Patent Publication Number: US-2012023645-A1

Title: Undergarment With Leak Control and Natural Look and Feel

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit to U.S. Provisional Application 61/296,115, filed Jan. 19, 2010, incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to undergarments and particularly relates to undergarments with control of body fluids but possessing a natural look and feel. 
     Undergarments have been described to alleviate problems associated with conditions such as incontinence, which incorporate absorption layers sufficient to contain substantial amounts of body liquids. However by necessity these undergarments require bulky absorption materials, which are apparent to the user as well as others. 
     However, this invention is directed at the problem of spotting of clothing due to leakage of bodily fluids such as urine from minor urinary incontinence or absence of drying oneself after urination. With conventional underwear, only a few drops of liquid may soak through and create an embarrassing wet spot on outer clothing. Undergarments designed for urinary incontinence typically consist of a plastic, waterproof lining and/or a permanent or disposable absorbent pad. The absorbent pad is bulky and less comfortable than conventional underwear. Underwear with an absorbent pad also is visibly different from conventional underwear. This difference may cause embarrassment to the user in locations such as athletic locker rooms. 
     There is a need for underwear for both men and women, which have the appearance of conventional underwear products, but control minor leakage of body liquids. 
     SUMMARY OF THE INVENTION 
     An undergarment has a fabric body portion and an attached cotton-appearing fabric crotch portion, which crotch portion comprises a separate, breathable, hydrophobic, cotton-appearing fabric layer. In an aspect of the invention, the crotch portion comprises an interior panel and an exterior panel, at least one of which comprises a separate, breathable, hydrophobic, cotton-appearing fabric layer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a boxer-style men&#39;s underwear according to this invention. 
         FIG. 2  illustrates a brief-style men&#39;s underwear according to this invention. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     Some persons experience minor leakage of body fluids into undergarments. Conventionally, persons who have difficulty in controlling leakage of urinary or menstrual fluids could use impervious liquid barriers or absorbent pads incorporated into underwear. However, these products may be uncomfortable and may be apparent to others, which causes embarrassment to the users. 
     Typical conventional undergarments that are comparable to those of the present invention are constructed of lightweight cotton fabric. Undergarments have a body, which typically incorporates a front, back (or seat), leg openings, and a waist opening which typically includes an elastic waistband. Although the body portion of such garments may be made of various fabrics including cotton, polyester, and nylon, typically the body fabrics are constructed from a single layer of cotton fabric and the crotch area portion may be reinforced with multiple layers of cotton fabric. In a typical men&#39;s brief, the front area is constructed of multiple panels, which form an opening or “fly.” This area also functions to reinforce the crotch area. In order to create an undergarment suitable for this invention, the fabric incorporated into the crotch area of such garment must have a natural look and feel similar to cotton fabric. 
     A garment with a natural look and feel does not have extra panels of fabric sewn into the garment other than the typical layers of non-laminated fabric found in typical cotton undergarments, such as those panels constructed as the “fly” panels of men&#39;s briefs. A garment with a natural look and feel to cotton fabric is visibly similar to cotton fabric and possesses the same type of tactile characteristics to a normal consumer. Types of fabrics, which do not have a natural look and feel to cotton, include sheet or woven plastic (such as polyethylene, polypropylene, polyester, and polyvinyl), or fabrics made predominately (&gt;75%) from fibers of such plastics. 
     The crotch area of undergarments of this invention typically has a cotton fabric layer positioned interior relative to the wear&#39;s body and a separate, breathable, water-resistant, cotton-appearing layer positioned exterior relative to the wear&#39;s body. “Cotton appearing” refers to the visual and textural properties which are similar to and characteristic of cotton fabric. Thus, “cotton appearing” refers to the look and feel of the fabric. In use, an undergarment of this invention should have the same look and feel as a similarly constructed undergarment made from cotton fabric. Thus, an observer of a person wearing such an undergarment normally would not identify such an undergarment as having moisture resistant properties. Similarly, a person wearing such an undergarment would not normally perceive a difference between such an undergarment and a similar all-cotton undergarment. However, the wearer could perceive a benefit in that minor amounts of body fluid would not leak from the undergarment and potentially cause apparent wetting of an exterior garment. 
     In an aspect of this invention, an undergarment is constructed with an interior cotton crotch layer and a separate exterior crotch breathable, water-repellant (hydrophobic), cotton-appearing layer. In another aspect of this invention, an undergarment also has a cotton cover layer exterior to the breathable, water-resistant, cotton-appearing layer. In a further aspect of this invention, an undergarment also may have a polyester fiber containing fabric wicking layer interior to the cotton layer and adjacent to a wearer&#39;s body. 
     In an alternative aspect of the invention, a separate layer of lightweight breathable, hydrophobic fabric which may not be cotton appearing is placed between layers of lightweight cotton-appearing fabric such that an observer will not see the interior layer and would not normally perceive a difference between such an undergarment and a similar all-cotton undergarment. 
     A water-repellent hydrophobic cotton fabric useful in this invention also is vapor permeable. Thus, although water-based liquid does not readily pass through such fabric, vapor, such as water vapor, will pass through the fabric, i.e. the fabric is described as “breathable.” A benefit of a breathable fabric as used in this invention is that minor amounts of liquid water absorbed in an interior cotton layer may evaporate and pass through the water-repellent fabric layer. Thus, the undergarment will dry during wearing and will not require that the wearer change undergarments. 
     In a typical undergarment of this invention, the layers of fabric, which constitute the crotch area portion, are separate in the sense that such layers are not fused, bonded, or laminated together. Preferably, the layers of the crotch portion are attached to the body or to each other through stitching at the seams. In this aspect of the invention, the crotch portion is distinct from the body portion, and the combination of a crotch portion stitched to the body portion constitutes the undergarment. These layers may be part of fabric panels which form the crotch area portion of the undergarment. In men&#39;s underwear, separate fabric panels may form a fly opening. 
     Preferably, in an aspect of this invention, the both the body and crotch fabrics are cotton appearing. 
     Undergarments of this invention may be of differing colors, prints, and styles as created for typical undergarments. 
     Hydrophobic cotton fabric is a cotton fabric, which has been chemically modified at the molecular level to bond hydrophobic groups onto the cellulosic structure of cotton (cellulosic cotton). Preferably, cotton fibers are modified rather than an addition of an external layer of hydrophobic material. An example is attaching hydrophobic acyl groups or fluorocarbon-containing groups onto cellulosic cotton as described in U.S. Pat. Nos. 6,379,753, 6,380,336, 6,485,530, 6,599,327, 6,607,564, and 6,617,267, all incorporated by reference herein. Suitable hydrophobic cotton fabrics useful in this invention are cotton fabrics treated with Nano-Tex™ technology, which modifies the surface energy of textile fibers in a manner that prevents the absorption of liquids yet maintains vapor transmission. In a preferable aspect, the yarn from which the fabric is constructed is chemically modified, although the chemical modification may be made to fibers, yarn, or fabric during manufacture. A hydrophobic cotton fabric useful in this invention has a similar look and feel as untreated fabric used in other areas of the undergarment. 
     Cotton fabric useful for underwear in this invention, typically, is a lightweight spun cotton fabric typically used for underwear. A typical lightweight fabric useful for underwear has a weight of less than 400 grams per square meter. Other typical fabrics useful for underwear have weights less than 350 g/m 2  (sometimes preferably less than 250 g/m 2 ), typically above 100 or 120 g/m 2 , and further typically between about 100 to 240 g/m 2  or particularly between 160 to 230 g/m 2 , especially for a cotton rib fabric used in men&#39;s undergarments. A typical specified range for cotton fabric useful for underwear is 120 to 390 g/m 2 . Another typical range is 140 to 350 g/m 2 . A typical cotton fabric is a rib knit cotton fabric having a weight of about 190 g/m 2 . Other suitable fabrics include a lightweight jersey material with a typical weight of less than about 150 g/m 2  such as 109 to 140 g/m 2  for men&#39;s undergarments and 109 to 130 g/m 2  for women&#39;s undergarments. Cotton fabric preferably is 100% cotton, although minor amounts of other fibers may be present, which do not significantly detract from the look, feel, and function of the fabric suitable for use in underwear. Common cotton fabrics may contain 5%, 10%, 30% or more other fiber content, such as polyester or spandex. A typical cotton fabric may contain about 5 to 10 wt. % polyester or spandex fibers. Cotton fabric that has been chemically modified to produce hydrophobic cotton fabric useful in this invention typically is based on the same type of lightweight spun cotton fabric. 
     Underwear of this invention may be in various forms such as men&#39;s brief-style, boxer-style, low-rise-style, and bikini-style underwear. Further, women&#39;s panty or knickers underwear in various styles may be constructed according to this invention. 
     Aspects of this invention are described further by reference to the Figures.  FIG. 1  illustrates a men&#39;s boxer-style underwear constructed according to an aspect of this invention. The underwear is constructed with a body portion  10  having leg openings  12  and  12 ′ and a waist opening  14  with a waistband  16 . The underwear also is constructed with a crotch portion  20  having a fly constructed with an interior panel  22  and an exterior panel  24 , which are stitched to the body  10  and which form a fly opening  26 . The combination of the body and crotch portions constitutes the undergarment. 
       FIG. 2  illustrates a men&#39;s brief-style underwear having the same attributes as identified in  FIG. 1  for boxer-style underwear. 
     In an aspect of this invention, each of the interior and exterior panels,  22  and  24 , of either boxer- or brief-style underwear, is formed from one or more layers of cotton-appearing fabric. In an aspect of the invention, the interior panel  22  is constructed of an inner layer of cotton fabric and an outer layer of a lightweight chemically modified cotton-appearing fabric. An exterior panel  24  is formed from untreated lightweight cotton fabric. In a further aspect, the outer panel may be formed from a cotton-appearing fabric such as all cotton or a polyester-containing fabric. 
     In another aspect of the invention, the interior panel  22  is formed from untreated cotton fabric and the exterior panel  24  is formed from chemically modified cotton-appearing fabric. In a further aspect of this invention, a layer of polyester or cotton/polyester blend fabric forms an inner layer of the interior panel  22  to create a wicking layer between a wearer&#39;s body and the outer untreated layer of the inner panel in conjunction with a panel containing a chemically modified cotton-appearing fabric. 
     In another aspect of this invention, both the interior and exterior panels are formed from chemically modified cotton-appearing fabric. In another aspect of this invention the interior panel  22  is formed from untreated cotton fabric while the exterior panel  24  is formed from chemically modified cotton-appearing fabric. 
     In the aforementioned aspects of this invention, preferably the lightweight fabrics used in the body and crotch underwear portions are constructed from cotton or cotton-appearing fabrics. Preferably, the fabrics which form the body and crotch portions have the same look and feel such that a normal consumer (i.e. not a fabrics or textile expert) will not notice a difference among the fabrics used to construct the underwear of this invention. 
     A similar women&#39;s underwear may be constructed without a fly opening with a crotch portion constructed with interior and exterior panels as illustrated by the men&#39;s underwear. 
     In an example of the invention, the inner layer (closest to the wearer&#39;s body) of the interior panel was a 100% polyester rib knit fabric with a weight of 165 grams per square meter. The outer layer of the interior panel was a 1×1 rib knit fabric with a weight of 190 grams per square meter made from 100% ring spun cotton yarn. This outer layer was treated with Nano-Tex Resists Spills™ chemical modification to form a hydrophobic, breathable cotton-appearing fabric. The two layers of the interior panel were attached to each other only at the seams of the garment; they are not fused or bonded together. The outer panel and the body of the undergarment was constructed from a 1×1 rib knit fabric with a weight of 190 grams per square meter made from 100% ring spun cotton yarn. In this example, the inner layer of the interior panel acts to wick moisture away from the skin to provide a dry feel. The outer layer of the interior panel acts as a liquid barrier. This layer also is breathable, thus allowing bodily fluids to evaporate and the undergarment to dry over time. 
     As shown in  FIGS. 1 and 2 , a small portion of the interior panel is visible at the fly opening. The Nano-Tex™ chemical modification does not significantly alter the appearance of the treated fabric, and is not visibly different from conventional underwear. 
     Use of an undergarment as described in this invention prevents minor amounts of body liquids from being transported to outer clothing. Typically, a minor amount of such liquid is less than about 10 milliliters and may be less than about 5 or less than about 2 milliliters.