Abstract:
An improved lidded container includes a receptacle portion with a brim having a plurality of lateral substantially straight brim wall segments provided with medial sealing beads extending between corners of the brim. The medial sealing beads are characterized in that they project away from the respective walls upon which they are disposed a maximum distance at a central portion of the wall and the medial sealing beads extend over a major portion of the length of the lateral sealing wall upon which they are disposed. Most preferably, the beads are flush with and terminate at rounded corners between the wall segments.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention is directed to an improved disposable bib formed of multiple plies of material and having superabsorbent and liquid retention properties. Preferably, the disposable bib comprises at least a first ply of liquid permeable and partially absorbent flexible sheet material forming the front of the bib and a second ply of liquid impermeable flexible sheet material forming the back of the bib and bonded to the first ply with a quantity of superabsorbent natural or synthetic polymer having the capability to retain absorbed liquid disposed between the plies.  
       BACKGROUND OF THE INVENTION  
       [0002]     Disposable bibs commonly consist of a layered structure of plies, generally comprising a front layer that is liquid permeable, often simply an absorbent paper, laminated to a liquid impermeable rear layer, there being some means by which the bib is secured to the user. Most of such bibs have a limited absorbability and once saturated must be changed. Furthermore, since the front ply is also the absorbent ply it can quickly become of little use for wiping the user&#39;s face.  
         [0003]     Examples of disposable bibs include U.S. Pat. No. 4,733,411 which describes a bib comprising an outer absorbent paper layer and an inner waterproof layer configured to provide an apron with a yoke and bonded together in overlapping relationship with adhesive and overlocking edge stitching. The bib of this patent relies solely on the outer absorbent paper layer and, therefore, has limited absorbability.  
         [0004]     U.S. Pat. No. 5,661,851 describes a disposable bib having a backing layer of water repellent material and a front central portion made of water absorbent ply material. The front area of this bib around the central portion of water absorbent material is described as a water repellent ply. The effect of this structure is to limit the water absorbable area of the bib to the central portion of the front ply.  
         [0005]     U.S. Pat. No. 6,237,150 describes a bib having three layers, a first water permeable outer layer that is preferably quilted paper, a middle absorbent layer of fiber fill material and a relatively non-porous plastic bottom layer. A debris catching pocket is provided adjacent the bottom edge. Fiber fill is limited in its liquid absorbent capability with the result that excess liquid either runs off the bib or is expressed back through the water permeable outer layer.  
         [0006]     U.S. Pat. No. 6,256,788 describes a disposable bib having a pressure sensitive adhesive over substantially the entire back surface of the bib to provide secure attachment to the wearer despite movement. The bib is constructed of absorbent sheet material, such as used in household paper towels and may have a liquid impervious layer on the back side. A neck shaped cut-out allows for placement of the bib adjacent to the user&#39;s neck with the piece of material removed therefrom reservable as an auxiliary wipe provided one remembers to do so when removing the bib from its backing sheet. A pouch is provided on the back side of the bib with a transverse slit in the front providing access to the pouch.  
         [0007]     U.S. Pat. No. 6,308,333 describes a disposable bib having an upper member of thin plastic mesh material which allows liquid substances to flow therethrough to a first absorbent member of thin paper material. A second absorbent member of thin absorbent cotton material is provided to absorb any liquids not absorbed by the first absorbent member. The bib is also provided with a bottom planar member that is water resistant adjacent to the second absorbent member.  
         [0008]     The prior art relies on conventional absorbent materials to provide liquid absorbency in disposable bibs. As such the absorbency and water holding capabilities of disposable bibs are limited to the point that, often, multiple bibs are required. Furthermore, those disposable bibs which include a pouch for capturing solid detritus do not make full use of the absorbent materials of the bibs in their structure.  
         [0009]     Thus, there is a need for a disposable bib having improved and superabsorbent liquid retention properties, together with a structure which makes the most of the absorbent and superabsorbent liquid retention properties in a bib that is readily and easily used.  
       SUMMARY OF THE INVENTION  
       [0010]     Presented here is a disposable bib having increased absorbability and liquid retention which has the added feature of maintaining a dry outer surface which can be used for wiping one&#39;s face and hands even after the bib has absorbed a significant quantity of liquid. In an alternative embodiment, the bib is provided with a pouch adjacent the bottom edge for the capture of solid detritus and liquid and which makes full use of the superabsorbent and liquid retention properties of selected polymers. In a still further embodiment, the bib includes a removable portion, tearable from the main bib along a perforation, which may be used as a wipe and may be removed as needed during the course of a feeding or other use of the bib. If not needed as a wipe, it remains in place to provide extra protection for the user.  
         [0011]     To achieve the superabsorbent and liquid retention properties, the subject bib employs a quantity of one or more superabsorbent polymer materials disposed between a liquid permeable front layer and a liquid impermeable rear layer, the front and rear layers being bonded together along their common edges so as to retain the superabsorbent polymer and absorbed liquids within the bib. The superabsorbent polymers are preferably those that retain absorbed liquid in a gel state so as to prevent the absorbed liquids from seeping back through the front layer. An exemplary bib is shown in the accompanying drawing figures.  
         [0012]     It is therefore an object of the invention to provide a disposable bib comprising a laminated flexible panel adapted to substantially cover a human chest and having means at one end to secure the bib about a human neck whereby the panel is disposed over the chest, the laminated panel comprising: an upper sheet of liquid permeable, flexible material, a lower sheet of liquid impermeable flexible material, and an absorbent material disposed therebetween, whereby the upper sheet and the lower sheet are secured together at least along their common edges whereby the absorbent material is confined therebetween, and the absorbent material comprises at least one superabsorbent natural or synthetic polymer having the capability to absorb and retain liquid passing through the upper sheet.  
         [0013]     It is a still further object to provide a multilayer, disposable, absorbent bib comprising a front, liquid permeable layer, a rear, liquid impermeable layer, and an intermediate absorbent layer disposed between the front layer and the rear layer, wherein the intermediate absorbent layer comprises a non-woven mat of absorbent fibers and a quantity of superabsorbent natural or synthetic polymer dispersed among the fibers, the front and rear layers being laminated together to form a single, flexible panel.  
         [0014]     It is an even further object to provide an improved disposable bib comprising a laminated flexible panel of a front, liquid permeable layer and a rear liquid impermeable layer adapted to substantially cover a human chest and having means at one end to secure the bib about a user&#39;s neck whereby the panel is disposed over the chest, wherein the improvement comprises a quantity of at least one natural or synthetic superabsorbent polymer disposed between the front and rear layers whereby liquid passing through the front layer is absorbed and retained by the polymer, and a pouch and detachable wipe provided on the bib, the pouch and the wipe comprising integral portions of the bib including the superabsorbent polymer. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a plan view of a disposable bib in accordance with the present invention.  
         [0016]      FIG. 2  is a cross section along line  2 - 2  of  FIG. 1 .  
         [0017]      FIG. 3 ( a )-( d ) illustrate plan views of alternative embodiments of the disposable bib where the area of superabsorbency is less than the entire area covered by the bib.  
         [0018]      FIG. 4  is a plan view of the disposable bib of the present invention having a pouch formed thereon.  
         [0019]      FIG. 5  is a cross section along line  5 - 5  of  FIG. 4 .  
         [0020]      FIG. 6  is a plan view of the disposable bib of the present invention having a pouch and removable wipe formed thereon.  
         [0021]      FIG. 7  is a cross section along line  7 - 7  of  FIG. 6 .  
         [0022]      FIG. 8  is a plan view of a disposable bib according to the present invention having a tear-off portion along the lower edge.  
         [0023]      FIG. 9  is a partial cutaway view of the intermediate absorbent layer of the bib of the present invention.  
         [0024]      FIG. 10  is a cross section along line  10 - 10  of  FIG. 1  showing an alternative embodiment of the bib of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]      FIG. 1  illustrates a bib  1  in accordance with the present invention comprising a chest covering portion  2  and neck straps  3  with releasable securing means  4  on opposite sides of each neck strap. As releasable securing means  4  there may be used spots of hook and loop fasteners, pressure sensitive releasable adhesive, snap fasteners, or the like. Bibs corresponding to the present invention may have different shapes and sizes and means of securing about the neck of the user without departing from the scope of the claims herein. The shapes and fastening means illustrated and described herein are representative.  
         [0026]     Referring to  FIG. 2 , the disposable bib of the preferred basic configuration of the present invention comprises a front layer  5 , rear layer  6  and an intermediate absorbent layer  7 . The front layer  5  is a woven or nonwoven liquid permeable material having a mesh size sufficiently small that liquid may pass therethrough but that a superabsorbent polymer in loose powder form cannot. Suitable materials for this layer include, but are not limited to, quilted paper, woven or non-woven fabrics of natural or synthetic materials. A particularly suitable material is a nonwoven hydrophobic polypropylene having a basis weight of from about fifteen (15) to about thirty (30) grams per square meter. If desired, a ply of wet-strength tissue may be applied on each side of the front layer  5  to form an envelope thereabout, and which tissue sheet has overlapped longitudinally extending edge portions disposed between the front layer  5  and the rear layer  6 . Such tissue paper is excellent for obviating sifting out of the superabsorbent polymer where such is in a particulate form. At least the front layer  5  and the rear layer  6  are bonded together around the entire common periphery to confine the intermediate absorbent layer  7  therebetween.  
         [0027]     The intermediate absorbent layer  7  comprises at least a superabsorbent polymer. Although the superabsorbent polymer  11  may be disposed loose between front layer  5  and the rear layer  6 , it is preferred that the superabsorbent polymer  11  be disposed within the pores of a core of an airlaid matt of cellulosic fibers  10  which are substantially unbonded to each other through the thickness of the core. This core of airlaid cellulosic fibers  10  and superabsorbent polymer  11  comprises the intermediate absorbent layer  7 . The matt may have a basis weight of from about three-hundred-ten (310) grams per square meter to about twelve-hundred-forty (1240) grams per square meter and density of about three hundredths (0.03) to about seven-hundredths (0.07) grams per cubic centimeter. The rear layer  6  is a liquid impermeable material to prevent any soak through from soiling the user&#39;s clothing and may be a matte-finish polyethylene having a nominal thickness of about one mil (about 0.0254 mm).  
         [0028]     The intermediate absorbent layer  7  may be co-extensive with the front layer  5  and rear layer  6  or it may be restricted to the area of the chest covering portion  2  of the bib  1  or to one portion of the chest covering portion  2 , such as the upper one half of that area, thereby leaving the lower one half to serve as a cloth for wiping the user&#39;s face and hands. Alternatively the intermediate absorbent layer  7  may be further restricted to an area  8  substantially centrally located about the chest covering portion  2  of the bib  1  as represented by the broken lines in  FIG. 3   a . In embodiments where the intermediate absorbent layer  7  is to be limited in area it is advantageous to manufacture the intermediate absorbent layer  7  as a package by confining a piece of the airlaid matt  10  and superabsorbent polymer  11  within a wet-strength tissue wrapping  12  as described above. Such tissue paper is excellent for obviating sifting out of the fibers of the superabsorbent polymer  11  where such is in a particulate form. Indeed, regardless of the extent of the intermediate absorbent layer  7 , it may comprise the matt of airlaid fibers  10  as described with the superabsorbent polymer  11  dispersed between the fibers, the whole confined between layers of wet strength tissue  12  sealed around the periphery to form a self contained packet  13  as shown in  FIG. 9 . This packet may then be placed between the front layer  5  and rear layer  6  which are adhered together around the periphery of the bib.  
         [0029]     Alternatively, the superabsorbent polymer  11  may be evenly dispersed between the front layer  5  and rear layer  6  with those layers bonded together around their common peripheries as well as along lines  18  in a criss-cross or other pattern across at least the chest covering portion  2 , as shown in  FIG. 1 , to form a quilted structure wherein quantities of superabsorbent polymer  11  are confined within individual pockets  19  of the quilting, as shown in  FIG. 10 . A sheet of wet strength tissue  12  may be applied to the inner surface of at least front layer  5  to prevent the particulate superabsorbent polymer  11  from sifting out through the pores of front layer  5 . If needed a corresponding sheet of wet strength tissue  12  may also be applied to the inner surface of rear layer  6 .  
         [0030]     In a still further alternative embodiment, the combination of the air laid matt  10  of fibers and superabsorbent polymer may be applied between the front layer  5  and rear layer  6  and quilted together as above. A thicker and more cushioned bib results from this construction and has the added advantage of the absorbency of both the fibers of the air laid matt  10  and the superabsorbent polymer  11 .  
         [0031]     The layers of the bib  1  may be adhered together and the lines  18  of quilting may be formed by any means commonly used to bond multiplayer absorbent webs. For example, sewing, hot melt glue, pressure sensitive adhesives, etc.  
         [0032]     It is, not intended to limit the present invention to these materials or weights or the like inasmuch as such parameters may be changed to provide embodiments of the invention in a variety of sizes, and capacities, and the like.  
         [0033]     Referring now to the superabsorbent polymer, hydrogels are particularly effective. By “hydrogel”, as used herein, is meant an inorganic or organic compound capable of absorbing aqueous fluids and retaining them under moderate pressures. For good results, the hydrogels should be water insoluble. Examples are inorganic materials such as silica gels and organic compounds such as cross-linked polymers. Cross-linking may be by covalent, ionic, vander Waals, or hydrogen bonding. Examples of polymers include, but are not limited to, polyethylene oxide, polyvinyl pyrrolidone, polyacrylamides, polyvinyl alcohol, ethylene maleic anhydride copolymers, polyvinyl ethers, hydroxypropyl cellulose, methyl cellulose, carboxymethyl cellulose, polyvinyl alcohol-acrylate copolymers, polyvinly morpholinone, polymers and copolymers of vinyl sulfonic acid, polyacrylic acid base compolymers, hydrolysis of starch acrylonitrile graft copolymers, starch-acryl acid graft copolymers, polyacrylates, polyacrylamides, polyvinyl pyridine, dextran, agar, gelatine, propylene glycol alginate, sodium alginate, polyethylene imine, and the like. Other suitable hydrogels are those disclosed in U.S. Pat. No. 3,901,236, issued to Assarsson et al., Aug. 26, 1975, the disclosures of which are incorporated herein by reference. Particularly preferred polymers for use herein are hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, polyacrylates, and isobutylene maleic anhydride copolymers, or mixtures thereof.  
         [0034]     For the purpose of utilizing hydrogels in the present invention, it is essential that relatively dry hydrogel particles be used. Also, neither the fibers, the particles nor the mixture of fibers and particles should be exposed to water in its liquid form, or another solvent, at any time during this process or subsequent thereto. When wet hydrogel particles are used, the fibers tend to become entangled and/or bonded with the particles which result in undesirable stiffness of the absorbent structure. Additionally, wet hydrogel particles would obviously have less absorbency efficacy in the product inasmuch as their potential absorbency would already be diminished.  
         [0035]     As used herein, “dry” does not mean “absolutely water-free”. For example, under normal storage and handling conditions, hydrogel particles take up some moisture. The hydrophilic fibers also take up some moisture during storage. Furthermore, it may be desirable to use humidified air for air transport of the fibers and the hydrogel particles, to avoid dusting. Under such process conditions, the hydrogel particles and the fibers will take up even more moisture, but such should be limited so that it does not unduly affect the practice of the present invention.  
         [0036]     The superabsorbent polymer which is employed in the intermediate absorbent layer  7  will generally comprise particles of a substantially water-insoluble, slightly cross-linked, partially neutralized, hydrogel-forming polymer material. The term “particles”, as used herein, can refer to particles in any form, such as in the form of pellets, flakes, or fibers.  
         [0037]     In one embodiment, the intermediate absorbent layer  7  is a laminate comprised of a layer of superabsorbent polymer material, such as in the form of particles, disposed between two air-laid tissues, first and second tissue layers (or “upper” and “lower” tissue layers). The first and second tissue layers provide containment of the superabsorbent polymer material, improve lateral wicking of the absorbed exudates throughout the intermediate absorbent layer  7  and provide a degree of absorbency. In addition, the first and second tissue layers may be quilted together in the manner described previously before being placed between the front layer  5  and the rear layer  6  of the bib  1 .  
         [0038]     A suitable laminate is the superabsorbent laminate WATER-LOCK L-535 available from the Grain Processing Corporation of Muscatine, Iowa (WATER-LOCK registered TM by Grain Processing Corporation). Such superabsorbent laminates are disclosed in U.S. Pat. No. 4,467,012, entitled “Composition For Absorbent Film And Method Of Preparation”, which issued to Pedersen et al. on Aug. 21, 1984, and U.S. Pat. No. 4,260,443, entitled “Laminated Absorbent Process”, which issued to Lindsay et al. on Apr. 7, 1981.  
         [0039]     In a particularly preferred embodiment, as described above, the intermediate absorbent layer  7  is a laminate comprising an airlaid matt of cellulosic fibers in which the superabsorbent polymer is dispersed, the fibers of the matt providing some absorbency themselves and serving to confine the particles of superabsorbent polymer before, during and after they are exposed to and absorb liquid. The matt and associated polymer are laminated between layers of tissue with the edges of the tissue layers bonded together so as to confine the matt and polymer particles in a package which can then be disposed between the front layer  5  and rear layer  6  of the bib. Such a package may be produced in virtually any shape and/or size to fit anywhere within the bib as indicated in FIGS.  3 ( a )-( d ) where the area  8  of the intermediate absorbent layer  7  is indicated by broken lines. These particular embodiments are intended as illustrative only and are not considered to limit the present invention.  
         [0040]     The rear layer  6  is impervious to liquids and, thus, prevents liquid absorbed by the bib  1  from passing through and soiling the clothing of the user. Any material used in the art for such purpose can be utilized herein. Suitable materials include embossed or nonembossed polyethylene films and laminated tissue. A suitable polyethylene film is manufactured by Monsanto Chemical Corporation and marketed in the trade as Film No. 8020.  
         [0041]     In a further embodiment, illustrated in  FIGS. 4 through 7 , the bib  1  may be provided with a pouch  9  on the front side to catch crumbs and large globs of food and the like. In this embodiment the bib is formed from a sheet of the laminated structure of front layer  5 , rear layer  6  and intermediate absorbent layer  7  having an extra length to the chest covering portion  2  thereby permitting the pouch  9  to be formed by folding the lower end of the chest covering portion  2  upward and sealing the folded portion to the rest of the bib along the edges  14 . This is shown in  FIG. 5  which is longitudinal cross section taken along line  5 - 5  of  FIG. 4 . With this construction, the front layer  5  of the bib  1  forms the inside of the pouch  9  such that liquids and semi-liquids dropped from the user and caught in the pouch will be absorbed into the bib  1  through the liquid permeable front layer  5  to be absorbed by the intermediate absorbent layer  7 . Furthermore, by forming the pouch  9  by folding the lower end of the chest covering portion  2  upward, the liquid impermeable rear layer  6  becomes the front of the pouch  9  thereby preventing liquids from seeping out through the front of the pouch  9 . Alternatively, the pouch may also be formed by laying a second layer of the liquid impermeable material of rear layer  6  over the lower area of chest covering portion  2  and securing it to the bib  1  around the bottom and two side edges leaving the top edge open to form the pouch  9 . Clearly, where the bib  1  is provided with the pouch  9 , it is preferred that the intermediate absorbent layer  7  extend into the area covered by the pouch  9 .  
         [0042]     In a further embodiment illustrated in  FIG. 8 , the bib  1  is provided with a lower portion  15  separable from the chest covering portion  2  by a line of perforation  16 . In this manner, the lower portion  15  is removable from the rest of the bib  1  to serve as a napkin or wipe. Lower portion  15  may include the superabsorbent polymer, in which case, preferably, the layers  5 ,  6  and  7  of the bib will be sealed together along lines  17  on each side of the perforation to prevent spillage of the superabsorbent polymer when the lower portion  15  is removed.  
         [0043]     A still further embodiment, illustrated in  FIGS. 6 and 7 , combines the features of the pouch  9  and the tear-off wipe or napkin  15 . In this embodiment, the chest covering portion  2  of the bib  1  is of sufficient length to permit it to be folded upward as in the embodiment of  FIG. 4 , with the common edges  14  sealed as before to form a pouch  9 . In addition, an extra portion of the length of bib  1  extends beyond the open edge of pouch  9  and is separable therefrom by a line of perforation  16  thereby providing a portion  15  which may be torn off for use as a wipe or napkin. As shown in  FIG. 7 , this embodiment includes the intermediate absorbent layer  7  through the chest portion  2  of the bib, the pouch  9  and into the tear-off wipe  15  and by forming the pouch  9  and wipe  15  by simply folding the bib material as shown, the front layer  5  of the bib  1  forms the inside of the pouch  9  such that liquids and semi-liquids dropped from the user and caught in the pouch will be absorbed into the bib  1  through the liquid permeable front layer  5  to be absorbed and retained by the intermediate absorbent layer  7 , while the tear-off wipe  15  is provided with the front layer  5  outermost so that, if desired, the wipe  15  may be simply left in place over the outer surface of the pouch  9  to catch spills that miss the opening of the pouch  9 .  
         [0044]     While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, that all such modifications and changes are within the true spirit and scope of the invention as recited in the following claims.