Method of manufacturing closure tabs for absorbent articles

0001This application is a divisional of U.S. patent application Ser. No. 10/875,389, filed Jun. 24, 2004 now U.S. Pat. No. 7,373,698.

BACKGROUND

00021. Technical Field

0003The present disclosure generally relates to closure tabs for use on absorbent articles, and more particularly, to mechanical closure systems having greater integrity by the application of compression bonding.

00042. Background of the Related Art

0005Absorbent articles such as, for example, disposable diapers, adult incontinent pads, sanitary napkins, pantiliners, incontinent garments, etc. are generally worn, in cooperation with garments and disposed against a body surface, etc., by infants or adult incontinent individuals. The absorbent article is employed to collect, absorb, etc. body fluid discharge, such as, for example, blood, menses, urine, aqueous body fluids, mucus, cellular debris, etc. For example, the absorbent article may be disposed between the legs of an individual adjacent a crotch area. The absorbent article is positioned with a garment and drawn into engagement with a body surface of the crotch area to collect fluid discharge.

0006As is known, absorbent articles typically include a fluid permeable coverstock for engaging the body surface, a fluid impermeable back sheet and an absorbent core supported therebetween. The backsheet serves as a moisture barrier to prevent fluid leakage to the garment. The absorbent core usually includes a liquid retention material that faces the body surface. The absorbent core can include loosely formed cellulosic fibers, such as wood pulp, for acquiring and storing fluid discharge.

0007Fastening of the absorbent articles with an individual requires the use of closure tabs or other closure systems employing fastening members. For example, in typical diaper-type garments, the garment is affixed to a wearer by attaching one or more closure tabs that extend across the wearer's hips to hold the back and front halves of the garment to one another. These closure systems typically include a fastening member or “tab material,” and mechanical closure material (such as hook and loop material) attached to the tab material. This composite of tab material and the mechanical closure material is fixed or secured to the absorbent article. Generally, such securing to the absorbent article is accomplished by adhesive, ultrasonic bonding, stitching and the like.

0008The securing of the mechanical closure material to the fastening members of absorbent articles, however, may suffer from occasional separation and dislodging. These separations cause the closure system to fail, thereby preventing attachment of the absorbent article to an individual and rendering such absorbent article ineffective. Failure can also occur, for example, because wearers typically move their bodies while the fasteners are attached, sometimes causing the closure tabs to become loose, uncomfortable or even unfastened. Yet another factor complicating the task of fastener tab design is the fact that the caregivers applying the tabs do so in a variety of ways that may or may not be suitable to properly affix tabs of the particular design being applied. Moreover, these drawbacks can disadvantageously result in wasted product and unpleasant product experience for the consumer.

0009Despite these and other efforts by absorbent garment manufacturers and others to provide suitable closure tabs for absorbent garments, there is still a need to provide a more comfortable, better fitting, and easily applied tab. These are just a few of the disadvantages of the prior art that the preferred embodiments seek to address. It would therefore be desirable to overcome the disadvantages and drawbacks of the prior art by providing a closure tab that contains hook and loop material that is securely and permanently attached thereto. It would also be desirable if the secure attachment of the hook and loop material to the tab material is easily and more efficiently manufactured.

SUMMARY

0010Accordingly, a closure tab and manufacturing process is disclosed that includes a closure tab with hook and loop material that is securely and permanently attached to fastening and attachment members. The method of attaching the hook and loop material and its constituent parts are easily. and efficiently manufactured. Other objects and. advantages of the present disclosure are set forth in part herein and in part will be obvious therefrom, or may be learned by practice of the present disclosure that is realized and attained by the instrumentalities and combinations pointed out in the appended claims for the devices and methods of the present disclosure consisting of its constituent parts, constructions, arrangements, combinations, steps and improvements herein shown and described.

0011The closure tabs of the present disclosure may include fastening and/or attachment members that include hook and loop attachment with greater integrity and security by way of mechanical application of compression bonding. The advantage of this construction provides for a manufacturing process and travel path that includes less manufacturing errors and down time due to the higher incidence of secure and permanent hook and loop material attachment.

0012In one particular embodiment, a closure tab is provided, in accordance with the principles of the present disclosure. The closure tab includes a first substrate and a second substrate. The second substrate is adhesively attached to the first substrate. The second substrate has mechanical closure material formed thereon. A compression bond pattern is applied to the first substrate and the second substrate. The compression bond pattern includes at least one outwardly extending protrusion. The compression bond pattern may include, for example, circular bond points, stripes, or a decorative element. More specifically, the second substrate is compressed onto the first substrate by a patterned roller. The second substrate may be compressed onto the first substrate by a plurality of pins. The second substrate may be a laminate of two or more materials.

0013The plurality of pins may be spaced in alternating offset rows. The plurality of pins can have a height of approximately 0.020″ to 0.060″ inches. The plurality of pins are configured so not to crush/deform a majority of closure members on the mechanical closure material. Further, the pins are configured so not to perforate the first or second substrates. The second substrate is attached to the first substrate by a plurality of compression bond points. The compressions bond points act to reduce longitudinal shear between the first and second substrates. More specifically, the compression bond points deform a portion of the first substrate and the second substrate.

0014In another embodiment, a method for making the closure tab is provided. The method includes the steps of providing a first substrate, similar to that described; adhesively adhering a second substrate, similar to that described, to the first substrate; and compressing the first substrate to the second substrate with a patterned roller. The step of compressing the first substrate to the second substrate may include a patterned roller having a plurality of pins. The plurality of pins are configured not to crush a majority mechanical closure members formed on the second substrate. In addition, the plurality of pins are configured not to perforate the first and second substrate. The compressing step may further include compressing the second substrate to a degree that deforms a base material of the second substrate. Preferably, at least ten percent (although other percentages are contemplated) of a thickness/width of the base material of the second substrate is deformed into an adhesive and the first substrate to further secure the second substrate to the first substrate. Desirably, the deformation of the second substrate does not perforate the first substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

0015The objects and features of the present disclosure are set forth with particularity in the appended claims. The present disclosure, as to its organization and manner of operation, together with further objectives and advantages may be understood by reference to the following description, taken in connection with the accompanying drawings, in which:

0016<figref idref="DRAWINGS">FIG. 1</figref> is a plan view of an absorbent article including closure tabs in accordance with the principles of the present disclosure;

0017<figref idref="DRAWINGS">FIG. 2</figref> is an enlarged cutaway view of the absorbent article illustrating a closure tab shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0018<figref idref="DRAWINGS">FIG. 3</figref> is a side view of a manufacturing process including a patterned roller used in making the closure tab shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0019<figref idref="DRAWINGS">FIG. 3A</figref> is an enlarged view of the indicated area of detail in <figref idref="DRAWINGS">FIG. 3</figref>;

0020<figref idref="DRAWINGS">FIG. 4</figref> is a front view of the patterned roller shown in <figref idref="DRAWINGS">FIG. 3</figref>;

0021<figref idref="DRAWINGS">FIG. 4A</figref> is an enlarged view of the indicated area of detail in <figref idref="DRAWINGS">FIG. 4</figref>;

0022<figref idref="DRAWINGS">FIG. 5A</figref> is a front view of a compression bond pattern applied to the closure tab shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0023<figref idref="DRAWINGS">FIG. 5B</figref> is a front view of an alternative compression bond pattern applied to the closure tab shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0024<figref idref="DRAWINGS">FIG. 5C</figref> is a front view of another alternative compression bond pattern applied to the closure tab shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0025<figref idref="DRAWINGS">FIG. 5D</figref> is a front view of another alternative compression bond pattern applied to the closure tab shown in <figref idref="DRAWINGS">FIG. 1</figref>.

0026<figref idref="DRAWINGS">FIG. 6</figref> is a enlarged cutaway side view of the closure tab shown in <figref idref="DRAWINGS">FIG. 1</figref>; and

0027<figref idref="DRAWINGS">FIG. 7</figref> is a perspective view of a manufacturing process for making the closure tab shown in <figref idref="DRAWINGS">FIG. 1</figref>.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

0028The exemplary embodiments of the closure tab and methods of manufacture disclosed are discussed in terms of an absorbent article including a closure tab with hook and loop material that is securely and permanently attached to fastening and attachment members. The presently disclosed closure tab includes include hook and loop attachment with greater integrity and security by way of mechanical application of compression bonding. It is contemplated that the closure tab may be employed with absorbent articles such as disposable diapers, adult incontinent pads, feminine pads, sanitary napkins, incontinent garments, or other articles intended to avoid leakage, overflow, etc., of fluid discharge, such as, for example, blood, menses, urine, aqueous body fluids, mucus, cellular debris, etc.

0029In the case of diapers and most adult incontinent products, the garment often is provided fully formed with factory-made side seams and the garment is donned by pulling it up the wearer's legs. In the case of diapers, wherein, for example, a baby lies on his or her back, a caregiver usually places the diaper between the baby's legs, pulls the front end of the diaper up between the legs and then attaches one or more closure tabs to the rear end of the diaper, thereby forming a pant-like structure.

0030In the discussion that follows, the term “body facing surface” refers to a portion of a structure that is oriented towards a body surface, and the “garment facing surface” refers to a portion of the structure that is oriented towards a garment and is typically opposing the body facing surface and may be referred to as such. As used herein, the term “body surface” refers to a portion of an individual's body that the absorbent article is disposed with for collecting, absorbing, etc. fluid discharge from the individual.

0031The following discussion includes a description of an absorbent article including a closure tab, followed by a description of a method of manufacture in accordance with the present disclosure. Reference will now be made in detail to the exemplary embodiments of the disclosure, which are illustrated in the accompanying figures.

0032Turning now to the figures, wherein like components are designated by like reference numerals throughout the several views. Referring initially to <figref idref="DRAWINGS">FIGS. 1-7</figref>, there is illustrated a closure tab(s) <b>33</b>, constructed in accordance with the principles of the present disclosure. Closure tabs <b>33</b> may be used to fasten absorbent articles, such as, for example diaper <b>10</b>. Diaper <b>10</b> includes a backsheet <b>12</b> bonded to a topsheet <b>14</b> and an absorbent core <b>16</b> disposed therebetween. Diaper <b>10</b> extends from a rear end <b>18</b>, configured for engagement with a rear portion of a subject, to a front end <b>20</b>, configured for engagement with a front portion of a subject, along a longitudinal axis x defined by diaper <b>10</b>. Each of two lateral extensions <b>34</b> is made from partially elastic material and is adhesively bonded to respective opposite sides <b>24</b>, <b>26</b> of rear end <b>18</b>. Lateral extension <b>34</b> is extensible in a direction along transverse axis y relative to longitudinal axis x. Each of closure tabs <b>33</b> is attached distally to respective lateral extensions <b>34</b> by adhesive bonding. It is contemplated herein that lateral extensions <b>34</b> and closure tabs <b>33</b> may be formed with materials that are elastic, non-elastic or a combination thereof.

0033Closure tab <b>33</b> comprises a first substrate, such as, for example, tab material <b>36</b> and a second substrate, such as, for example, a mechanical closure material employing hook or loop. Mechanical closure material includes a substrate or base <b>39</b> having formed thereon a plurality of hooks, loops or the like. that mate with a partner material on diaper <b>10</b>. In the illustrative embodiment, mechanical closure material or hook member includes hook stems or hooks <b>40</b> formed thereon and is herein referred to as hook material or hook member <b>38</b>. Hook member <b>38</b> is adhesively attached to tab material <b>36</b>. It is contemplated that either of hook member <b>38</b> or tab material <b>36</b> may comprise a laminate of two or more materials.

0034Hook member <b>38</b> may comprise any hook-and-loop type fastener, adhesive fastener, or other type of fastener that is capable of holding diaper <b>10</b> on a wearer. Suitable hook-and-loop fasteners are readily available from 3M Corp. (St. Paul, Minn.), Aplix, Inc. (Charlotte, N.C.), and Velcro USA, Inc. (Manchester, N.H.). Hook member <b>38</b> operates by engaging with or adhering to a corresponding surface or object (not shown) located on the opposite end of the diaper <b>10</b>, for example, front end <b>20</b>.

0035The present disclosure provides an improved closure tab <b>33</b> wherein a compression bond pattern <b>44</b> is applied to hook member <b>38</b> and tab material <b>36</b>. This compression bond provides an improvement in the adhesion between hook member <b>38</b> and tab material <b>36</b>. In the illustrative embodiments, a patterned roller <b>42</b> is used to compress hook member <b>38</b> onto tab material <b>36</b>. Alternatively, a patterned stamp (not shown) or other means may be used to apply compression bond pattern <b>44</b>.

0036Patterned roller <b>42</b> has a plurality of outwardly extending protrusions <b>50</b> on the roller's external circumference. In the illustrative embodiment, the roller comprises an anvil <b>42</b> having a plurality of pins <b>50</b> formed on a circumference thereof. Pins <b>50</b> have a height of approximately 0.020 to 0.060 inches, and a diameter d. Alternatively, the height of a respective pin <b>50</b> may be a percentage of the thickness T of hook base <b>39</b>. Pins <b>50</b> are spaced on the anvil's circumference in a plurality of alternating offset rows. The number of rows may be based on, for example, the width of hook member <b>38</b>, or the diameter(s) of pins <b>50</b> and/or hooks <b>40</b>. While the illustrative embodiment includes five (5) pin rows, there could be more rows if a wider hook member <b>38</b> was used. Consequently, as the pinned anvil <b>42</b> compresses hook member <b>38</b> onto tab material <b>36</b>, pins <b>50</b> apply thereto a pattern <b>44</b> of deformations, bond zones or bond points <b>46</b>.

0037More specifically, as pinned anvil <b>42</b> rotates over and exerts pressure on hook material <b>38</b> and tab material <b>36</b>, these materials <b>36</b>, <b>38</b> come into contact with pins <b>50</b> on the anvil's circumference. Consequently, each pin <b>50</b> forms a deformation or a set of deformations <b>46</b>a, <b>46</b>b, and <b>46</b>c as shown in <figref idref="DRAWINGS">FIG. 6</figref>. In particular, pins <b>50</b> deform hook material <b>38</b> into adhesive <b>48</b> and tab material <b>36</b> to further secure hook material <b>38</b> to tab material <b>36</b>. This will be described in more detail later with regard to a method for manufacturing closure tab <b>33</b>.

0038Instead of pins <b>50</b>, patterned roller <b>42</b> may comprise protrusions having other shapes so to apply various compression bond patterns <b>44</b> to hook member <b>38</b> and tab material <b>36</b>. For example, a plurality of elongated protrusions would result in a bond pattern <b>44</b> of stripes or the like (not shown). Other suitable bonding patterns include circles, squares, triangles, diamonds, waves, dashes, etc. Alternatively, compression bond pattern <b>44</b> may comprise a decorative pattern or element, such as a teddy bear, logo, or the like (<figref idref="DRAWINGS">FIGS. 5A-5D</figref>).

0039Applicants recognize that hook member <b>38</b> loses function in proportion to the number of individual hook stems <b>40</b> that may be crushed or deformed by pins <b>50</b> as roller <b>42</b> compresses hook member <b>38</b> to tab material <b>36</b>. Advantageously, pattern roller <b>42</b> is designed to avoid crushing or deforming hooks <b>40</b>, while providing enhanced integration of an adhesive <b>48</b> with hook member <b>38</b> and tab material <b>36</b>. For example, compression pattern <b>44</b> of circular bond points <b>46</b> may be in offset rows. With this pattern <b>44</b>, pins <b>50</b> are spaced far enough apart from each other so not to crush a majority of the plurality of hooks <b>40</b>. In addition, each bond point <b>46</b> has a diameter d′ sufficiently small not to crush hooks <b>40</b>, yet large enough not to push through or perforate hook member <b>38</b> or tab material <b>36</b> (<figref idref="DRAWINGS">FIG. 6</figref>). Accordingly, compression bond pattern <b>44</b> may be suitably applied to hook members <b>38</b> having a variety of hook densities and configurations.

0040In this regard, <figref idref="DRAWINGS">FIG. 6</figref> is an enlarged cutaway side view of closure tab <b>33</b>. Hook member <b>38</b> is attached to tab material <b>36</b> by a plurality of compression bond points <b>46</b> (only one bond point <b>46</b> is shown). To form compression bond point <b>46</b>, each pin <b>50</b> deforms a portion of hook member <b>38</b> and tab material <b>36</b>. These deformations include deformations <b>46</b>a, <b>46</b>b, and <b>46</b>c. Preferably, at least ten percent (although other percentages are contemplated) of the thickness of hook substrate <b>39</b> is deformed into adhesive <b>48</b> and tab material <b>36</b>, to further secure hook member <b>38</b> and tab material <b>36</b>. Consequently, compression bond points <b>46</b> reduce longitudinal shear between hook member <b>38</b> and tab material <b>36</b>. In this regard, deformations <b>46</b>b and <b>46</b>c interfere with each other and thus contribute to reducing shear.

0041A method of manufacturing a closure tab <b>33</b>, similar to that described, in accordance with the principles of the present disclosure is provided. The process can best be understood by reference to an illustrative embodiment shown in <figref idref="DRAWINGS">FIG. 7</figref>. A generally continuous length of hook material <b>38</b> is provided from supply roll <b>60</b>. Adhesive <b>48</b> is applied to hook material <b>38</b> by applicator <b>62</b>. Tab material <b>36</b> is provided from supply roll <b>64</b> and has a width W′. Hook material <b>38</b> is adhered to tab material <b>36</b> as a result of adhesive <b>48</b> applied to hook material <b>38</b> by applicator <b>62</b>. Nip rollers <b>66</b> facilitate adhesive contact between hook material <b>38</b> and tab material <b>36</b>. The adhering of hook material <b>38</b> to tab material <b>36</b> forms a composite <b>70</b>.

0042Other means of adhering hook material <b>38</b> to tab material <b>36</b> are contemplated. For example, in addition to adhesive attachment, it is possible to thermally bond (including ultrasonic bonding), chemically bond, or sew hook material <b>38</b> to tab material <b>36</b>. Alternatively, honk material <b>38</b> can be purchased with adhesive <b>48</b> already applied. It is further envisioned that adhesive <b>48</b> may be applied to tab material <b>36</b> (instead of hook material <b>38</b>) by applicator <b>62</b>. Applicator <b>62</b> may comprise, for example, a slotcoater, spray applicator, bead applicator, curtain applicator, or printer.

0043Composite <b>70</b> of hook material <b>38</b> and tab material <b>36</b> then travels towards pinned anvil <b>42</b> and smooth roller <b>43</b> opposed thereto. As pinned anvil <b>42</b> exerts pressure on/compresses composite <b>70</b>, pins <b>50</b> engage composite <b>70</b> and apply a pattern <b>44</b> of bond points <b>46</b> thereto, similar to that described. More specifically, pins <b>50</b> deform base portion <b>39</b> of hook material <b>38</b> into adhesive <b>48</b> and tab material <b>36</b> to further secure hook material <b>38</b> to tab material <b>36</b>. Each pin <b>50</b> creates a set of deformations <b>46</b>a, <b>46</b>b, and <b>46</b>c. Preferably, at least ten percent (although other percentages are contemplated) of a thickness/width of hook base material or substrate <b>39</b> is deformed into adhesive <b>48</b> and tab material <b>36</b>. The deformation does not perforate hook material <b>38</b> and tab material <b>36</b>.

0044Composite <b>70</b> is then cut by cutter <b>68</b> to form individual closure tabs <b>33</b>. Closure tabs <b>33</b> are then conveyed on conveyer <b>72</b> to a location for application to an absorbent article.

0045Cutter <b>68</b> may comprise rotary cutters, air knives, thermal knives, pinch cutters, ultrasonic cutters, lasers, and the like. Conveyor <b>72</b> may comprise a conveying belt, vacuum drum, transfer layers, gripper fingers, and the like. It is envisioned that the process of applying bond pattern <b>44</b> to composite <b>70</b> may be performed separate from the process of applying adhesive <b>48</b> to hook material <b>38</b> or tab material <b>36</b>, and separate from the process of cutting closure tabs <b>33</b>.

0046It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplification of the various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.