MXPA99010535A - A method of manufacturing an article absorbs - Google Patents

Abstract

A method for manufacturing an absorbent article which includes attaching a perforated liner to a top sheet layer of the article. The method includes providing an absorbent article frame having a liquid-permeable top sheet layer, a bottom sheet layer and an absorbent structure placed therebetween. The absorbent article has a front waist section, a rear waist section and an intermediate section interconnecting the two waist sections. The perforated liner is attached to the upper sheet layer in a position whereby the perforated liner at least partially defines a rear part of the side surface to the body of the article and the upper sheet layer at least partially defines a front part of the surface from side to body. The perforated liner defines a fecal target area and increases the capacity of the absorbent article to contain low viscosity faecal materials and separate such materials from the wearer's skin. The perforated liner can be formed by laminating a perforated film to a low density fibrous material. The method may also include placing an absorbent body under the perforated liner. A part or all of the perforated liner can cover the top sheet layer and the absorbent body can be placed between the perforated liner and the top sheet layer.

Description

A MANUFACTURING METHOD PE AN ABSORBENT ARTICLE Background of the Ition Field of the Ition The present ition relates to absorbent articles for absorbing and containing body exudates. More particularly, the present ition relates to a method for manufacturing disposable absorbent articles, such as disposable diapers, training pants and adult incontinence garments, which are designed to contain body exudates, including fecal matter. of low viscosity.

Description of Related Art Absorbent articles, such as disposable diapers, often employ an absorbent core located between a liquid-permeable top sheet positioned on one side of the wearer's body and a lower sheet impervious to the liquid defining the outer surface of the garment. Liquid exudates, such as urine, penetrate the upper leaf and are absorbed by the core while the upper leaf impermeable to the liquid helps maintain a clean, dry outer surface.

Cotional absorbent garments are also generally used to contain and absorb solids and semi-solid exudates such as fecal matters which can vary significantly in viscosity. Absorbent garments have typically included elasticated waistbands and pier cuffs to inhibit the flow of both solid liquid exudates. Cotional absorbent garments may also include secondary containment or barrier fins in the leg or waist sections of the article to further inhibit runoff.

Some cotional absorbent garments may also include a hollow space with a large opening for receiving solid waste materials. The newly developed absorbers have also been designed to include a topsheet having openings for providing an increased capacity to contain the low viscosity materials as exemplified by United States Patent No. 5,342,338.

Synthesis of the Ition The present ition provides a method for manufacturing a disposable absorbent article including fastening a perforated liner to the article to provide the article with an increased capacity to contain absorbing low viscosity faecal materials.

In one form thereof, the present ition provides a method for the manufacture of an absorbent article which includes providing a lower ho layer, a liquid-permeable top sheet layer bonded to the lower sheet layer and an absorbent structure placed between the upper sheet layer and the lower sheet layer thus define an article frame. A perforated liner is attached to the upper sheet layer in a position whereby the upper sheet at least partially defines a front pair of the side surface to the body of the article and the perforated liner at least partially defines a back pair of the article. surface side to the body of the article.

Some embodiments of the present ition involve attaching the perforated liner in a relationship overlap with the top sheet. The perforated liner can also be fastened to an upper sheet so that the entire perforated forge lies on the upper sheet.

Additional incorporations may involve placing an absorbent body between the perforated liner and upper sheet layer. The method can also include the form a laminate which includes both the perforated liner and the absorbent body and cut the laminate in a single operation. When such a laminate is cut in a single operation, the absorbent core will have the outer perimeter edges, for example the perimetric edges, which are essentially coextensive with the perimetric edges of the perforated liner. This laminated segment can then be attached to the absorbent article.

The present ition provides numerous advantages in the manufacturing process of an absorbent article having a body side surface which includes a perforated part in the fecal target area of the article.

By using a perforated liner the cu is separated from the top sheet layer, the present fabrication method facilitates the use of a perforated liner which has physical characteristics different from those of the upper ho layer. This allows the top sheet layer and the perforated for to be optimized conveniently and independently by their respective different functions. This method also allows a conventional topsheet to be employed in absorbent article which also includes a perforated portion by increasing the capacity of the article to contain fecal materials of low viscosity.

Another advantage provided by the present invention is that in some embodiments this provides a manufacturing method which can be easily implemented by making only relatively minor changes to the pre-existing disposable article assembly machinery. For example, the Pre-existing diapers can be easily modified to cut and place a liner pierced on a conventional top sheet layer and produce by an absorbent article having a perforated liner and increasing the capacity to contain low viscosity faecal materials.

Brief Description of the Drawings The invention will be more fully understood and the additional advantages will become more apparent when reference is made to the following detailed description of the invention and the accompanying drawings in which: Figure 1 is a top plan view of an absorbent garment made in accordance with the present invention Figure 2 is a sectional view taken along line 2-2 of Figure 1; Figure 3 is a perspective view of the absorbent garment of Figure 1; Figure 4 is a top plan view partly cut away of another absorbent garment made in accordance with the present invention; Figure 5 is a sectional view taken along line 5-5 of Figure 4; Figure 6 is a schematic partially cut away perspective view of a perforated liner and fastened to the absorbent body; Figure 7 is a schematic perspective view of a process for assembling a perforated liner, the upper sheet layer and the emergence layer according to the present invention; Y Figure 8 is a schematic perspective view of an alternate process for assembling a perforated forr, the top sheet layer and the emergence layer which is in accordance with the present invention.

The corresponding reference characters indicate the corresponding parts through the different views. Although the drawings are intended to illustrate the present invention, the drawings are not necessarily limited and certain features may be exaggerated. The described embodiments are set forth to exemplify invention. The embodiments described are not intended to be an exhaustive illustration of the invention or to be construed as limiting the scope of the invention to a method for making the precise forms described.

Detailed description of the invention The following detailed description will be made in the context of making a disposable diaper which is adapted for use by infants around the lower torso. It is readily apparent, however, that the method of the present invention will be suitable for making other absorbent articles such as incontinence garments, training underpants, and other similar articles which are used to absorb or contain urine or faecal materials.

With reference to figures 1-3, there is illustrated an absorbent article in the form of a disposable diaper 20. disposable diaper 20 includes a front waist section 2 a rear waist section 24 and an intermediate section which interconnects the waist sections back front. The side edges of the intermediate section 2 are defined by a pair of opposite lateral side edges 28 while the edges of the front belt sections 22 and rear 24 are defined by a pair of longitudinally opposite end edges 30.

A perforated liner 62 and the absorbent body are generally placed on the back surface side of the body 21. The perforated liner 62 has a perforated layer 64 which can be formed by means of a perforated film. The perforated liner 62 may also include a low density fibrous layer 66 attached to the underside of the perforated layer 64.

The openings located in the liner pierce the fecal materials to be absorbed and contained in the fibrous layer of low density 66 and in the absorbent body 68 which are both located below the perforated layer 64. The fecal materials contained or absorbed in The low density fibrous ca 66 or the absorbent body 68 will be in direct contact with the wearer's skin.

The methods of manufacturing an absorbent article having a perforated liner are illustrated in the relevant part in Figures 7 and 8, and are discussed below in terms of making a diaper.

With reference to Figure 7, the apparatus used to manufacture the diaper 20 having a perforated liner includes unrolling 78 for the perforated liner 62. (The perforated liner 62 may comprise a laminate including both a perforated ca 64 and a fibrous layer of low density 66 or only u perforated layer 64). An uncoiling 76 for the absorbing layer 68 is also provided.

As the perforated liner 62 and absorbent layer 68 are unwound, the two materials are delaminated together. A glue gun 68 applies adhesive to the underside (eg, the side opposite the body side surface) d perforated liner 62 and a roller of pressure 82 compresses the perforated for 62 and the absorbent layer 68 together with the adhesive material between them to thereby form a laminate c the two materials. Alternate lamination methods, such as thermal bonding, can also be employed to form laminate which includes both perforated liner 62 and absorbent ca 68.

The perforations may also be placed on the absorbent body 68 to provide an increased void volume for receiving and containing the fecal materials. For example, the liner 62 and the absorbent layer 68 can be perforated in a single manufacturing operation. The formation of the openings through both the liner 62 and the absorbent cap 68 in a single manufacturing operation may also be sufficient to join the perforated liner 62 to the absorbent ca 68 thereby limiting or decreasing the need for an adhesive or other means of Union.

The perforations may also be formed separately and the absorbent layer 68 before joining the perforated for 62 to the absorbent layer 68. When the absorbent body 68 includes perforations, the perforations of the absorbent body do not need to be in complete agreement with the perforations in the absorbent body. perforated liner 62. Absorbent body perforations may be formed separately and subsequently placed in coincidence, partial coincidence or complete non-coincidence with openings in the overlying for 64. All openings present in a particular embodiment may have a similar overlap openings in the absorbent body 68 may have different coincidences which may be present in various percentages and in various spatial distributions.

The top sheet material is provided on a roll and dispensed in the top sheet unwinding 8 Similarly, the sprouting material is stocked from the uncoiling of sprouting layer 86. The perforated liner and the sprinkler layer materials are attached to the opposite sides of the top sheet layer using cutting and placing modules 88 and 90 which are well known in the art.

In the method illustrated here, both the cutting and placing modules 88 and 90 operate in a similar manner. The modules cut the material to be applied, for example, be it the perforated liner or the emergence material, and include at least one roller which rotates at a speed which is greater than the material velocity rate. When the roller in contact with the material to be applied moves at a rotational speed higher than the rate of supply of material, the roller will create a space between a segment of material which is cut off from the supply material due to the differential speeds and therefore will allow the segments of the material to be fastened to another material in a spaced arrangement. An adhesive is applied to either the top sheet layer or the applied material before contacting the top sheet layer and the applied material.

Alternate methods of securing the material segments to the top sheet layer in a spaced relationship can also be employed. Suitable alternate methods are described in U.S. Patent No. 5,616,478 issued February 10, 1998 to Boothe et al., The description of which is incorporated herein by reference. As exemplified by this reference description, the Cutting and placement may also use a plurality of arched transfer segments which rotate about a common axis. The transfer segments define less than 360 degrees of a cylindrical surface that allows the segments to rotate relative to one another and thus allows the rotational velocity of each segment to be varied. In this way, a transfer segment can receive material at a time. First rotational speed, increase the rotational speed to a second rotational speed, subsequently transfer the material in a spaced pattern a woven material which is moved at a speed which is greater than the original speed of material that is still attached to the fabric .

As is evident from the configuration of the diaper 20 the cutting and placing modules 88 and 90 are arranged to hold the emergence layer and the perforated liner on opposite sides of the top sheet layer with the perforated liner being attached on the surface of the sheet. face to the body of the upper sheet layer.

The matching guides 92 and 94, which are well known in the art, are used to ensure that the emergence layer and the perforated liner are held in the desired positions on the top sheet layer. The correspondence or coincidence guides monitor the progress of the upper sheet cap and can either cut or increase the length of the upper sheet displacement to implement slight adjustments in the spacing between the adjacent segments of the materials which are applied to the top sheet layer after the correspondence guides.

A vacuum conveyor 96 is illustrated between the cutting and positioning module 90 used to apply the emergence cap and the matching guide 92 that precedes the attachment of the perforated liner.

An alternate manufacturing method is illustrated in FIG. 8 which is similar to that shown in FIG. 7. The most significant difference between the methods illustrated in FIGS. 7 and 8 is that in the method illustrated in FIG. Perforated liner 62 is adhered to the absorbent layer 68 prior to assembly of the absorbent article.

As shown in Figure 8, the laminate d absorbent body / perforated liner can therefore be provided on a single roll in a laminated unwind 98. By pre-rolling the perforated liner 62 and absorbent body 68 off line, of the unrolled a set of an adhesive equipment, for example, a glue gun and a pressure point roller can be removed from the diaper machine and located at a more convenient location outside the line. This off-line lamination process can facilitate the use of a pre-existing diaper machine for the manufacture of a disposable absorbent garment having a perforated liner by reducing the amount of equipment that must be integrated into the pre-existing diaper machine.

Other alternate manufacturing methods may also be employed. For example, the unwinding roller 9 illustrated in Figure 8 can be used to unwind only the perforated liner 64 to manufacture an absorbent article which does not include a low density fibrous layer 62 or an absorbent cap 68. In addition, the perforated liner The top sheet layer can be fastened before the emergence of the layer of emergence or the emergence layer can be omitted completely. It is also possible to form or cut an aperture or openings in the upper sheet layer before the perforated liner is joined on, or under such openings in the upper sheet layer.

In some alternate methods, the top sheet 3 may include a large opening and the outer edges of the perforated forr 62 may be attached to the top sheet 34 on the opposite side of the side-to-body surface. Therefore, the outer edges of the perforated liner 62 can overlap the upper blade 34 in an underlying manner but the opening in the upper blade 34 will still allow the perforated liner 62 to define a part of the body side surface 21.

The illustrated top sheet layer 100 which both has an emergence material and a liner material perforates attached thereto in a spaced array can be fed with many different convention diaper machine configurations which are well known in the art.

In the diaper machine, the top sheet layer 100 is attached to the bottom sheet layer or other diaper frame part with the emergence material and the perforated lining material in a suitable match with the rest of the diaper and with an absorbent structure placed between the bottom sheet layer and the cover layer. top sheet The individual diapers are subsequently separated and packaged.

Figures 1-6 illustrate the absorbent articles which can be produced with the present method. Co can be seen in Figure 1, the absorbent article can be disposable diaper 20. Absorbent articles which can be manufactured in accordance with the present invention are also described in the United States of America patent application serial No. 09 / 195,267 filed on November 18, 1998, entitled "An Absorbent Article Having a Perforated Form" by Merrill et al. and having Advocate Matter No. 13,620, the disclosure of which is incorporated herein by reference.

The general configuration of the illustrated diaper includes the front waist sections 22 and rear 24 l which are constructed to extend essentially over the front and back abdominal regions of the user respectively, during use. The intermediate section 2 includes the general part of the diaper 20 which is constructed to extend through the crotch region of the wearer between the legs. The opposite side edges 28 define the leg openings for the diaper and are generally curvilinear or contoured to closely fit the user's legs. The opposite end edges 30 define a waist opening for the diaper 20 and are typically straight but may also be curvilinear.

Figure 1 is a plan view of the diaper 20 in a flat non-contracted state with the surface of the diaper contacting the wearer, for example, the side-to-body surface 21, facing the observer. Figure 2 is a representative cross-sectional view of the diaper 2 taken through a portion of the intermediate section 26.

The diaper 20 includes a lower sheet essentially impermeable to liquid 32, a liquid-permeable and porous upper sheet 34 placed in a facing relationship with the lower sheet 32 and an absorbent structure 3 such as an absorbent pad, located between the lower ho 32 and the top sheet 34. In the garment illustrated in Figures 1-3, the absorbent structure 36 includes both a primary absorbent body 35 and an emergence layer 60. The diaper also defines a lateral axis 38 and a longitudinal axis 40. L axes Lateral and longitudinal are also mentioned here as the lateral and longitudinal directions.

The upper sheet 34 suitably presents a surface facing the body which is docile, of soft feel and non-irritating to the wearer's skin. In addition, the top sheet 34 may be less hydrophilic than the absorbent structure 3 to present a relatively dry surface to the user and sufficiently porous to be permeable to the liquid, allowing the liquid to easily penetrate through its thickness. A suitable top sheet 34 can be manufactured from a wide selection of fabric materials, such as porous foams, crosslinked foams, perforated plastic films, natural fibers (e.g., cotton or wood fibers), synthetic fibers (e.g., polyester or polypropylene fibers) or a combination of natural and synthetic fibers. The topsheet 34, or a portion thereof, may also be treated to impart a greater degree of either hydrophobicity or hydrophilicity to the selected material. The topsheet 34 is suitably employed to help isolate the user's skin from liquids maintained in an absorbent structure. 36 In some absorbent articles the top sheet 34 may comprise a woven polypropylene fabric woven composed of fibers of about 2.8-3.2 deni formed into a fabric having a basis weight of about 2 grams per square meter (g / m2) and a density of around 0.13 grams per cubic centimeter (g / cc). The fabric can be treated on the surface with a surfactant to improve the hydrophilic properties in a manner which art is well known.

The top sheet 32 can suitably be composed of a material which is either liquid permeable or liquid impervious. It is generally preferred that the lower blade 32 be formed of a material which is essentially impermeable to liquids. The lower sheet 32 can optionally be composed of a microporous breathable material which allows to escape the vapors of the absorbent body 36 while still preventing the liquid exudates from passing through the lower sheet 32.

A typical bottom sheet can be made of a thin plastic film or other flexible liquid impervious material such as a polyethylene film having a thickness of about 0.012 millimeters about 0.051 millimeters. The lower sheet 32 can be given a further fabric-type feel by employing a polyolefin film having a non-woven fabric laminated to the outer surface thereof, such as a bonded fabric made of polyolefin fibers.

For example, the bottom sheet can be formed with a stretched-thinned polypropylene film having a thickness of about 0.015 millimeters (0.6 mil). Polypropylene film can also have a woven fabric and yarn of polypropylene fibers thermally laminated thereto. The fibers that form the yarn-bonded fabric can have a thickness of about 1.5 to 2.5 denier per filament with the fabric bonded with non-woven yarn having a basis weight of about 17 g / m2 (0.5 ounces per square yard).

The primary absorbent body 35 of the absorbent structure 36 may suitably comprise a hydrophilic fiber matrix, such as a cellulosic fluff fabric mixed with particles of a high absorbency material known in the art and commonly referred to as superabsorbent material. The superabsorbent material is typically in the form of discrete particles and may be present in a quantity ranging from about 5 to about 90 weight percent based on the total weight of the body absorbed.

The primary absorbent body 35 may have any of a number of shapes. For example, the absorbent number may be rectangular, I-shaped, or it is generally preferred that the primary absorbent body 35 be narrower in the crotch area than in the front or back portions of the diaper 20. The size and The absorbent capacity of the primary absorbent body 35 must be compatible with the size of the intended user and the liquid load imparted by the intended use of the absorbent article.

The size and absorbent capacity of the primary absorbent body 35 should be adjusted to account for the absorbent capacity and the placement of the perforated liner 62 and underlying absorbent body 64 which are schematically illustrated in Figure 6.

Optionally, a substantially hydrophilic tis envelope sheet can be employed to help maintain the integrity of the primary absorbent body which can consist of a fibrous structure placed by air. The tissue wrapping sheet is typically placed around the absorbent body on at least two major frontale surfaces thereof and is composed of an absorbent cellulose material such as creped wadding or a tissue of moisture resistance.

The marginal portions of the diaper 20, such as the marginal sections of the lower sheet 32 and of the upper sheet 34, may extend beyond the end edges of the absorbent structure 36. In the illustrated diaper 20, the lower ho 32 extends toward outside beyond the terminal marginal edges of the absorbent body 36 to form the lateral margins 42 and the end margins 44 of the diaper 2 The upper sheet 34 is generally coextensive with the lower ho 32 but may optionally cover an area which is larger or smaller than the area of the lower sheet 32 co desired.

In order to provide an improved notch and help reduce runoff from the diaper body exudates 2 the side margins 42 and the end margins 44 of the cloth can be elastified with the suitable elastic members, t as the elastic leg members 46 and the limbs. Elastic waist 48.

The various components of the diaper 20 s integrally assembled together using various types of suitable fastening means, such as the adhesive, the sonic joints, the thermal joints or the combinations thereof. As used here, the "union" of one component to another component tries to encompass both direct union and indirect union through means of an intervening component unless the description explicitly refers to either a direct or indirect union .

In the illustrated articles, the upper sheet 3 and the lower sheet 32 are joined to each other and the absorbent structure 36 with an adhesive, such as a hot-melt adhesive sensitive to pressure. The adhesive can be applied as a continuous and uniform layer of adhesive, as a layer with adhesive pattern, as a spray pattern of adhesive, or as an array of separate lines, swirls or spots of adhesive. In a similar fashion, other diaper components, such as elastic members 46 and 48 may be assembled in diaper 20 by employing one or more of the above-identified binding means.

In the illustrated articles, the elastic members 46 and 48 are secured to the diaper 20 in an elastically contractible condition such that in a normal tensioned configuration, the elastic members effectively contract against the diaper 20. For example, the elastic members 46 and 48 can be elongated and can be secured to diaper 20 while the diaper is in a contracted condition. In Figures 1 and 2, the elastic members 46 and 4 are illustrated in their non-contracted and stretched condition for the purposes of clarity. Figure 3 illustrates the diaper 20 with the elastic members 46 and 48 in their contracted state.

The diaper 20 also includes a pair of fastener 50 which are employed to secure the diaper 20 around the waist of a wearer. Suitable fasteners include interlock materials (such as hook and loop or mushroom and curl fasteners), tape fasteners, buttons, bolts, automatic fasteners and the like. A cooperative side panel member may be associated with each fastener and may be constructed to be non-elastic, or to be stretchable elastically for less along the lateral direction 38 of the diaper 20.

The diaper 20 may also include a pair of longitudinally extending and elasticized containment flap 52. The containment flaps 52 are configured to maintain perpendicular and vertical arrangement in at least a portion of the intermediate section 26. The containment flaps function in accordance with the present invention. a barrier for lateral flow of the body exudates The illustrated containment fins 52 include an elastic element 58 near a distal edge of the fins and are attached to the body-side surface of the diaper 20 by means of adhesives, ultrasonic bonding, or other suitable means.

The diaper 20 can also include the laterally extending front and rear barrier elements. The barrier elements 56 are elastified and are held in a position which covers the longitudinal ends of the containment fins 52 as can be seen in figures 1 and 3. The barrier elements 56 are attached to the diaper 20 on one side the longitudinal edges 30 and laterally outside the side bord of the barrier elements 56. The longitudinally inward bord 58 of the elements of the bar 56, however, are not joined directly to the diaper 20. joining the barrier elements 56 so that they cover the remote edges 54 of the containment fins 52 help push the far edges 58 of the barrier elements 5 outward from the side surface to the body of the diaper 20 The absorbent structure 36 of the diaper 20 may optionally include an additional component in the form of the emergence management layer 60 placed directly below the topsheet 34 and above the absorbent primary body 35 of the absorbent structure. The emergence management layer 6 is configured to efficiently contain and rapidly distribute the liquid exudates to the primary absorbent body 35. The emergence management layer 60 has a fibrous structure with a greater porosity and a lower base weight than the absorbent body. primary 35 to allow rapid distribution of liquid exudates. Such emergence management layers are known in the art and are described in greater detail in U.S. Patent No. 5,364,382 which is incorporated herein by reference.

As discussed above, a perforated liner is also attached to the diaper frame. In the illustrated articles, the perforated liner 72 covers the top sheet 34 in an overlapping manner and defines the side surface of the body in the fecal target area of the diaper. The objective area of the diaper is the area which immediately surrounds the cuff on the surface from side to body which is opposite the user's anus. The fecal target area is generally located on the back of the side-to-body surface 21 but may also extend slightly to the front of the side-to-body surface.

The illustrated liner 62 is shown in a schematic cross-sectional perspective view in the figure and includes a perforated layer 64 and a low absorbent density fibrous layer 66. The low density fibrous layer 66 is attached to the underside of the layer perforated 64 whereby the perforated layer 64 forms the side-to-body surface of the perforated forge 62. The absorbent layer 66 is not necessary, however, and the perforated liner 62 may alternatively consist of only the perforated layer 64.

Perforated liner 62 and upper sheet 34 s two separate component parts. In other words, the perforated for 62 and the upper sheet 34 are not a single integral piece of material and must be attached separately to the diaper as, for example, by joining them together.

In the illustrated articles, the perforated layer 6 is a hydrophobic polyethylene film. More specifically, the illustrated perforated layer 64 consists of 95.8% (by weight) low density polyethylene, eg, LDPE, and 4.2% Ti02. One such film is available from Edison Plastic under the trade name XP3134A and consists of 94% of Rexe (a low density polyethylene that has a melt index of 5.5 and a density of 0.923 g / cc) and 6% Ampacet (or concentrate Ti02 consisting of 70% Ti02 and 30% d low density polyethylene).

The perforations may be provided in the layer 64 with a pin roller or other suitable means known in the art. The perforated and illustrated layer 64 has an open area of 28%. Thus, in a diaper 20, the perforations in the perforated layer 64 define an open area 1 which is about 28% of the surface portion of the body defined by the perforated layer 64. The alternating amounts of open area, varying from about 20% to 60% can also be effectively employed with the perforated cap 64. The opening area of the apertures present the perforated layer 64 can vary from an approximately equivalent circular diameter of from about 400 to 30 microns or more. , alternatively, from about 400 to 13 microns. The perforations present in the illustrated embodiment have an opening area which is equivalent to a circular opening with a diameter of approximately 700 microns. The process of manufacturing the perimeter roller to form the illustrated openings often introduces some variation in the size and shape of the individual openings. For example, original circular openings can often become slightly oval due to the subsequent pulling of the material.

In alternate methods, the size and / or shape of the openings may be selectively varied. A single piercing liner may include two or more differently sized or shaped discrete opening groups. For example, the perforated cap 64 may include a certain percentage of relatively small apertures with the rest of the apertures consisting of relatively larger apertures where the smaller apertures are similar in size and in shape with each other and the larger apertures They are also similar in size and for one another. Alternatively, the perforations may vary continuously in size or shape. The different openings can be segregated, they can be placed homogeneously to form a pattern or they can be placed at random on the perforated cap 64.

Alternate materials which can be used to form a perforated layer 64 include thermoplastic films with open areas and fibrous nonwoven materials. Material foams, particularly closed cell foam materials which have a "skin" can also be effectively employed as the perforated cap 64. A thin foam material pierced will typically have a "soft" feel which is an advantageous property for the surface material from side to body.

Additional alternate materials for the perforated cap 64 include the thermoplastic network which contains highly permeable regions of defined size. Such network is produced by Nalle Plastics, Inc., which has offices in Austin Texas, under the name of Naltex. The biplane filtering network produced by AET Specialty Net and Profile that has offices in Salem, Massachusetts can also be used.

The perforated layer 64 can also be treated to reduce adhesion and staining of the fecale materials by, for example, imparting a protein resistance to material or by increasing or imparting hydrophobic properties to the material. Such materials include treatment with fluorocarbons, silicones, PLEURONICS (or triblock copolymer of ethylene oxide, propylene oxide, ethylene oxide produced by BASF of Germany), surfactants and other treatments containing ethylene oxide and other surface treatments. known in art.

Fibrous materials, such as woven fabrics, are more likely to require an increase in their hydrophobic properties with surface treatments than film materials which are naturally hydrophobic. The resistance of a fibrous material to wetting or penetration of a liquid will depend on a factor number including the chemical nature, the geometry, the roughness of the fiber surface and the capillary separation of the material.

Another advantage for the use of a film to form the perforated layer 64 is that a film has a relatively smooth surface. The relatively smooth surface of a film is less likely to trap fecal matter in localized surface irregularities. U fibrous material, in contrast, has a surface formed by individual fibers and, therefore, has a textured surface with many localized peaks and valleys which can collect fecal materials. If fecal materials are trapped in peaks or depressions located on the surface from side to body, fecal materials are likely to remain in contact with the user's skin and remain visible. Therefore, the smooth surface of the film can have beneficial effects on stain reduction and health. The textured surface provided by a fibrous material, however, is an advantage for a material which is used as a "first cleaning" to remove faecal materials from a user's skin and which must "grab" or absorb fecal materials. to remove them from skin.

Containing faecal materials down the side surface to the body defined by the perforated layer provides a generally more clean side-to-body liner drier than conventional non-perforated hydrophilic side-sheathing materials which can absorb fecal fluids and tend to retain the fec material on the upper part of the surface from side to body diaper.

It should be recognized that while relatively hydrophobic materials can be used to provide advantageous perforated liners due to the significant content of fecal materials of low viscosity, the fecal materials are composed of more than water. Even though the other constituents of the faecal materials can or have an affinity for the various hydrophobic materials which can be used to form the perforated layer 6 the hydrophobic materials will not have an affinity for primary constituent, for example, water, which It can be present in fecal materials. It is also taught that the hydraulic gradient created by placing a hydrophilic material on the side of a hydrophobic material may possibly have a minor influence on the pulling of the fecal fluids through the perforations in layer 64.

The perforated layer 64 may itself be used or include a fibrous layer of low density 66 laminated thereto or placed thereunder. In the embodiment illustrated in Figure 6, a low density fibrous layer 66 is laminated to the underside of the perforated layer 64. The illustrated low density fibrous ca 66 is a woven bicomponent woven fabric bonded through air with a weight base about 23.7 g / m2 (0.7 ounces per square yard), and density of 0.03 g / cc in an uncompressed condition. The low density fibrous ca 66 has 100% agglutinate fibers wherein the fibers have a polypropylene core and a concentric low density polyethylene vai with a core / sheath ratio of 50/50. The fibers are from 6 to 10 denier p filaments (dpf) and treated with 0.5% by weight of wettable ends. Such material can be obtained from Chisso de Japó under the name fiber ESC with a finished HR6.

The low density fibrous layer 66 can also be formed with a variety of other materials such as the fibers formed with polyester, rayon, pulp, nylon, polyethylene polyethylene or combinations or mixtures thereof. Particularly advantageous materials for use as the low density fibrous cap 66 are the elastic fibrous fabrics which maintain sufficient hollow volume under the load to provide the hollow volume to contain the anticipated fecal discharge. The total available hollow volume may differ for the different garments depending on the intended user and the anticipated load. For example, garments intended for use with adults will have a greater total hollow volume than the garments intended for use with infants.

The illustrated low density fibrous layer 66 is attached to the perforated layer 64 which uses heat and pressure to form the discrete joined areas 65. It is also possible to use another known means of laminating layers together to join the layers 64 and 66 or to joining the layers 64 and 66 to the diaper 20 without first joining the layers. The bonded surface area comprises 8-12% of the total surface area of the perforated liner 62 in the illustrated embodiment but the bonded surface area is not limited to this range. It is also possible that the joints 6 are configured to carry information or to form a decorative pattern.

The polyethylene material forming the illustrated perforated cap 64 is hydrophobic and therefore does not absorb fecal fluid or experience staining associated with absorption. The perforations in the layer 64 allow the passage of faecal materials therethrough while the hydrophilic qualities of the fibrous layer of low density 6 allows this layer to absorb the fecal fluid and the low density of layer 66 leaves sufficient egg space to receive significant amounts of fecal materials. The elastic fibrous materials may be advantageously used to form the layer 66 that lies beneath the perforated layer 64.

A more substantial absorbent body 68 may be placed between the perforated liner 62 and the topsheet 34 to provide an increased capacity to absorb and retain fecal matters. The absorbent body 68 is completely covered by the perforated liner 62.

If a top sheet 34 below the perforated liner 62 is not present, the absorbent body 68, if present, is positioned between the perforated liner 62 and the absorbent structure 36. In alternate configurations e where the absorbent body 68 is not used, the perforated lining 6 (including only one perforated layer 64 or both a perforated layer 64 and a low density fibrous layer 66) may be placed directly on the absorbent structure 36. In the diaper 2 illustrated in Figures 1-3 and 6, the absorbent body 68 adhered to the lower side of the perforated liner 62.

In the illustrated articles, the body absorbs 68 is a non-compressively dried cellulosic fabric. M specifically the illustrated absorbent body 68 is a bleached chromo-thermo-mechanical pulp air dried and creped with a basis weight of approximately 40-45 g / m2 and a density of approximately 0.3 g / cc. The absorbent body has a three-dimensional surface with an overall surface depth of approximately 0.10 millimeters or may The woven which is used to form the absorbent body 68 may also include a wet strength agent and at least 10 percent dry weight of high performance pulp fibers. The virgin yield pulp fibers and virgin high yielding softwood pulp fibers can be advantageously employed to form such a fabric. "Performance pulp fibers" are papermaking fibers produced by pulping processes which provide yields of approximately 65 percent or greater. Such pulp reduction processes include bleached mechanical quimo-thermo pulp, thermomechanical pulp, chemical thermomechanical pulp, high yield sulfite pulps and high yield kraft pulps. These processes leave the resulting fibers with higher levels of lignin. High performance fibr is also known for its rigidity (both dry and wet state) in relation to typical pulp reduced fibers. Lignin resists the softening effect of water and helps the resulting fabric to maintain rigidity and shape after wetting.

The basis weight of the fabrics may be about 10 grams per square meter or greater, and m may specifically vary from about 20 to grams per square meter, from about 30 to grams per square meter, or from about 30 to about grams per square meter. In the illustrated embodiment, the basis weight of the absorbent body 68 is approximately grams per square meter. The fiber composition of the fabric may have from about 10 to 100 percent fibr of wood pulp and, more specifically, may contain about 70 percent to 90 percent wood pulp fibers or greater. Additionally, it is advantageous for the soft wood fibr to comprise about 70 to 90 percent or m of the fiber composition.

Three major factors involved in production of the cellulosic tissues having the desired properties for the absorbent body 68 are 1) a three-dimensional structure of high volume (low density) obtained without significant compression during drying and advantageously obtained without creping; 2) yield pulp fibers, advantageously comprising at least 10 p percent of the tissue fibers; and 3) the use of one or more moisture resisting agents so that the ratio of the wet geometric head strength to be about 0.1 or greater. Wet strength agents are used to make the bonds between the fibrins resistant to rupture in the wet state. Such wet strength agents are well known in the art and are commercially available from a wide variety of sources. Such agents include polyamide-polyamide-epichlorohydrin (PAE) type resins, polyamide epichlorohydrin resins., the aminoplast resins obtained by reaction of formaldehyde with melamine or urea. The patent application of the United States of America No. 08 / 912.9 entitled "Wet-Resistant Fabrics and Disposable Articles Made with the Same", filed on August 15, 1997, name of Chen et al. 11,700.3, describes suitable wet strength agents and a method for producing suitable cellulosic fabrics for use as the absorbent body 68 in greater detail and is incorporated herein by reference.

The cellulosic fabrics made according to the three factors described above will generally have properties of low density and high moisture elasticity showing greater resistance to wet collapse. Such fabrics also have favorable absorbency characteristics, such as high take-up rates, high permeability in plane, high absorption capacity and fast flat distribution of liquids.

Other absorbent materials, or the combination of the materials can also be used to form the absorbent body 68. Examples of such alternating materials include non-woven fabrics having approximately 70 percent of oriented rayon fibers as well as the absorbent materials previously described as being suitable for the absorbent structure 36 or the low density layer 66. Such alternate materials include the superabsorbent materials which can be used as either a substitute or a supplement for the absorbent capacity of the absorbent body 68.

Additional features such as fins and barriers (not illustrated) can be used to separate the urine and fecal discharge areas on the diaper. The use of such features can serve to minimize the possibility that the absorbent body 68 is pre-saturated with the urine to prevent movement of fecal materials to an area where the surface from side to body is defined by the top sheet layer 34. instead of perforated lining 62.

As discussed above, the absorbent body and the perforated liner 62 can be secured adhesively or otherwise together before joining the absorbent body 68 and perforated liner 62 to the diaper frame. The absorbent body may have an outer perimeter which is essentially coextensive with the perforated liner 62 or the outer edges of the perforated liner 62 may extend essentially beyond the perimeter of the absorbent body 68. The use of the body absorbs 68 and of the perforated liner 62 that have substantially coextensive outer perimeters, allows the absorbent body 68 and perforated liner 62 to be cut together in a single operation of cutting a previously formed laminate by joining absorbent body 68 to perforated liner 62. The laminate absorbent body 68 / perforated liner 62 It can then be attached to the disposable garment shell.

The perforated liner 62 is placed on the side surface of the body 21 of the diaper 20 to receive the fecal insults. Thus, the perforated liner 62 is positioned to define at least a portion of the back side of the surface 21 to the body 21, for example, that part of a surface facing the body 21 placed rearwardly of the side trim 38. lateral axis 38 is positioned at the mid-point leg openings defined by the edges of the laterally opposite 28 and divides the side surface to the body 21 in a front part and in a back part.

The outer perimeter of the perforated liner 62 is defined by the front edge 70, two opposite lateral side edges 72 and a trailing edge 74. The perforated liner 6 illustrated in Figures 1-3 is configured to have a front edge 70 which is placed near the mid-longitudinal point of the intermediate section corresponding to the axis 38 More specifically, the front edge 70 illustrated in FIGS. 1-3 is placed approximately one inch (2.5 centimeters) in front of the lateral axis 38.

The perforated liner 62 extends backward from its front edge 70 to its trailing edge 74. The back edge 74 can advantageously be placed approximately 0.5 inches (2.3 centimeters) forward of the longitudinal end edge of the rear diaper 30. This placement of the bord rear 74 allows the rear barrier element 56 to hide the trailing edge 74. The trailing edge 74 can also be placed alternately. For example, the posterior bord 74 of the perforated liner 62 may coincide with the posterior bord 30 of the diaper 20.

The side edges 72 of the perforated liner 6 can advantageously be placed laterally within the fins 52. The fins 52 therefore generally hide the side edges 72 of the view before placing the diaper 20 on a wearer.

The perforated liner 62 can be attached to the upper ho 34 so that the upper sheet 34 lies underneath the entire perforated liner 62, lies beneath only a pair of the perforated liner 62 or does not lie beneath any perforated liner part 62. In the illustrated diaper 20, the entire perforated liner 62 lies on the upper sheet 34, in other words, there is no opening in the upper sheet layer below the perforated liner 62 in the embodiments illustrated The upper sheet layers 34 which include an opening below the perforated liner 62 can be used to form the entire side-to-body surface if perforated liner 62 is not bonded to cover the upper ho layer 34. In other words, the present invention may involve attaching a perforated liner 62 to cover a portion of a top sheet layer 34 of a conventionally configured absorbent article. This allows the liner to perforate 62 to be easily integrated or to be selectively attached to the diaper having an otherwise completely functional frame. This allows a single manufacturing line to efficiently and selectively produce the absorbent articles c and without the absorbent perforated liner 62 by selectively joining or not attaching a perforated liner 62 to the otherwise absorbent absorbent articles.

It is thought that perforations in the perforated forge allow a greater amount of fecal material and larger fecal particles to pass through the perforated liner than through a side-to-body liner joined with conventional spinning. For absorbent structures which include small loose particles, such as superabsorbent materials, openings, or perforations extending through the perforated liner, they also increase potential for outward migration of such loose particles to the surface from side to side. body 21 of the article.

Not all absorbent structures 36 include loose particles capable of migrating through the perforations in liner 64. However, an intervening material can be used with absorbent structures 36 containing such loose particles. placing an intervening layer of material, such as sheet 34, between the perforated layer 64 of the liner 62 and the absorbent structure 36 helps to prevent the particles forming absorbent structure 36 from migrating through the openings in layer 64 to the surface sideways to the body of the absorbent article. This grid-like function can alternatively be partially or completely performed by the low density fibrous layer 66 or by the absorbent body 68. The tissue wrapping can also be used as an intervenient layer between the perforated layer 64 and the absorbent structure 36 to inhibit the outward migration of the particles of the absorbent structure.

The intervening layer advantageously has smaller openings extending therethrough the openings extending through the perforated layer 6 to inhibit outward migration of the particles, such as particles of superabsorbent material. The intervening cap may also inhibit outward migration of the particles even if the apertures are as large or larger than the openings in layer 64, provided the intervening cap is of sufficient thickness or other properties such as affinity with the particles. of the absorbent material which inhibits the outward migration of such particles.

Although the invention has been described in detail it will be apparent to a person with ordinary skill in the art that various changes and modifications may be made if departing from the spirit and general principles of the invention. All those changes and modifications are contemplated as being within the scope of the invention. scope of the present invention as defined by the appended claims. In addition, this application is intended to cover such items of the present description as falling within the known or customary practice in the art to which this invention pertains.

Claims (17)

R E I V I N D I C A C I O N S

1. A method for making an article absorb that has a side-to-body surface that can be placed on one side of a user when the article is in use, said method comprising: a) providing a bottom sheet layer, or liquid permeable top sheet layer bonded to said bottom sheet layer and an absorbent structure positioned between the top sheet layer and said bottom sheet layer to define article frame, said article frame it has a front bor, a trailing edge and an intermediate section placed between said front and rear edges; Y b) attaching a perforated liner to said upper ho layer in a position whereby said upper foil layer at least partially defines a front side surface of the body and said perforated liner at least partially defines a rear part of the body. the surface of the body.

2. A method as claimed in clause 1, further characterized in that it comprises the step of forming said perforated liner by joining a perforated film layer to a fibrous layer.

3. A method as claimed in clause 1, characterized in that at least a part of a perforated liner covers said upper sheet layer and said method further comprises a placement step of placing an absorbent body between said perforated liner and said layer of higher leaf.

4. A method as claimed in l Clause 3 wherein said step of colocacio comprising attaching an absorbent body to said bore and wherein said absorbent body attached has perimeter edges lining it which are essentially coextensive with perimetrale edges of said perforated lining , and said step of joining said perforated forr to said intermediate section comprises directly attaching said absorbent body to said upper leaf layer.

5. A method as claimed in clause 4, characterized in that said perimeter edges d said perforated liner and said absorbent body are formed after joining said absorbent body to said perforated liner

6. A method as claimed in clause 1, further characterized in that the step of providing said article frame with a pair of containment fins extending longitudinally and wherein said perforated liner is joined in a position whereby said lining perforated extends longitudinally backward from the front edge said perforated liner and laterally between said containment fins, said front edge being positioned near longitudinal mid-point of said intermediate section.

7. A method as claimed in clause 6, characterized in that said perforated liner is joined in a position whereby said front edge is placed longitudinally forward of the longitudinal midpoint of said intermediate section.

8. A method as claimed in clause 1, characterized in that said perforated liner is joined to said upper sheet layer in one position, whereby a part of said perforated liner covers said upper sheet layer.

9. A method as claimed in clause 1, characterized in that said perforated liner is joined to said upper sheet layer in one position, whereby all perforated lining covers said upper sheet layer.

10. A method as claimed in clause 1, further characterized in that the step of selecting perforated liner material and upper sheet layer material whereby a perforated film layer forms a side-to-body surface defined by said lining perforates and a fibrous material forms said surface sideways to the body defined by the upper sheet layer.

11. A method as claimed in clause 1, further characterized in that it includes the step of placing an absorbent body between said perforated liner and the absorbent structure, whereby said liner pierces completely covers said absorbent body.

12. A method for making an article absorb that has a side-to-body surface that can be placed on one side of a user when the article is in use, said method comprising: a) providing a bottom sheet layer, or liquid permeable top sheet layer bonded to said bottom sheet layer and an absorbent structure positioned between the top sheet layer and said bottom sheet layer to define article frame, said article frame it has a front bor, a trailing edge, and an intermediate section placed between said front and back edges; Y b) attaching a perforated liner to said upper leaf layer in one position, whereby said upper sheet layer at least partially defines a front part of the side-to-body surface and said perforated liner partially defines a part of it. of the surface of the body and therefore said liner perforated at least partially with the top sheet layer.

13. A method as claimed in clause 12, further characterized in that it comprises the step of forming said perforated liner by joining a perforated film layer to a fibrous layer.

14. A method as claimed in clause 12, characterized in that the overlapping portion of the perforated liner covers said upper sheet layer and said method further comprises a placement step of placing an absorbent body between said perforated liner and said upper layer of ho .

15. A method as claimed in clause 14, characterized in that the laying step comprises attaching an absorbent body to said perforated liner wherein said bonded absorbent body has perimeter edges which are essentially coextensive with the perimetral edges of said perforated liner, and said step of joining said perforated for to said intermediate section comprises the a directly said absorbent body to said upper ho layer.

16. A method as claimed in clause 15, characterized in that said perforated lining covers said upper sheet.

17. A method as claimed in clause 15, characterized in that said perimeter edges said perforated liner and said absorbent body are formed after joining said absorbent body to said perforated lining R E S M E N A method for manufacturing an absorbent article and which includes attaching a perforated liner to a top sheet layer of the article. The method includes providing an absorbent article frame having a liquid permeable top sheet layer, a bottom sheet layer and an absorbent structure positioned therebetween. The absorbent article has a front waist section, a back waist section d and an intermediate section interconnecting the two waist sections. The perforated liner is attached to the top sheet layer in a position whereby the perforated forr at least partially defines a back part of the side surface to the article body and the top sheet layer at least partially defines a front part of the surface from side to body. The perforated liner defines a fecal target zone and increases the ability of the absorbent article to contain low viscosity faecal materials and separate such materials from the wearer's skin. The perforated liner can be formed by laminating a perforated film to a low density fibrous material. The method may also include placing an absorbent body under the perforated liner. A part or all of the perforated liner may cover the top sheet layer and the absorbent body may be placed between the perforated liner and the top sheet layer.