MXPA97002823A - Single clamp suspension system using consolid ramification type tabs - Google Patents

Abstract

A diaper is provided with an adhesive fastening tab of the configuration Y type, which includes a consolidated joint at the branch point between the fastener tape portions and the tongue release tape, the consolidated joint being free from the diaper. The bonded joint comprises a direct consolidation between the substrates of the fastener tape portions and the tongue detachment tape, or bonded joints between each of those two substrates and an intermediate bonding substrate.

Description

Diaper Fastening System USING CONSOLIDATED BRANCH TYPE TABS This invention relates to curling systems for baby diapers and incontinence diapers for adults, and more particularly to systems where the diaper fastening tabs, each formed as minimum of two different tapes, commonly referred to as fastening tape and release tape, to form tabs of the branch configuration type. BACKGROUND OF THE INVENTION Tapes of this general type are combined in long lengths to provide rolls of diaper tab material. A diaper manufacturer then supplies and transversally cuts the combined tapes in a sequential fashion, to form tabs of individual diapers and apply them to the edges of diapers which are manufactured. This operation forms the permanent "fabrication" joint between each individual re-attachable tab and its associated diaper. When the tongue is used to hold the diaper on a wearer, the free end of the tongue is deployed for adhesive fastening directly to another part of the diaper, or to a reinforcement tape (also called a target tape on a contact zone tape) transported in that other part of the diaper. The fastener establishes a temporary "user" joint between the tongue and this other part of the diaper.

When applied to a diaper, the portion of fastening tape of the tongue generally bends around the diaper edge in a storage position, with the free end of the fastening tape portion being conveyed in a release liner which it is provided on the outside of the release or release portion of the tab. The free end of the fastening tape portion is detached from the release liner to deploy the fastening tab. In this unfolded condition of the tongue, the fastening tape portion extends from its posterior distal end, beyond the diaper edge and is adhesively anchored to the polyethylene backing sheet or the like on the outer face of the diaper. Beyond the edge of the diaper, the portion of the release tape of the tab is attached to the portion of the fastening tape at a branch point. From this branch point, the portion of the release or detachment strip of the tab extends over and is adhesively anchored to the front sheet of the non-woven fabric permeable to moisture or the like on the inner side of the diaper. Tabs of this type of branching configuration are of various different sub-types, including union Y, junction contact surface Y, release joint and Adam (an acronym derived from "area bifurcation adhesive means"), which is the title of the US patent No. 3,833,456 of Reed et al., Common transferee now expired). These various sub-types are referred to below in more detail. The connection between the portions of the fastening tape and the release tape of the tongue at the branching point of the tongue strongly contributes to the distribution and absorption of the tongue tension forces imposed on the tongue joint of the tongue when product is in use. If the union at the branch point yields or fails, these forces are not properly distributed, and can destroy the relatively weak diaper elements to which the tongue is attached at its factory gasket, ie the thin polyethylene backsheet on the outer face of the diaper and the thin front sheet of the non-woven fabric permeable to moisture or the like on the inside face. BRIEF DESCRIPTION OF THE INVENTION In some applications, the fastening tabs of diaper closure systems require adhesive, so-called "repositionable", which exhibits significantly lower release resistance values than other more permanent "probably" adhesives. The lower peel strength allows the tongue joint end of the tongue, be removable from weak surfaces such as polyethylene backing sheet or uncoated-for-release reinforcement tapes (also referred to as target tapes or contact zone tapes) on the diaper backsheet, without destruction or tearing. Since the same adhesive is usually part of the binding of tape portion / release tape portion at the branching point of the tab, the adhesive can exhibit the same relatively low release strength or force and cause the system to of diaper fail. In this application, the present invention ensures an ultra-high permanent bond between the fastener tape and release tape portions, even when the adhesive must satisfy a different and inconsistent priority -, providing relatively easy detachment in order to achieve controlled adhesion . However, the invention is not limited to this particular application, but is generally useful for providing ultra-high bond strength at the point of branching between the portions of the fastening tapes and the release tape of the diaper tab, so such as to allow adequate distribution and absorption of the tongue tension forces imposed on the tongue joint of the tongue when the product is in use. The invention involves providing a consolidated joint at the point of branching between the portions of the fastening tape and the release tape of the tongue, the consolidated joint being free of the diaper. The consolidated joint comprises a direct consolidation between the substrates of the fastener tape and release tape portions or welds between each of those two substrates and an intermediate bond substrate. The result is ultra high strength at the branch point, the resistance approaches or equalizes the breaking strength of the substrate material itself. The features and advantages of the invention will be more fully understood from the more detailed description given below. PATENTS OF PREVIOUS TECHNIQUE The patent of the U.S.A. No. 5,176,670 issued to Roessler, shows a hook-and-loop fastener for diapers. The fastener comprises a long fastening tape and a second short tape. The two straps connect to opposite faces of the diaper at the factory seal. Figure 5, taken in conjunction with column 6, lines 6 through 13, are part of the description. If this is taken to refer to thermal bonding of sonic bonding in the joined areas, indicated by dots in the drawing (the applicants do not admit the correctness of this interpretation) this would include a consolidation of each tape to the diaper, as well as a weld between the tapes The consolidation between the tapes is not free of the diaper but will be extended to it, and will not establish a diaper-free consolidation union at the tongue branching point. Because the bond between the tab tapes will not be independent of the marginal layers of diaper, the tension in the tape will not be evenly distributed to the inner and outer sides of the diaper. Since the consolidation between the tapes and one side of the diaper margin will be continuous, consolidation will have to be performed at the diaper manufacturing site. In addition, as mentioned above, the tongue is not an adhesive fastener but a loop-and-hook fastener "U.S. Pat. No. 5,288,546 issued to Roessler, discloses an adhesive diaper tab where there may be a sonic bond between the outer end of the fastening tape and a finger release tape. See column 16 lines 41 to 47. U.S. Pat. No. 5,053,028 issued to Zola, discloses fastening the inner end of a hook-and-loop diaper tongue between the inner and outer diaper margins by sonic bonding. See column 8, lines 50 to 54 (the '670 from Roessler contains similar illustrations in Figures 7 to 9). The patent of the U.S.A. No. 5, 147,347 issued to Haang, describes fastening the inner end of an adhesive diaper tab by sonic union. See column 7, lines 58 to 62. DESCRIPTION OF THE DRAWINGS In the drawings, Figure 1 is a schematic illustration of a novel diaper combination with novel fastening tabs, embodying the invention, as seen from the waterproof backsheet side. diaper moisture, but partially blown to reveal the moisture permeable front sheet of the diaper. Figure 2 is an illustration similar to Figure 1, but fragmentary, showing a combination of the prior diaper technique, with fastening tabs of the prior art. Figures 3A-3C are diagrammatic cross sections of a direct Y bonding tab embodying the invention. Figures 3A'-3C correspond to Figures 3A-3C and show a variant form of direct Y-binding tab incorporating the invention (Figure 3C is only fragmentary). Figures 4A-4C are diagrammatic cross sections of a joining tab Y embodying the invention. Figures 5A-5C are diagrammatic cross sections of a release tie tab embodying the invention. Figures 6A-6C are diagrammatic cross sections of a tab Adam embodying the invention. (The drawing "A" in each series and shows a cross section of an individual tab before it is applied around a diaper edge). Drawing "A" in each series of drawings can also be considered as showing a cross-section of the tape material for the tab, with fastening tape, release tape and binding tape (if any) assembled in preparation for cutting into individual tabs . Drawing "B" in each series shows the configuration of the tongue as the diaper edge is applied, as is taken in the plane of line B-B of Figure 1. This can be referred to as storage configuration. Drawing "C" in each series shows the tongue in the clamping configuration, wherein the free end of the tongue fastening portion of the tongue is deployed to connect to another part of the diaper, as is taken in the line plane CC of Figure 1. Figures 7A-7C, 8A-8C, 9A-9C, and 10A-10C are diagrammatic cross sections showing configuration tabs for branching of the prior art respectively sub-types of direct Y bonding, bonding And consolidated, detachment bond and Adam, and Figures 3A-3C, 4A-4C, 5A-5C and 6A-6C are included for comparison purposes respectively. The drawings "B" and "C" of each of these series of the prior art are taken in the planes of the lines B'-B 'and C'-C of Figure 2. DESCRIPTION nffTAT.t.AnA nv. T.A Ttt? NCtn »? In Figure 1, a diaper D includes a fibrous material block material 12, of water-absorbent material, circumscribed between a moisture-impermeable backing sheet 14 of polyethylene or the like and a moisture-permeable non-woven fabric front sheet 16. or similar. The sheets 14 and 16 extend beyond the block of fibrous material 12, to form the marginal portion 16 around the diaper where the sheets 14 and 16 can contact each other. The diaper is configured as shown to fit an infant. When used, the backing sheet is on the outside and the front sheet is on the inside against the skin of the infant.

The diaper 10 is provided with tongue fasteners 20 at its side edges. These tabs are of the branching configuration type but are of novel construction which will be described below. As seen in Figure 1, the left tab holder 20 is in the storage position and the right tab holder is deployed to hold. These tab fasteners can extend only over the marginal portion 18 of the diaper, as illustrated, or they can also extend over a small portion of the block of fibrous material 12. A reinforcing tape 19 (also referred to as an objective tape or zone tape). contact) can be applied to the backsheet 14 in the outer front waist portion of the diaper. Each tab 20 is held by directing its portion of fastening tape over the associated end of the reinforcement tape 19 and pressing the fastening tape portion over the reinforcing tape to releasably adhere the two. The more the latter is directed over the first, the tighter the diaper adjustment will be. If reinforcement tapes are not used, the tape fastening portions of the tabs are directed over the same regions of the diaper as occupied by the reinforcement tape in Figure 1, and then applied directly to the backing sheet 14 with the intention to adhere liberally both.

Sub-types of tab clamps of the branching configuration type To allow for the operation and scope of the present invention, the four sub-types of tab clamps most readily comprised of the branch configuration type will now be described in detail. A pair of tongue fasteners of the prior art 30 is illustrated in Figure 2; the left tab fastener 30 is in the storage position and the right tab fastener 30 is deployed for fastening. The tongue fasteners 30 are of the branch configuration type and represent any of the sub-types illustrated in Figures 7A-7C, 8A-8C, 9A-9C and 10A-10C, including the direct Y-bonding tab respectively 30a, tongue of joint contact surface Y 30b, detachment tongue 30c and tab Adam 30d. Each of the tongue fasteners 30a, 30b, 30c and 30d has a portion of fastening tape 31a, 31b, 31c and 3Id, and each also has a portion of release tape 32a, 32b, 32c or 32d. The fastening tape portion of each tab fastener includes a fastening tape substrate 33a, 33b, 33c or 33d. The fastening tape portion of each tab fastener also includes fastening tape adhesive 34a, 34b, 34c or 34d. The release tape portion of each tab fastener includes a release ribbon substrate 35a, 35b, 35c or 35d. The release ribbon portion of each tab fastener also includes release ribbon adhesive 36a, 36b, 36c or 36d. Each portion of release tape further includes a lacquer or release liner for deployment 37a, 37b, 37c or 37d. The tongue 30a, 30b, 30c or 30d can be cut from the feed of a material roll (not shown) comprising a combination of fastening tape and release tape. To allow the material roll to be self-drilled without the use of a separate release liner, an un-winding release liner (not shown) can be applied over the entire exposed surface of the fastener tape substrate 33a, 33b, 33c or 33d (the upper surface as seen in the drawings). This coating is omitted from the drawings for clarity purposes. Before cutting and before application to the edge of the diaper D ', the configuration of the tongue is generally as illustrated in Figures 7A, 8A, 9A or 10A (but with a release liner for the above-mentioned unbinding). The tab 30a, 30b, 30c or 30d is no longer wrapped around the edge of the diaper D 'to fasten on both sides thereof as illustrated in 7B, 8B, 9B, or 10B, with the releasable end of the fastener tape portion being conveyed in the deployment release liner 37a, 37b, 37c or 37d. When the diaper is to be fastened, the releasable end of the fastening tape portion 31a, 31b, 31c or 31d is lifted from its associated release release liner to release it and deploy the fastening tab as illustrated in FIG. Figure 7C, 8C, 9C or 10C. In this unfolded condition of the tongue, the fastening tape portion extends from its distal end backward beyond the diaper edge D ', and is adhesively anchored to the polyethylene backing sheet or the like in the marginal portion of the diaper and the outer face of the diaper (either directly attached adhesively as in the configurations of Figures 7-9 or indirectly anchored in adhesive form by the coated end of non-release of the release tape portion, as in the configuration of the Figure 10). At or just outward beyond the diaper edge, the release ribbon portion 32a, 32b, 32c or 32d of the tab is attached to its associated fastening tape portion at a branch point 38a, 38b, 38c or 38d. From this branch point, the release tape portion also extends rearwardly beyond the edge of the diaper and is adhesively anchored to the inside face of the diaper at the marginal position of the diaper. The connection between the fastening tape portion and the releasing or releasing tape portion of the tab at the branching point strongly contributes to the distribution and proper absorption of the tongue tension forces that are imposed on the gasket. factory, while wearing the fastened diaper. Those forces, when not properly distributed, can easily destroy relatively weak elements such as polyethylene backing sheet to which tongue fastener is attached. The direct Y-bonding configuration of the tongue 30a (Figure 7) is generally perceived as the strongest combination of fastening tape and release tape. The bonding contact surface configuration Y of the tongue 30b (Figure 8) is similar, but uses a narrow additional strip of tape, to provide the contact surface substrate 39b. In the tabs 30a and 30b, portions of the fastener and release tape are combined, directly or by the contact surface, over a few millimeters of the width of the tapes (length of the tab). As a result, each of the tabs 30a or 30b provides a branch point 38a (Figure 7) or 38b (Figure 8) of which the tension forces, generated while using the fastened diaper, are evenly distributed to the inner sides and outside of the diaper on the factory board. Tape-to-tape joints at branch points can only be separated by overcoming the shear strength of the joints, which are generally higher (often much higher than their peel strengths).

The detachment configuration of the tongue 36 (Figure 9) also uses an additional narrow tape to provide a bonding substrate 39c, at the branch point 38c. From this branch point, the tension forces generated while using the subject diaper, are uniformly distributed to the inner and outer sides of the diaper at the factory tip. In the Adam configuration of the tab 30d (Figures 10A-10C) when the fastener is attached to the diaper in the diaper factory, the release ribbon portion 32b (as well as the fastening tape portion 3Id) extends around the diaper edge from one side of the diaper to the other, such that the fastening tape portion 3Id is indirectly supported on the associated face of the diaper margin, the indirect support is through the portion of the release tape portion. underlying 32d, which adheres to the diaper on the same face. From the branch point 38d the tension forces, generated while using the subject diaper, are evenly distributed to the inner and outer sides of the diaper at the factory seal. The fastening tape portions 31a, 31b, 31c and 31d of the tabs described are all; They extend around the diaper rim from one diaper side to the other, when the fastener is attached to the diaper at the factory. The fastening tape substrates 33a, 33b, 33c and 33d all extend around the edge without interruption, as do the fastening tape adhesives 34a, 34b and 34c. However, the fastening tape adhesive 34d of the Adam type fastener (Figures 10A-10C) is preferably interrupted by a small space as illustrated. The release joint configuration of the tongue 30c (Figures 9A-9C) and the Adam configuration of the tongue 30d, (Figures 10A-10C) are perceived as being weaker than the configurations of Figures 7A-7C and Figures 8A-8C since the configurations of Figures 9A-9C and Figures 10A-10C experience peel action, when subjected to the tension forces generated while the subject diaper is worn, while the configurations of Figures 7A-7C and Figures 8A-8C only undergo shear action when subjected to these tensile forces. This can be more easily understood by comparing branch points 38a and 38b of Figures 7C and 8C on the one hand with branch points 38c and 38d of Figures 9C and 10C, on the other hand. (It should be remembered that the tabs are illustrated diagrammatically in these Figures as being unfolded for clamping, but before being clamped and therefore before undergoing tensile forces.Therefore, as illustrated, the tabs still have to be stretched and stretched. by tension forces resulting from for example the contortion of an infant It will be understood that this tensioning and stretching will contribute to the detachment action in the joints 38c and 38d In the case of Adam's construction illustrated in Figure 10, in stressed condition, the bifurcation point, ie the branching point tends to form at the point between the fastening tape adhesive 34d and the release tape substrate 35d, where the deployment release coating 37c terminates. analogous illustrations of this condition where an "area bifurcation" occurs, of Figure 3A and column 5, lines 5 to 17 of the US patent No 4,020,842 of Richman et al., Of common transferee, now recently expired, in Figure 6d of the U.S. patent. No. 4,050,121 to Richman, the descriptions of which are incorporated herein by reference). The Adam configuration of the 30d tab (Figure 10) has been in commercial use for many years of life which is convenient for low cost production and high speed supply. However, since Adam's configuration is subject to detachment action as described above, presents a particular problem if the Adam configuration is employed in diaper closure systems that require a so-called "repositionable" adhesive, which exhibits relatively low resistance values. As mentioned previously, the relatively low peel strength allows the tongue user end of the tongue to be removed from weak surfaces such as polyethylene backing sheet or uncoated reinforcement ribbons for detachment (also referred to as target tapes or ribbons). of contact area) on the diaper backsheet, without destruction or tearing. Since the same adhesive is usually part of the binding of tape portion / release tape portion at the branching point of the tab, the adhesive exhibits the same resistance to relatively low release force and can result in system failure. of the diaper. It is not always possible to balance the conflicting requirements of (1) easy or "controlled" detachment required to open or reposition the subject diaper tab and (2) sufficient detachment strength to provide adequate strength at the branch point of the tongue. of configuration Y. The same remarks apply to the peel attachment configuration of Figure 9. To complete, there may be mentioned another tab of two tapes of the art (not illustrated). It is referred to as a tongue without a joint. It simply comprises a portion of fastening tape applied to the backing sheet of the diaper and a portion of release tape applied to the front face sheet, without connection between the two. In the storage position, the front sheet is folded around the edge of the diaper on the release sheet. In the unfolded position, the fastening tape portion is unfolded from the edge of the diaper and extends, at which point the two tape portions come off. The configuration will appear similar to that of Figures 7B and 7C, but without any contact between the tape portions except for support of the fastening tape portion in the release liner of the release tape portion in the storage position. While the present invention is directed more specifically to tabs of the release joint and Adam types, it can be applied to provide improved diaper tabs of any of the types discussed above. The Tab Fasteners of the Present Invention The tabs 20 of Figure 1 are tabs of the branching configuration type embodying the invention, and represent any of the sub-types illustrated in Figures 3-6, including tongue-and-groove connection Y direct 20a, connecting tab Y of contact surface 20b, detachment tab 20c and tab Adam 20b. Each of the tongue fasteners 20a, 20b, 20c and 20d has a fastening tape portion 21a, 21b, 21c or 21d and each also has a release portion 22a, 22b, 22c or 22d. The fastening tape portion of each tab fastener includes a fastening tape substrate 23a, 23b, 23c or 23d. The fastening tape portion of each tab fastener also includes a fastening tape adhesive 24a, 24b, 24c, or 24d. The release tape portion of each tab fastener includes a release strip substrate 25a, 25b, 25c or 25d. The fastening tape portion of each tab fastener also includes release tape adhesive 26a, 26b, 26c or 26d. Each portion of tape further includes a lacquer or coating for deployment release 27a, 27b, 27c or 27d. Each of the tab fasteners has with respect to its longitudinal direction, a first terminal segment si, a central segment s2, and a second terminal segment s3. Each strip portion 22a, 22b, 22c or 22d extends over at least the first end segment if and part of the center segment s2 (the strip portion 22d extends over all three segments if, s2 and s3). Each portion of the release tape is adhesively anchored to the inner face of the diaper, to define a portion of the factory seal between the tab and the diaper. Each portion of fastening tape 21a, 22a, 23a or 24a superimposes its corresponding release strip portion and extends over all three segments si, s2 and s3. Each portion of the fastening tape is adhesively anchored, either directly or through the release strip portion 22d in the case of the fastening tape 21d, to the outer face of the diaper, to define the other part of the factory seal between the tongue and the diaper. Like the tabs of the prior art, the tongue 20a, 20b, 20c or 20d can be cut from the release feed of a material roll (not shown) comprising a combination of fastening tape and release tape. To allow the roll of material to be self-wound without the use of a separate release liner, an unbinding release liner (not shown) can be applied over the entire exposed surface of the fastening tape substrate 23a, 23b, 23c or 23d (the upper surface as seen in the drawings). This coating is omitted from the drawings for clarity purposes. Before cutting and before application to the edge of the diaper D ', the tongue configuration is generally as illustrated in Figures 3A, 4A, 5A or 6A (but with the aforementioned unwind release liner). The tab 20a, 20b, 20c or 20d is then wrapped around the edge of the diaper D 'to fasten on both sides thereof as illustrated in 3B, 4B, 5B, or 6B, with the releasable end of the tape portion. 21a, 21b, 21c or 21d, which is transported in the deployment release liner 27a, 27b, 27c or 27d. When the diaper is to be fastened, the releasable end of the fastening tape portion 21a, 21b, 21c or 21d is lifted from its associated deployment release liner, to release it and deploy the fastening tab as illustrated in FIGS. Figures 3C, 4C, 5C or 6C. In this unfolded condition of the tongue, the fastening tape portion extends from its distal end backward, beyond the diaper edge D ', and as indicated externally.; that is, the fastening tape portion is adhesively anchored to the polyethylene backing sheet or the like in the marginal portion of the diaper and on the outer face of the diaper (either directly attached to the backing sheet adhesively as in the configurations of Figures 3-5 or indirectly anchored adhesively to the backing sheet by the non-releasing coated end of the release strip portion, as in the configuration of Figures 6A-6C. The release or release portion 22a, 22, 22c or 22d of the tab is attached to its associated fastening tape portion at a branch point 28a, 28b, 28c or 28d From this branch point, the portion of tape of detachment also extends backward, beyond the edge of the diaper and is adhesively anchored to the inside face of the diaper in the marginal position of the diaper.As fasteners 30a, 30b, 30c and 30 d the fastening tape portions 21a, 21b, 21c and 21d of the fasteners 20a, 20b, 20c and 20d, all extend around the diaper rim from one side of the diaper to the other when the fastener is attached to the diaper at the factory of diapers. As in the Adam 30d type prior art fastener, in the preferred Adam type fastener 20d of the present invention, when the fastener is attached to the diaper in the factory, the fastening tape adhesive (24d) is interrupted by a small fastener. space. However, in the practice of the present invention in the manufacture of fasteners other than those of the Adam type, the fastening tape adhesives 24a, 24b and 24c are preferably similarly interrupted by small spaces as illustrated to allow similar consolidation procedures. to those that will be described below. The fasteners 20b and 20c respectively use bonding substrates 29b and 29c. The branching configurations of the tongue fasteners 20a, 20b, 20c and 20d will be seen to correspond generally to those of the tongue fasteners 30a, 30b, 30c and 30d. However, tongue fasteners 20a, 20b, 20c and 20d each include bonded joints between their fastener tape substrate and release tape substrate at their branch point. The consolidated bond joining the fastening tape substrate 23a and release tape substrate 25a comprises a simple consolidation 40a. The consolidated bond joining the fastening tape substrate 23b and the release tape substrate 25 comprises the two consolidations 40b bonding substrate 29b. The welded contact surface joining the fastening tape substrate 23c and the release tape substrate 25c comprises the two consolidations 40c and the contact surface substrate 29c. The consolidated bond joining the fastening tape substrate 23d and the release tape substrate 25d comprises a single consolidation 40d. Consolidated joints comprise simple consolidation such as consolidations 40a and 40d, are simpler to perform than those comprising two consolidations and a joining substrate. A currently preferred construction of the tab 20d illustrated in Figures 6a-6c. The currently preferred practice for forming this construction will now be described. In this description, it will be understood that they are references to the construction as seen in Figure 6a, however interpreted to apply not to discrete diaper tabs but to the continuous sections of the diaper tab material as it is formed, coated and Combined by the manufacturer of the diaper tape material. In presently preferred practice, the manufacturer of the diaper tab material covers one side of the fastening tape substrate with an unzipping release liner (not shown), patterned the other side with the fastening tape adhesive, leaving the small space shown (which can be say 6 mm in width) covers in patterned part of the width of one side of the release strip substrate with the liner to detach-unfold, then combine that release tape substrate face against the fastener tape adhesive before the release tape substrate has received its coating adhesive for release, then apply the SONOTRODE of a sonic welder directly to the exterior or coated face for release-unbundling (the upper part or outer face as seen in Figure 6A) of the fastening tape substrate in the center of the small adhesive space, while supporting the release tape substrate (which is still uncoated with adhesive). detachment tape) with a ceramic or stainless steel backing roller. After consolidation, the exposed face of the release tape substrate is coated with release tape adhesive and the material is then wound onto a self-winding roll. The consolidation is continuous and of course extends over the direction of the coating and rolling lines and therefore through the direction of widths of the diaper tabs that are cut from the material. In tests using polypropylene with a thickness of 6 to 120 microns, the applied SONOTRODE is operated at amplitudes between 25 and 60 microns and placed at a distance from the plot equal to half the amplitude (between 12.5 microns to 30 microns). Good consolidation is obtained at speeds between 30 and 90 m / minute at a frequency of 36 kHz. Other frequencies (for example 25 KHz) are possible but require other adjustments.

The consolidation equipment used in the tests was the model generator SG25-500-36 Khz with model converter SE-26 / 20-36 Khz manufactured by Telsonic Ultrasonics AG, Bronschhofen, Switzerland. All these consolidated joints are diaper free D in the sense that there is no union between them and any part of the diaper; on the contrary, they are bound to the diaper only by unsupported stretches of the adhesive tape substrate coated on adhesive and / release tape substrate. The tension forces generated while the diaper is worn are therefore distributed from the branching point of each of these fasteners homogeneously to the inner and outer sides of the diaper at the factory seal, while at the same time the bond between the substrate of fastening tape and the release tape substrate is equal to the strength of the substrate material itself. With respect to the direct Y bonding tab 20a, and the contact surface bonding tongue Y 20b, providing diaper-free consolidated joints at the branching point according to the invention means that uniform distribution of tension forces is maintained. while substrate-to-substrate bonding is improved to the point where it can only be separated by exceeding the breaking strength of the substrate material itself.

With respect to the detachment tab 20c, and the Adam 30d tab, providing diaper-free consolidated joints at the branch point means the same. Further, since the Adam configuration (and the release joint configuration) are subject to the detachment action, as described above, the invention is particularly advantageous if the Adam configuration (or the detachment attachment configuration) is employed in diaper closure systems that require a so-called "repositionable" adhesive that exhibits relatively low peel strength values. As mentioned previously, the relatively low peel strength allows the tongue user end of the tongue to be relieved from weak surfaces such as polyethylene backing sheet or non-peeled coated reinforcing tapes (also referred to as target tapes or contact zone tapes) on the diaper backsheet, without destruction or tearing. To date, since the same adhesive is usually part of the fastening tape portion / release tape portion at the branching point of the tongue, the adhesive exhibits the same strength strength at relatively low release and can result of failure of the diaper fastening system. In this application, the present invention ensures an ultra high permanent bond and peel strength at the point of branching between the fastener tape and release tape portions, allowing the adhesive to be chosen in uncommitted manner to meet a priority different and previously inconsistent - that provides an easy detachment in order to achieve controlled adhesion. It has been known to use separate side-by-side coatings of different adhesives instead of providing the same adhesive as the fastening tape adhesive in all areas on the fastening tape substrate. In these constructions, one adhesive provides the junction at the branch point and the other provides the releasable attachment to another part of the diaper. However, these constructions require patterning the two different adhesives side by side in the fastening tape substrate and are not as simple as the present invention. To be complete, a variant form of direct Y bonding tab is illustrated in Figures 3A'-3C corresponding to Figures 3A-3C. Like the tongue fasteners previously described, the tongue 20a 'illustrated in Figures 3A'-3C has respect to its longitudinal direction, a first terminal segment si, a central segment s2, and second terminal segments s3. The tongue 20a 'has a fastening tape portion 21a', a release tape portion 22A ', a fastening tape substrate 23a', a fastening tape adhesive 24a ', a release tape substrate 25a', a release ribbon adhesive 26a ', a release liner 27a', a branch point 28a 'and a consolidated joint 40a'. The tongue 20a ', differs from the tongue 20a in that the consolidated joint 40a' of the tongue 20a 'is attached to the upper surface of the release strip substrate 25a' (the opposite face of the face receiving the tape adhesive of the tape 20a '). detachment 26a '), while the consolidated joint 40a of the tongue 20a, joins the lower face bent backward from the release strip substrate 25a (the same face that the release tape adhesive 26a receives). The tongue 20a 'is generally similar to the tongue 20a in concept and operation, as will be easily understood. In some circumstances, the tongue 20a 'may be preferable, since its elements may be placed more conveniently to carry out the consolidation step during fabrication. It should be evident that this description is by way of example, and that various changes can be made by adding modify or delete details without departing from the fair scope of the teachings contained in this description. The invention is therefore not limited to particular details of this description except for the extent to which the following claims are necessarily limited.

Claims (4)

1. REINFORCEMENTS 1. In a disposable diaper that is provided with a tongue fastening system that includes a tongue fastener of the type Y configuration, the tongue fastener has length, width and thickness directions, and also has respect to its longitudinal direction , first and second terminal segments of a central segment between the terminal segments, the tongue fastener comprises first and second tongue portions, each comprising a substrate of resinous film ribbon and a layer of adhesive supported on the substrate, the first The tab portion comprises a releasable tape portion, which extends over the first end segment and also over at least the center segment, the second tab portion comprises a portion of the fastener tape superimposed on the portion of the release tape and which is extends over the first terminal segment, the central segment and the second segment ends l, a release liner between the fastening tape portion and the release tape portion, on the first end segment of the lug, whereby the gripping tape portion is releasable from the release liner portion on the liner. first terminal segment, for releasing and deploying the end of the fastening tape portion associated with the first end segment, the improvement characterized in that the substrates of the first and second tongue portions are joined by consolidated bonding of the resinous films of the substrates , the consolidated joint extends through the width direction of the tongue fastener in the central segment, the consolidated joint is free of connection with the diaper.
2. 2. An article according to claim 1, characterized in that the consolidated joint comprises a bond directly between the resinous films of the substrates.
3. 3. An article according to claim 1, characterized in that a bond strip of resinous film material extends through the width direction of the tongue fastener in the central segment, the consolidated joint comprising (1) the film resinous of the joining strip (contact surface); (2) a first consolidated bond between the resinous film of the bond strip and the resinous film of the substrate of the first tongue portion; and (3) a second consolidated bond between the resinous film of the tie strip (contact surface) and the resinous film of the substrate of the second tongue portion.
4. 4. An article according to claim 2, characterized in that the tongue of the type configuration Y is of the sub-type wherein the first tongue portion comprises the portion of the release strip extending over the second terminal segment as well as over the first terminal segment and the central segment.