Patent Application
20080287899
This invention relates generally to disposable absorbent undergarments, e.g., disposable underwear, adult and youth briefs, and training pants for children. More specifically, this invention relates to articles of the type that can be manufactured efficiently and economically and which exhibit protection from leakage, good fit and comfort.
Absorbent articles such as disposable diapers, training pants, adult incontinence garments, and the like are known, their major function being to absorb and contain body exudates. Such articles are thus intended to prevent the soiling, wetting, or other contamination of clothing or other articles, such as bedding, that come into contact with the wearer. In the case of disposable protective undergarments, a variety of designs and manufacturing techniques have been developed to maximize performance and comfort to the wearer and to obtain a high degree of efficiency in manufacturing while minimizing the amount of waste material, thereby keeping production costs as low as possible. However, many of the current designs and manufacturing methods have been unable to achieve an optimum balance between these desirable, yet often diverging goals. While many developments have been made in the art of disposable absorbent undergarments, there remains a need for further improvements in both design and manufacturing.
In one aspect, the invention provides a protective undergarment comprising a front portion and a back portion longitudinally spaced from one another, each of the front and back portions having a waist area, a leg area longitudinally spaced from the waist area, and a belly area positioned between the waist area and the leg area. The belly area comprises an ultrasonically bonded, stretchable film. A crotch insert is also included having a front end fixed to the front portion and a back end fixed to the back portion. The crotch insert bridges a gap between the front and back portions, such that portions of the leg area of the front portion, the leg area of the back portion, and the crotch insert together define leg openings.
In another aspect, the invention provides a protective undergarment comprising a front portion and a back portion each of the front and back portions having a waist area, a leg area longitudinally spaced from the waist area, and a belly area between the waist area and the leg area. A crotch insert is also included having a front end overlapping with the front portion and a back end overlapping with the back portion at the belly area. Ultrasonic bonds fix the front end of the crotch insert to the front portion and fix the back end of the crotch insert to the back portion. Portions of the leg area of the front portion, the leg area of the back portion, and the crotch insert together define leg openings.
In yet another aspect, the present invention provides a method of manufacturing a protective undergarment comprising the step of forming front and back undergarment portions each having a belly area comprising a stretchable film. The method further includes the steps of spacing the front and back undergarment portions longitudinally from one another, fixing a front end of a crotch insert to the front portion, and fixing a back end of the crotch insert to the belly area of the back portion by ultrasonic bonds to bridge a gap between said front and back undergarment portions.
In still yet another aspect, the invention provides a method of manufacturing a protective undergarment comprising the steps of forming from at least one continuous web of material outer front and back portions each having a waist end and a crotch end longitudinally spaced from the waist end. The method further includes the steps of applying stretchable film, under tension, onto each of the outer front and back portions at a belly area of each of the front and back portions and applying an ultrasonic bond to the stretchable film and the outer front and back portions. The method also includes the step of fixing a front end of a crotch insert to the front portion and a back end of the crotch insert to the back portion, thereby bridging a gap between the front and back portions.
The invention is best understood from the following detailed description when read in connection with the accompanying drawing. It is emphasized that, according to common practice, the various features of the drawing are not rendered to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. Included in the drawing are the following figures, in which like reference numerals refer to similar features in the respective Figures:
Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.
Referring generally to the drawing,
With reference to
As shown in
Similar to the front portion 20, the back portion 30 of the disposable protective undergarment 10, according to the exemplary embodiment of
As illustrated in
When fully assembled, as shown in
Referring again to the exemplary embodiment of the invention illustrated in
According to the embodiment as shown in
In addition, as shown in
Referring to
The material forming the front 20 and rear 30 portions of the chassis, including the back portion inner and outer layers 37, 38 and front inner and outer layers 27, 28, shown in
The absorbent composite of an exemplary embodiment of the disposable absorbent undergarment can be configured as shown in
In another embodiment, the ADL may comprise two separate layers including an acquisition layer and a distribution layer. While one exemplary embodiment of a crotch insert and absorbent composite is shown for purposes of illustration, a wide variety of portions and composites are optionally used within the scope of this invention.
Referring to the embodiment illustrated in
In the exemplary embodiment shown in
The ADL 44b can be a thru-air bonded/carded web, a spunbond bi-component non-woven web, a web of crosslink cellulosic fibers, apertured 3D (three dimensional) film or the like. One particularly suitable material is a thru-air bonded bi-component fiber material with a finish surfactant available from PGI Non-Wovens of Landisville, N.J., which has an overall basis weight of 40 gsm. The bi-component fibers are made of a polypropylene inner core and a polyethylene outer sheath. The ADL 44b may be adhesively secured in place by any suitable construction adhesive, such as 34-373A adhesive available from National Starch and Chemical of Bridgewater, N.J.
Interposed between the ADL 44b and the barrier layer 44d is the absorbent core 44c. The absorbent core 44c, according to one embodiment, is made from untreated pulp and contains superabsorbent polymer. The absorbent composite 44, as shown in the embodiment illustrated in
The absorbent core 44 is disposed above the barrier layer 44d. In the embodiment shown herein, the absorbent composite 44 is of a generally rectangular shape. If desired, it may have a central portion of increased thickness as compared to its side marginal portions. The thickened central portion of the absorbent core 44c may taper from the front to the rear. These structural features of the core 44c and its location ensures that the maximum thickness of the core is located at the anatomical position at which the urine insult from the wearer will be initiated.
The core 44c can be formed of any suitable material(s), such as an airlaid composite, containing pulp, superabsorbent particulates and/or fibers, and binders. The binders may be chemical or thermal.
In accordance with one exemplary embodiment, the core 44c is made up of mainly cellulosic fibers, e.g., wood pulp fluff made of up bleached sulfate wood pulp containing soft wood fibers, such as that available from International Paper of Tuxedo, N.Y., co-mingled with hydrogel polymer particulates (known as Super Absorbent Polymer or “SAP”) such as cross-linked polyacrylate IM-3900 available from BASF Corporation of Charlotte, N.C. If desired, these materials may be optionally wrapped in tissue. The amount of each absorbent material and SAP/fluff ratio depends on the size of the protective underwear, whether it is used for children (e.g., training pants) or for adults, and whether or not a transfer or fluid acquisition layer component is to be included in the absorbent composite 44. In this regard, the ADL 44b as shown herein may be optionally omitted from the undergarment 10.
In order to prevent the egress of fluid out through the non-woven sheets of the chassis, the crotch insert 40 also includes the heretofore identified barrier layer 44d. The barrier layer 44d is interposed between the core 44c and the chassis and is formed of a liquid impervious material, e.g., a microporous polyfilm which is vapor permeable (breathable). In the embodiment shown herein, the barrier layer 44d is of the same generally rectangular shape and size as the cover 44a and is located in the crotch insert 40 of the undergarment 10. In accordance with one exemplary embodiment, the barrier layer 44d is formed of a film of 0.5 mil polypropylene available from Pliant Corporation of Williamsburg, Va.
The crotch insert 40 of the absorbent garment also includes two sets of elastic threads 45 comprising at least one elastic strip each. The elastic threads 45 extend along the longitudinal direction of the crotch insert 40 for a distance along each side 43 of the crotch insert 40 such that each elastic thread 45 also overlaps the belly areas 25, 35 of the front 20 and back 30 portions. The elastic threads 45 are sandwiched between the cover 44a and barrier layer 44d and are attached using construction adhesive. In addition, the crotch insert 40 of the undergarment 10 includes an outer cover 44e, such as a non-woven layer, as illustrated.
It will be appreciated that the foregoing description of crotch insert 40 is provided for purposes of illustration of one exemplary embodiment. Alternative absorbent inserts are optionally utilized depending on performance, cost, comfort, and manufacturing considerations. For example, the crotch insert may be optionally provided with standing leg gathers to help promote fit and to prevent or reduce leakage.
As shown in
In another exemplary aspect of the invention, as shown in
By providing non-stretchable gaps or portions 50, 51, this aspect of the invention allows for each of the waist areas 11, 16, belly areas 12, 15 and leg areas 13, 14 to have different degrees of stretchability suited for fit around the waist, the belly, and the legs of the wearer, respectively. This allows the selection of elastics materials and/or the selection of their respective degrees of tension so that individualized fit characteristics can be provided at the waist, belly and legs. Thus, this configuration permits flexibility in the design and manufacture of the absorbent undergarment so as to provide improved performance and fit. The respective tensions applied at the waist, belly, and legs can be the same or differ. Also, the respective materials used for the waist, belly, and leg elastics can be the same or differ.
Additionally, by providing non-stretchable gaps or portions 50, 51 according to this exemplary aspect of the invention, the absorbent garment can be configured to approximate briefs and undergarments in terms of fit and comfort. For example, the gaps or portions 50, 51 allow the waist, belly, and leg elastic portions to be independently stretched by the wearer, for better comfort and fit. This exemplary feature also allows for independent stretching of one or more of the waist, belly, and leg portions as the absorbent undergarment is donned by the wearer. Further, less elastic material is required in the undergarment provided with gaps or portions 50, 51, thereby providing a cost savings.
The protective undergarment 10 can include non-stretchable portions 50, 51 that each have a width in the longitudinal direction of about 0.5 cm to about 3 cm, or preferably, the non-stretchable portions 50, 51 each have a width in the longitudinal direction of about 1 cm.
As shown in
In another embodiment, the invention provides a protective undergarment 10 comprising a front portion 20 and a back portion 30 longitudinally spaced from one another. Further, each portion has a waist area 11, 16, a leg area 13, 14 longitudinally spaced from the waist area 11, 16 and a belly area 12, 15 positioned between the waist areas 11, 16 and the leg areas 13, 14. The belly areas 12, 15 include an ultrasonically bonded, stretchable film. A crotch insert 40 having a front end 41 fixed to the front portion 20 and a back end 42 fixed to the back portion 30 bridges a gap between the front 20 and back 30 portions, such that portions of the leg area 13 of the front portion 20, the leg area 14 of the back portion 30, and the crotch insert 40 together define leg openings 18. In this example, the stretchable film may be bonded on one side to a material, such as a non-woven material, and the other side remains exposed. The ultrasonic bonding of the belly areas 12, 15 results in a composite having a more cotton-like, or underwear-like, look and feel.
This embodiment also has front 20 and back 30 portions that are made up of inner portion layers 27, 37 and an outer portion layers 28, 38, with a stretchable elastomeric film sandwiched therebetween. In this example, the undergarment includes ultrasonic bonds for securing both the inner and outer portion layers and the elastics. Optionally, the belly areas 12, 15 may be uni-directionally stretchable in a direction across a wearer's belly, and/or the undergarment may include a front 20 portion and a back portion 30 that each have a wave-shaped pattern along crotch ends 22, 32 of the respective portions. Alternatively, the undergarment, as shown in
Accordingly, referring to
Optionally, in a variation of this embodiment, the front 20 and back 30 portions are made breathable in the waist, belly and/or leg areas of the undergarment. For example, the front 20 and back 30 portions may optionally be made breathable by utilizing suitable elastomeric film, such as laminate film. The front 20 and back 30 portions could also be rendered breathable by providing perforations or otherwise providing holes or openings or apertures so as to provide a breathable undergarment. Such breathability provides enhanced comfort for the wearer. Alternatively, during the lamination process, the front 20 and back 30 portions may be rendered breathable.
As discussed with respect to
Thus, in another aspect, the invention provides for an embodiment of an absorbent protective undergarment 110, as shown in
Referring now to
Alternatively, the absorbent protective undergarment, as shown in
The waist, belly and leg elastics, for example as shown in
In the embodiment shown in
Optionally, the undergarment stretch material includes a bi-directionally stretchable web having a width to thickness ratio of at least 3:1. The undergarment the stretch material can include elastomeric stretch film or at least one thread of an elastic filament. The undergarment stretch material may be attached to the non-woven by adhesive bonding, ultrasonic bonding, heat or embossing as well as by other attachment means.
In the embodiment as shown in
This embodiment of the undergarment is designed in a configuration such that the longer of the inner layer 127, 137 and outer layer 128, 138 of the front 120 and back 130 portions is folded over the shorter of the inner 127, 137 or the outer 128, 138 layer of the front 120 and back 130 portions at the waist end to sandwich the stretchable web therebetween.
The undergarment of this embodiment includes elastomeric film as the stretchable waist material. Further, the undergarment stretchable web can be attached to the front and back portions by adhesive bonding, ultrasonic bonding, heat or embossing or other attachment means. Moreover, the stretchable web of the front 120 and back 130 portions may be either a single web of material divided into two pieces, one for each of the front 120 and back 130 portions, or it may be separate elastic webs, one set for each of the front 120 and back 130 portions. These embodiments incorporate elastomeric film as the waist elastics 134, such that the waist elastics 134 extend to cover the circumference of the product. In other words, when fully assembled, the undergarment 110 includes waist elastics 124 and 134 attached from end to end to form waist opening 117. Thus, the position and dimensions of the elastomeric film in relation to the rest of the finished product are advantageous.
These improved waist designs as described above and as shown in
In another aspect, the absorbent undergarment can be formed by the mating of a front portion 120, a back portion 130, and a crotch portion 140 such that the crotch portion 140 bridges a gap between the front 120 and back 130 portions. Specifically, the method includes forming from at least one continuous web of material into outer front and back portions each having a waist end and a crotch end longitudinally spaced from the waist end. A stretchable film, under tension, is applied onto each of the outer front and back portions at a belly area of each of the front and back portions. An ultrasonic bond is applied to the stretchable film and the outer front and back portions. Finally, a front end of a crotch insert is fixed to the front portion and a back end of the crotch insert is fixed to the back portion thereby bridging a gap between the front and back portions.
With reference to
The method may optionally include steps of forming from at least one continuous web of material inner front and back portions each having a waist end and a crotch end longitudinally spaced from the waist end for mating with the outer front and back portions, and mating the inner front and back portions to the outer front and back portions with the stretchable film sandwiched therebetween, prior to the step of applying the ultrasonic bond. A further optional step may include deactivating the leg elastics of the front and back portions, prior to fixing the crotch insert to the portions, by cutting or alternatively removing a portion of the leg elastics at locations where the crotch insert overlaps the front and back portions.
In still another aspect, the invention provides a method of manufacturing a protective undergarment including the step of forming from at least one continuous web of material, such as non-woven material, front and back outer portions. The process is directed to assembling a stretch material located at the waist area of the finished product. The stretch material is preferably stretchable in the cross-machine direction (CD) and in the machine direction (MD) and, unlike conventional methods, does not require turning of the elastic material or use of “cut and place” equipment.
In an embodiment according to this aspect, the invention includes assembling two web materials, such as a non-woven backsheet, or other outer cover material, and a CD/MD stretch material with retractive force qualities. Next, the method includes elongating the stretch material along its length, or machine direction, and then attaching the material to the area of the non-woven which will become the waistband of the product. In the process, the front waistband is constructed on the drive or operator side of the machine and the rear waistband is constructed on the opposite side of the machine. A next step includes folding the non-woven over to completely cover the stretch material or, alternatively, including an additional non-woven component to be placed over the stretch material. Alternatively, one side of the stretch material may be uncovered if the elastic material has sufficient aesthetic and tactile qualities to make it comfortable against the wearer of the product.
Optionally, the elastic material is attached to the other web at intermittent points, so that less than 100% of the area of the elastic web is attached to the non-woven. In addition, there may be regular pattern with distinct areas of no attachment followed by areas of intermittent attachment.
In further steps, the method includes coupling a first continuous web of stretch material to the front outer portion along a machine drive side of the non-woven material to form a front waistband. The web of stretch material may be, for example, a bi-directionally stretchable web having a width to thickness ratio of at least 3:1 (as compared to an elastic thread having a thickness ratio of about 1:1), or other stretchable film. Alternatively, the stretch material may, for example, include at least one elastic thread such as LYCRA® spandex.
In another step, the method includes coupling a second continuous web of stretch material to the back outer portion along a machine operator side of the non-woven material to form a rear waistband. The coupling of the stretch material to the non-woven may be performed by application of adhesive bonds, ultrasonic bonds, heat or embossing or other attachment means.
In an optional step, the method may include the step of elongating the stretch material along its length prior to coupling the material to the front and back outer portions. In yet another optional step, the method may include folding a portion of the non-woven material over the front and rear waistbands and connecting the front and rear waist bands to form a continuous waist opening.
Though the manufacturing steps described and claimed herein are optionally performed in the order described or claimed, they can be performed in any order, depending upon the equipment and processes selected and the preferences of the manufacturer.
In an alternative embodiment according to this aspect, the invention provides a method of manufacturing a protective undergarment including the step of forming from at least one continuous web of non-woven material front and back outer portions. The method further includes the steps of coupling a first continuous web of stretch material having a width to thickness ratio of at least 3:1 to the front outer portion along a machine drive side of the non-woven material to form a front waistband and coupling a second continuous web of stretch material having a width to thickness ratio of at least 3:1 to the back outer portion along a machine operator side of the non-woven material to form a rear waistband. The webs of stretch material may be coupled to the non-woven by applying adhesive bonds, ultrasonic bonds, heat or embossing, for example. Further, the method includes the step of connecting the front and rear waist bands to form a continuous waist opening.
In an optional step, the method of further comprises elongating the stretchable web along its length prior to coupling the web to the front and back outer portions. In additional optional steps, the method may include the steps of folding each of the front outer and back outer portions over the stretchable webs to cover the web, adding an additional non-woven web of material over the stretchable web to cover the web, and/or forming from a second continuous web of non-woven material front and back inner portions and sandwiching the first stretchable web between the inner front portion and the outer front portion and the second stretchable web between the inner back portion and the outer back portion.
The method may also include the optional steps of attaching the stretchable web to the front and back outer panels at intermittent points of attachment so that less than 100% of the stretchable web is attached to the front and back portions and/or creating repeating patterns from the points of attachment.
Still yet other optional steps of the method include forming the front and back portions with a repeating wave-shaped pattern along a crotch end of the portions and/or indexing the front and back outer portions to align a peak of a wave of the wave-shaped pattern with a peak of an opposing wave of the wave-shaped pattern, for example, as shown in
Alternatively, referring to the embodiment shown in
In yet another aspect, and according to yet another embodiment, the invention is directed to a protective undergarment 210 comprising a front portion and a back portion each having a waist area, a leg area longitudinally spaced from the waist area, and a belly area between the waist area and the leg area. The undergarment further includes a crotch insert having a front end overlapping with the front portion and a back end overlapping with the back portion at the belly area.
Referring specifically to
Optionally, the ultrasonic bonds 260 comprise at least one line substantially parallel to a waist end of the back portion, as shown in
According to this embodiment, the ultrasonic bonds are optionally applied to an area covering less than about 95% of the stretchable material. Optionally, the ultrasonic bonds are applied to an area covering less than about 25% of the stretchable material. Further, the undergarment can optionally include belly areas of the front and back portions having stretchable material.
Exemplary patterns for the ultrasonic bond are illustrated in
As shown in
In a related aspect, the invention provides a method of manufacturing a protective undergarment. The method includes the steps of forming front and back undergarment portions, each having a belly area comprising a stretchable film and spacing the front and back undergarment portions longitudinally, or in the CD direction, from one another. The method further includes the steps of fixing a front end of a crotch insert to the front portion and fixing a back end of the crotch insert to the belly area of the back portion by ultrasonic bonds, to bridge a gap between the front and back undergarment portions.
Optionally, the method can include the step of fixing a back end of the crotch insert to the belly area of the back portion by applying at least one repeating ultrasonic bond pattern that is at least partially aligned with the profile of a crotch end of the back portion. Alternatively, the crotch insert can be affixed to the belly area of the back portion by applying an ultrasonic bond that includes at least one line parallel or substantially parallel to a waist end of the back portion. Preferably, the ultrasonic bond includes from one to three lines that are parallel to the waist end of the back portion. A further optional step includes fixing a back end of the crotch insert to the back portion by applying an ultrasonic bond to an area covering less than about 25% of the stretchable film. The ultrasonic bond can also, more preferably, be applied to an area covering less than about 95% of the stretchable film. The ultrasonic bond can be applied in either the machine direction or in the cross-machine direction. Further, in process, the application of the ultrasonic bond can be made either before or after the wave cut is applied to the front and back portions.
Accordingly, the above-described bonding process includes the sealing of two portions of the product, the belly elastic, which can be stretched and the crotch insert, which also may be stretched. The belly elastic materials that can be bonded together are preferably elastomeric stretch film, e.g. formed in-line, or a pre-laminated film, e.g. formed off-line. Further, the method is preferably used for protective underwear undergarments, but it could also be utilized for producing training pants, diapers or feminine hygiene products or other absorbent products.
As described in greater detail below with reference to
More specifically, and as shown in
In still yet additional alternative embodiments,
With this configuration, less elastic material is required for the back portion 630, 730, thereby resulting in cost savings. Further, the configuration provides additional coverage for the front portion 620, 720 along the side seams of the front portion, as shown in
The embodiment as described above is designed to minimize and/or eliminate waste of valuable stretch material, including stretch film, film-laminated non-woven and/or tri-laminated non-woven to replace non-woven laminated elastic threads. The design cutout conforms to the wearer's body providing an overall better fit and improved fluid handling. As noted previously, the attachment of the back panel to the crotch insert creates a dead-ended zone along the attachment. Due to this zone the front and back portions are designed to have stretch material placement that provides strategic stretch points around the waist and sides of the buttocks while conserving this material. As shown, the front portion 620, 720 is cut to resemble real underwear and to provide coverage over the crotch insert with better fitting contours around the thighs of the wearer. Leg portions 670, 770 provide increased coverage to the back portion 630, 730 while the front portion 620, 720 can be provided with less material. Optionally, the length of the side seams can be the same so as to be aligned during bonding by ultrasonic bonding, glue, or heat seal, for example. Further, the cut could be as a 0.5 (man favoring design) or 1.5 (female favoring design) sinusoidal wave as described above in connection with
In still yet another aspect, according to an exemplary embodiment of the invention, the invention is directed to a method of manufacturing a protective undergarment. In this embodiment, the manufacturing method may include several steps performed in a substantially continuous operation. A first step includes forming front and back portions of the undergarment from at least one continuous web of material. Each of the front and back portions have a waist end and a crotch end that are longitudinally spaced apart and have substantially straight edges. In another step, the front end of the crotch insert is fixed to the front portion while the back end of the crotch insert is fixed to the back portion. The crotch insert thus bridges the gap between the front and back portions. In yet another step, material from the front and back portions is removed at the crotch ends of at least one of the portions to form wave-shaped edges, for example, as shown by crotch ends 822 and 832 in
In an embodiment according to this aspect, substrates are provided that are used to form the front and back inner and outer portion layers. The continuous web that makes up the front and back inner portions is loaded into a processing machine. As the inner layer material moves through the machine, the web is cut into two web portions along a straight line longitudinally extending in the machine direction (direction B-B shown in the figures), the two webs comprising the web portions that form each of the front inner portion and the back inner portion. Each of these front and back inner portions have a waist end and a crotch end longitudinally spaced from the waist end and have a substantially straight edge. Similarly, the outer portion layers are also loaded into the machine and likewise cut into two webs. The webs thus formed are generally rectangular in shape. Optionally, the back portion outer layer is longer in the cross-machine direction (direction A-A shown in the figures) than the front portion outer layer.
The front and back inner web portions are processed through a series of rollers after which waist elastics, belly elastics and leg elastics are applied. The elastics, which may optionally be applied in a pretensioned state, are then coated with adhesive, such as glue applied by strand coating glue heads. The leg elastics are applied so as to align with the contours of the intended finished undergarment's crotch edges. In an alternative embodiment, one or all of the waist elastics, belly elastics and leg elastics may comprise elastomeric material which is applied by ultrasonic bonding of the elastomeric material to the outer front and back portions instead of adhesive.
Then, the inner front portion web is “married-up” with the outer front portion web portion as the inner and outer portion webs are combined by a combining drum, thus sandwiching the elastic threads therebetween. The term “married up” is used herein to mean that the inner and outer web portions are substantially aligned and at least partially joined together to form a single portion or panel. After being combined by the combining drum, the front portion passes through a roller and under the insert attachment glue head at which point adhesive is applied to the front portion by a speed coat slot nozzle glue head. The adhesive is applied in a rectangular region so as to correspond to the overlap between the crotch insert and the front portion, as discussed in more detail below.
After the front and back portion inner and outer portion webs are married up, a thin strip of the crotch end of the back portion is removed to deactivate a section of the leg elastics of the front and/or back portion. The strip that is removed includes some of the web material and may also include portions of the leg elastics disposed in the area where the crotch insert is to be attached on the back portion of the undergarment. In other words, the leg elastics, which may include threads or filaments, are optionally applied to the front and/or back portions along a continuous length. The removal of a portion of the crotch end of the front and back portions may therefore remove a portion of the leg elastics in the location at which the crotch section is fixed to the front and back portions of the undergarment.
The step of removing a portion of the crotch end of the front and back portions therefore optionally involves retaining the crotch end of the front and back portions in a crotch insert fixation region. This is optionally accomplished by removing portions of the crotch end of the front and/or back portions on opposite sides of the crotch insert fixation region. Though this step can be performed in any order, in some embodiments the step of removing a portion of the crotch end of the front and/or back portions is advantageously performed before the step of fixing the front end of the crotch insert to the front portion and the back end of the crotch insert to the back portion.
Adhesive is next applied by a speed coat slot nozzle glue head. The adhesive is applied such that the entire area that the crotch insert will cover on the front and back portions is coated. While the adhesive is applied so as to ensure that as much of the peripheral edges of the crotch insert are adhered to the front and back portions, the adhesive is also applied so as to minimize adhesive leakage beyond the overlapping regions of the crotch insert with the front and back portions, respectively, from overspray or over application of the adhesive. Any such leakage may result in unintended adhesion of portions of the absorbent undergarment during the manufacturing and packaging processes.
After the adhesive is applied, the front and back ends of the crotch insert are placed on the corresponding front and back portions of the undergarment. Upon drying, the adhesive holds the crotch insert firmly in place along the entire periphery where it overlaps the front and back portions of the absorbent undergarment. As shown, for example in
In alternative embodiments, after the crotch insert is applied, thin strips are removed from the crotch end of the front portion and the back portions. The strips that are removed include portions of the front and back portions, such that removal of these strips form the curved crotch edges of the front portion and back portions. This is exemplified in
As shown in
In an alternative embodiment, such as shown by the undergarment 110 of
In an aspect of the invention, the crotch insert of the absorbent undergarment is then folded so as to align the waist end and opposing sides of the front portion with the waist end and opposing sides of the back portion. By connecting the front and the back portions along their sides, the arrangement forms a pants-shaped chassis having a waist opening and two leg openings. Individual products are then cut from the continuous web at the side connections of the undergarments.
Alternatively, the method may not include a folding step. In this case, the undergarment is not folded and the sides of the undergarment (and consequently the front and back portions) are not connected together during the manufacture of the undergarment. In such an embodiment, the undergarment optionally includes fasteners, such as adhesive tapes, hook and loop fasteners, or other conventional fasteners that are used in conventional disposable diapers that can be secured together at the time of use to form a pants-shaped chassis.
In another embodiment in which the outer web portions of the front and back portions are longer than the inner web portions, the longer outer webs are optionally folded over the shorter inner web, to provide an undergarment having the configuration as shown in
In another aspect, for example as shown in
As shown in
Optionally, in an embodiment as shown in
In another embodiment, in which the stretch material comprises an elastomeric film, such as laminate film, trilaminate film and the like, that is ultrasonically bonded to at least one of the inner and/or outer layers, the stretch material can also be deactivated by providing an area, such as area 981 of
Optionally, the undergarment of this aspect may further include graphic design or designs incorporated on the front end of the crotch insert. For example, the graphic design can include a wide variety of shapes and characters aesthetically pleasing to wearers, such as cartoon characters for children. It has been found that the crotch insert cover, such as that shown in
Therefore, one of the advantages provided by the configuration of this aspect is that the design allows for easier incorporation of graphic designs on the front part of the product than if the crotch insert were applied to the body-side of the front portion. Further, because the outer non-woven is optional, a reduction in material cost is achieved.
In a further aspect of the invention, the invention provides a method of manufacturing a protective undergarment, including forming front and back undergarment portions that each have a body-side surface and a garment-side surface and spacing the front and back undergarment portions longitudinally from one another. Further steps include fixing a front end of a body-side of a crotch insert to the garment-side of the front portion and fixing a back end of a garment-side of the crotch insert to the body-side of the back portion. For example, such bonding in the back of the product may occur by fixing the crotch insert to either the body-side of the stretch film or the inner portion layer. Likewise, such bonding in the front of the product may occur by fixing the crotch insert to either the garment-side of the stretch film or, if the optional outer portion layer is utilized, to the outer portion layer. By the front and back end portions of the crotch insert to the front and back portions as described, the crotch insert bridges the gap between the front and back undergarment portions. Fixing the front end of a body-side of the crotch insert to the garment-side of the front portion can comprise, for example, adhesively bonding the front end of the crotch insert to the garment-side of the front portion or ultrasonically bonding the front end of the crotch insert to the garment-side of the front portion.
The method may optionally further include deactivating a section of stretch material included in the front portion where the crotch insert is fixed to the front portion, such as by mechanically cutting the stretch material or providing an area devoid of stretch material.
Other optional steps include ultrasonically bonding the front portion during the forming step. In such a case, deactivating the stretch material, for example elastomeric film, in the deactivation area includes zoning a section of stretch material so that is free of ultrasonic bonding where the crotch insert is fixed to the front portion.
In still yet another aspect, the invention for example as shown in
As discussed above, deactivation of the stretching ability of the absorbent undergarments according to the various embodiments of the invention may be achieved by mechanically cutting the stretch material or by providing an area substantially devoid of stretch material. Alternatively, in embodiments in which the undergarment includes stretch material, such as elastomeric film, ultrasonically bonded to at least one of the inner and/or outer portion layers, the film may also be deactivated by including an area substantially free of ultrasonic bonding to the inner and/or outer layers.
While the invention includes the various embodiments described above, other embodiments of the invention may also include features as shown and described in U.S. patent application Ser. Nos. 10/617,218 to Glaug et al., filed on Jul. 10, 2003 and 11/236,994 to Babusik et al., filed on Sep. 28, 2005, which application is incorporated herein by reference. Each of the embodiments of the present invention is expected to provide equal or better functional performance and customer acceptance at a lower cost as compared to conventional protective undergarments. In particular, equal or improved performance is expected with respect to characteristics such as leakage control, coverage in the front, coverage in the back, fit at the waist, fit at the legs, overall fit, comfort, and ease of donning and doffing the undergarment.
While preferred embodiments of the invention have been shown and described herein, it will be understood that such embodiments are provided by way of example only. Numerous variations, changes and substitutions, including but not limited to the materials that make up the various components of the absorbent protective undergarment, will occur to those skilled in the art without departing from the spirit of the invention. Accordingly, it is intended that the appended claims cover all such variations as fall within the spirit and scope of the invention. For example, although the invention has been described as an absorbent undergarment having a three-component configuration, i.e. a front portion, a back portion and a crotch insert, the absorbent undergarment may have a one-piece rectangular or hour-glass configuration. Also, the steps of the fabrication methods described herein can be performed in various orders, depending on manufacturing, cost, and design considerations.
This application claims priority to U.S. Provisional Patent Application Ser. No. 60/930,119, filed May 14, 2007, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60930119 | May 2007 | US |
