COMPOSITE WEB

Abstract

A composite web including a first continuous web having a first face and a second face; the first web includes a molded portion having at least one protrusion, at least partly delimited by a base portion, on the first face; the composite web includes a segment of a second continuous web joined to the second face of the first web at least at the base portion.

Claims

1. A composite web comprising a first continuous web having a first face and a second face, the first continuous web comprising at least one molded portion having at least one protrusion, the protrusion being at least partly delimited by a base portion, the composite web comprising a segment of a second continuous web joined to the second face of the first continuous web at least at the base portion, the composite web having at least one cavity that is delimited by the first continuous web and the segment at the molded portion.

2. The composite web according to claim 1, wherein the molded portion has a multiplicity of protrusions delimited by a multiplicity of base portions, the composite web comprising a segment of a second continuous web joined to the second face of the first continuous web at the multiplicity of base portions, the composite web having a multiplicity of cavities that are delimited by the first continuous web and the segment at the molded portion.

3. The composite web according to claim 2, wherein the multiplicity of protrusions defines a pattern on the first face.

4. The composite web according to claim 1, wherein the first continuous web is molded along its full length, the segment defining the molded portion of the composite web.

5. The composite web according to claim 4, comprising a discrete succession of segments of second continuous web joined to the first continuous web, each segment defining a corresponding molded portion of the composite web.

6. The composite web according to claim 1, wherein the molded portion comprises a protrusion having a bubble shape.

7. The composite web according to claim 1, wherein the molded portion comprises a protrusion having a wave shape.

8. The composite web according to claim 1, wherein the molded portion of the first continuous web and the segment of the second continuous web are joined by thermal welding or thermomechanical welding or ultrasonic welding.

9. The composite web according to claim 1, comprising an adhesive layer, the adhesive layer being disposed between the base portion of the molded portion of the first continuous web and the segment of the second continuous web.

10. The composite web according to claim 1, wherein the base portion is outside the protrusion.

11. An absorbent article, comprising: a topsheet, an impermeable backsheet, an absorbent core disposed between the topsheet and the backsheet, wherein the topsheet comprises a segment of a composite web according to claim 1, the segment of the second continuous web being disposed between the first continuous web and the absorbent core.

12. A method for the production of a composite web (for sanitary articles) comprising the following steps: feeding a first continuous web, molding the first continuous web to obtain at least one protrusion, the protrusion being delimited at least partly by a base portion, joining at least one segment of a second continuous web to the first continuous web at least at the base portion to delimit at least one cavity between the first continuous web and the segment.

13. The production method according to claim 12, comprising the steps of feeding, cutting and spacing the second continuous web to obtain the segment from the second continuous web.

14. The production method according to claim 12, wherein the step of joining the segment to the first continuous web comprises a step of welding the segment to the first continuous web at least at the base portion.

15. The production method according to claim 12, wherein the step of joining the segment of the second continuous web to the first continuous web comprises a step of holding the segment on the first continuous web.

16. The production method according to claim 12, wherein the step of joining the segment to the first continuous web comprises a step of disposing a layer of adhesive between the segment and the first continuous web.

17. he production method according to claim 12, wherein the step of molding the first continuous web comprises a step of molding the first continuous web along the full length thereof, the step of joining the segment to the first continuous web defining a molded portion at least at the segment.

18. The production method according to claim 17, wherein the step of joining at least one segment of a second continuous web to the first continuous web comprises a step of joining a discrete succession of spaced segments to the first web, each segment of the discrete succession defining a corresponding molded portion in the composite web.

19. A forming unit for making a composite web, the forming unit comprising: a molding device configured to mold a pattern on a first continuous web, the pattern comprising at least one protrusion and a base portion, the molding device comprising a first drum and a second drum positioned relative to each other to define a through-gap through which the first continuous web passes; the forming unit comprising: an applicator device configured to join at least one segment of a second continuous web to the first continuous web at the base portion, the applicator device being disposed downstream of the molding device in a feed direction of the first continuous web.

20. The forming unit according to claim 19, wherein the applicator device comprises a cutting device configured to cut the segment of second web from the second continuous web.

21. The forming unit according to claim 20, wherein the cutting device comprises an anvil and a rotary knife acting in conjunction with the anvil.

22. The forming unit according to claim 20, wherein the cutting device, specifically the anvil, is configured to space the segments.

23. The forming unit according to claim 19, wherein the applicator device comprises a joining device comprising a welder for welding the segment of second continuous web to the first continuous web.

24. The forming unit according to claim 23, wherein the welder comprises at least one welding drum that is substantially tangent to the first drum.

25. The forming unit according to claim 19, wherein the applicator device comprises an adhesive dispenser, the dispenser being disposed downstream of the molding device in the feed direction of the first continuous web.

26. The forming unit according to claim 19, wherein the first drum and the second drum comprise male and female portions, respectively, the male and female portions being shaped to match each other so as to mold the pattern on the first continuous web.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0093] The main features of the invention are more apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate a preferred embodiment of the invention purely by way of non-limiting example, and in which:

[0094] FIG. 1 illustrates a detail of a composite web according to the description in a schematic cross sectional view;

[0095] FIG. 2 illustrates a detail of a composite web according to the description in a schematic perspective view;

[0096] FIG. 3 illustrates a detail of a composite web according to the description in a schematic perspective view;

[0097] FIG. 4 illustrates an absorbent article according to the description in a schematic plan view;

[0098] FIG. 5A illustrates a unit for the production of a composite web according to the description in a schematic front view;

[0099] FIG. 5B illustrates a unit for the production of a composite web according to the description in a schematic front view;

[0100] FIG. 6 illustrates a detail of a unit for the production of a composite web according to the description in a schematic view;

[0101] FIG. 7A illustrates a detail of a unit for the production of a composite web according to the description in a schematic view;

[0102] FIG. 7B illustrates a detail of a unit for the production of a composite web according to the description in a schematic view;

[0103] FIG. 8 illustrates an absorbent article according to the description in a schematic cross sectional view.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0104] With reference to the accompanying drawings and, in particular, FIG. 1, the numeral 1 denotes a composite web according to the description.

[0105] The composite web 1 is preferably intended for the production of absorbent sanitary articles such as diapers, an example of which, labelled 200, is illustrated in FIG. 4.

[0106] The composite web 1, as explained in more detail below, allows making what are known as three-dimensional or 3D topsheets for absorbent sanitary articles such as diapers.

[0107] The composite web 1 comprises a first continuous web 2 having a first face 2A and a second face 2B.

[0108] As illustrated, the first web 2 comprises at least one molded or contoured portion 3; in the example of FIG. 1, two molded portions 3 are shown.

[0109] The contoured portion 3 is a web portion on which a pattern is stamped, that is, a portion of the first web with the molded pattern on it.

[0110] The molded portion 3 has at least one protrusion 4. The protrusion 4 is at least partly delimited by a base portion 5, outside the protrusion 4.

[0111] With reference to the accompanying drawings, the molded portions 3 are greatly scaled up in the illustrations so as to make it easier to understand the description.

[0112] The contoured portions 3 will constitute the 3D portions of the topsheet, provided normally to improve the comfort of the diaper.

[0113] The composite web 1 comprises a segment 6 of a second continuous web 16 joined to the second face 2B of the first web 2 at least at the base portion 5.

[0114] The composite web 1 has at least one cavity 7. The cavity 7 is delimited by the first web 2 and by the segment 6 at the molded portion 3.

[0115] In other words, the cavity 7 is delimited by the second face 2B of the first web 2 at the protrusion 4 and by the segment 6 of second web 16.

[0116] When the composite web 1 is used in an absorbent sanitary product, the wearer is in contact with the first face 2A of the first web 2.

[0117] Advantageously, the molded portion 3 allows ensuring the comfort of the wearer who comes into contact at least with the protrusion 4 present on the first face 2A.

[0118] The segment 6 keeps the molded portion 3 in the required shape.

[0119] In an embodiment, the first web 2 comprises non-woven fabric.

[0120] In an embodiment, the first web 2 comprises polymer fibers.

[0121] In an embodiment, the segment 6 comprises non-woven fabric.

[0122] In an embodiment, the segment 6 is a liquid acquisition and distribution layer (ADL).

[0123] Advantageously, applying an ADL allows acquiring the liquids from the upper layers and directing them towards an absorbent core, thereby increasing the efficiency of the absorbent sanitary product.

[0124] In an embodiment, the segment 6 comprises a layer of carded fibers.

[0125] In an embodiment, the segment 6 comprises cellulose fibers.

[0126] In an embodiment, the segment 6 is airlaid material.

[0127] In an embodiment, the segment 6 is spunlace material.

[0128] In an embodiment, the molded portion 3, on its first face 2A has a multiplicity of protrusions 4, delimited by a respective multiplicity of base portions 5 surrounding the protrusions 4.

[0129] In an embodiment, the composite web 1 comprises a segment 6 of a second web joined to the second face 2B of the first web 2 at least at the multiplicity of base portions 5. In this embodiment, the composite web 1 has a multiplicity of cavities 7, delimited by the first web 2 and the segment 6 at the molded portion 3.

[0130] The multiplicity of protrusions 4 defines a motif M. In other words, the multiplicity of protrusions 4 defines a pattern that will constitute the three-dimensional (3D) portion of the topsheet.

[0131] In an embodiment, the first web 2 is contoured, or molded along its full length.

[0132] In an embodiment, the composite web 1 comprises a discrete succession of segments 6 of second web 16.

[0133] The segments 6 keep the first web 2 in its molded shape at least at the segments 6 themselves.

[0134] The composite web 1 has a succession of molded portions 3, each kept in the required shape by the corresponding segment 6.

[0135] The first web 2 may lose the shape derived from molding in the zones where the segment 6 is not present. With reference to FIG. 1, the first web 2 is shown without protrusions at the ends of it.

[0136] In an absorbent article 200 which uses a segment of the composite web 1 as topsheet, this segment will have a molded portion 3 for the wearer's comfort, where the segment 6 is disposed and where this segment simultaneously keeps the molded portion 3 in the required shape and defines an ADL.

[0137] In an embodiment, the protrusions 4 of the first web 2 have a bubble shape, illustrated, for example, in FIGS. 3 and 4.

[0138] In an embodiment, the protrusions 4 of the first web 2 have a wavy shape, illustrated, for example, in FIG. 2.

[0139] In an embodiment, the waves molded on the first web 2 comprise waves with crests parallel to the main direction of extension of the first web 2.

[0140] In an embodiment, the waves molded on the first web 2 comprise waves with crests transverse to the main direction of extension of the first web 2.

[0141] The protrusions 4 of the first web 2 may have different shapes: for example, diamond, heart, oval, teardrop, elliptic, shamrock.

[0142] The first web 2 and the segments 6 of the second web 16 are joined, for example, by welding and/or adhesive.

[0143] In an embodiment, the molded portion 3 of the first web 2 and the segment 6 of the second web 16 are joined by welding, in particular, thermal welding or thermomechanical welding.

[0144] In an embodiment, the molded portion 3 of the first web 2 and the segment 6 of the second web 16 are joined by ultrasound welding.

[0145] In an embodiment, the composite web 1 comprises a layer of adhesive 8, visible, for example, in FIG. 2.

[0146] The layer of adhesive 8 is disposed between the web 2 and the segments 6, in particular, between the base portion 5 of the molded portions 3 of the first web 2 and the segment 6 of the second web 16.

[0147] This description also has for an object an absorbent article illustrated, for example, in FIG. 4 and denoted by the reference numeral 200.

[0148] The absorbent article 200, described only insofar as necessary for understanding this invention, essentially comprises: a topsheet 201, an impermeable backsheet 202 and an absorbent core 203 disposed between the topsheet 201 and the backsheet 202.

[0149] The topsheet 201 is the part of the article 200 which, in use, is in contact with the wearer.

[0150] The topsheet 201 comprises a segment of a composite web 1 according to the features described above.

[0151] The composite web 1 is cut to make a segment of composite web to be assembled in the article 200.

[0152] The segment of composite web comprises a segment of the first web 2 and at least one segment 6 of second web 16.

[0153] In an embodiment, the segment 6 of second web 16 is smaller in length than the segment of first web 2.

[0154] In an embodiment, the segment 6 of second web 16 is smaller in width than the segment of first web 2.

[0155] As illustrated, for example, in FIG. 8, the segment 6 of second web 16, included in the composite web 1, is disposed between the first web 2 (included in the composite web 1) and the absorbent core 203.

[0156] This description has for an object a method for the production of a composite web 1. The composite web 1 is preferably used for making absorbent sanitary articles such as, for example, the article 200.

[0157] The method comprises a step of feeding a first continuous web 2.

[0158] The method comprises a step of molding at least one portion of the first continuous web 2 to obtain at least one molded portion 3 having at least one protrusion 4, delimited at least partly by a base portion 5.

[0159] Preferably, the method, in particular, the step of molding, comprises a step of embossing the first continuous web 2 along its entire length. By “embossing” is meant stamping or molding a 3D pattern on the first web 2.

[0160] The method used to mold the first web 2 is commonly known as embossing.

[0161] Advantageously, making protrusions 4 on the first web 2 allows enhancing the comfort of the wearer in contact with the first web 2.

[0162] The method comprises a step of joining at least one segment 6 of a second web 16 to the first continuous web 2 at least at the base portion 5 to delimit at least one cavity 7 between the first continuous web 2 and the segment 6 at the at least one molded portion 3.

[0163] The segment 6 is joined to the first web 2 at the base portions 5 on the side opposite the protrusions 4 so as to also define the cavities 7.

[0164] In an embodiment the method comprises a step of feeding, cutting and spacing a second continuous web 16 to obtain segments 6 of second web 16.

[0165] The web segments can be cut and spaced from each other to obtain discrete components using a method known as slip and cut, whereby the segments are cut and allowed to slide.

[0166] In an embodiment, the step of joining at least one segment 6 of a second web 16 to the first continuous web 2 comprises a step of welding the segments 6 of second web 16 to the first continuous web 2.

[0167] In an embodiment, the step of welding the segment 6 to the first web 2 is performed by ultrasound welding.

[0168] In an embodiment, the step of joining at least one segment 6 of a second web 16 to the first continuous web 2 comprises a step of disposing a layer of adhesive 8 between the segments 6 of the second web and the first web 2.

[0169] Joining the segments 6 of the second web 16 to the first web 2 allows fixing and keeping, at least at the segments 6, the 3D pattern that has been imparted to the first web 2.

[0170] In a preferred embodiment, the first web 2 is molded with the pattern M along its full length and a succession of suitably sized and spaced segments 6 is then applied to it. The segments 6 are applied at the base portions 5 on the side opposite the protrusions 4 in a zone in which the molded portion 3 is defined and where the second segment 6 is and preferably defines an acquisition and distribution layer.

[0171] This description has for an object a forming unit 100 for making, for example, composite webs like the web 1.

[0172] The unit 100 comprises a molding device 101 for molding the 3D pattern on the first web 2. The device 101 is of a type substantially known in the trade and is also called embossing device.

[0173] In the examples illustrated in FIGS. 5A and 5B, the device 101 comprises a first roller or drum 102, rotatable about an axis a2 in anticlockwise direction, and a second roller or drum 103, rotatable about an axis a3, parallel to a2, in clockwise direction, positioned relative to each other to define a gap 104 through which the first web 2 passes; for simplicity, the rollers 102 and 103 are considered to be substantially tangent.

[0174] In an embodiment, the drum 102 and the drum 103 are provided, on their cylindrical outer surfaces, with male and female portions, respectively, which are shaped to match each other and to impart the aforementioned 3D pattern or motif to the first web 2.

[0175] The first web 2 is molded by conveying it between the drums 102, 103.

[0176] The male-female portions allow making the protrusions 4 on the first web 2.

[0177] The male and female portions are shaped according to the shape which the protrusion 4 should have.

[0178] In FIG. 6, for example, the drums 102 and 103 are shaped to impart to the first web 2 wavy protrusions 4 where the crests 4A are parallel to the main directions of extension of the first web 2.

[0179] In an embodiment, the drum 103 is patterned and the drum 102 acts as anvil.

[0180] The first web 2 advances in a direction V2 through the gap 104 in such a way that the outside surfaces of the drums 102, 103 act in conjunction to engage the first web 2 and to impart the 3D pattern thereto.

[0181] Downstream of the molding device 101, the forming unit comprises an applicator device 105 for applying the segments 6.

[0182] In an embodiment, the applicator device 105 comprises a cutting device 110 to obtain the segments 6 from a continuous web 16.

[0183] In an embodiment, the cutting device 110 comprises an anvil 106, preferably in the form of a drum that is rotatable clockwise about an axis a6, and a rotary knife 107 that is rotatable anticlockwise about an axis a7, as illustrated in the example of FIG. 5A, and acting in conjunction with the anvil 106 to cut the segments 6 from a web 16.

[0184] The knife 107 cuts the second continuous web 16 to form the segments 6 which are suitably spaced, for example on the drum 106 itself with a known slip and cut method not further described.

[0185] In an embodiment, illustrated in the example of FIG. 7A, the drum 106 is tangent to the drum 102 to transfer the segments 6 onto the web 2 being fed by the drum 102.

[0186] The segments 6 are, for example, held by suction on the web 2 being fed by the drum 102.

[0187] The applicator device 105 comprises a joining device for joining the segments 6 to the web 2.

[0188] In an embodiment, the joining device comprises a welder which, in the example illustrated in FIG. 5A, comprises a welding drum 108 that is rotatable about an axis a8, clockwise in the example illustrated, disposed downstream of the drum 106 in the feed direction V16 of the web 16.

[0189] The drum 108 is tangent to the drum 102 and allows carrying out the step of joining the segments 6 to the first web 2, that is to say, joining the segments 6 to the base portions 5, as illustrated schematically in FIG. 7B.

[0190] In an embodiment, the drum 108 and the drum 102 are configured to weld the segments 6 to the web 2, for example by ultrasound welding.

[0191] In another embodiment, illustrated in the example of FIG. 5B, the drum 106 is tangent to the drum 108. The segments 6 are, in this case, transferred by the drum 106 to the drum 108 and welded onto the web 2 being fed by the drum 102 tangent to the drum 108.

[0192] In an embodiment, the applicator device comprises an adhesive dispenser 109.

[0193] The dispenser, preferably disposed downstream of the molding device 101, dispenses the layer of adhesive 8 to the web 2 so that the segments 6 can be joined to the first web 2 by the adhesive.