US-12616613-B2 - Apparatus for forming and applying a pleated core wrap

US12616613B2US 12616613 B2US12616613 B2US 12616613B2US-12616613-B2

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, so as to form a continuous pleated web of material with a portion of the web of material overlapped in a cross-machine direction. A core-forming drum receives the continuous pleated web of material, the core-forming drum including at least one depression provided on an outer circumferential surface thereof, the depression having a floor having one or more inserts protruding radially outward therefrom. A vacuum system provided a vacuum to the depression that is communicated through the floor to suction the continuous pleated web of material down into the depression, with regions of the continuous pleated web of material separating upon being suctioned down into the depression.

Inventors

Hubert P. Van de Pas
Randy J. Teresinski, Jr.
Christopher S. Lawrence
Jeffrey W. Fritz
Cory D. Veldman
Zachary J. Giffey

Assignees

CURT G. JOA, INC.

Dates

Publication Date: 20260505
Application Date: 20230223

Claims (20)

1 . An apparatus comprising: a feeding mechanism configured to feed a 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 running in the machine direction so as to form a continuous pleated web of material with a portion of the web of material overlapped in a cross-machine direction; a core-forming drum rotating in the machine direction and positioned 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 depression provided on an outer circumferential surface of the core forming drum, with the at least one depression including a floor having one or more inserts protruding radially outward therefrom; and a vacuum system configured to provide a vacuum to the at least one depression, the vacuum communicated through the floor to suction the continuous pleated web of material down into the at least one depression, with regions of the continuous pleated web of material separating upon being suctioned down into the at least one depression.
2 . An apparatus according to claim 1 , further comprising an adhesive applicator positioned downstream in the machine direction from the pleating unit, the adhesive applicator configured to apply adhesive to non-overlapped portions of a top surface of the pleated web of material.
3 . An apparatus according to claim 2 , wherein the adhesive applicator is configured to apply adhesive to non-overlapped portions of the top surface of the pleated web of material that are offset from the one or more inserts in the cross-machine direction.
4 . An apparatus according to claim 2 , further comprising a heated roller positioned between the pleating unit and the adhesive applicator, the heated roller configured to apply heat to the continuous pleated web of material to set the one or more folds thereof.
5 . An apparatus according to claim 2 , further comprising a bonding unit positioned between the pleating unit and the adhesive applicator, the bonding unit configured to tack bond the continuous pleated web of material to set the one or more folds thereof.
6 . An apparatus according to claim 1 , wherein the pleating unit comprises: a top roll and a bottom roll positioned to form a nip therebetween through which the continuous web of material is fed, the top and bottom rolls including features thereon that act on the continuous web of material to predispose the continuous web of material to folding; and a folding board and one or more folding skis positioned downstream in the machine direction from the top and bottom rolls, the folding board and the one or more folding skis positioned in an overlapped arrangement; wherein the continuous web of material is controlled and constrained into a pleated shape when traveling in the machine direction as it passes the one or more folding skis and the folding board.
7 . An apparatus according to claim 1 , wherein the one or more inserts comprise a first insert and a second insert each generally aligned in the machine direction, with the first insert and the second insert spaced apart in the cross-machine direction by a first distance.
8 . An apparatus according to claim 7 , wherein the pleating unit is configured to: form a first fold in the continuous web of material running in the machine direction; and form a second fold in the continuous web of material running in the machine direction; wherein the first fold and the second fold are spaced apart in the cross-machine direction by a second distance greater than the first distance.
9 . An apparatus according to claim 7 , wherein the pleating unit is configured to: form a first pair of folds in the continuous web of material in a first pleated area, each fold of the first pair of folds running in the machine direction; and form a second pair of folds in the continuous web of material in a second pleated area, each fold of the second pair of folds running in the machine direction; wherein the folds of the first pair of folds are located so as to be positioned on opposing sides of the first insert when the continuous pleated web of material is fed into the at least one depression; and wherein the folds of the second pair of folds are located so as to be positioned on opposing sides of the second insert when the continuous pleated web of material is fed into the at least one depression.
10 . An apparatus according to claim 7 , wherein the at least one depression comprises a center region positioned between the pair of inserts in the cross-machine direction, and side regions positioned on opposing sides of the center region and outside of the pair of inserts in the cross-machine direction; and wherein the vacuum system is configured to selectively communicate a vacuum to the center region and the side regions.
11 . An apparatus according to claim 10 , wherein the vacuum system comprises: a first vacuum shoe positioned at a lay-down 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 a vacuum to the center region and block a vacuum to the side regions; and a second vacuum shoe positioned downstream in the machine direction from the first vacuum shoe, the second vacuum shoe configured to communicate a vacuum to the side regions and block a vacuum to the center region.
12 . An apparatus according to claim 7 , wherein each of the first insert and the second insert has an inverted triangular shape.
13 . An apparatus according to claim 7 , wherein each of the first insert and the second insert has one or more spaces or ventilation channels formed therein that provides for airflow therethrough.
14 . An apparatus comprising: a feeding mechanism configured to feed a 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 to receive the continuous web of material, the core-forming drum comprising at least one depression provided on an outer circumferential surface of the core-forming drum, with the at least one depression including a floor having one or more inserts protruding radially outward therefrom; and a vacuum system that provides a vacuum to the at least one depression, the vacuum communicated through the floor to suction the continuous web of material down into the at least one depression; wherein 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 depression to provide a multi-stage, progressive laydown of the continuous web of material into the at least one depression.
15 . An apparatus according to claim 14 , wherein the one or more inserts comprise a first insert and a second insert each aligned in the machine direction, with the first insert and the second insert spaced apart in the cross-machine direction by a first distance; and wherein in selectively controlling communication of the vacuum to a plurality of cross-machine direction arranged regions of the at least one depression, the vacuum system is configured to: initially communicate a vacuum to a center region positioned between the pair of inserts; and subsequently communicate a vacuum to side regions positioned on opposing side of the center region and outside of the pair of inserts in the cross-machine direction, or to both the side regions and the center region.
16 . An apparatus according to claim 15 , wherein the vacuum system comprises one or more vacuum shoes configured to communicate or block a vacuum to the center region and the side regions.
17 . An apparatus according to claim 14 , further comprising a pleating unit positioned upstream in the machine direction from the core-forming drum, the 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 running in the machine direction so as to form a continuous pleated web of material with a portion of the web of material overlapped in a cross-machine direction; wherein regions of the continuous pleated web of material separate during the multi-stage, progressive laydown of the continuous web of material into the at least one depression.
18 . An apparatus according to claim 17 , wherein the pleating unit comprises: a top roll and a bottom roll positioned to form a nip therebetween through which the continuous web of material is fed, the top and bottom rolls including features thereon that act on the continuous web of material to predispose the continuous web of material to folding; and a folding board and one or more folding skis positioned downstream in the machine direction from the top and bottom rolls, the folding board and the one or more folding skis positioned in an overlapped arrangement; wherein the continuous web of material is controlled and constrained into a pleated shape when traveling in the machine direction as it passes the one or more folding skis and the folding board.
19 . An apparatus according to claim 17 , further comprising an adhesive applicator positioned downstream in the machine direction from the pleating unit, the adhesive applicator configured to apply adhesive to non-overlapped portions of a top surface of the pleated web of material.
20 . An apparatus according to claim 19 , wherein the adhesive applicator is configured to apply adhesive to non-overlapped portions of the top surface of the pleated web of material that are offset from the one or more inserts in the cross-machine direction.

Description

CROSS REFERENCE TO RELATED APPLICATION This application is the U.S. National Stage of PCT/US2023/063175 with international filing date of Feb. 23, 2023, and which claims priority to U.S. Provisional Application No. 63/268,618 filed on Feb. 28, 2022, the contents of which are incorporated by reference in their entireties. BACKGROUND OF THE INVENTION Embodiments of the invention relate to an apparatus for forming and applying a pleated core web in the manufacture of disposable absorbent articles such as diapers or incontinence control garments. More particularly, embodiments of the invention relate to such an apparatus forming a pleated core wrap and applying the pleated core wrap into one or more depressions of a core forming drum in the manufacture of absorbent cores, with the depression(s) including one or more inserts therein that provide for the formation of one or more channels in the absorbent cores. As the pleated core wrap is drawn down into a depression of the core forming drum, the pleats in the core wrap unfold so as to allow for the core wrap to better conform to the depression, including conforming about the insert(s) therein. 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. The articles may thus include a thin flexible liquid impermeable backing sheet on which a permeable nonwoven sheet is overlayed. An absorbent core is disposed between the two sheets and the sheets are adhered at their edges to form a unitary article that prevents liquid body exudates from seeping out of the edges of the article. In disposable absorbent articles as referenced above, the absorbent core is typically formed of an absorbent material (e.g., granules of superabsorbent polymer material (SAP)) contained inside a mixture of containment cellulose pulp (fluff) and absorbent material binder. The absorbent material is sandwiched between or wrapped by one or more layers of nonwoven fabric. To improve performance in terms of absorption, comfort and distribution of absorbed liquids, the absorbent core may be provided with longitudinal channels formed therein that are free or substantially free of absorbent material between the two layers of nonwoven fabric. 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 includes a continuous three-dimensional fluff receiving pocket or depression (or a plurality of discrete, three-dimensional fluff receiving pockets or depressions) on an outer circumferential surface thereof. The base web is laid down onto the core forming drum and drawn down into the depression(s) via a vacuum system internal to the core forming drum, with the vacuum creating a suction that attracts the base web down into the depression(s). In the depression(s), the base web conforms to inserts (i.e., protrusions) positioned therein that extend radially outward from a floor of the depressions. Absorbent material, such as SAP, fluff, or a mixture thereof, is then blown into the depression(s) and on top of the base web. The absorbent material is caused to adhere to the base web by way of an adhesive previously applied onto the base web, in combination with the suction provided by the vacuum system. A cover web is then applied over the base web and over the pocket(s) of absorbent material provided thereon. The cover web is then bonded to the base web via adhesive or an adhesive-free bonding means such as mechanical, thermal, or ultrasonic bonding, and bonded to the absorbent material to produce an absorbent core. Core forming drums designed for the manufacture of higher capacity cores typically include pockets designed with deeper depression(s) and inserts having an increased height corresponding to the increased depression depth. When exposed to these pocket geometries, the base web may experience higher stress and tension when caused to conform to the depression(s) and about the inserts. That is, as the base web is initially laid down into a depression in a flat configuration, and then caused to conform under vacuum to the increased depression depth and insert height, the base web experiences stress and tension in the cross-machine direction. This increased stress and tension placed on the base web can cause the web to tear at locations corresponding to the depression inserts. 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 stress and tension placed on the base web as the web is laid down into pocket geometries including depressions and one or more channel-forming inserts on the core forming drum. BRIEF DESCRIPTION OF THE INVENTION Embodiments of the invention are expressed and characterized in the independent claims, while the dependent claims explain other characteristi