Apparatus for forming and applying pleated core wrap

Abstract

An apparatus for forming and applying a pleated core wrap includes a feeding mechanism configured to feed a continuous web of material in a machine direction and a pleating unit configured to form one or more continuous folds in the continuous web of material to form a continuous pleated web of material with a portion of the web of material overlapping in a cross machine direction. A core-forming drum receives the continuous pleated web of material, the core-forming drum including at least one recess in an outer circumferential surface thereof, the recess having a floor with one or more inserts projecting radially outward therefrom. A vacuum system provides a vacuum to the recess communicating through the floor to draw the continuous pleated web of material into the recess, and a region of the continuous pleated web of material separates as it is drawn into the recess.

Description

[Technical field]

[0001] The present invention relates to an apparatus for forming and applying a pleated core web in the manufacture of disposable absorbent articles such as diapers or incontinence garments. More particularly, the present invention relates to such an apparatus for forming a pleated core wrap and applying the pleated core wrap to one or more recesses of a core-forming drum in the manufacture of absorbent cores, the recesses including one or more inserts that form one or more channels in the absorbent core. As the pleated core wrap is drawn into the recesses of the core-forming drum, the pleats in the core wrap unfold to allow the core wrap to better fit into the recesses and around the inserts therein. [Background technology]

[0002] Disposable absorbent articles, such as diapers, incontinence-type articles, or feminine hygiene products, are typically formed from a combination of multiple web layers, absorbent structures, and elastic elements. Thus, the article may include a thin, flexible, liquid-impermeable backing sheet onto which a permeable nonwoven sheet is layered. An absorbent core is placed between the two sheets, which are bonded at their edges to form a unitary article that prevents liquid body exudates from seeping out of the edges of the article.

[0003] In such disposable absorbent articles, the absorbent core is typically formed from absorbent material (e.g., granules of superabsorbent polymer material (SAP)) contained within a mixture of encapsulated cellulosic pulp (fluff) and absorbent material binder. The absorbent material is sandwiched between or enveloped by one or more layers of nonwoven fabric. To improve performance in terms of absorption, comfort, and distribution of absorbed liquid, the absorbent core may be formed with longitudinal channels that are free or substantially free of absorbent material between two layers of nonwoven fabric.

[0004] In the manufacture of channeled absorbent cores, a continuous web of nonwoven material or base web is fed onto a rotating core-forming drum that contains a continuous three-dimensional fluff-receiving pocket or recess (or a plurality of distinct three-dimensional fluff-receiving pockets or recesses) on its circumferential surface. The base web is placed onto the core-forming drum and drawn into the recess via a vacuum system internal to the core-forming drum, the vacuum creating a suction force that draws the base web into the recess. In the recess, the base web conforms to an insert (i.e., a protrusion) located therein that extends radially outward from the floor of the recess. An absorbent material, such as SAP, fluff, or a mixture thereof, is then blown into the recess and onto the top of the base web. The absorbent material is bonded to the base web by an adhesive previously applied on the base web in combination with the suction provided by the vacuum system. A cover web is then applied over the base web and the pockets of absorbent material provided thereon. The cover web is then bonded to the base web via an adhesive or adhesive-free bonding means such as mechanical, thermal, or ultrasonic bonding, and bonded to the absorbent material to create an absorbent core.

[0005] Core-forming drums designed to produce higher capacity cores typically include pockets designed with deeper recesses and inserts with increased heights corresponding to the increased recess depths. When subjected to these pocket geometries, the base web can be subjected to higher stresses and tensions as it is forced to conform around the recess(es) and inserts. That is, when the base web is first placed in the recesses in a flat configuration and then forced to conform to the increased recess depth and insert height under vacuum, the base web is subjected to stresses and tensions in the cross machine direction. This increased stress and tension placed on the base web can tear the web at locations corresponding to the recess inserts.

[0006] It is therefore desirable to provide an improved apparatus for forming and applying a nonwoven base web to a core-forming drum that reduces the stresses and tensions placed on the base web when the web is placed into a pocket shape including a recess and one or more channel-forming inserts on the core-forming drum. Summary of the Invention

[0007] Embodiments of the invention are set out and characterized in the independent claims, while the dependent claims describe further features and variants of the invention, which features and variants recited in the dependent claims can be used in combination with one another or separately, depending on the embodiments of the invention.

[0008] According to some embodiments, the apparatus includes a feeding mechanism configured to feed the continuous web of material in a machine direction and a pleating unit configured to form one or more folds in the continuous web of material, each of the one or more folds including a continuous fold extending in the machine direction to form a continuous pleated web of material with a portion of the web of material overlapping in the cross-machine direction. The apparatus also includes a core-forming drum that rotates in the machine direction and is disposed downstream in the machine direction from the pleating unit to receive the continuous pleated web of material, the core-forming drum including at least one recess provided on an outer peripheral surface of the core-forming drum, the at least one recess including a floor having one or more inserts protruding radially outward therefrom. The apparatus further includes a vacuum system configured to provide a vacuum to the at least one recess, the vacuum communicating through the floor to draw the continuous pleated web of material into the at least one recess, and a region of the continuous pleated web of material separating when drawn into the at least one recess.

[0009] In some embodiments, an adhesive applicator is disposed downstream in the machine direction from the pleating unit, the adhesive applicator configured to apply adhesive to the non-overlapping portions of the upper surface of the pleated web of material.

[0010] In some embodiments, the adhesive applicator is configured to apply adhesive to a top surface of the pleated web of material in a non-overlapping portion that is offset in the cross machine direction from the one or more inserts.

[0011] In some embodiments, a heated roller is disposed between the pleating unit and the adhesive applicator, the heated roller being configured to apply heat to the continuous pleated web of material to set one or more folds therein.

[0012] In some embodiments, a bonding unit disposed between the pleating unit and the adhesive applicator, the bonding unit configured to tuck bond the continuous pleated material web to set one or more folds thereof.

[0013] In some embodiments, the pleating unit of the apparatus includes upper and lower rolls arranged to form a nip therebetween through which the continuous web of material is fed, the upper and lower rolls including features acting on the continuous web of material to facilitate folding the continuous web of material. The pleating unit also includes a folding plate and one or more folding skis arranged downstream in the machine direction from the upper and lower rolls, the folding plate and the one or more folding skis arranged in an overlapping arrangement. The continuous web of material is constrained in a controlled pleated shape as it moves in the machine direction as it passes through the one or more folding skis and the folding plate.

[0014] In some embodiments, the one or more inserts include a first insert and a second insert each substantially aligned in the machine direction, the first insert and the second insert being spaced apart in the cross machine direction by a first distance.

[0015] In some embodiments, the pleating unit is configured to form a first crease in a continuous material web extending in the machine direction and to form a second crease in the continuous material web extending in the machine direction, the first crease and the second crease being spaced apart in the cross-machine direction by a second distance that is greater than the first distance.

[0016] In some embodiments, the pleating unit is configured to form a first pair of folds in the continuous web of material in a first pleat region, each fold of the first pair of folds extending in the machine direction, and a second pair of folds in the continuous web of material in a second pleat region, each fold of the second pair of folds extending in the machine direction, the folds of the first pair of folds positioned to be on opposite sides of the first insert when the continuous pleated web of material is fed into the at least one recess, and the folds of the second pair of folds positioned to be on opposite sides of the second insert when the continuous pleated web of material is fed into the at least one recess.

[0017] In some embodiments, the at least one recess includes a central region disposed between the pair of inserts in the cross machine direction and side regions disposed on opposite sides of the central region and outboard of the pair of inserts in the cross machine direction, and the vacuum system is configured to selectively communicate a vacuum to the central region and the side regions.

[0018] In some embodiments, the vacuum system includes a first vacuum shoe disposed at a laydown zone location of the core forming drum where the continuous pleated web of material is fed onto the core forming drum, the first vacuum shoe configured to communicate vacuum to the central region and block vacuum to the side regions. The vacuum system also includes a second vacuum shoe disposed downstream in the machine direction from the first vacuum shoe, the second vacuum shoe configured to communicate vacuum to the side regions and block vacuum to the central region.

[0019] In some embodiments, the first insert and the second insert each have an inverted triangular shape.

[0020] In some embodiments, each of the first insert and the second insert is formed with one or more spaces or ventilation channels that provide air flow therethrough.

[0021] According to another embodiment, the apparatus includes a feeding mechanism configured to feed the continuous web of material in a machine direction, and a core-forming drum arranged to rotate in the machine direction from the feeding mechanism and downstream in the machine direction to receive the continuous web of material, the core-forming drum including at least one recess provided in an outer peripheral surface of the core-forming drum, the at least one recess including a floor having one or more inserts protruding radially outward therefrom. The apparatus also includes a vacuum system for providing a vacuum to the at least one recess, the vacuum communicating through the floor to draw the continuous web of material into the at least one recess, the vacuum system configured to selectively control communication of the vacuum to multiple cross-machine direction disposed regions of the at least one recess and to gradually deposit the continuous web of material into the at least one recess in multiple stages.

[0022] In some embodiments, the one or more inserts include a first insert and a second insert aligned in the machine direction, respectively, the first insert and the second insert being spaced apart in the cross machine direction by a first distance. In selectively controlling communication of vacuum to the multiple cross machine direction disposed regions of the at least one recess, the vacuum system is configured to first communicate the vacuum to a central region disposed between the pair of inserts, then communicate the vacuum to lateral regions disposed on opposite sides of the central region and then outboard of the pair of inserts in the cross machine direction, or to both the lateral regions and the central region.

[0023] In some embodiments, the vacuum system comprises one or more vacuum shoes configured to communicate or block vacuum to the central and side regions.

[0024] In some embodiments, the pleating unit is disposed upstream in the machine direction from the core-forming drum, and the pleating unit is configured to form one or more creases in the continuous web of material, each of the one or more creases including a continuous crease extending in the machine direction, forming a continuous pleated web of material with portions of the web of material overlapping in the cross-machine direction, regions of the continuous pleated web of material separating during multi-stage gradual disposition into at least one recess in the continuous web of material.

[0025] In some embodiments, an adhesive applicator is disposed downstream in the machine direction from the pleating unit, the adhesive applicator configured to apply adhesive to the non-overlapping portions of the upper surface of the pleated web of material.

[0026] In some embodiments, the adhesive applicator is configured to apply adhesive to a top surface of the pleated web of material in a non-overlapping portion that is offset in the cross machine direction from the one or more inserts.

[0027] These and other advantages and features will be more readily understood from the following detailed description of preferred embodiments of the invention, which are provided in connection with the accompanying drawings. [Brief description of the drawings]

[0028] The drawings illustrate embodiments presently contemplated for carrying out the invention.

[0029] In the following figures:

[0030] [Figure 1A] FIG. 2 is a top view of a channeled absorbent core that may be formed by the apparatus of the present invention.

[0031] [Figure 1B] 1B is a cross-sectional view of the channeled absorbent core of FIG. 1A taken along line 1B.

[0032] [Diagram 2] Schematic diagram showing the layout of an apparatus for forming a pleated core wrap according to an embodiment of the present invention and applying the pleated core wrap onto a forming drum.

[0033] [Figure 3A] Perspective view of a pleat unit included in the apparatus of FIG. 2 according to an embodiment of the present invention.

[0034] [Figure 3B] Perspective view of a pleat unit included in the apparatus of FIG. 2 according to an embodiment of the present invention.

[0035] [Figure 3C] Perspective view of a pleat unit included in the apparatus of FIG. 2 according to an embodiment of the present invention.

[0036] [Figure 4] Cross-sectional view of a pleated web of nonwoven material that can be provided by any of the pleat units of FIGS. 3A - 3C according to an embodiment of the present invention.

[0037] [Diagram 5] Cross-sectional view of a pleated web of nonwoven material that can be provided by any of the pleat units of FIGS. 3A - 3C according to another embodiment of the present invention.

[0038] [Figure 6] Cross-sectional view of a pleated web of nonwoven material that can be provided by any of the pleat units of FIGS. 3A - 3C according to another embodiment of the present invention.

[0039] [Figure 7] Detailed perspective view of a part of the forming drum included in the apparatus of FIG. 2 showing the recesses and inserts provided on the forming drum for forming an absorbent core according to an embodiment of the present invention.

[0040] [Figure 8] FIG. 13 is an end view of an insert involved in forming a drum recess, showing the fit of a foam-on-web within the recess, according to one embodiment of the present invention.

[0041] [Figure 9] FIG. 1 is an end view of an insert contained in a forming drum recess showing the fit of a form-on-web within the recess according to one embodiment of the present invention.

[0042] [Figure 10] FIG. 1 is an end view of an insert contained in a forming drum recess showing the fit of a form-on-web within the recess according to one embodiment of the present invention.

[0043] [Figure 11] FIG. 2 is an end view of an insert included in a forming drum recess according to one embodiment of the present invention.

[0044] [Figure 12] FIG. 2 is an end view of an insert included in a forming drum recess according to one embodiment of the present invention.

[0045] [Figure 13A] 1 illustrates an end view of an insert contained in a forming drum recess according to one embodiment of the present invention. [Figure 13B] 1 illustrates a side view of an insert included in a forming drum recess according to one embodiment of the present invention.

[0046] [Figure 14A] 1 illustrates an end view of an insert contained in a forming drum recess according to one embodiment of the present invention. [Figure 14B] 1 illustrates a side view of an insert included in a forming drum recess according to one embodiment of the present invention.

[0047] [Figure 15] 3 illustrates a pleated web of nonwoven material aligned with the recesses of the forming drum of FIG. 2 according to one embodiment of the present invention.

[0048] [Figure 16] Shows the pleated web of FIG. 15 after being supplied to the recess and adapted to the recess by suction.

[0049] [Figure 17] Shows a pleated web of nonwoven material supplied to the recess of the forming drum of FIG. 2 according to another embodiment of the present invention.

[0050] [Figure 18] Shows the pleated web of FIG. 17 after being supplied to the recess and adapted to the recess by suction.

[0051] [Figure 19] It is a layout diagram of the recess of the forming drum of FIG. 2 and the positioning of the vacuum shoe with respect thereto according to an embodiment of the present invention.

[0052] [Figure 20] It is a layout diagram of the recess of the forming drum of FIG. 2 and the positioning of the vacuum shoe with respect thereto according to an embodiment of the present invention.

[0053] [Figure 21] It is a layout diagram of the recess of the forming drum of FIG. 2 and the positioning of a pair of vacuum shoes with respect thereto according to an embodiment of the present invention.

[0054] [Figure 22] It is a schematic diagram showing the layout of an apparatus for forming a pleated core wrap and applying the pleated core wrap onto a forming drum according to an embodiment of the present invention.

[0055] [Figure 23] It is a cross-sectional view of a pleated web of nonwoven material that can be provided by any of the pleat units of FIGS. 3A - 3C according to an embodiment of the present invention.

[0056] [Figure 24]FIG. 2 is a cross-sectional view of a channeled absorbent core having a single foam-on-web wrapped around an absorbent particulate material according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] An embodiment of the present invention relates to an apparatus for forming and applying a pleated core wrap during the manufacture of an absorbent pad. The formation of the pleated core wrap and its subsequent application onto a forming drum allows the pleated core wrap to better fit into one or more recesses in the forming drum and the inserts contained therein. The improved apparatus disclosed herein reduces the stress and tension on the core wrap when the web is placed into the recesses, thereby reducing the occurrence of tears in the core wrap during the manufacture of the absorbent pad.

[0058] Although the disclosure herein is provided in sufficient detail to enable one skilled in the art to practice the invention, the physical embodiments disclosed herein are merely illustrative of the invention which may be embodied in other specific structures. Although preferred embodiments have been described above, details may be changed without departing from the invention.

[0059] 1A and 1B, there is shown an exemplary absorbent core 2 that may be manufactured (in part) by using an apparatus for forming and applying a pleated core wrap, as described below. The absorbent core 2 shown in FIG. 1 may be incorporated into a disposable absorbent article, such as, for example, a baby diaper or an adult incontinence product.

[0060] The absorbent core 2 comprises a first layer 4, a second layer 6, and an absorbent material 8 interposed between the first and second layers 4, 6. The first and second layers 4, 6 are, for example, made of a nonwoven material and are joined to one another. The absorbent material 8 is composed of one or more absorbent materials, for example cellulose fibers (fluff) and / or superabsorbent materials (SAP), and is secured between the first layer 4 and the second layer 6.

[0061] In the illustrated example, the absorbent core 2 has two zones or channels 10 that are free or substantially free of absorbent material. In some embodiments, the first and second layers 4, 6 are directly bonded to one another, such as via an adhesive or adhesive-free bond. In these embodiments, the first layer 4 and second layer 6 are directly attached to one another at the zones or channels 10. In alternative embodiments, the first and second layers 4, 6 may remain unattached to one another, and in some cases may remain physically spaced apart from one another at the channels 10.

[0062] Referring now to Figure 2, there is shown a schematic diagram of an exemplary apparatus 12 capable of forming, in one embodiment, the absorbent core 2 as shown in Figure 1. In the embodiment of Figure 2, a feed mechanism 14 is provided that feeds and advances a continuous web 16 of nonwoven material (hereinafter referred to as "form-on-web 16" for simplicity). Thus, the feed mechanism 14 may include a material roll 18 from which the form-on-web 16 can be unwound, along with one or more material handling rollers 20 that advance the form-on-web 16 in a machine direction 22. As will be described in more detail below, the form-on-web 16 is fed towards a core-forming drum 24 (hereinafter "forming drum 24") and drawn into a recess in the forming drum 24 by vacuum pressure. The forming drum 24 rotates in the direction of arrow 26 (i.e., in the machine direction 22) about a drive shaft 28 to advance the form-on-web 16 through one or more absorbent core forming stages, ultimately resulting in an absorbent core 2 that is dispensed from the forming drum 24. Depending on the embodiment, the absorbent core 2 may be formed on the forming drum 24 as a continuous ribbon or pad, or as separate pads.

[0063] In some embodiments, the foam-on-web 16 provided by the feeding mechanism 14 is a nonwoven material, such as a meltblown or spunbond-meltblown-spunbond (SMS) material, although it will be appreciated that the foam-on-web 16 may be any suitable woven, nonwoven, or tissue material. The foam-on-web 16 is at least semi-permeable to air flow such that air can move through the foam-on-web 16 when fed onto the forming drum 24, thereby allowing the foam-on-web 16 to be secured thereto by a vacuum.

[0064] As the form-on-web 16 advances in the machine direction 22, the web 16 is fed into a pleating unit 30 which functions to form one or more creases therein. The pleating unit 30 forms creases in the continuous form-on-web 16 which extends oriented in the machine direction 22. The successive creases formed in the machine direction 22 overlap one or more portions of the form-on-web 16 in the cross-machine direction 32 (FIGS. 3A-3C), thereby forming a continuous pleated web of material which is subsequently advanced downstream of the forming drum 24.

[0065] 3A-3C, an exemplary pleat unit as may be provided in pleat unit 30 is shown in more detail. Referring initially to FIG. 3A, pleat unit 30 includes a web entrance side 34 and a web exit side 36, where form-on-web 16 is fed into pleat unit 30 at web entrance side 34 and advances in machine direction 22 to web exit side 36. At web entrance side 34, upper roll 38 and lower roll 40 are disposed to form a nip therebetween through which form-on-web 16 is fed. Rolls 38, 40 are configured to include one or more features 42 circumscribing a surface of rolls 38, 40. Features 42 may be provided as corresponding protrusions and recesses formed in / on rolls 38, 40 that contact form-on-web 16 as it passes through the nip between rolls 38, 40. Features 42 function to stress or "break" the foam-on-web 16 at desired locations in the cross-machine direction 32 (i.e., along the break lines) in a manner that allows the web to better fold later, so that the foam-on-web 16 will tend to subsequently fold to form pleats.

[0066] The form-on-web 16 then advances in the machine direction 22 to an arrangement of folding skis 44 and folding plates 46 (held in place by one or more support rods 47) which function to form creases in the form-on-web 16 as it extends in the machine direction 22. As shown in FIG. 3A, the folding skis 44 and folding plates 46 are arranged in an overlapping arrangement. Each of the folding skis 44 has a generally flat end surface 48 at its upstream opposing end aligned in the cross machine direction 32 with a protrusion extending outward therefrom on the downstream side in the machine direction 22. The folding skis 44 are positioned above and overlap the folding plates 46 such that the form-on-web 16 is aligned with the folding skis 44 in the cross machine direction 32 such that the cuts formed in the form-on-web 16 (by the features 42) are aligned with the folding skis 44. As the form-on-web 16 moves in the machine direction 22, a central region of the web 16 is fed under the folding plate 46 and side regions of the web 16 are fed into the area between the folding plate 46 and the folding skis 44. The form-on-web 16 is then controlled and constrained into a pleated shape as it moves in the machine direction 22 as a portion of it passes under, around and over the folding skis 44 and between the folding skis 44 and the folding plate 46. In one embodiment, the folding plate 46 preferably remains horizontal (in the machine direction 22) over its entire span while the folding skis 44 lie in a plane that decreases in the Z direction as the folding skis 44 extend downstream in the machine direction 22. At the inlet of the folding ski 44, the vertical clearance between the folding ski 44 and the folding plate 46 is approximately equal to the thickness of the form-on web 16, providing sufficient clearance to allow a portion of the web 16 to pass between the folding ski 44 and the folding plate 46. At the outlet of the folding ski 44, the folding ski 44 interferes with the folding plate 46 in the Z direction to constrain the pleats of the web 20 therebetween.

[0067] Referring to FIG. 3B, a pleat unit 30 according to another embodiment is shown. The pleat unit 30 is structurally similar to the pleat unit of FIG. 3A, except that its features are arranged in an inverted configuration. That is, at the web entrance side 34, the positioning of the upper roll 38 and lower roll 40 (i.e., the protrusions and recesses formed in / on the rolls 38, 40) is vertically reversed, so that the cuts formed in the form-on-web 16 cause the web to fold in the opposite direction to that formed in the pleat unit of FIG. 3A. The positioning of the folding skis 44 and folding plate 46 is also vertically reversed in the pleat unit 30 of FIG. 3B, with the folding plate 46 positioned above and overlapping the folding skis 44 and having a support rod 47 extending upward from a base 49 of the pleat unit 30 to support the folding plate 46. The foam-on-web 16 is then controlled and constrained into the pleated shape as it moves in the machine direction 22 as a portion of it passes over the folding plate 46, between the folding skis 44 and the folding plate 46, and is guided around and under the folding plate 44.

[0068] Referring to Figure 3C, a pleat unit 30 according to yet another embodiment is shown. The pleat unit 30 of Figure 3C differs from the pleat unit 30 of Figures 3A and 3B in that the pleat unit 30 of Figure 3C forms more break lines and creases in the form-on-web 16. At the web entrance side 34, the upper roll 38 and the lower roll 40 each include a plurality of features 42 thereon that interact with each other to form break lines in the form-on-web 16. The form-on-web 16 advances in the machine direction 22 into an arrangement of folding skis 44 that are staggered in the cross machine direction 32 and further arranged in a stacked arrangement. Each of the folding skis 44 has a generally flat end surface 48 at its upstream facing end aligned in the cross machine direction 32 with a protrusion extending outward therefrom downstream in the machine direction 22. The form-on-web 16 is aligned with the folding skis 44 in the cross machine direction 32 such that the break lines on the form-on-web 16 are aligned with the folding skis 44. The form-on-web 16 is controlled and constrained into a pleated shape as it moves in the machine direction 22 as it passes between and over the folding skis 44. In the configuration shown in FIG. 3C, the pleat units 30 are configured to form three folds. In alternative embodiments, it is contemplated that the configuration of the pleat units 30 may be modified to form more or fewer folds.

[0069] According to one embodiment, the number and / or location of the folding skis 44 and folding plates 46 in the pleating unit 30 of Figures 3A-3C can be adjusted to control the number and / or location of the creases formed in the foam-on-web 16. That is, the number and location (in the cross machine direction 32) of the folding skis 44 and folding plates 46 can be controlled depending on the number and location of the creases formed in the foam-on-web 16. Examples of foam-on-webs 16 that may be output from the pleating unit 30 are shown in Figures 4-6 according to embodiments. As shown in the illustrated examples, the number and / or location of the creases 50 formed in the foam-on-web 16 can be varied based on the configuration of the pleating unit 30 to provide a continuous pleated foam-on-web 52 in a desired configuration.

[0070] Referring again now to FIG. 2, according to one embodiment, upon exiting the pleating unit 30, the pleated form-on-web 52 may proceed to a unit 54 that serves to set or hold in place the creases 50 in the web. A unit 54 configured to set or hold in place the creases is shown in FIG. 2, recognizing that such a unit 54 may be included or omitted based on the particular configuration of the apparatus 12, including the configuration of the form-on-web 16 (e.g., material properties or thickness of the form-on-web 16) and the distance between the pleating unit 30 and the forming drum 24. In embodiments of the apparatus 12 in which such a unit 54 is included, the unit 54 may function to set or hold the creases 50 in the pleated form-on-web 52 via a number of different mechanisms. In one embodiment, the unit 54 may be provided as a heated roller that the pleated form-on-web 52 passes over as it advances in the machine direction 22. A heated roller may be disposed adjacent to the top surface of the pleated foam-on-web 52 to apply heat to the web, thereby further "setting" the folds 50 in place as the pleated foam-on-web 52 continues to advance in the machine direction 22. In one example, the heated roller may be configured to apply heat and pressure intermittently at spaced intervals on the web 52. In another embodiment, the unit 54 may be provided as a bonding unit that forms weak bonds on the pleated foam-on-web 52 that bond overlapping portions of material together. The bonds temporarily hold the folds 50 in place as the pleated foam-on-web 52 continues to advance in the machine direction 22 until a force large enough to break the tack bonds is applied to the web. In yet another embodiment, the unit 54 may be provided as an adhesive applicator configured to dispense a temporary adhesive according to a predetermined pattern. According to an embodiment, the bonds may be formed by application of a temporary adhesive, tack bonds, needle punching, or static pin bonds, as non-limiting examples.

[0071] According to the illustrated embodiment, the apparatus 12 also includes an adhesive applicator 56 disposed downstream of the pleating unit 30 (downstream of unit 54, if included in the apparatus 12) that applies an adhesive 58 (FIGS. 4-6) to an upper surface of the pleated form-on-web 52, although it will be recognized that such an adhesive applicator 56 is not required. In some examples, the adhesive 58 may be a hot melt adhesive, such as either a contact hot melt adhesive or a non-contact hot melt adhesive. In other examples, the adhesive 58 may be any other suitable adhesive for application onto a nonwoven web. Additionally, the adhesive 58 may be applied using any suitable application technique, including spray application, slot coat application, or another suitable application technique.

[0072] According to an embodiment, the adhesive 58 is applied to the pleated foam-on-web 52 according to a pattern determined based on the number and locations of the folds 50 formed in the pleated foam-on-web 52, as shown in Figures 4-6. Specifically, the adhesive 58 is applied to the pleated foam-on-web 52 in a pattern defining adhesive zones 59a and non-adhesive zones 59b, where the adhesive zones 59a are aligned with the non-overlapping portions of the pleated foam-on-web 52 and the non-adhesive zones 59b are aligned with the overlapping portions of the pleated foam-on-web 52. An example of a pattern in which the adhesive 58 is applied to the pleated foam-on-web 52 is shown in Figures 4-6, where it can be seen that the adhesive 58 is not applied to the locations of the pleated foam-on-web 52 where the folds 50 are formed (in the cross machine direction 32), but is applied only to the non-overlapping portions of the pleated foam-on-web 52.

[0073] 2, after the adhesive 58 is applied to the pleated form-on-web 52, the web 52 continues downstream in the machine direction 22 adjacent the forming drum 24, onto which the pleated form-on-web 52 is then drawn by vacuum pressure. As shown in FIG. 2, and also shown herein in FIG. 7, the exemplary forming drum 24 can include a movable cylindrical outer forming surface 60 that extends around the circumference of the forming drum 24. The forming drum 24 is mounted on a drive shaft 28 that is rotationally driven by a suitable motor (not shown) to rotate the forming drum 24 in the direction 26, thereby coinciding with and matching the translation of the form-on-web 16 in the machine direction 22.

[0074] A vacuum system 62 is disposed radially inward of the forming surface 60 in fluid communication with the forming surface 60 for drawing air through vacuum openings 64 formed therein. The vacuum system 62 may include a suitable arrangement of ducts or conduits (not shown) extending between the forming surface 60 and a vacuum source 66 (e.g., an exhaust fan) through which a vacuum may be communicated to the forming surface 60. The vacuum communicated to the forming surface 60 acts to draw the foam-on-web 16 against the forming drum 24 as the foam-on-web 16 advances around the forming drum 24, as described further below, and also serves to draw absorbent particulate material against the forming surface 60.

[0075] According to an embodiment, the forming surface 60 is configured to include one or more recesses or pockets 68 defined in its circumferential surface in which the absorbent cores are formed. The one or more recesses 68 extend and / or are aligned along the circumferential dimension (i.e., machine direction 22). In the illustrated embodiment, a single continuous recess 68 is defined in the forming surface 60 in which a continuous absorbent core is formed (which can later be segmented or cut into separate pads). It will be appreciated that in other embodiments, multiple separate recesses 68 may be defined in the forming surface 60 and aligned in the circumferential dimension in which separate absorbent cores are formed.

[0076] An arrangement of cover plates 70 may be attached to the forming drum 24 on the forming surface 60 to define recesses 68 in the forming surface 60. The cover plates 70 may be operably retained and attached on the forming surface 60 by using any suitable attachment mechanism, including, by way of non-limiting example, a system of nuts and bolts or other fasteners. The cover plates 70 cover a portion of the forming surface 60 to block vacuum at a particular portion of the forming surface 60. The cover plates 70 define the recesses 68 and provide vacuum communication at the locations of the recesses 68, and the cover plates 70 allow absorbent cores of different shapes to be formed on the forming drum 24 depending on the particular configuration or structure of the cover plates 70.

[0077] 7 and 8-14, the cover plate 70 is configured to define a three-dimensional recess 68 defined by one or more side walls 72 and a floor 74. According to an embodiment, the side walls 72 define the shape of the recess 68 (and the resulting absorbent core produced), and the walls 72 may be formed as vertical or sloping walls. The height of the walls 72, and the corresponding depth of the recess 68, may vary depending on the details of the manufacturing process for forming the absorbent core, including, by way of example, the dimensions and / or type of the foam-on-web 16 and the desired thickness of the absorbent core to be formed.

[0078] The floor 74 of the recess 68 includes a baffle or screen 76 that allows air flow therethrough so that a vacuum can be communicated through the forming surface 60 (i.e., the vacuum openings 64) and the floor 74. The vacuum communicating through the floor 74 allows the foam-on-web 16 to be sucked and retained within the recess 68, and also allows the absorbent particulate material that is deposited within the recess 68 (on the foam-on-web 16) to be retained.

[0079] For a cover plate 70 located at a location in the circumferential dimension along the forming drum 24 where a given discrete core is formed (from a continuous core), the cover plate 70 is further configured to include one or more protrusions or inserts 78 disposed within the recesses 68 that aid in forming channels of the absorbent core that are free or substantially free of absorbent material (see, for example, channel 10 in FIG. 1). In the illustrated embodiment, the recesses 68 include two inserts 78, but it is recognized that a single insert 78 or three or more alternating inserts 78 may be provided. The inserts 78 extend radially outward from a floor 74 of the recesses 68, and in one embodiment, the height of the inserts 78 is equal to the height of the walls 72. The inserts 78 are disposed such that they are generally oriented in the machine direction 22, and the inserts 78 are spaced apart from one another in the cross machine direction 32 by a distance D1. In the illustrated embodiment, the inserts 78 have a generally linear shape, but it is envisioned that the inserts 78 may alternatively have a non-linear shape. Thus, only the portion of the cover plate 70 that contains the inserts 78 and the settings of inserts 78 provided on the forming drum 24 are spaced apart in the circumferential dimension (ie, machine direction 22).

[0080] Examples of inserts 78 that may be provided in recesses 68 according to embodiments of the present invention are shown in Figures 8-10. Figure 8 shows an insert having a rectangular cross section and illustrates the resulting conformance of the foam-on-web 16 with the insert 78 and floor 74 of the recess 68. Figure 9 shows an insert having a cross section that may be described as an inverted isosceles or equilateral triangle, along with the resulting conformance of the foam-on-web 16 with the insert 78 and floor 74 of the recess 68. Figure 10 shows an insert having a cross section that may be described as an inverted right triangle (with the angled faces of the insert facing each other) along with the resulting conformance of the foam-on-web 16 with the insert 78 and floor 74 of the recess 68.

[0081] It will be appreciated that various designs and configurations of the insert 78 implemented in the forming drum 24 may be selected based on various design considerations including, by way of example, ease of manufacture and the amount of conformance provided around the insert 78 for the foam-on-web 16. The insert 78 of Figure 8 may facilitate ease of manufacture, while the insert 78 of Figure 9 provides greater conformance to the foam-on-web 16 and floor 74 around the insert 78, and the insert 78 of Figure 10 provides greater conformance to the foam-on-web 16 and floor 74 around the insert 78 (compared to the insert 78 of Figure 8) while also providing maximum free swell of absorbent particulate material between the channels 10 of the resulting absorbent core 2.

[0082] Further examples of inserts 78 that may be provided in recesses 68 according to embodiments of the present invention are shown in Figures 11-14. Figures 11 and 12 show inserts having T-shaped and inverted L-shaped cross sections, respectively, that provide greater conformance of the foam-on-web 16 around the insert 78 and floor 74. Figures 13A and 13B show an insert 78 having a pedestal type structure, with the upper surface elevated from the floor by a pair of supports. Figures 14A and 14B show an insert 78 having an upper surface supported by a base structure having ventilation channels formed therein. Thus, for each of the inserts 78 in Figures 13A and 13B and 14A and 14B, air flow is provided through the base of the insert 78, i.e., through the space between the supports or through the ventilation channels, which further enhances conformance of the foam-on-web 16 around the insert 78 and floor 74.

[0083] 15-18, feeding of the pleated foam-on-web 52 onto the forming drum 24 relative to the recess 68 (and insert 78 therein) at different points in the feeding process and according to different embodiments is shown. According to embodiments, the pleated foam-on-web 52 is fed onto the forming drum 24 such that the folds 50 of the pleated foam-on-web 52, along with the adhesive 58 deposited thereon, are aligned in a desired manner with the insert 78 in the recess 68. The folds 50 of the pleated foam-on-web 52 unfold as the pleated foam-on-web 52 is sucked into the recess 68, thereby allowing the pleated foam-on-web 52 to better conform to the walls 72 and insert 78 of the recess 68 and reducing the amount of cross-directional stresses and tensions present in the web.

[0084] 15 and 16, the pleated form-on-web 52 is shown as being fed onto the forming drum 24, the pleated form-on-web 52 including a pair of machine direction creases 50 formed therein. As shown in FIG. 15, the pleated form-on-web 52 is fed onto the forming drum 24 such that it is generally aligned in the cross machine direction 32 with a recess 68 defined by a cover plate 70 and provided on the forming surface 60. More specifically, the pleated form-on-web 52 is fed onto the forming drum 24 such that the creases 50 and adhesive 58 of the pleated form-on-web 52 are aligned in a desired manner with the inserts 78 of the recesses 68. With respect to the creases 50, the creases 50 are formed such that the outward edges 52a of the pleats are spaced apart in the cross machine direction 32 by a distance D2 that is greater than the distance D1 between the outwardly facing surfaces of the inserts 78. The pleated form-on-web 52 is aligned with the insert 78 such that the outward surface of the insert 78 is disposed between the outward edges 52a of the pleats in the cross machine direction 32. With respect to the adhesive 58, the pleated form-on-web 52 is aligned with the insert 78 such that the adhesive 58 applied on the pleated form-on-web 52 is offset from the insert 78 in the cross machine direction 32.

[0085] As the pleated form-on-web 52 is drawn onto the forming drum 24 and sucked (via operation of the vacuum system 62, FIG. 2) into the recess 68, the pleated form-on-web 52 unfolds as shown in FIG. 16. Specifically, the folds 50 unfold downward (i.e., radially inward toward the floor 74 of the recess) as the pleated form-on-web 52 is sucked into the recess 68. Thus, as the pleated form-on-web 52 unfolds, the width of the web increases in the cross machine direction 32, allowing the web to better conform to the walls 72, floor 74, and insert 78 of the recess 68. Upon such unfolding, the adhesive 58 on the form-on-web 16 is disposed within the recess 68 at a location offset in the cross machine direction 32 from the insert 78, such that the adhesive 58 is adjacent to the areas of the walls 72 and floor 74.

[0086] 17 and 18, the pleated foam-on-web 52 is shown as being fed onto the forming drum 24, the pleated foam-on-web 52 including four machine direction folds 50 formed therein that define two distinct pleat regions 80 and 82. As shown in FIG. 17, the pleated foam-on-web 52 is fed onto the forming drum 24 such that it is generally aligned in the cross machine direction 32 with a recess 68 defined by a cover plate 70 and provided on the forming surface 60. More specifically, the pleated foam-on-web 52 is fed onto the forming drum 24 such that the folds 50 and adhesive 58 of the pleated foam-on-web 52 are aligned with the inserts 78 of the recesses 68 in a desired manner. With respect to the creases 50, the creases 50 in the first pleat region 80 are formed such that the outward edges 52a of the pleats are spaced apart in the cross machine direction 32 a distance D3 greater than the width of the individual inserts 78D4, while the creases 50 in the second pleat region 82 are similarly formed such that the outward edges 52a of the pleats are spaced apart in the cross machine direction 32 a distance D3 greater than the width of the individual inserts 78. The pleated form-on-web 52 is aligned with the inserts 78 such that the creases 50 in the first pleat region 80 are disposed in the cross machine direction 32 around a first one of the inserts 78, and the creases 50 in the second pleat region 82 are disposed in the cross machine direction 32 around a second one of the inserts 78. With respect to adhesive 58 , pleated form-on-web 52 is aligned with insert 78 such that adhesive 58 applied on pleated form-on-web 52 is offset in cross machine direction 32 from insert 78 .

[0087] As the pleated foam-on-web 52 is drawn onto the forming drum 24 and sucked (via operation of the vacuum system 62, FIG. 2) into the recess 68, the pleated foam-on-web 52 unfolds downwardly, as shown in FIG. 18. Thus, as the pleated foam-on-web 52 unfolds, the width of the web increases in the cross machine direction 32, allowing the web to better conform to the walls 72, floor 74, and insert 78 of the recess 68. When so unfolded, the adhesive 58 on the foam-on-web 16 is disposed within the recess 68 at a location offset in the cross machine direction 32 from the insert 78, such that the adhesive 58 is adjacent to the areas of the walls 72 and floor 74.

[0088] As shown in FIGS. 15-18 , as the pleated foam-on-web 52 is fed onto the forming drum 24 and drawn into the recesses 68, the vacuum communicated to the recesses 68 can be selectively controlled to better conform the web around the floor 74 and the inserts 78. According to an embodiment, the vacuum communicated to the recesses 68 can be controlled in a stepwise progression beginning by communicating the vacuum to a central region 84 of the recesses 68 (between the inserts 78) and continuing by communicating the vacuum to side regions 86 of the recesses 68 adjacent the central region 84 in the cross machine direction 32 (outside the inserts 78). Selectively controlling the communication of the vacuum to the central region 84 and the side regions 86 of the recesses 68 can reduce the stresses and tensions experienced by the pleated foam-on-web 52 as it is drawn into the recesses 68 to conform around the floor 74 and the inserts 78, thereby reducing the occurrence of tears in the web 52 during the manufacture of the absorbent cores 2.

[0089] As shown in FIG. 2 and herein in FIGS. 19-21, the vacuum system 62 further includes one or more vacuum shoes 88 (disposed in a fixed manner below the cylindrical outer forming surface 60) selectively configured to gradually communicate a vacuum in a stepwise manner to a central region 84 and side regions 86 of the recess 68 when a portion of the recess 68 is aligned with the vacuum shoe 88. In one embodiment, the vacuum shoe 88 is disposed within the forming drum 24 at a laydown zone location 90 where the pleated form-on-web 52 is fed onto the forming drum 24, and the vacuum shoe 88 only allows the vacuum to be communicated to the central region 84 of the recess. By limiting the vacuum suction to only the central region 84, the pleated form-on-web 52 is initially drawn into the central region 84 and can begin to conform to the bed 74 around the central region 84 and the insert 78 while stresses and tensions in the cross machine direction 32 are reduced.

[0090] Once the pleated foam-on-web 52 is initially drawn into the central region 84, the vacuum communicating to the recesses 68 can be changed so that the vacuum communicates to both the central region 84 and the side regions 86 of the recesses 68, or only to the side regions 86. That is, the pattern of vacuum communicating to the recesses 68 can be switched from a first vacuum communication pattern at the laydown zone location 90 to a second vacuum communication pattern at a mixing zone location 92 downstream in the machine direction 22 from the laydown zone location 90, where the foam-on-web 16 is fully conformed just prior to the deposition of absorbent particulate material thereon. As described below, the change in the vacuum pattern communicating to the recesses 68 can be accomplished by using only the vacuum shoe 88, or by using both the vacuum shoe 88 and a second vacuum shoe 94.

[0091] 19, the vacuum shoe 88 is configured to provide an abrupt change from a first vacuum communication pattern at the laydown zone location 90 to a second vacuum communication pattern at the mixing zone location 92. That is, the vacuum shoe 88 is configured to provide a constant first vacuum communication pattern, with the edges of the vacuum shoe 88 aligned parallel to and covering the side regions 86 of the recess 68. As the forming drum 24 (i.e., its forming surface 60) rotates in the machine direction 22 past the end of the vacuum shoe 88 to the mixing zone location 92, the vacuum shoe 88 terminates and permits a second vacuum communication pattern, where vacuum is communicated to both the central region 84 and the side regions 86 of the recess 68.

[0092] 20, the vacuum shoe 88 is configured as a tapered vacuum shoe that provides a transition from a first vacuum communication pattern at a laydown zone location 90 to a second vacuum communication pattern at a mixing zone location 92 downstream in the machine direction 22 from the laydown zone location 90. That is, the vacuum shoe 88 is configured to gradually expand the area within the recess 68 to which the vacuum is in communication, the vacuum shoe 88 tapering outwardly in the cross machine direction 32 such that vacuum communication to the recess 68 transitions from only being provided in the central region 84 to both the central region 84 and the side regions 86. The first vacuum communication pattern provided by the vacuum shoe 88 (at its first end) allows for vacuum communication only to the central region 84 of the recess 68 while blocking vacuum to the side regions 86, as discussed above. As the vacuum shoe 88 tapers outward, the area within the recess 68 through which the vacuum is communicated gradually expands, and the vacuum shoe 88 tapers outward such that the vacuum to the side regions 86 is no longer blocked by the vacuum shoe 88. As the forming drum 24 (i.e., its forming surface 60) rotates in the machine direction 22 past the end of the vacuum shoe 88 to the mixing zone location 92, the vacuum shoe 88 terminates, allowing a second vacuum communication pattern in which vacuum is communicated to both the central region 84 and the side regions 86 of the recess 68.

[0093] In another embodiment, as shown in FIG. 21, a second vacuum shoe 94 is provided within the forming drum 24 at a different mixing zone location 92 than the vacuum shoe 88. The vacuum shoe 88 is configured to provide a consistent first vacuum communication pattern, with the edges of the vacuum shoe 88 aligned parallel to and covering the side regions 86 of the recesses. As the forming drum 24 (i.e., its forming surface 60) rotates in the machine direction 22 past the end of the vacuum shoe 88 to the mixing zone location 92, the vacuum shoe 88 terminates and the second vacuum shoe 94 is aligned with the same portion as the recesses 68. The second vacuum shoe 94 is configured to provide a second vacuum communication pattern, where vacuum is only communicated to the side regions 86 of the recesses 68, while the second vacuum shoe 94 blocks vacuum from the central region 84.

[0094] By selectively phasing the vacuum communicated to the recess 68 via the embodiment shown and described in Figures 19-21, a two-stage drawdown of the pleated foam-on-web 52 into the recess 68 is provided. In a first stage of the drawdown, the pleated foam-on-web 52 can be initially seated in a central region 84 of the recess 68 between the inserts 78 by selectively communicating a vacuum to only the central region 84, such as by using a vacuum shoe 88. When seated in the central region 84, the folds 50 of the pleated foam-on-web 52 unfold and the web conforms to the floor 74 around the central region 84 and the inserts 78, which is accomplished with minimal distortion disposed on the pleated foam-on-web 52. In a second stage of the drawdown, the remaining portion of the pleated foam-on-web 52 (adjacent the side regions 86) may then be drawn into the recess 68 by communicating a vacuum only to the side regions 86 of the recess 68 (using the second vacuum shoe 94) or by communicating a vacuum to both the central region 84 and the side regions 86 (with or without a gradual transition between the two vacuum patterns). As the side regions 86 are sucked, tension is maintained on the foam-on-web 16, and the web is secured to the edges of the recess 68 (i.e., against the walls 72) without being sucked into the central region 84. The foam-on-web 16 is thus made to be positioned and conform to the recess 68 in the desired manner, providing for the subsequent application of absorbent particulate material onto the foam-on-web 16 (within the recess 68) to provide for the production of the absorbent core 2.

[0095] 2, as the forming drum 24 rotates in the direction 26 and the developed foam-on-web 16 is pulled via vacuum into the recess 68 of the forming drum 24, the foam-on-web 16 enters a particulate material delivery system 96 disposed adjacent a portion of the forming drum 24. Inside the particulate material delivery system 96, particulates of absorbent material 98 (e.g., absorbent material 8, e.g., in FIG. 1) are deposited onto the foam-on-web 16. More specifically, the absorbent particulate material 98 is deposited onto the foam-on-web 16 within the recess 68 formed on the forming drum 24. Within the recess 68, the absorbent particulate material 98 is delivered onto the adhesive 58 applied onto the foam-on-web 16 such that the particulate material 98 is stabilized or immobilized on the foam-on-web 16 by the adhesive 58.

[0096] According to the illustrated embodiment, the particulate material delivery system 96 may perform a single application of absorbent particulate material 98 onto the foam-on-web 16 in the recess 68. In such an embodiment, the mixture of SAP granules, fluff, and absorbent material binder may be delivered to the delivery system 96 from one or more hoppers 100, with a connecting tube 102 extending between each hopper 100 and the delivery system 96 to convey the particulate material 98 therebetween. In the illustrated embodiment, a single hopper 100 is provided from which the absorbent particulate material 98 is provided to the particulate material delivery system 96. In some embodiments, the connecting tube 102 may include a metering device (not shown) that operates to ensure that only a specified amount (e.g., by volume or by weight) of the particulate material 98 flows through the connecting tube 102 per unit time.

[0097] According to one embodiment, after the absorbent particulate material 98 has been deposited in the desired location on the foam-on-web 16 and within the recesses 68, excess particulate material 98 may be removed and / or the top surface of the granular material may be smoothed via a scarf unit 104. The scarf unit 104 may extend above the level of the recesses 68 (i.e., beyond the walls 72) and function to scrape off particulate material 98 that may be located on the inserts 78, which is then discharged and returned to the system through a discharge 106.

[0098] After exiting the particulate material delivery system 96, the foam-on-web 16, now including the adhesive 58 and particulate material 98, advances to a location 108 on the forming drum 24 where a second continuous web of nonwoven material 110 (hereinafter referred to for simplicity as the "cover web 110") is applied. The cover web 110 may be unwound from a roll 112 of cover web material or may be transported adjacent to the forming drum 24 via one or more material handling rollers 114.

[0099] An adhesive applicator 116 applies adhesive to the cover web 110 as it is advanced toward the forming drum 24 by the material handling roller 114. In some examples, the adhesive may be a hot melt adhesive, such as either a contact hot melt adhesive or a non-contact hot melt adhesive, and the adhesive is applied using any suitable application technique, including spray application, slot coat application, or another suitable application technique. In some embodiments, the adhesive is applied to the cover web 110 according to a "dual pattern" type application. That is, the adhesive applicator 116 may be configured to apply adhesive to the cover web 110 in a continuous overall pattern on some portions of the web and to apply adhesive to the cover web 110 in an intermittent pattern on some other portions of the web. The intermittent adhesive pattern may correspond to locations on the forming drum 24 where the insert 78 is present within the recess 68, and no adhesive is applied on the cover web 110 at locations aligned with the insert 78, such that the channels 10 formed in the absorbent core 2 (FIG. 1) are free of adhesive. In yet other instances, the adhesive applicator 116 may be omitted entirely.

[0100] After the cover web 110 reaches location 108 and is applied onto the foam-on-web 16 and the particulate material 98, the cover web 110 is bonded to the foam-on-web 16 and the absorbent particulate material 98. To facilitate this bonding, a nip roll 118 may be located immediately downstream of location 108, which acts to press the cover web 110 down onto the foam-on-web 16 and the particulate material 98. Thus, the nip roll 118 bonds the adhesive applied on the cover web 110 to the foam-on-web 16 and the particulate material 98, thereby forming a continuous absorbent core (or separate absorbent cores, such as absorbent core 2 shown in FIG. 1 ).

[0101] Once the cover web 110 has been adhered to the foam-on-web 16 and particulate material 98, the resulting absorbent core 2 may be transferred from the forming drum 24 to an adjacent transfer drum 120. In one embodiment, the transfer drum 120 may include a knife or other cutting element 122 thereon (or adjacent thereto) that cuts the continuous absorbent core (formed in the continuous recesses 68) into separate pads such as absorbent cores 2. The separate absorbent cores 2 are rotated along the face of the transfer drum 120 and then deposited, for example, on a conveyor 124 for further processing.

[0102] Thus, the apparatus 12 described above is operable to perform a method of forming and providing a pleated web of material 52 to a core-forming drum 24 as part of the manufacture of an absorbent core 2. The apparatus 12 is operable to convey a continuous web of material 16 in a machine direction 22 and to operate the pleating unit 30 to form one or more folds 50 in the continuous web of material 16 extending in the machine direction 22, the one or more folds 50 providing a continuous pleated web of material 52 with a portion of the continuous pleated web of material 52 overlapping in the cross-machine direction 32. The apparatus 12 is further operable to feed the continuous pleated web of material 52 into at least one recess 68 formed in a peripheral surface 60 of the core-forming drum 24 rotating in the machine direction 22, the at least one recess 68 including one or more inserts 78 projecting radially outward from a floor 74 of the recess 68. As the continuous pleated web of material 52 is fed into the at least one recess 68 , regions of the continuous pleated web of material 52 separate as the continuous pleated web of material 52 is drawn into the at least one recess 68 .

[0103] Although the apparatus 12 described above is shown as having rolls of material 18, 112 providing the foam-on-web 16 and separate cover web 110 for producing the absorbent core 2, it will be appreciated that the absorbent core 2 can be formed using only a single web of material. That is, a single, wider continuous web of material can be provided for the foam-on-web and folded about the absorbent core downstream of the forming drum to encapsulate the particulate material 98 therein and form the absorbent core 2.

[0104] 22, there is shown a schematic diagram of an exemplary apparatus 130 capable of forming an absorbent core 2 using only a single web of material. The apparatus 130 shares many common components with the apparatus 12 of FIG. 2, and thus similar components of the apparatus 130 are numbered the same as the components of the apparatus 12. To facilitate the manufacture of the absorbent core 2 using only a single web of material, a wide form-on-web 132 is provided from a roll of material 18. The form-on-web 132 can be characterized as including a central portion 134 and side portions 136 (FIG. 23) disposed side by side in the cross machine direction 32, the side portions 136 being wide enough to provide a turn-up thereof to cover the central portion 134 when folded inward.

[0105] In operation of the apparatus 130, the foam-on-web 132 provided by the material roll 18 is advanced to the pleating unit 30, and a central portion 134 of the web passes through the pleating unit 30 to form the folds 50 therein, as previously described in detail in FIGS. 3A-3C. With the central portion 134 thus configured as a pleated web, the foam-on-web 132 continues downstream, optionally through an adhesive application station 56 (where adhesive 58 is applied to the web 132), to the forming drum 24. The foam-on-web 132 is pulled onto the forming drum 24 via vacuum, with the central portion 134 of the foam-on-web 132 being sucked into the recesses 68, while the side portions 136 remain outside of the recesses 68, as previously described. Absorbent particulate material 98 is deposited into the recesses 68 and on the central portion 134 as the foam-on-web 132 rotates in the machine direction 22 about the forming drum 24.

[0106] Upon rolling to a location adjacent the transfer drum 120, the foam-on-web 132 and particulate material 98 contained thereon are transferred from the forming drum 24 onto the transfer drum 120. The foam-on-web 132 and particulate material 98 are rolled along the face of the transfer drum 120 and subsequently deposited onto the conveyor 124. Once deposited on the conveyor 124, a folding unit 138 acts on the foam-on-web 132 to fold the sides 136 onto the particulate material 98 such that the particulate material 98 is surrounded by the foam-on-web 132. According to an embodiment, the folding unit 138 may include any known folding device, such as, by way of non-limiting example, one or more plow folders, one or more folding plates, or one or more roller edge folders. The folding unit 138 folds the sides 136 inwardly in the cross machine direction 32 over and above the particulate material 98. The sides 136 may be of a width such that when folded, they overlap each other in the cross machine direction 32, as shown, for example, in FIG.

[0107] Once the form-on-web 132 is folded, the resulting absorbent core 2 can be cut by a knife or other cutting element 140 that cuts the continuous absorbent core (formed in the continuous recesses 68) into separate pads such as absorbent cores 2. The separate absorbent cores 2 can then continue to advance along the conveyor 124 for further processing.

[0108] Advantageously, therefore, embodiments of the present invention provide an apparatus for forming and applying a pleated core wrap during the manufacture of an absorbent pad. The formation of the pleated core wrap and its subsequent application onto a forming drum allows the pleated core wrap to better fit into one or more recesses in the forming drum and the inserts contained therein. The pleats in the core wrap reduce stress and tension on the core wrap as the web is placed into the recesses, thereby reducing the occurrence of tears in the core wrap during the manufacture of the absorbent pad.

[0109] Thus, according to one embodiment of the present invention, the apparatus includes a feeding mechanism configured to feed the continuous web of material in a machine direction and a pleating unit configured to form one or more folds in the continuous web of material, each of the one or more folds including a continuous fold extending in the machine direction to form a continuous pleated web of material with a portion of the web of material overlapping in the cross machine direction. The apparatus also includes a core-forming drum that rotates in the machine direction and is disposed downstream in the machine direction from the pleating unit to receive the continuous pleated web of material, the core-forming drum comprising at least one recess provided in an outer peripheral surface of the core-forming drum, the at least one recess including a floor having one or more inserts protruding radially outward therefrom. The apparatus further includes a vacuum system configured to provide a vacuum to the at least one recess, the vacuum communicating through the floor to draw the continuous pleated web of material into the at least one recess, and a region of the continuous pleated web of material separating when drawn into the at least one recess.

[0110] According to another embodiment of the invention, an apparatus includes a feeding mechanism configured to feed a continuous web of material in a machine direction, and a core-forming drum arranged to rotate in the machine direction from the feeding mechanism and downstream in the machine direction to receive the continuous web of material, the core-forming drum including at least one recess provided in an outer peripheral surface of the core-forming drum, the at least one recess including a floor having one or more inserts protruding radially outward therefrom. The apparatus also includes a vacuum system for providing a vacuum to the at least one recess, the vacuum communicating through the floor to draw the continuous web of material into the at least one recess, the vacuum system configured to selectively control communication of the vacuum to multiple cross-machine direction disposed regions of the at least one recess and to gradually deposit the continuous web of material into the at least one recess in multiple stages.

[0111] While the present invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the present invention is not limited to such disclosed embodiments. Rather, the present invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the present invention. Moreover, while various embodiments of the present invention have been described, it should be understood that aspects of the present invention may include only some of the described embodiments. Thus, the present invention should not be deemed limited by the foregoing description, but is limited only by the appended claims.

Claims

1. a feeding mechanism configured to feed the continuous web of material in a machine direction; a pleating unit configured to form one or more folds in the continuous web of material, each of the one or more folds comprising a continuous fold extending in a machine direction such that a portion of the web of material overlaps in a cross-machine direction to form a continuous pleated web of material; a core-forming drum that rotates in the machine direction and is positioned downstream in the machine direction from the pleating unit to receive the continuous pleated web of material, the core-forming drum including at least one recess in an outer peripheral surface of the core-forming drum, the at least one recess including a floor having one or more inserts protruding radially outward therefrom; a vacuum system configured to provide a vacuum to the at least one recess, the vacuum communicating through the floor to draw the continuous pleated web of material into the at least one recess, and regions of the continuous pleated web of material separating as they are drawn into the at least one recess; An apparatus comprising:

2. 10. The apparatus of claim 1, further comprising an adhesive applicator positioned downstream in a machine direction from the pleating unit, the adhesive applicator configured to apply adhesive to non-overlapping portions of the upper surface of the pleated web of material.

3. The apparatus of claim 2 , wherein the adhesive applicator is configured to apply adhesive to non-overlapping portions of the top surface of the pleated web of material that are offset in the cross-machine direction from the one or more inserts.

4. 3. The apparatus of claim 2, further comprising a heated roller disposed between the pleating unit and the adhesive applicator, the heated roller configured to apply heat to the continuous pleated web of material to set one or more folds therein.

5. 3. The apparatus of claim 2, further comprising a bonding unit disposed between the pleating unit and the adhesive applicator, the bonding unit configured to tuck the continuous pleated material web to set one or more folds thereof.

6. The pleat unit is upper and lower rolls arranged to form a nip therebetween through which the continuous web of material is fed, the upper and lower rolls including features acting on the continuous web of material to facilitate folding of the continuous web of material; a folding plate and one or more folding skis disposed downstream in the machine direction from the upper roll and the lower roll, the folding plate and one or more folding skis disposed in an overlapping arrangement; The apparatus of claim 1 , wherein the continuous web of material is constrained into a controlled pleated shape as it moves in a machine direction as it passes through the one or more folding skis and the folding plate.

7. 2. The apparatus of claim 1, wherein the one or more inserts include a first insert and a second insert, respectively, generally aligned in the machine direction, the first insert and the second insert being spaced apart in the cross-machine direction by a first distance.

8. The pleat unit is forming a first fold in the continuous web of material extending in the machine direction; configured to form a second fold in the continuous web of material extending in the machine direction; The apparatus of claim 7 , wherein the first fold line and the second fold line are spaced apart in the cross-machine direction by a second distance greater than the first distance.

9. The pleat unit is forming a first pair of folds in the continuous web of material within a first pleat region, each fold of the first pair of folds extending in the machine direction; forming a second pair of folds in the continuous web of material within a second pleat region, each fold of the second pair of folds extending in the machine direction; the pleated web of material is positioned such that the folds of the first pair of folds are located on opposite sides of the first insert when the continuous pleated web of material is fed into the at least one recess; 8. The apparatus of claim 7, wherein the folds of the second pair of folds are positioned to be located on opposite sides of the second insert when the continuous pleated material web is fed into the at least one recess.

10. 8. The apparatus of claim 7, wherein the at least one recess includes a central region disposed between the pair of inserts in the cross-machine direction and lateral regions disposed on opposite sides of the central region and outboard of the pair of inserts in the cross-machine direction, and the vacuum system is configured to selectively communicate vacuum to the central region and the lateral regions.

11. the vacuum system comprises: a first vacuum shoe disposed at a laydown zone location of the core-forming drum where the continuous pleated web of material is fed onto the core-forming drum, the first vacuum shoe configured to communicate vacuum to the central region and block vacuum to the side regions; a second vacuum shoe positioned downstream in the machine direction from the first vacuum shoe, the second vacuum shoe configured to communicate vacuum to the side regions and block vacuum to the central region.

12. The apparatus of claim 7 , wherein the first insert and the second insert each have an inverted triangular shape.

13. 8. The device of claim 7, wherein the first insert and the second insert each have one or more spaces or ventilation channels formed therein that provide airflow therethrough.

14. a feeding mechanism configured to feed the continuous web of material in a machine direction; a core-forming drum rotating in the machine direction and positioned downstream in the machine direction from the feeding mechanism for receiving the continuous web of material, the core-forming drum including at least one recess in an outer peripheral surface of the core-forming drum, the at least one recess including a floor having one or more inserts protruding radially outward therefrom; a vacuum system that provides a vacuum to the at least one recess, the vacuum communicating through the floor to draw the continuous web of material into the at least one recess; the vacuum system is configured to selectively control communication of the vacuum to a plurality of cross-machine direction arranged regions of the at least one recess to gradually deposit the continuous material web into the at least one recess in multiple stages.

15. the one or more inserts include a first insert and a second insert each aligned in the machine direction, the first insert and the second insert being spaced apart a first distance in the cross-machine direction; In selectively controlling communication of the vacuum to a plurality of cross-machine direction disposed regions of the at least one recess, the vacuum system: first, connecting a vacuum to a central region disposed between a pair of inserts; The apparatus of claim 14, further configured to communicate a vacuum to side regions located on opposite sides of the central region and located outside the pair of inserts in the cross-machine direction, or to both the side regions and the central region.

16. The apparatus of claim 15 , wherein the vacuum system includes one or more vacuum shoes configured to communicate or block vacuum to the central region and the side regions.

17. a pleating unit disposed upstream in the machine direction from the core-forming drum, the pleating unit configured to form one or more folds in the continuous material web, each of the one or more folds including a continuous fold extending in the machine direction such that a portion of the material web overlaps in the cross-machine direction to form a continuous pleated material web; 15. The apparatus of claim 14, wherein regions of the continuous pleated web of material separate during multi-stage gradual placement into the at least one recess in the continuous web of material.

18. The pleat unit is upper and lower rolls arranged to form a nip therebetween through which the continuous web of material is fed, the upper and lower rolls including features acting on the continuous web of material to facilitate folding of the continuous web of material; a folding plate and one or more folding skis disposed downstream in the machine direction from the upper roll and the lower roll, the folding plate and one or more folding skis disposed in an overlapping arrangement; 20. The apparatus of claim 17, wherein the continuous web of material is constrained in a controlled pleated configuration as it moves in the machine direction as it passes through the one or more folding skis and the folding plate.

19. 20. The apparatus of claim 17, further comprising an adhesive applicator positioned downstream in a machine direction from the pleating unit, the adhesive applicator configured to apply adhesive to non-overlapping portions of the upper surface of the pleated web of material.

20. 20. The apparatus of claim 19, wherein the adhesive applicator is configured to apply adhesive to non-overlapping portions of the top surface of the pleated web of material that are offset in the cross-machine direction from the one or more inserts.

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