Pant-type wearing article and method for making the same

A pant-type wearing article configured so that fasteners used to connect front and rear waist regions with each other can be engaged with and disengaged from each other in a repetitive manner. Of the front and rear waist regions, at least one waist region, for example, the front waist region is formed in its transversely opposite lateral zones with inelastic regions being neither elastically stretchable nor elastically contractible in a waistline direction. These inelastic regions are provided with first fastener members selected from the first fastener members and second fastener members. The front waist region is further formed inside the respective inelastic regions as viewed in the waistline direction with a plurality of film-like joints defined by integrated sheet members forming the lateral zones.

RELATED APPLICATION

This application is a 35 U.S.C. §371 national phase filing of International Patent Application No. PCT/JP2009/057870, filed Apr. 20, 2009, through which and to which priority is claimed under 35 U.S.C. §119 to Japanese Patent Application No. 2008-146313, filed Jun. 3, 2008.

TECHNICAL FIELD

The present invention relates to pant-type wearing articles suitable to be used as disposable diapers or disposable toilet-training pants and also to methods for making the same.

RELATED ART

Various designs have already been proposed for pant-type wearing articles having front and rear waist regions adapted to be connected with each other along respective pairs of transversely opposite lateral zones thereof via a fastener in a manner that these lateral zones may be unfastened and, if desired, refastened. For example, a disposable absorbent article disclosed in JP 2005-95574 A (PATENT DOCUMENT 1) is provided along the respective pairs of transversely opposite lateral zones of front and rear waist regions with fastener members each extending from a peripheral edge of a waist opening to respective peripheral edges of leg-openings. The fastener members provided along the lateral zones of the front waist region are engaged with the associated fastener members provided along the lateral zones of the rear waist region to achieve a desired function as the fastener. During a production process for this absorbent article, the respective lateral zones of the front and rear waist regions along which these fastener members are attached are pretreated to become inelastic. To obtain such inelastic lateral zones, respective elastic members extending under tension across the front and rear waist regions in initial several steps are left contract only along the lateral zones in the subsequent step using a known snap-back technique.[PATENT DOCUMENT 1] JP 2005-95574 A

DISCLOSURE OF THE INVENTION

Problem to be Solved by the Invention

In the case of the absorbent article disclosed in PATENT DOCUMENT 1, repeated engagement and disengagement between the front and rear waist regions via the fasteners may sometimes lead to breaks of the sheet members occurring in the vicinity of boundaries between the fastener members and the sheet member to which these fastener members attached and eventually such breaks may propagate. In view of the problem as has been described just above, it is an object of the present invention to improve the wearing article of prior art so as to prevent the sheet member defining the lateral zones from being broken or torn and so as not to eventually propagate such break or tear even if engagement and disengagement between the front and rear waist members are repeated.

Measure to Solve the Problem

The object set forth above is achieved by an improvement in a pant-type wearing article according to the present invention on a first aspect thereof and by an improvement in a method for making the same according to the present invention on a second aspect thereof.

On the first aspect, the present invention relates to an improvement in a pant-type wearing article comprising a first waist region defined by one of front and rear waist regions, a second waist region defined by other of front and rear waist regions and a crotch region extending between these first and second waist regions wherein respective inner surfaces of second fastener members provided along transversely opposite lateral zones of the second waist region are detachably engaged with respective outer surfaces of first fastener members provided along transversely opposite lateral zones of the first waist region to obtain the pant-type wearing article having a waist-opening and a pair of leg-openings formed upon the engagement.

The improvement in the wearing article according to the present invention on the first aspect thereof is characterized as described below. At least one waist region of the first waist region and the second waist region includes a plurality of elastic members bonded thereto under tension so as to extend across the one waist region and, in the transversely opposite lateral zones of the one waist region, the elastic members are respectively cut at several points in a longitudinal direction thereof to form inelastic regions being neither elastically stretched nor elastically contractible in the longitudinal direction. The first fastener members or the second fastener members both provided in the one waist region are provided in the inelastic regions. Transversely opposite lateral zones of the one waist region are formed inside the inelastic regions as viewed in a waistline direction with a plurality of film-like joints comprising sheet members put flat together to define the transversely opposite lateral zones and integrated or comprising the sheet members and the elastic members integrated and the joints define joint areas extending in a vertical direction of the wearing article from the waist-opening to the leg-openings.

According to one preferred embodiment of the present invention on this first aspect, the elastic members are respectively cut in the one waist region also in regions spaced inward from the inelastic regions as viewed in the waistline direction so as to form the joints in regions further spaced inward from the regions formed spaced inward from the inelastic regions.

According to another preferred embodiment of the present invention on this first aspect, at least one of the sheet members put flat together comprises thermoplastic synthetic fiber and, at a plurality of the joints at which the elastic members are cut, components of the thermoplastic synthetic fiber are melt-solidified together.

According to still another preferred embodiment of the present invention on this first aspect, the sheet members are melt-solidified together at the joints.

On the second aspect, the present invention relates to an improvement in a method for making a pant-type wearing article comprising a first waist region defined by one of front and rear waist regions, a second waist region defined by the other of the front and rear waist regions and a crotch region extending between the first and second waist regions wherein respective inner surfaces of the second fastener members provided along transversely opposite lateral zones of the second waist region are detachably engaged with respective outer surfaces of first fastener members provided along transversely opposite lateral zones of the first waist region to obtain the pant-type wearing article having a waist-opening and a pair of leg-openings formed upon the engagement.

The improvement in such method according to the present invention on the second aspect thereof is characterized as described below. At least one of the first waist region and the second waist region includes a plurality of elastic members bonded thereto under tension so as to extend across the one waist region and, in the transversely opposite lateral zones of the one waist region, the elastic members are respectively cut at several points in a longitudinal direction thereof to form inelastic regions being neither elastically stretched nor elastically contractible in the longitudinal direction. The first fastener members or the second fastener members both provided in the one waist region are provided in the inelastic regions. Transversely opposite lateral zones of the one waist region are formed inside the inelastic regions as viewed in a waistline direction with a plurality of film-like joints comprising sheet members put flat together to define the transversely opposite lateral zones and integrated or comprising the sheet members and the elastic members integrated and the joints define joint areas extending in a vertical direction of the wearing article from the waist-opening to the leg-openings. The inelastic regions and the joint areas are formed by following at least the steps of:

a. subjecting a composite web to a cutter at regular intervals in the machine direction, wherein the composite web comprises first and second webs put flat and bonded together by adhesive and continuously fed in a machine direction and a plurality of continuous elastic members sandwiched between the first and second webs so as to extend in the machine direction and bonded under tension to at least one of the first and second webs, the thereby cutting the continuous elastic members at several points within predetermined ranges of the composite web to obtain the inelastic regions within the predetermined ranges; and

b. using a plurality of pins to pressurizing, with or without heating, the composite web comprising the first and second webs put flat and bonded together by adhesive and continuously fed in the machine direction and a plurality of the continuous elastic members sandwiched between the first and second webs so as to extend in the machine direction and bonded under tension to at least one of the first and second webs in a plurality of points lying inside the predetermined ranges of the composite web to be formed with the inelastic regions as viewed in the machine direction and thereby forming a plurality of joints at which the first web and the second web are integrated together in a film or at which the first web, the second web and the continuous elastic members are integrated together in a film so that these joints are distributed in a cross direction with respect to the machine direction and thereby the joint areas are obtained.

According to one preferred embodiment of the present invention on the second aspect thereof, at least one of the first and second webs comprises thermoplastic synthetic fiber and the cutter and the pins constituting a single roll adapted to be rotated in the machine direction and to be heated so that components of the thermoplastic synthetic resin are melt-solidified together at a plurality of the points at which the continuous elastic members are cut and a plurality of the points at which the joints are formed.

Effect of the Invention

The pant-type wearing article and the method for making the same according to the present invention is characterized in that the inelastic regions in at least one of the first waist region and the second waist region to be provided with the first fastener members or the second fastener members are formed by cutting the respective elastic members at a plurality of points arranged in the longitudinal direction of these elastic members. Such unique design allows the sheet members put flat together in the transversely opposite lateral zones of the one waist region in which the inelastic regions are formed to be bonded together by adhesive before the elastic members are cut. Aside inward from these inelastic regions as viewed in the waistline direction, the lateral zones are provided with a plurality of the film-like joints formed by the sheet members put flat and integrated together or a plurality of the film-like joints formed by the sheet members and the elastic members put flat and integrated together so as to define the joint areas. With such unique design, even if the sheet members are broken or torn along the respective boundaries between the sheet members and the first fastener members and/or the second fastener members, the film-like joints defining the respective joint areas prevent such break or tear from propagating. The film-like joints of the sheet members and the elastic members prevent the elastic members from being immobilized together with the sheet members from contracting.

IDENTIFICATION OF REFERENCE NUMERALS USED IN THE DRAWINGS

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The pant-type wearing article and the method for making the same will be described hereunder in more details with reference to the accompanying drawings.

FIG. 1is a partially cutaway side view showing a diaper1as an example of a pant-type wearing article according to the present invention andFIG. 2is a partially cutaway side view showing the diaper1having one of lateral zones thereof opened. A front-back direction, a vertical direction and a circumferential direction are indicated by double-headed arrows A, B and R, respectively. The diaper1has a front waist region6, a rear waist region7and a crotch region8extending between these two waist regions6,7. These regions6,7and8respectively comprise a liquid-pervious inner sheet2, a liquid-impervious outer sheet3and a body fluid absorbent core4(SeeFIG. 3) sandwiched between these two sheets2,3. In the front waist region6, front lateral zones11opposite in the waistline direction R and extending in the vertical direction B are provided on respective outer surfaces thereof with front fastener members12attached thereto (SeeFIG. 2). In the rear waist region7, rear lateral zones13opposite in the waistline direction R and extending in the vertical direction B are provided with rear fastener members14attached thereto. The inner sheet2is formed, for example, of a nonwoven fabric made of thermoplastic synthetic fibers and the outer sheet3is formed, for example, of a thermoplastic synthetic resin film, a nonwoven fabric made of thermoplastic fibers or a composite sheet comprising these film and nonwoven fabric.

The front fastener members12are associated with the rear fastener members14to form fasteners20for connecting the front and rear waist regions6,7in a manner that these waist regions are able to be unfastened and refastened, respectively, wherein the hook members constituting the mechanical fastener widely known in the trade name of Magic Tape are used here as the front fastener members12and the loop members constituting this mechanical fastener are used here as the rear fastener members14.FIG. 1shows the diaper1wherein a pair of front lateral zones11is connected with a pair of the associated rear lateral zones13via the fasteners20andFIG. 2shows the diaper1wherein a pair of front lateral zones11is connected with a pair of the associated rear lateral zones13via the fasteners20on the remote side and a pair of front lateral zones11has been disengaged from the associated rear lateral zones13on the near side. Obviously, the pant-type disposable diaper according to the invention can be put on and taken off from the wearer in the same manner as the diaper of prior art. The diaper according to the invention is distinguished from the diaper of prior art in that it is easy for the inventive diaper to open one of the lateral zones and thereby to check whether urination and/or defecation has occurred or not even when the wearer is in upright posture. This advantage can be effectively utilized by the user particularly when the diaper is delivered to the user in the pant-shape.

Referring toFIG. 1, the front and rear waist regions6,7are detachably connected to each other and thereupon a waist-opening31and a pair of leg-openings32are formed, in other words, the diaper1is shaped into a pant. The front fastener members12and the rear fastener members14respectively extend from the waist-opening31to the leg-openings32. It should be noted that, in the illustrated embodiment, the front fastener members12are respectively divided into upper and lower portions.

FIG. 3is a partially cutaway plan view of the diaper1with the front waist region6and the rear waist region7having been connected together via the fasteners20in the phase ofFIG. 1being disengaged from each other and flatly developed wherein a transverse direction of the front and rear waist regions6,7is indicated by a double-headed arrow C. In the diaper1shown byFIG. 3, the core4illustrated herein as partially broken away has a concave shape curved inwardly. The inner and outer sheets2,3sandwich the core4therebetween extend outward beyond a peripheral edge of the core4and bonded to each other in these portions extending outward by hot melt adhesive (not shown) coated intermittently and evenly on these portions. These portions of the inner and outer sheets2,3extending outward include the front lateral zones11and the rear lateral zones13. The inner and outer sheets2,3are bonded also to upper and lower surfaces of the core4by hot melt adhesive (not shown).

Various elastic members are sandwiched between the inner and outer sheets2,3. Specifically, the front waist region6is provided with waist elastic members16extend under tension in the transverse direction C, the rear waist region7is provided with waist elastic members17extending under tension in the transverse direction C and the crotch region8is provided with leg elastic members18extending under tension so as to describe curves along respective peripheral edges of the leg-openings32. In addition to these elastic members, front intermediate elastic members36are provided between the front waist-biasing elastic members16and the leg elastic members18so as to extend under tension in the transverse direction C and rear intermediate elastic members37provided between the rear waist-biasing elastic members17and the leg elastic members18so as to extend under tension in the transverse direction C. These elastic members16,17,18,36,37are intermittently bonded over full lengths thereof to the inner sheet2and/or the outer sheet3by hot melt adhesive wherein the elastic members16,36extend across the front waist region6and the elastic members17,37extend across the rear waist region7. The front and rear waist regions6,7are stretched and contracted in the transverse direction C, in other words, in the waistline direction R inFIG. 1as these elastic members16,17,36,38are stretched and contracted, respectively. It should be noted here that the front lateral zones11of the front waist region6are respectively formed with first front inelastic regions51and second front inelastic regions52. A plurality of spot-like front joints91inside the second front inelastic regions52and these front joints91define the front joint areas53. In the rear lateral zones13of the rear waist region7, first rear inelastic regions61and second rear inelastic regions62are formed. Inside the second rear inelastic regions62, a plurality of spot-like rear joints92are formed and these rear joints92define the rear joint areas63.

The first front inelastic regions51include the front waist elastic members16extending across the front waist region6, the front intermediate elastic members36extending also across the front waist region6and the leg elastic members18. Of these elastic members16,36,18, at least the elastic members16,36may be cut at a plurality of points55along length thereof to form the first front inelastic regions51. In consequence, these first front inelastic regions51are neither elastically stretched nor elastically contract. To cut these elastic members16,18,36, cutter blades may be pressed against one of the inner sheet2and the outer sheet3from the outer side to form a plurality of cuts56. In other word, the first front inelastic regions51formed in such away are areas of assembly of cuts56. Pieces of the elastic members16,18,36created by this cutting operation remain in the first front inelastic regions51in each contracted state. Each of these first inelastic regions51is preferably dimensioned to be same as or slightly larger than a size of the front fastener member12attached to the first inelastic region51. In this way, the front fastener members would not gather under contraction of the elastic members16,18,36and, in consequence, an engagement area between the front fastener members12and the associated rear fastener members14would not be substantially reduced. The second front inelastic regions52are formed aside inward from the associated first front inelastic regions51as viewed in the transverse direction C and preferably spaced from the associated first front inelastic regions51by a distance in a range of 5 to 15 mm. The second front inelastic regions52are formed by cutting at least the elastic members16,36of these elastic members16,18,36, respectively, each at a single point57in the form of cuts58. The presence of these second front inelastic regions52effectively eliminate a possibility that the front fastener members12might be directly pulled by at least the elastic members16,36of these elastic members16,18,36in the waistline direction R when the front waist region6and the rear waist region7are repetitively connected with and disconnected from each other. It should be understood here that the present invention may be exploited without forming the second front inelastic regions52unless such effective function of the second front inelastic regions52is required.

The front joints91may be formed by pressurizing the inner and outer sheets2,3put flat together in a spot-pattern at ambient temperature or by pressurizing them in a spot-pattern under heating, or by pressurizing them together with one or more of the elastic members16,18,36in a spot-pattern at ambient temperature or under heating. As a result of such pressurizing operation, these two sheets and elastic members are integrated to film thinner than a sum of the initial thickness thereof. For example, in the case of the inner sheet2and/or outer sheet3comprising thermoplastic synthetic fibers, the thermoplastic synthetic fibers is fused together, resulting in loss of texture peculiar to the initial fiber, i.e., presents a film-like state. If both the inner sheet2and the outer sheet3are film-like sheets made of thermoplastic synthetic resin from the start, these film-like sheets are fused together to form integrated film-like sheet which is thinner than a summed thickness of the inner sheet2and the outer sheet3. Preferably, the inner sheet2and/or the outer sheet3may be pressurized under heating to form the front joints91wherein at least one of these sheets2,3is melt-solidified. These front joints91are formed immediately inside the respective second front inelastic regions52as viewed in the waistline direction R inFIGS. 1 and 2so as to extend in the vertical direction B from the waist-opening31to the leg-openings31over a range substantially same as or longer than the first front inelastic regions51(SeeFIGS. 1 and 2). The expression “the front joints91in a spot-pattern” means that a plurality of joints91are intermittently distributed at least in the vertical direction A. While any particular shape of the individual front joints91is not specified, each of them is preferably circular dot having a diameter in a range of 0.5 to 5 mm.

With the diaper1having the front joint areas53comprising such front joints91, should the inner sheet2and/or the outer sheet3be broken or torn in the vicinity of the front fastener members12in the course of handling the front fastener members12, the front joints91reliably prevent such break or tear from being further propagated. For example, even when there is concern that the component fibers of nonwoven fabric might be forcibly drawn apart one from another and, in consequence, a local break of nonwoven fabric might propagate, the front joints91reliably prevent the component fibers from being drawn apart because the front joints91respectively comprise a plurality of component fibers integrated in a film-like state to prevent propagation of the break or tear. Assumed that the second front inelastic regions52are not provided, the front joints91will be preferably spaced from the associated first inelastic regions51by a distance of 5 to 30 mm.

The first rear inelastic regions61are formed by cutting the rear waist elastic members17, the leg elastic members18and the rear intermediate elastic members37included therein, more specifically at least the elastic members17,37thereof, at a plurality of points65along length thereof. In consequence, these first rear inelastic regions51can be neither elastically stretched nor elastically contracted in the transverse direction C. These elastic members17,18,37may be cut by the cutter blade to form cuts66which are similar to the cuts56in the case of the elastic members16,18,36. Each of these first rear inelastic regions61is preferably dimensioned to be same as or slightly larger than a size of the rear fastener member14attached to the first inelastic region61. In this way, the rear fastener members14would not be formed with gathers undulating in the transverse direction C, i.e., in the waistline direction R inFIG. 1. The second rear inelastic regions62are formed aside inward from the associated first rear inelastic regions61as viewed in the transverse direction C and preferably spaced from the associated first rear inelastic regions61by a distance in a range of 5 to 15 mm. The second rear inelastic regions62are formed by cutting at least the elastic members17,37of these elastic members17,18,37to define cuts68each at least a single point67. The presence of these second rear inelastic regions62prevent the rear fastener members14from being directly pulled by the elastic members17,18,37in the waistline direction R when the front waist region6and the rear waist region7are repetitively connected with and disconnected from each other. It should be understood here that the present invention may be implemented without forming the second rear inelastic regions62unless such effective function of the second rear inelastic regions62is required.

According to the embodiment shown byFIG. 4, the rear joints92are formed in the similar manner as the front joints91except that these rear joints92formed immediately inside the second rear inelastic regions62. These rear joints92are similar to the front joints91with respect to the shape as well as the size and intermittently distributed over the all range defined between the waist-opening31and the leg-openings32. With the diaper1having the rear joint areas63comprising such rear joints92, should the inner sheet2and/or the outer sheet3be broken or torn in the vicinity of the rear fastener members14in the course of handling the rear fastener members14, the rear joints91reliably prevent such break or tear from being further propagated. Assumed that the second rear inelastic regions62are not provided, the rear joints92will be preferably spaced apart from the associated first rear inelastic regions61by a distance of 5 to 30 mm.

While each of the front fastener members12is divided into upper and lower halves according to the particular embodiment of the invention shown byFIG. 1so that the front lateral zones11are easily deformed between the upper and lower halves of the respective front fastener members12and thereby improve fitness to the wearer's body. However, the front fastener members12each divided into the upper and lower halves may be replaced by the not divided but continuous front fastener members12unless such effect is required. While the rear fastener members14is implemented in the form of the loop members adapted to be engaged with the associated front fastener members12in the illustrated embodiment, the inner sheet2to which these rear fastener members14are attached may replace the rear fastener members14so far as the inner sheet2can be repetitively engaged with and disengaged from the associated front fastener members. Regarding the fasteners20in the illustrated embodiment, it is possible to use the loop members of the mechanical fastener as the front fastener members12and to use the hook members adapted to be engaged with the associated loop members as the rear fastener members14. Furthermore, it is also possible to attach the front fastener members12to the inner surface of the front lateral zones11and to attach the rear fastener member14to the inner surface of the rear lateral zones13.

FIG. 4is a view similar toFIG. 3, showing one preferred embodiment. In the diaper1shown inFIG. 4as has been flatly developed, the core4inFIG. 3is replaced by a body fluid absorbent panel80attached to the inner surface of the inner sheet2. The panel80comprises a body fluid absorbent core81, a liquid-pervious sheet82covering the upper surface of the core81and a liquid-impervious thermoplastic synthetic resin film sandwiched between the core81and the inner sheet2. The panel80is provided along transversely opposite side edges thereof with leak-barriers themselves known art, respectively. With the diaper1put on the wearer's body these leak-barriers84raise themselves from the panel80toward the wearer's skin so that these leak-barriers84would be held in contact with the wearer's thighs with fitness required to prevent body fluids from leaking sideways. Each of the leak-barriers84includes an elastic member85extending under tension in the longitudinal direction of the leak-barrier84. In this diaper1, the inner sheet2and the outer sheet3are bonded to each other by adhesive (not shown) coated on these sheets2,3so as to be uniformly distributed thereon. According to this embodiment also, the elastic members16,17,18,36,37are attached under tension so as be sandwiched between these sheets2,3and, similarly to the embodiment shown in FIG.3, the front lateral zones11and the rear lateral zones13are formed with the first and second front inelastic regions51,52and the first and second rear inelastic regions61,62, respectively. In the embodiment shown byFIG. 4, the front lateral zones11and the rear lateral zones13are further provided with the front joint areas53defined by the front joints91and the rear joint areas63defined by the rear joints92, respectively. The front fastener members12are attached to the first front inelastic regions51and the rear fastener members14are attached to the first rear inelastic regions61. To make such diaper1, a composite sheet consisting of the inner and outer sheets2,3put flat and bonded together may be previously prepared and then the panel80may be attached to such composite sheet by adhesive. The embodiment shown inFIG. 4is distinguished from the embodiment shown inFIG. 3in that it is possible to use a liquid-impervious thermoplastic synthetic resin film may be used as the inner sheet2.

FIG. 5is a schematic diagram partially illustrating a production process for the diaper1shown byFIG. 1wherein a machine direction is indicated by an arrow MD and a direction orthogonal to the machine direction MD is indicated by a double-headed arrow CD.

Referring toFIG. 5, in a step I, respective continuous materials116,117,118,136and137for the front waist elastic members16, the rear waist elastic members17, the leg elastic members18, the front intermediate elastic members36and the rear intermediate elastic members37are attached to a web103which is continuous material for the outer sheet3being fed in the machine direction MD by hot melt adhesive (not shown). The continuous material118for the leg elastic members18comprises continuous material118aand continuous material118bdescribing sine curves intersecting with each other.

In a step II, the panel-like body fluid absorbent cores4are at intervals attached to the web103at predetermined locations thereon as viewed in the machine direction MD by hot melt adhesive (not shown).

In a step III, web102which is continuous material for the inner sheet2is fed in the machine direction MD so as to cooperate with the web103to sandwich the continuous materials116,117,118,136,137of the respective elastic members and the individual cores4. Specifically, the web103and the web102are put flat and bonded together by hot melt adhesive (not shown) intermittently and uniformly coated on one of these two webs102,103to form first composite web171. This first composite web171is elastically stretchable and contractible in the machine direction MD.

In a step IV, the first composite web171is fed into a roll nip defined between a first roll161and a second roll162adapted to rotate at a predetermined velocity and to cooperate together to form a cutter160so as to cut the continuous materials116,117,118,136and137for the respective elastic members locally in a region defined between each pair of the adjacent cores4,4and to form a plurality of cuts55,57,65and67. In this way, the step IV results in formation of a second composite web172having a plurality of cuts55,57,65,67as seen inFIG. 3, the first and second front inelastic regions51,52cyclically arranged in the machine direction MD and the first and second rear inelastic regions61,62cyclically arranged in the machine direction MD in a manner similar to the first and second front inelastic regions51,52. The step IV further includes a sub-step of using the first and second rolls161,162to form the front joint areas53comprising the front joints91and the rear joint areas63comprising the rear joints92as shown inFIGS. 1 through 3.

In a step V, the front fastener members12shown inFIG. 1are attached to the web102constituting the second composite web172in the first front inelastic regions51while the rear fastener members14are attached to the web103constituting the second composite web172in the first rear inelastic regions61. The step V further includes a sub-step of cutting out disc-like laminate184consisting of the webs102,103put flat and bonded together from the second composite web172between each pair of the adjacent cores4to obtain a third composite web173formed with openings132.

In a step VI, the third composite web173is cut along respective center lines T (See the steps IV and V) extending in the cross direction CD between each pair of the adjacent cores4,4and the rear fastener members14are engaged with the associated front fastener members12to obtain the individual pants-like diapers1. By cutting the third composite web173in this manner, the first and second front inelastic regions51,52, the first and second rear inelastic regions61,62, the front joint areas53and the rear joint areas63are obtained on both sides of the respective center lines T. At the same time, the openings132are respectively bisected so as to form the respective peripheral edges of the leg-openings32.

FIG. 6illustrates a portion of the first roll161constituting the cutter160used in the production process illustrated inFIG. 5as has been flatly developed. The first roll161is used with a second roll162having a smooth peripheral surface (not shown) wherein some (117,137) of the elastic members to be cut by the cutter160are indicated by imaginary lines. The first roll161is formed on the peripheral surface164thereof with a plurality of blade segments180and a plurality of pins190in the form of columnar projections.

These blade segments180radially project from the peripheral surface164and serve to cut the respective continuous materials116,117,118,136and137lying between these blade segments180and a peripheral surface of the second roll162under a pressure with or without heating. Such blade segments180are arranged intermittently in an axial direction X to form a blade array181. The first roll161has a plurality of the blade arrays181extending in parallel one to another and, inFIG. 6, first through fifth pairs of blade arrays181athrough181eare arranged so as to be symmetric one with another about an imaginary line S extending in the axial direction X. On the first roll161, the first, second and third blade arrays181a,181b,181care used to form the diaper1with the first front inelastic regions51and the first rear inelastic regions61. The fourth and fifth blade arrays181d,181eare used to form the diaper1with the second front inelastic regions52and the second rear inelastic regions62. According to a preferred first roll161, the angle at which the individual blade segments180are oblique with respect to the axial direction X as well as the distance in the axial direction X by which each pair of the adjacent blade segments180are spaced from each other are substantially common to all of the blade arrays181. In each of the blade arrays181, the individual blade segments180are arranged in a unique manner. More specifically, assumed that these individual blade segments180are moved in a circumferential direction, each pair of the blade segments180adjacent in the axial direction X will partially overlap each other and provide a same effect as a single blade continuously extending in the axial direction X will provide. Consequentially, the respective continuous materials116,117,118,136and137for the respective elastic members extending in the machine direction MD as shown byFIG. 5are reliably cut by these blade arrays181.

The pins190are used to pressurize the first composite web171sandwiched between these pins190and the second roll162with or without heating and thereby to form the front joints91and the rear joints92.

The blade segments180and the pins190may be heated at a desired temperature to facilitate the continuous materials116,117,118,136and137for the respective elastic members to be cut, to melt-solidify regions of nonwoven fabric or film-like sheet forming the web102and the web103being in contact with the blade segments180, and to assist the pins190to form the front joints91and the rear joints92. The second roll162also is adapted to be adjustably heated at a desired temperature. A distance by which the first roll161and the second roll162are spaced from each other is adjustable. Even under such conditions, the web102and/or the web103might be damaged when the continuous materials116,117,118,136,137for the respective elastic members are cut by the blade segments180. In such a case, the component fibers forming the nonwoven fabric might be drawn apart and/or break or tear of the film-like sheet might propagate in the course of the cutting operation. However, the regions of the nonwoven fabric or the film-like sheet being in contact with the blade segments180and/or the pins190may be melt-solidified to prevent such damage from propagating.

With the cutter160comprising the roll pair, a clearance (not shown) between the blade segments180and the second roll162is set to be smaller than a clearance between the pins190and the second roll162. The first composite web171fed in the machine direction MD so as to be guided through the roll nip defined between the first roll161and the second roll162is pressurized by the pins190cooperating with the second roll162and then by the blade segments180cooperating with the second roll162. Such unique process of pressurization in incremental steps is effective to reduce the risk that the first composite web171might be damaged in comparison with the case in which the first composite web171is pressurized at one stroke.

The method exemplarily illustrated inFIG. 5as well as the roll161exemplarily shown inFIG. 6should not be construed to impose limitations to the present invention and may be appropriately varied or modified depending on the particular shape and construction of the diaper1. For example, it is possible to design the step V so that the third composite web173may be folded back onto itself along a center line W (SeeFIG. 5) bisecting a transverse dimension of this composite web173to obtain the diaper1which has been flatly folded back on itself having the front fastener members12and the rear fastener members14put in engagement. The number of the blade arrays181as well as the circumferential distance between each pair of the adjacent blade arrays181on the first roll161may be appropriately selected. Furthermore, the length of the individual blade segments180, the inclination angle of the individual blade segments180with respect to the axial direction X and the distance between each pair of the adjacent blade segments180in the respective blade arrays181may be also appropriately selected. Concerning the pins190also, it is possible to vary the tip's shape, the tip's diameter and the distribution pattern of these pins on the first roll161. For the method according to the present invention, the order in which the first composite web171is formed with the first and second front inelastic regions51,52, the first and second rear inelastic regions61,62, the front joint areas53and the rear joint areas63is not specified. For example, it is possible to form the first composite web171with the front melt-solidified joints91and the rear melt-solidified regions92using a roll pair provided separately of the first and second rolls161,162after the first composite web171has been formed with the first and second front inelastic regions51,52as well as the first and second rear inelastic regions61,62using the first and second rolls161,162. It is also possible to form the first composite web171with the second front inelastic regions52and the second rear inelastic regions62using a roll pair provided separately of the first and second rolls161,162after the first composite web171has been formed with the first front inelastic regions51and the first rear inelastic regions61using the first and second rolls161,162.

The present invention as has been described on the basis of the disposable diaper as the typical example may be exploited also, for example, in the form of a toilet-training pant, incontinent briefs or a disposable pant.