied to the material.

[0097]

Table 1

[0098] Example 2 To demonstrate a consistent rate of volatile emission from the disclosed substrates when used in combination with a dispensing device 200, over a period exceeding one month, the substrate 250 was inserted into the dispensing device 200 and the emission rate of the substrate 250 was measured. In this example, the substrate 250 includes three layers such as a first layer 252, a second layer 254, and a third layer 256. Further, in this embodiment, the first layer 252 is a woven material having a honeycomb weave pattern, having a pore size of 3 mm and a thickness of 0.3 mm, the second layer 254 is a fibrous material composed of 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. Approximately 2400 mg of transfluthrin was administered to the substrate 250, and the concentration of transfluthrin in the substrate 250 at different positions within a sealed chamber was measured over 75 days. During this test, the substrate 250 was exposed to an air flow of approximately 4.8 meters per minute. The data collected is shown in FIGS. 15A, 15B, and 15C.

[0099] As shown in FIGS. 15A - 15C, the dispensing device 200 having the substrate 250 constantly emitted volatile substances over 75 days and emitted an activator (i.e., transfluthrin) at a constant rate between about 4 mg / day and 6 mg / day. FIG. 15A depicts the concentration of the activator within the substrate 250 of the dispensing device 200, and the dispensing device 200 was in a first location within a sealed chamber. At this location, the dispensing device 200 (or the substrate 250) constantly emitted about 4 mg / day for a period exceeding 70 days. FIG. 15B depicts the concentration of the activator within the substrate 250 of the dispensing device 200, where the dispensing device 200 was in a second location within a sealed chamber. At this position, the dispensing device 200 (or the substrate 250) constantly emitted about 6 mg / day for a period exceeding 70 days. Finally, FIG. 15C depicts the concentration of the activator within the substrate 250 of the dispensing device 200, where the dispensing device 200 was in a third location within a sealed chamber. At this position, the dispensing device 200 (or the substrate 250) constantly emitted about 4 mg / day for a period exceeding 70 days.

[0100] As shown in FIGS. 15A - C, the substrate 250 of the present disclosure has the ability to release volatile substances or activators such as transfluthrin over a long period. In this particular example, the substrate 250 was designed to emit a volatile substance having transfluthrin as an activator for repelling insects (e.g., mosquitoes) over a long period without the need to replace or re - administer the substrate 250. Looking at FIGS. 15A - 15C, the substrate 250 used in this particular embodiment could be saturated with about 2400 mg of transfluthrin and could release transfluthrin at a release rate in the range of about 4 mg / day to about 6 mg / day. Further, high correlation values of 0.978, 0.988, and 0.989 (i.e., R 2As shown by the fitted linear regression line with a (value), the release rate was constant over 75 days. Using these linear regression lines, it can be determined that the substrate 250 disclosed herein provides a constant divergence of active agents such as transfluthrin over long periods exceeding about one month, two months, three months, etc. More specifically, using the linear regression line, it can be seen that the substrate 250 of the present embodiment has the function of diverging transfluthrin, which is an active agent, at a constant linear rate over a period exceeding one year.

[0101] Example 3 A plurality of characteristics and dimensions of the substrate 250 were changed to demonstrate the influence of the characteristics on the release or divergence rate of volatile substances from the substrate 250.

[0102] First, the thickness of the substrate 250 was changed by varying the thickness of its layer (e.g., the second layer 252), and the proportion of volatile substances (i.e., transfluthrin) remaining in the substrate 250 after 72 hours was measured. The collected data is depicted in FIG. 16.

[0103] Next, the pore size of the first layer 252 of the substrate 250 was changed, and the proportion of volatile substances remaining in the substrate 250 after 72 hours was measured. The collected data is depicted in FIG. 17.

[0104] Third, the pore size of the third layer 256 of the substrate 250 was changed, and the proportion of volatile substances remaining in the substrate 250 after 72 hours was measured. The collected data is depicted in FIG. 18.

[0105] As shown in FIGS. 16 to 18, the release rate of volatile substances from the substrate 250 showed a positive linear correlation with the thickness of the substrate 250, the pore size of the first layer 252, and the pore size of the third layer 256.

[0106] In addition, statistical analysis was also performed, and the results are shown in Tables 2 and 3. As shown in Tables 2 and 3, a high correlation value of about 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 volatile substances from the substrate 250. Furthermore, the F ratio was the minimum.

[0107]

Table 2

[0108]

Table 3

[0109] Example 4 As already described in this specification, the characteristics related to the dispensing devices 100, 200 and the substrate 250 may be changed to provide optimal divergence of volatile materials from the dispensing devices 100, 200. According to another aspect of the present disclosure, the surface area / density of the substrate 250 was varied to demonstrate the effect of the surface area / density on the divergence or release rate of volatile materials from the substrate 250. More specifically, by changing the layer of the substrate 250, the surface density of the substrate 250 was varied between about 10 m 2 / bulk m 2 and about 100 m 2 / bulk m 2 and the release or divergence rate from the substrate was measured. The data collected is depicted in FIG. 19. Furthermore, as shown in FIG. 19, a positive linear relationship was observed between the surface density of the substrate 250 and the release rate of volatile substances therefrom. The correlation between the release rate and the density (g / m 2 or GSM) × surface area BET (i.e., actual m 2 / bulk m 2 ) provides directional guidance on how to select a commercially available mesh of the substrate 250 to provide a desired release or divergence rate for a particular application using the substrate 250.

[0110] Continuing to refer to FIG. 19, g / m 2*BET represents the amount of available surface area per unit volume. That is, a low value corresponds to a small surface area corresponding to a given volume of the substrate 250, and a high value corresponds to a large surface area corresponding to a given volume of the substrate 250. Further, BET refers to the Brunauer - Emmett - Teller theory, which is an analytical method for measuring the specific surface area of materials such as the substrate 250, more specifically, the surface area of the fibers per unit mass of the sample (m 2 / g). The results shown in Figure 19 illustrate a linear relationship between the amount of available surface area and the release rate (or emission rate) of the active agent or volatile substances within the substrate 250. In short, as g / m 2 *the BET increases, the emission rate also increases.

[0111] Example 5 As further discussed herein, the proportion of the substrate 250 that is exposed can potentially change the emission of volatile materials from the dispensing devices 100, 200. Thus, according to another aspect of the present disclosure, the proportion of the surface area of the substrate 250 that is exposed was varied to demonstrate the effect that the exposed proportion has on the emission or release rate of volatile materials from the substrate 250. More specifically, the proportion of the exposed substrate 250 was varied between approximately 10% and approximately 100%, and the release rate from the substrate was measured. The data collected is depicted in Figure 20. Further, as shown in Figure 20, a positive linear relationship was observed between the exposed proportion of the surface area of the substrate 250 and the release rate of volatile substances therefrom.

[0112] Method for manufacturing the substrate All the findings herein can be utilized to optimize the substrate 250 and manufacture the substrate 250 for passively and steadily emitting volatile substances over a specified period. Further, the substrate 250, and its layers, can be modified or adjusted to provide the substrate 250 for specific applications.

[0113] A design method has been developed to determine the materials and properties necessary to achieve the desired release rate and product life for the substrate 250. FIG. 21 is a diagram schematically showing the design method for constructing the substrate 250.

[0114] First, as supported by the non-limiting examples in this specification, the release of volatile materials or active agents from the substrate 250 can be modeled using a linear regression line, and it is understood that the concentration of volatile materials in the substrate 250 at any given time can be determined using Equation 6.

[0115]

Equation

[0116] Here, when the concentration of the volatile substance or active agent in the substrate 250 is C(t), the initial concentration or dosage of the volatile substance or active agent is X, and the desired release rate or emission rate of the volatile substance or active agent is ER, the concentration of the volatile substance or active agent can be any of C(t), X, and ER.

[0117] Step 1 of the design method includes selecting the minimum desired product life of the substrate 250, or the minimum desired product life of the dispensing devices 100, 200 that will include the substrate 250. For example, as already described in this specification, a dispenser with a one-week product life may be desired, or alternatively, a dispenser with a three-month product life may be desired.

[0118] Step 2 of the design method includes selecting the minimum desired release rate (ER) for the substrate 250, or the dispensing devices 100, 200. For example, in some embodiments of this specification, a release rate between about 1.4 mg / day and 1.6 mg / day is desired, and in other embodiments, a release rate between about 4 mg / day and 6 mg / day is desired.

[0119] Step 3 in designing the substrate 250, or the dispensing devices 100, 200, includes calculating the minimum value of the initial concentration of the volatile material or the active agent. The minimum value of the initial concentration of the volatile material or the active agent may be calculated by using Equation 6 and plugging in the minimum desired product life from Step 1 for t and the minimum desired divergence rate from Step 2 for ER. For example, if the minimum desired product life and the minimum desired divergence rate of 3.6 mg / day are selected in Steps 1 and 2 respectively for 3 months (i.e., 90 days), the minimum value of the initial concentration of the volatile substance or the active agent will be 324 mg of the active agent (e.g., transfluthrin).

[0120] Step 4 in designing the substrate 250, or the dispensing devices 100, 200, includes selecting the first layer 252 and / or the third layer 256 for the substrate 250 that provides the minimum desired divergence rate (ER) determined in Step 2. FIGS. 17 and 18 provide a linear correlation between the pore size and the divergence rate or release rate of the active agent (i.e., transfluthrin). Further, Table 1 herein provides the average divergence rate or release rate of a plurality of fabrics manufactured by Guilford - Tricot Warp Knitted Fabrics located in Johnsonville, NY and Dolgeville, NY that can be used for the first layer 252 or the third layer 256. Using this knowledge, a fabric from Table 1 can be selected for the first layer 252 and / or the third layer 256 to provide the desired divergence rate. For example, if an average divergence rate of 0.15 mg / hr (or 3.6 mg / day) is desired, the fabric SHR 714 F manufactured by Guilford - Tricot Corporation may be selected for the first layer 252 or the third layer 256, or the fabric SHR 884 may be selected for both the first layer 252 and the third layer 256. Alternatively, if a fabric other than those disclosed in Table 1 is desired, Table 1 serves as a basis for comparison and FIGS. 17 and 18 may provide the necessary correlation information between the fabric properties (e.g., pore size) and the effect on the divergence rate. Thus, the divergence rate of other fabrics contemplated for the first layer 252 and / or the third layer 256 can be approximately estimated using these values and calculations.

[0121] Step 5 in designing the substrate 250 or the dispensing devices 100, 200 involves selecting a second layer 254 for the substrate 250 that provides a desired saturation capacity for the initial concentration of the volatile material or the active agent determined in step 3. For example, if it is determined that the minimum value of the initial concentration of the volatile material or the active agent is 324 mg of the active agent, e.g., 324 mg of transfluthrin, the material, thickness, and density of the second layer 254 may be varied so that the second layer 254 can hold 324 mg of the active agent therein.

[0122] After steps 1 - 5, the substrate 250 may be constructed by combining the first layer 252 and / or the 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 known in the art, including adhesives, adhesives, etc. 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 third 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 joined together during the weaving process. More specifically, in these embodiments, the layers 252, 254, 256 may be joined during the weaving process such that the substrate 250 (and its layers) are completely constructed using a loom. In certain embodiments, the substrate 250 may be constructed using a raschel knitting machine and may be a warp knit, such as a two - needle bed raschel type spacer knit.

[0123] This design method may include additional steps not specifically illustrated in FIG. 21. In some embodiments, the design method may also include the step of determining an optimal wicking rate for the substrate 250. For example, a substrate 250 having a high wicking rate may be desired, and in these embodiments, step 4 of the design method, which includes the selection of the first and / or third layers 252, 254, may include the selection of the first and / or third layers 252, 254 having the desired wicking rate. To assist with this step, Table 1 described herein provides the average wicking rates of a plurality of fabrics manufactured by Guilford-Tricot warp knit fabrics located in Johnsonville, N.Y. and Dolgeville, N.Y., and FIG. 14 illustrates these wicking rates over a period of time.

[0124] In other embodiments, the design method can also include constructing a dispenser or dispensing device for use with a substrate 250, such as dispensing device 100 or dispensing device 200. As discussed earlier herein, the rate of emission of volatile materials or active agents from the substrate 250 is positively linearly correlated with the proportion of the surface area of the substrate 250 exposed to the ambient environment. More specifically, FIG. 20 shows a positive linear correlation between the rate of emission of volatile substances from a substrate having an active agent and the proportion of the surface area of the substrate exposed to the ambient environment. Further, the dispensing devices 100, 200 disclosed herein include one or more openings 120, 208, 210 that expose a portion of the surface area of the substrate 250 enclosed therein, and the number and / or size of the openings 120, 208, 210 may be changed to increase or decrease the proportion of the surface area of the substrate 250 exposed to the ambient environment. Thus, in these embodiments, an additional step of the design method may include determining the percentage of the surface area of the substrate 250 required to provide the desired emission rate from step 2, using the minimum emission rate of the substrate 250 determined in step 2 and the selection of the first substrate 252 and the third substrate 256 in step 4. After determining the proportion of the surface area of the substrate 250 that needs to be exposed to provide the desired emission rate, the openings 120, 208, 210 of the dispensing devices 100, 200 may be adjusted to provide the desired emission rate. It should be understood that this step can also affect step 4 because the designer can select a particular first layer 252 and / or third layer 256 after determining the proportion of the surface area of the substrate 250 that is exposed to the ambient environment during use of the substrate 250.

[0125] Additional dispenser FIGS. 22 - 30 are diagrams showing additional dispensing devices that can be used in combination with the substrate 250 disclosed herein.

[0126] FIG. 22 shows a bracelet 400 that can be used in combination with the substrate 250 of FIG. 9. In this embodiment, the bracelet 400 includes an outer frame 402 having an internal groove 404 and a concave surface 406. A user may place the substrate 250 on the concave surface 406 and within the groove 404. Additionally, the bracelet 400 may include a strap 408 such as a Velcro® strap.

[0127] FIGS. 23 and 24 show a dispenser 500 that can be used in combination with the substrate of FIG. 9. In this embodiment, the dispenser 500 includes an outer frame 502 and a concave surface 504 within which the substrate 250 can be placed. Additionally, the dispenser 500 can include a clip 506, which can be used to secure the dispenser to a user.

[0128] FIG. 25 shows another bracelet 600 that can be used in combination with the substrate 250. In this embodiment, the bracelet 600 includes a housing 602 having a plurality of openings 604 in its front face 606 and a bracelet band 608. Here, the housing 602 may be opened and closed, and the substrate 250 may be inserted into or removed from the housing 602. When disposed within the housing, the substrate 250 may emit a volatile substance or an active agent from the substrate 250 through the openings 604.

[0129] Figures 26 and 27 illustrate two hangers 700, 800. In these embodiments, the hangers 700, 800 may include a first component 702, 802 having a front face 704, 804 that is releasably coupled to a second component 706, 806 having a reservoir or concave interior 708, 808. Further, the front faces 704, 804 and the back faces 710, 810 may include a plurality of apertures 712, 812. In use, a user may insert a substrate 250 into the concave interiors 708, 808 of the second components 706, 806 and couple the first components 702, 802 to the second components 706, 806, thereby enclosing the substrate 250 within the hangers 700, 800. After the substrate 250 is disposed within the hangers 700, 800, a volatile material or an active agent may emanate from the substrate 250 through the apertures 712, 812 of the hangers 700, 800.

[0130] Figure 28 depicts another dispenser 900 that can be used in combination with the substrate 250 discussed herein. In this embodiment, the dispenser 900 includes a front face 902 coupled to a back face 904 along a hinge 906, whereby the dispenser 900 can transition between an open state and a closed state (not shown) as shown in Figure 28. The front face 902 includes a receptacle 908 and the back face 904 includes a receptacle 910. Each receptacle 908, 910 can accommodate the substrate 250 therein, and when in the open state, the dispenser 900 allows for the emanation of a volatile material or an active agent from the substrate 250.

[0131] Figure 29 depicts another dispenser 1000 that can be used in combination with substrate 250. In this embodiment, similar to dispenser 900, dispenser 1000 includes a front face 1002 and a back face (not shown) coupled using hinge 1004. Further, front face 1002 may include a plurality of apertures 1006 through which air can flow into the dispenser and passively dissipate volatile material or active agent from substrate 250. In some embodiments, dispenser 1000 may be provided as a kit, which may include a pouch 1008 enclosing an amount of volatile material or active agent 1010 therein. In this embodiment, front face 1002 includes, on its inner surface, an element (not shown) that can puncture pouch 1008 when dispenser 1000 is closed. Thus, in use, a user can insert pouch 1008 into dispenser 1000 and close dispenser 1000, thereby puncturing pouch 1008 and releasing the volatile material or active agent 1010 therein. After pouch 1008 is punctured, substrate 250 within dispenser 1000 can absorb the volatile material or active agent 1010 and then dissipate the volatile material or active agent 1010 therefrom over a period of time.

[0132] Figure 30 illustrates a reservoir 1100 that can be used to dose substrate 250, or alternatively one or more of the dispensers disclosed herein. For example, bracelet 600 may be dosed with an amount of volatile material or active agent using reservoir 1100 by positioning an aperture 1102 on back face 1104 of housing 602 of bracelet 600 over nozzle 1106. Next, a user may position nozzle 1106 within aperture 1102 and apply a downward force. The downward force causes nozzle 1106 to release an amount of volatile substance from reservoir 1100, through nozzle 1106, into housing 602 that houses substrate 250 therein. As a result, substrate 250 can be redosed using reservoir 1100.

[0133] The foregoing variations and modifications are within the scope of the present disclosure. It is understood that the embodiments disclosed and defined herein cover all alternative combinations of two or more of the individual features mentioned or apparent from the text and / or drawings. All such 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.

[0134] As previously mentioned, the present invention has been described above in relation to specific embodiments and examples, but the present invention is not necessarily so limited, and it will be understood by those skilled in the art that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims appended 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 herein by reference.

[0135] Any of the embodiments described herein can be modified to include any of the structures or methodologies disclosed in relation to different embodiments.

Industrial Applicability

[0136] The dispenser, dispensing device, or side surface of the substrate described herein can advantageously combine the features of the dispensing device or protective housing and the multilayer substrate or mesh material to effectively dissipate the volatile material or active agent over a desired period of use. Further, the side surface of the dispenser or dispensing device provides an easy-to-use and inexpensive mechanism and a structurally stable and safe device. Accordingly, the disclosed dispenser or dispensing device can be used for a wide range of applications.

[0137] Numerous modifications to the present invention will be apparent to those skilled in the art from 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. Exclusive rights are reserved for all modifications that fall within the scope of the appended claims.

[0138] This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application 62 / 944,748, filed on December 6, 2019, the entire content of which is hereby incorporated by reference for all purposes.

[0139] There is no such matter with respect to references to federally sponsored research or development.

[0140] There is no such matter with respect to the sequence listing.

Claims

1. A system for stably releasing a volatile substance, comprising: a dispenser having at least one opening; a substrate adapted to fit within the dispenser, the substrate comprising: a first fabric layer having a first pore size; a second fabric layer having a second pore size; a third non-woven fiber layer extending between the first fabric layer and the second fabric layer; and a volatile substance, wherein the system has a steady weight loss of the volatile substance over a time period exceeding 30 days. A system.

2. The system according to claim 1, wherein the volatile substance comprises an active agent selected from the group consisting of metofluthrin, transfluthrin, tefluthrin, and vaporthrin.

3. The system according to claim 1, wherein the first pore size of the first fabric layer is between about 1 millimeter and about 10 millimeters.

4. The system according to claim 1, wherein the steady weight loss of the volatile substance is between about 1 mg / day and about 10 mg / day.

5. The system according to claim 1, wherein the initial weight of the volatile substance is between about 1 gram and about 5 grams.

6. The system according to claim 1, wherein the at least one opening of the dispenser exposes a portion of the first fabric layer.

7. The system according to claim 6, wherein the at least one opening of the dispenser exposes about 50% to about 99% of the surface area of the first fabric layer.

8. The system according to claim 1, wherein the system has a steady weight loss of the volatile substance over a time period of 60 days or more.

9. The system according to claim 8, wherein the system has a steady weight loss of the volatile substance over a time period of 70 days or more.

10. The system according to claim 1, wherein the first pore size is different from the second pore size.

11. The system according to claim 1, wherein the dispenser includes a front face and a back face, and the front face includes at least one opening.

12. The system according to claim 1, wherein the first fabric layer, the second fabric layer, and the third non-woven fiber layer are composed of the same material.

13. The system according to claim 1, wherein the first fabric layer and the second fabric layer are composed of a first material, the third non-woven fiber layer is composed of a second material, and the first material is different from the second material.

14. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A system for stably releasing a volatile substance, a frame having at least one opening, a substrate disposed within the frame, a first woven fabric layer having a plurality of pores, a second woven fabric layer having a plurality of pores, and a substrate including a third non-woven fiber layer extending between the first woven fabric layer and the second woven fabric layer, a volatile material, and the system provides a steady weight loss of the volatile material over a time period exceeding 30 days, system.

15. The system according to claim 14, wherein the steady weight loss of the volatile material is between about 4 mg / day and about 6 mg / day. The system according to claim 14.

16. The system according to claim 15, wherein the volatile substance is selected from the group consisting of metofluthrin, transfluthrin, tefluthrin, and vaporuthrin. The system according to claim 15.

17. The system according to claim 16, wherein the initial weight of the volatile material is between about 2 grams and about 3 grams. The system according to claim 16.

18. The system according to claim 17, wherein the steady weight loss of the volatile material is over a time period greater than 70 days. The system according to claim 17.

19. The system according to claim 18, wherein the frame includes a first opening exposing a portion of the first woven fabric layer and a second opening exposing a portion of the second woven fabric layer. The system according to claim 18.

20. A method of designing a system for constantly releasing a volatile substance, selecting a minimum time for the constant emission of the volatile substance, selecting a minimum emission rate of the volatile substance, calculating a minimum emission concentration of the volatile substance using the minimum time for the constant emission of the volatile substance and the minimum emission rate of the volatile substance, selecting a woven fabric layer for the substrate based at least on the minimum emission rate of the volatile substance, and selecting a non-woven fiber layer for the substrate based at least on the minimum concentration of the volatile substance, method.

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