Disposable absorbent articles are available in many different sizes, styles and configurations and are designed for absorbing human exudate, such as urine and fecal matter. Most disposable absorbent articles are intended to be worn by infants, toddlers, or adults and are designed for single or temporary use. By “single or temporary use” it is meant that the disposable absorbent article will be disposed of after being used once instead of being laundered or cleaned for re-use, as is typical of regular cloth underwear. Examples of some disposable absorbent articles include an infant diaper, a child training pant, a feminine menstrual pant and an adult incontinent undergarment. Many of such disposable absorbent articles are similar in appearance, size and shape to regular cloth underwear except that they are formed from a variety of materials including absorbent and elastic materials. The absorbent materials allow the disposable absorbent article to absorb and retain body waste while the elastic material permits the disposable absorbent article to snugly conform to the anatomy of the user's torso.
Most manufacturers of such disposable absorbent articles are constantly looking to improve the appearance, aesthetics and normalcy of such articles to simulate cloth underwear. The reason for this is that the adult users of disposable absorbent articles have been preconditioned by years of wearing cloth underwear. “Cloth” underwear includes underwear formed from various natural and/or synthetic materials, including cotton, nylon, rayon, SPANDEX, as well as other materials known to those skilled in the art that are used to manufacture undergarments. Especially in adult incontinent undergarments, site and handling tests have indicated that women who use such products prefer that their disposable absorbent articles appear to be similar to cloth underwear. They are asking for a disposable absorbent article that both feels like and appears similar to cloth underwear.
Now a disposable absorbent article for absorbing human discharges has been invented that is constructed from a material that visually appears to be very similar to cloth underwear.
Briefly, this invention relates to a disposable absorbent article having a unitary structure with a waist opening and a pair of leg openings. The unitary structure includes a front region, a back region and a crotch region positioned between the front and back regions. The front and back regions have an interior surface and an exterior surface. A portion of at least one of the front and back regions has a visual appearance with a Shadow Index of less than about 5 and/or a Gray-Level Percent Relative Standard Deviation of less than about 70.
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The disposable absorbent article 10 also includes a back region 26 having a first scalloped end 28 spaced apart from a second end 30 and a first side edge 32 spaced apart from a second side edge 34. Desirably, the first end 28 is scalloped. More desirably, the first scalloped end 14 of the front region 12 will be identical in size and configuration to the first scalloped end 28 of the back region 26. The back region 26 has an interior surface 36 and an exterior surface 38, see
The front and back regions, 12 and 26 respectively, are discontinuous from one another along the longitudinal axis X-X. The interior surfaces 22 and 36 of the front and back regions, 12 and 26 respectively, are in direct contact with the user's skin and are also sometimes referred to as the bodyside surfaces. The exterior surfaces 24 and 38 are situated opposite to the interior surfaces 22 and 36 and are spaced away from the user's skin. The exterior surfaces 24 and 38 are also sometimes referred to as the garment facing surfaces since they can be in direct contact with the inner surfaces of the user's outer clothing.
The front and back regions, 12 and 26 respectively, can be formed from a stretchable material. Desirably, the stretchable material is an elastic material. More desirably, the stretchable material is an elastic laminate that contains two or more layers wherein at least one of the layers is elastic. By “elastic layer” it is meant an elastic sheet, an elastic film, an elastic net-like material or a plurality of elastic strands aligned in a given plane. When a plurality of elastic strands is utilized, they can be positioned on a single carrier layer or be positioned between two or more outer layers. Each of the front and back regions, 12 and 26 respectively, can be formed such that essentially the entire region 12 and 26 is capable of being stretched and is also capable of being retracted. By “essentially the entire” it is meant that approximately about 90% to about 100% of the front region 12 is stretchable and retractable, and approximately about 90% to about 100% of the back region 26 is stretchable and retractable.
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The elastic laminate provides stretch and retraction in at least one direction. The stretch and retraction can be in one direction or in two or more directions. Desirably, the stretch and retraction of the front and back regions, 12 and 26 respectively, are in a direction approximately parallel to the transverse axis Y-Y. The transverse direction extends laterally across the torso from the left hip to the right hip. More desirably, the stretch and retraction of the front and back regions, 12 and 26 respectively, are in at least two directions, one direction being approximately parallel to the longitudinal axis X-X and the other direction being angled thereto. Most desirably, the stretch and retraction of the front and back regions, 12 and 26 respectively, are in multiple directions, or stated another way, in three or more directions extending over an arc of 360 degrees. The ability of the front and back regions, 12 and 26 respectively, to stretch and retract will provide a restrictive force during use of the disposable absorbent article 10 to ensure that it snugly conforms to the anatomy of the wearer's torso.
Desirably, the front and back regions, 12 and 26 respectively, are constructed from a stretch bonded laminate (SBL). Exemplary SBL materials are described in U.S. Pat. No. 4,720,415. In the stretch bonded laminate, the elastic core, or middle layer 42, is elongated before the two outer nonwoven layers 40 and 44 are attached. The attachment can be by an adhesive, by heat, by pressure, by a combination of heat and pressure, etc. Another material option for the front and back regions, 12 and 26 respectively, is a necked bonded laminate (NBL). The NBL material is also a three-layer laminate but the elastic core, or middle layer 42, is not pre-stretched prior to being attached to the two outer nonwoven layers 40 and 44. The outer layers 40 and 44 are necked stretched before the elastic core or middle layer 42 is attached to them. Exemplary NBL materials are described in U.S. Pat. No. 5,336,545. Other examples of elastomeric materials that can be used for the front and back regions, 12 and 26 respectively, include a continuous filament stretch bonded laminate (CFSBL) described in U.S. Pat. No. 5,385,775, a vertical filament laminate (VFL) described in Patent Publication 2002/0119722 A1 dated Aug. 29, 2002, a necked stretch bonded laminate (NSBL) and a necked thermal laminate (NTL). Combinations of the above materials can also be used.
It should also be noted that the front and back regions, 12 and 26 respectively, can be constructed from an elastic film that is capable of being stretched in at least one direction and desirably in both the machine direction and the cross-direction. Alternatively, the front and back regions, 12 and 26 respectively, can be formed from an elastic nonwoven that has a machine direction stretch and/or a cross-direction stretch. Extensible materials can also be used to form the front and back regions, 12 and 26 respectively, of the disposable absorbent article 10. Various other stretchable and elastic materials can be used which are known to those skilled in the art.
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The attachments 64 and 66 can be a permanent type of attachment as well as being a removable or releasable attachment. Desirably, the attachments 64 and 66 are permanent attachments where they are not designed to be removed without destroying the bond. The attachments 64 and 66 can be formed by using glue, adhesive, ultrasonic bonds, thermal bonds, heat bonds, pressure bonds, heat and pressure bonds, or any other attachment mechanism known to those skilled in the art. The attachments 64 and 66 can also include a chemical bond or a mechanical fastener, such as by sewing with thread, using buttons and button holes, using snaps, by employing hook and loop fasteners, etc. A hook and loop fastener is generally considered a releasable attachment. One type of hook and loop fastener is VELCRO wherein a hook material is releasably engaged into a loop material.
The attachments 64 and 66 can be formed along a continuous line or over a surface area having a predetermined length and width. Alternatively, the attachments 64 and 66 can consist of intermittent point bonds that are spaced apart from one another. For example, the intermittent point bonds can be formed by using a hot or a cold melt adhesive or by forming ultrasonic bonds. Various bond formations can be used which are known to those skilled in the art. Desirably, the attachments 64 and 66 are formed using intermittent bonds because it allows the elastic material forming the front and back regions, 12 and 26 respectively, to gather the absorbent assembly 46 as the elastic contracts. This gathering feature causes the absorbent assembly 46 to remain in direct contact with the user's body prior to and during the time period that the absorbent assembly 46 is being insulted with body fluid.
The front and back regions, 12 and 26 respectively, can be stretched in a direction approximately parallel to the transverse axis Y-Y, or in any other direction or directions, before the absorbent assembly 46 is secured to it. The amount of stretch can vary. No stretch is required if one does not wish to do so. Desirably, the front and back regions, 12 and 26 respectively, are stretched at least about 5% from a relaxed state before the absorbent assembly 46 is secured thereto. Desirably, the front and back regions, 12 and 26 respectively, are stretched at least about 10% from a relaxed state before the absorbent assembly 46 is secured thereto. More desirably, the front and back regions, 12 and 26 respectively, are stretched at least about 25% from a relaxed state before the absorbent assembly 46 is secured thereto. Most desirably, the front and back regions, 12 and 26 respectively, are stretched from between about 25% to about 500% from a relaxed state before the absorbent assembly 46 is secured thereto. The front and back regions, 12 and 26 respectively, extend laterally beyond the first and second side edges, 60 and 62 respectively, of the absorbent assembly 46. The front region 12 also extends longitudinally beyond the first end 56 of the absorbent assembly 46 and the back region 26 extends longitudinally beyond the second end 58 of the absorbent assembly 46. This size configuration of the front and back regions, 12 and 26 respectively, allow them to elastically conform to the torso of the wearer.
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The absorbent assembly 46 can be stretchable or non-stretchable in relation to the front and back regions, 12 and 26 respectively. Desirably, the absorbent assembly 46 is non-stretchable in relation to the front and back regions, 12 and 26 respectively. By having the absorbent assembly 46 be non-stretchable in relation to the front and back regions, 12 and 26 respectively, it is meant that the absorbent assembly 46 will not appreciably stretch in the longitudinal or transverse directions. The reason for this is that the front and back regions, 12 and 26 respectively, are elastically stretchable and can extend and retract to snugly conform to the user's anatomy, especially to his or her torso. It is not necessary for the absorbent assembly 46 to stretch and/or retract to the same extent. The absorbent assembly 46 could alternatively be constructed with a pleated or folded construction, so as to be capable of being expanded in the longitudinal or transverse directions, if expansion of the absorbent assembly 46 is needed. The pleating or folding should take place before the absorbent assembly 46 is secured to the front and back regions, 12 and 26 respectively.
Normally, there is no need to have the absorbent assembly 46 gather as the front and back regions, 12 and 26 respectively, retract. However, the absorbent assembly 46 can be constructed and attached to the front and back regions, 12 and 26 respectively, in a way that will allow the absorbent assembly 46 to be gathered as the front and back regions, 12 and 26 respectively, elastically retract in a direction parallel to the transverse axis Y-Y. In either circumstance, the absorbent assembly 46 should remain over the perineum. As the absorbent assembly 46 receives body fluid and/or excrement discharged by the wearer, it will be displaced outward, away from the user's torso. The attachments 64 and 66 assure that the absorbent assembly 46 will be aligned over the perineum of the user while allowing the absorbent assembly 46 to move outward, in the z-direction, away from the torso as additional body fluid is received and retained.
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The disposable absorbent article 10 also includes a waist band 72 formed from an elastic material. In
The waist band 72 has a first edge 74, a second edge 76, a first side edge 78 and a second side edge 80. The first edge 74 is straight or linear in configuration so that it is visually distinguishable from the scalloped first ends 14 and 28. The first edge 74 is spaced apart from the scalloped first end 14 of the front region 12 and from the scalloped first end 28 of the back region 26. The first edge 74 can be spaced apart from the scalloped first ends 14 and 28 by at least about 2 millimeters (mm). Desirably, the first edge 74 will be spaced apart from the scalloped first ends 14 and 28, by at least about 3 mm. More desirably, the first edge 74 will be spaced apart from the scalloped first ends 14 and 28, by at least about 4 mm. Most desirably, the first edge 74 will be spaced apart from the scalloped first ends 14 and 28, by less than about 10 mm. The reason for this spacing is to provide an aesthetically pleasing and comfortable scalloped edge 82 on the disposable absorbent article 10. The scalloped edge 82 will provide the disposable absorbent article 10 with a similar appearance to that of cloth underwear.
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The elastic strands can be aligned approximately parallel to one another or be angled or skewed relative to one another. The elastic strands can also be uniformly or randomly spaced apart from one another. The elastic strands can vary in shape, size, configuration, and/or length. The diameter and/or cross-sectional configuration of the elastic strands, the decitex (weight in grams per 10,000 meters of a strand) of the elastic strands, and the tension imparted into the elastic strands can all be varied to suit one's particular product needs. The elastic strands can have a round, semi-circular, square, rectangular, oval or some other geometrical configuration. The elastic strands can overlap, intersect or crisscross at least one other elastic strand. The various ways of positioning, orienting or securing the elastic strands to the outer members 84 and 86 are well known to those skilled in the art.
The number of elastic strands can range from 1 to about 50. The exact number of elastic strands that are present will depend on the width (w) of the waist band 72, the diameter of each elastic strand, the arrangement of the elastic strands on the outer members 84 and 86, etc. Desirably, from about 2 to about 25 elastic strands are present in the waist band 72. More desirably, from about 3 to about 20 elastic strands are present in the waist band 72. Most desirably, from about 3 to about 15 elastic strands are present in the waist band 72. In
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The first and second side edges, 102 and 104 respectively, of the leg band 90 are aligned with the first and second side edges, 18 and 20 respectively, of the front region 12. Likewise, the first and second side edges, 102 and 104 respectively, of the leg band 92 are aligned with the first and second side edges, 32 and 34 respectively, of the back region 26. Each of the pair of leg bands 90 and 92 can be constructed from two outer members 106 and 108 having an elastic material 110, such as one or more elastic strands, secured therebetween. Desirably, multiple elastic strands will be positioned between the two outer members 106 and 108. The outer members 106 and 108 can be formed from a non-elastic material as was explained above relative to the outer members 84 and 86 used to form the waist band 72. Likewise, the elastic material 110 can be the same as was explained above relative to the elastic material 88 used in the waist band 72. Normally, the leg bands 90 and 92 will have a narrower width than that of the waist band 72. Typically, from about 1 to about 6 elastic strands are present in each of the leg bands 90 and 92. Desirably, less than 4 elastic strands are present in each of the leg bands 90 and 92. In
The elastic strands in the leg bands 90 and 92 are typically aligned approximately parallel to the second ends 16 and 30 of the front and back regions, 12 and 26 respectively. The second ends 16 and 30 are located adjacent to the crotch region 68 of the disposable absorbent article 10. The elastic strands in the leg bands 90 and 92 can be uniformly or randomly spaced apart from one another and are normally located within about 0.3 inches (about 0.76 cm) of the leg openings 94 and 96.
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As noted above, the disposable absorbent article 10 is a unitary structure which includes the front region 12, the back region 26 and the crotch region 68. The front and back regions, 12 and 26 respectively, can be constructed from one or more materials, and desirably from a laminate, that visually appear to be very similar to cloth underwear. This visual appearance can be measured using the topography of the material itself to determine Shadow Index values and Gray-Level Percent Relative Standard Deviation values.
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The sample 122 will have an interior surface and an exterior surface. The interior and exterior surfaces will correspond to the interior and exterior surfaces of the material as it is present in the unitary structure of the disposable absorbent article. Each sample 122 will be tested with the exterior surface facing up. Only one sample 122, dimensioned approximately 8.5 inches (approximately 216 mm) by 5 inches (approximately 127 mm), is needed to perform the test because three separate and non-overlapping images will be obtained from this size sample 122. However, when a smaller size sample is used, then more than one sample may be necessary in order to obtain three separate and non-overlapping images. For example, a smaller size sample having an optical field of view defined by the dimensions of approximately 68 mm by approximately 53 mm can yield one field of view image. Two additional samples, each having an optical field of view size defined by the dimensions of approximately 68 mm by approximately 53 mm, would be needed to obtain the remaining two images.
The sample 122 to be analyzed should exclude any portion of the waist band 72, the pair of leg bands 90 and 92, the absorbent assembly 46 or the pair of seams 112 and 114. After the sample 122 has been cut out of the front or back regions of the product, it is placed so that the Y-Y direction of the material, as indicated in
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The video camera 136 used was a SONY® video camera (Model DXC-930P) with a synchronization and timing option (commonly called PAL format) and the red color channel was used. The adjustable 35-millimeter Nikon lens 138 was mounted on the video camera 136 via a 1:1 relay adaptor #C20047 (Century Optics, USA) 140. The 35-millimeter Nikon lens 138 had an f-stop setting of 4. The video camera 136 was mounted on a Polaroid MP-4 Land Camera (Polaroid Resource Center, Cambridge, Miss.) standard support 142. The support 142 was attached to a KREONITE macro-viewer 144 available from Kreonite, Inc., having an office in Wichita, Kans. An auto-stage 146, Model HM-1212, was placed on the upper surface of the KREONITE macro-viewer 144. The auto-stage 146 is a motorized apparatus known to those skilled in the analytical arts which was purchased from Design Components Incorporated, having an office in Franklin, Miss. The auto stage 146 was used to move the sample 122 in order to obtain three separate and distinct, non-overlapping images and associated measurements from the approximately 8.5 inch (approximately 216 mm) by 5 inch (approximately 127 mm) size sample 122.
The distance D, represents the distance between the upper surface of the sample 122 and the bottom of the lens 138. The distance D, was set to be approximately 33 centimeters (cm). The distance D2 represents the vertical distance between the lens 130 attached to the slide projector 128 and the upper surface of the sample 122. The distance D2 was set at 30 cm. The sample 122 was illuminated by the slide, projector 128. The distance D3 represents the horizontal distance between a vertical line extending to the center of the video camera lens 138 and a vertical line extending to the center of the slide projector lens 130. The distance D3 was set at 51 cm. These dimensions, combined with the video camera set-up, resulted in a field-of-view size of the sample 122 surface to be approximately 68 millimeters by approximately 53 millimeters. The slide projector 128 was connected to a POWERSTAT Variable Autotransformer, type 3PN117C, which was purchased from Superior Electric, Co. having an office in Bristol, Conn. The autotransformer is used to adjust the slide projector's 128 illumination level.
The image analysis system used to generate the data presented was a Quantimet 600 Image Analysis System available from Leica Microsystems, having an office in Wetzlar, Germany. The system was controlled and run by QWIN Version 1.06A software. The image analysis program ‘SHADIX3’ was used to acquire, process and measure images using Quantimet User Interactive Programming System (QUIPS) language. Alternatively, the SHADIX3 program could be used with a Quantimet 550 IW Image Analysis System which runs QWIN Version 2.4 software. The custom image analysis program is shown below.
Prior to testing the first sample 122, shading correction was performed using the QWIN software and a white, 803 Polaroid film positive (or equivalent white material) covered with an opaque, translucent film. Alternatively, other non-glossy white films or sheets could be used. The shading correction was performed using the ‘live’ mode. The system was also accurately calibrated using the QWIN software and a standard ruler with metric markings. The calibration was performed in the horizontal dimension of the video camera image.
After calibrating the system, the QUIPS routine SHADIX3 was executed via the QWIN software and this initially prompts the analyst to place the sample 122 within the field-of-view of the video camera 136. After positioning the sample 122 so the Y-Y direction is parallel to the light source and the sample 122 is properly aligned for auto-stage motion, the analyst will then be prompted to adjust the light level setting (via the POWERSTAT variable auto transformer) to register between Gray-Level readings of 197-200. During this process of light adjustment, the QUIPS routine SHADIX3 will automatically display the current Gray-Level value on the Quantimet 600 video screen.
After the light has been properly adjusted, the QUIPS routine SHADIX3 will then automatically acquire, detect, process and measure the image and the resulting shadows. The Gray-Level threshold value used in the routine to detect shadows is 31. The Gray-Level scale used on the Quantimet 600 system, or equivalent, is 8-bit and ranges from 0-255 (0 represents ‘black’ and 255 represents ‘white’). For shadow measurements, all regions in the image of the sample 122, that are at a Gray-Level of 31 or less, will be detected and measured by the SHADIX3 routine. For Gray-Level measurements, the entire Gray scale will be used.
The QUIPS routine SHADIX3 will then measure the Shadow Index value and the Gray-Level Percent Relative Standard Deviation values in the image. An explanation of each of the measurement parameters is described below:
Shadow Index—A derived parameter that combines shadow size and distribution across an entire image (Shadow Index=Shadow Area/Shadow Perimeter times percent area coverage). The “Shadow Area” is the area of an entire image that is covered by shadows at a predetermined detection threshold. The “Shadow Perimeter” is the distance around the outer boundary for the shadow area. For instance, if given two materials with equal percent area values, the material that has the larger sized individual shadows will also have a higher index value. This parameter gives an indication of both the distribution and level of shadow coverage.
Gray-Level Percent RSD (GL % RSD)—A normalized measure of a material's Gray-Level variation (GL % RSD=GL Std, deviation/Mean GL×100%). For example, a material with little or no noticeable topography (i.e., Hanes cotton briefs) will have a minimal GL % RSD value.
Data will be placed into corresponding histograms. The QUIPS routine SHADIX3 will then automatically move the auto-stage to position the sample 122 for next field-of-view to be measured. The analyst will again be prompted to re-adjust the light level, if needed, and the routine will again acquire, process, and measure the image. This process will be repeated until each of the three fields-of-view is measured. The data and basic statistics will then be available in an electronic format.
The whole image analysis and data collection process is repeated 3 times for each sample material (i.e., 3 replicate analyses). The mean data values are then determined from the 3 individual results obtained and these data can then be processed using Student's T analysis statistical methods to determine if significant differences exist between sample codes. Data are processed at the 90% confidence level.
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Table 1 below shows Mean Shadow Index and Gray-Level Percent Relative Standard Deviation values for these five products.
Data were collected from three different fields-of-view (FOV) for each sample with the exception that for the Hanes' Cotton Brief wherein only two different fields-of-views were collected because the sample was of a smaller size. The size of the Hanes' Cotton Brief sample was approximately 6 inches (approximately 152.4 mm) by approximately 5 inches (approximately 127 mm). Student's T statistical comparisons of the confidences ranges at 90% is presented below. The separation between the ranges for the Kimberly-Clark Corporation's 2005 POISE panty (current invention) and the other materials is quite convincing.
The actual test values for all five samples are shown in Table 2 along with the calculated mean values.
The data generated in Table 2 was subjected to a Student's T analysis at the 90% confidence level and yielded the ranges shown in the bar graphs depicted in Tables 3 and 4 below. Table 3 shows the ranges for the Shadow Index values and Table 4 shows the ranges for the Gray-Level Percent Relative Standard Deviation values.
One can see from Table 3 that the Hanes' cotton brief registered at 0 for the Shadow Index. Kimberly-Clark Corporation's 2005 POISE panty had a visual appearance that was closest to the Hanes' cotton brief. The Kimberly-Clark Corporation's 2005 POISE panty had a Shadow Index range of from between about 1.9 to about 3.8. One can broadly interpret this Shadow Index range to be less than about 5. One can also interpret this Shadow Index range to extend from between about 1.0 to about 5.0. One can also interpret this Shadow Index range to extend from between about 1.5 to about 4.5. Another way of interpreting this range is to say that the Shadow Index of the Kimberly-Clark Corporation's 2005 POISE panty is less than about 4.
One can also see that the remaining three products all had a Shadow Index range of above 8. The higher the values, the more unlike the appearance of the Hanes' cotton brief. This data clearly indicates that the K-C's 2005 POISE panty, wherein the front and back regions were constructed from the same material, i.e. a laminate, had a Shadow Index value of less than about 5. This Shadow Index value indicates that the material used to form the front and back regions of the K-C's 2005 POISE panty has a visual appearance approaching the Hanes' cotton brief.
One can see from Table 4 that the Hanes' cotton brief had a Gray-Level Percent Relative Standard Deviation range of from between about 33.66 to about 45.18. Kimberly-Clark Corporation's 2005 POISE panty had a visual appearance that was closest to the Hanes' cotton brief. The Kimberly-Clark Corporation's 2005 POISE panty had a Gray-Level Percent Relative Standard Deviation range of from between about 62.2 to about 67.17. One can broadly interpret this Gray-Level Percent Relative Standard Deviation range to extend from between about 60 to about 70. One can also interpret this Gray-Level Percent Relative Standard Deviation range to extend from between about 61 to about 68. Another way of interpreting this range is to say that the Gray-Level Percent Relative Standard Deviation of the Kimberly-Clark Corporation's 2005 POISE panty is less than about 70.
One can also see that the remaining three products all had a Gray-Level Percent Relative Standard Deviation range of above 79.62. The higher the values, the more unlike the appearance of the Hanes' cotton brief. This data clearly indicates that The Kimberly-Clark Corporation's 2005 POISE panty, wherein the front and back regions were constructed from the same material, i.e. a laminate, had a Gray-Level Percent Relative Standard Deviation of less than about 70. This GL % RSD value indicates that the material used to form the front and back regions of the K-C's 2005 POISE panty has a visual appearance approaching the Hanes' cotton brief.
While the invention has been described in conjunction with a specific embodiment, it is to be understood that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the aforegoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations that fall within the spirit and scope of the appended claims.