NZ240175A - Disposable nappy pants; elastic members converge towards transverse edges of the pants - Google Patents

Abstract

Disposable shaped nappy comprising a water-impermeable outer sheet (2), defining a narrower crutch area (27) between the two wider ends or waistband areas (28, 29), an absorbent pad (22), securing elements (24) for attaching the nappy, and elastic elements (4) tensionally secured to the water-impermeable sheet (2) on either side of the absorbent pad (22), substantially on all the length of the water-impermeable sheet. The elastic means have a higher tension in the crutch region (27) than in the end areas (28, 29), and have, in the latter (28, 29), sections (4c) converging in the direction of the transversal edges of the water-impermeable sheet, so that the elastic elements (4) form a virtually closed elastic barrier around the absorbent pad (22), thereby providing a water-impermeable sheet which is longitudinally elastic in the crutch area and transversally elastic in the ends.

Description

240175 a<o- \0- o 9-ro- °ll r< flblPfSliS 27 SEP 894 NEW ZEALAND PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION NAPPY-PANTS WITH ELASTIC CROTCH AND BELT MEMBERS AND PROCESS AND PLANT FOR THE CONTINUOUS MANUFACTURE OF SUCH NAPPY-PANTS iiN A fi -v V n«i { -9 OCT 1991*/] V fn/ We, PEAUDOUCE, a French corporation of 59, rue de la Vignette F-59126 Linselles, France, hereby declare the invention for which we pray that a patent may be granted to us, and the method by which if is to be performed, to be particularly described in and by the following statement:- - 1 -(followed by page la) - la - 240 1 7 5 The present invention relates to nappy-pants to be disposed of after use and to a process and to a plant for the continuous manufacture of such nappy-pants.

Such nappy-pants, which can be employed for young 5 children or for incontinent adults usually comprise a liquid-impervious outer sheet, a liquid-permeable inner sheet, the two sheets being of a substantially rectangular overall shape, preferably with median indentations cut out in their lengthwise edges to allow 10 legs to pass through and defining in the lengthwise direction of the nappy-pants a narrower crotch region between two wider end or belt regions. In addition, these nappy-pants comprise an absorbent pad whose dimensions are smaller than those of the said two sheets and which 15 is arranged between the said sheets so that its edges are set back in relation to the corresponding edges of the two sheets, the said two sheets being joined together by adhesive bonding along their edges, around the absorbent pad. Furthermore, these nappy-pants comprise fastening 20 members for closing the nappy-pants, using the two end regions, around the user's waist. These fastenings may be, for example, adhesive fastenings arranged on the lengthwise edges of the sheets, preferably in the vicinity of the transverse edge of the end region forming 25 the rear part of the nappy-pants.

In order to improve the sealing at the leg passage it is known, furthermore, to provide on such nappy-pants elastic crotch members adhesively bonded under tension to the inner face of the impervious outer 30 sheet, on each side of the absorbent pad, along each of the said indentations.

These elastic. . -crotch _ -members are; generally rectilinear, but it has also been proposed in Patent Application EP-A-048,010 to attach these elastic members 35 in a curved form to allow them to follow the shape of the » 240175 W - 2 - indentations. According to this document the elastic members are attached under tension to the impervious sheet solely in the crotch region.

It has furthermore been proposed by Patent 5 Application FR-A-2,542,979 to attach such lengthwise elastic members under variable tension to a pair of nappy-pants over the whole length of the latter, namely under high tension and in a curved form in the crotch region and under a lower tension in the end regions. 10 Furthermore, according to Patent Specification WO 86/02530, lengthwise elastic members are attached in a rectilinear form with a high tension in the crotch region of a pair of nappy-pants for incontinent individuals and are, furthermore, attached with a lower tension 15 and following a diverging or diverging and then converging path in the end regions of the nappy-pants.

According to this document the diverging and/or converging sections of the elastic members are inclined at an angle of the order of 30' in relation to the 20 lengthwise direction of the nappy-pants. These elastics improve the lateral sealing of the nappy-pants but do not contribute in any way to the improvement of sealing in the lengthwise direction (where the belt is).

Finally, Patent Application GB-A-2,173,689 25 discloses nappy-pants comprising both lengthwise elastics extending throughout the length of the nappy-pants, on both sides of the absorbent pad, and transverse elastic members extending throughout the width of the nappy-pants in the two end regions. The main disadvantage in using 30 these two types of elastic members consists of the difficulties of continuous manufacture of such nappy-pants when the elastic members must be attached in the stretched state to the impervious sheet. In fact, such nappy-pants are manufactured continuously, either in the 35 lengthwise direction or in the transverse direction, from a continuous strip of impervious sheet onto which either the lengthwise elastic members or the transverse elastic members are attached continuously in the stretched state.

On the other hand, the attachment under tension of other I v ^*2 9 APR 1994.- 240 1 7 elastic members extending perpendicularly to the direction of manufacture cannot be done continuously, and this considerably limits the rate of manufacture. In addition, the use of two lengthwise elastic members and 5 of two transverse elastic members on each pair of nappy-pants increases the cost of the nappy-pants.

The subject of the present invention is a pair of nappy-pants which, while being simple and inexpensive to manufacture, ensures good leakproofing both in the crotch 10 region and in the belt regions. Another subject of the invention is a process for the continuous manufacture of such nappy-pants, a process which is particularly simple and which permits particularly high rates of manufacture. A further subject of the invention is a plant for 15 implementing this process, designed so as to permit, on the one hand, a high rate of manufacture and, on the other hand, a particularly accurate placing of the elastic members.

The nappy-pants to be disposed of after use in 20 accordance with the invention comprise a liquid-impervious outer sheet, a liquid-permeable inner sheet, the two sheets being of a substantially rectangular overall shape with median indentations cut out from their lengthwise edges to allow legs to pass through and defining in 25 the lengthwise direction of the nappy-pants a narrower crotch region between two wider end or belt regions. The nappy-pants additionally comprise an absorbent pad whose dimensions are smaller than those of the two sheets and which is arranged between the said two sheets so that its 30 edges are set back in relation to the corresponding edges of the two sheets, the said two sheets being joined together by adhesive bonding at their edges, around the absorbent pad. The nappy-pants comprise, furthermore, fastening members for closing the nappy-pants, using the 35 two end regions, around the user's waist. Finally, the nappy-pants comprise, -elastic, .members, attached under tension by adhesive bonding to the inner face of the impervious sheet on both sides of the absorbent pad, substantially over the whole length of the impervious 240175 sheet, with a higher tension in the crotch region than in the end regions. According to the invention the elastic members arranged on the opposite sides of the absorbent pad have, in the two end regions, sections converging in 5 the direction of the transverse edges of the impervious sheet, so that the elastic members form a practically closed elastic barrier around the absorbent pad and provide the impervious sheet both with a lengthwise elasticity in the crotch region and a transverse 10 elasticity in the end regions.

With the nappy-pants in accordance with the invention it is therefore possible to obtain, with the aid of only two elastic members, a result equivalent to that obtained hitherto using four elastic members. 15 The converging sections of the elastic members preferably follow a substantially rectilinear path and are inclined by at least 45* and preferably at least 60° in relation to the lengthwise direction of the nappy-pants .

Furthermore, the length of the converging sections of the elastic members is preferably such that the length of the projections of the said sections onto the transverse edges of the nappy-pants corresponds to at least 40% and preferably to more than 50% of the length 25 of the said transverse edges of the nappy-pants.

Furthermore in the nappy-pants in accordance with the invention the converging sections of the two elastic members join together or approach each other as closely as possible near each transverse edge of the nappy-pants. 30 The maximum distance separating the two elastic members at or near the transverse edges of the nappy-pants corresponds to less than 20% and preferably to less than 15% of the length of the said edges, that is to say of the width of the nappy-pants where the transverse edges 35 are. Depending on the shape of the absorbent pad, this distance is also- less than 50% -and preferably less than 30% of the maximum width of the absorbent pad.

In the converging sections, the elastic members advantageously have a tension which is at least 50% lower ftAO 1 7 than the tension of the elastic members in the crotch region.

In the case of nappy-pants comprising an absorbent pad which is, just like the two sheets, 5 hourglass-shaped, that is to say of a rectangular overall shape with two opposite side indentations in the crotch region, it is advantageous that the elastic members have, in the median part of the crotch region, substantially rectilinear sections followed on both sides by outwardly 10 concave curved sections, themselves followed in the end regions by outwardly convex curved sections to which the said converging sections are joined. In this case, the said outwardly convex sections advantageously have a lower tension than the converging sections, themselves 15 having a lower tension than the tension of the elastic members in the crotch region.

Thus, the elastic members may be, for example, extended between approximately 100 and 200% in the crotch region, between approximately 5 and 10% in the outwardly 20 convex sections and between approximately 40 and 60% in the converging sections.

Within the scope of the invention each elastic member may either consist of an elastic strand or comprise a plurality of individual elastic strands 25 arranged parallel to each other.

Following the process in accordance with the invention for the continuous manufacture of such nappy-pants, a continuous impervious sheet is passed over a supporting and driving member. To attach the elastic 30 members by adhesive bonding onto the said sheet, continuous elastic members are brought into contact with the said sheet, on the said member, while varying at regular intervals the tension of the said elastic members at their points of contact with the said sheet. The said 35 points of contact are moved at regular intervals transversely to the lengthwise, direction of_the said sheet so as to attach the said elastic members by adhesive bonding onto the said sheet so that the said elastic members form, on the said sheet, two repetitive continuous 240179 outlines which are symmetrical in relation to the lengthwise axis of the sheet. According to the invention, the transverse movement, at regular intervals, of the points of contact between the elastic members and the 5 impervious sheet is controlled so that the said two outlines cross each other at regular intervals or come close to the point of touching each other or nearly touching each other.

To simplify the manufacture it is advantageous 10 not to apply adhesive to the elastic members but to apply adhesive to the impervious sheet on its face receiving the elastic members, with a view to the adhesive bonding of the latter onto the sheet.

In order to permit a retraction of the ends of 15 the elastic members when the impervious sheet and the elastic members adhesively bonded onto the latter are subsequently cut transversely, an adhesive-free strip can be left in the middle of the width of the impervious sheet during the application of the adhesive. 20 For the same purpose, it is possible to interrupt intermittently the application of adhesive to the impervious sheet in a region situated in the middle of the width of the said sheet, so as to form at regular intervals an adhesive-free window where the paths of the 25 elastic members cross or touch each other.

Still for the same purpose, it is also possible to apply adhesive to the impervious sheet continuously over its whole width and to spray an antiadhesive material at regular intervals onto the elastic members. 30 The plant for the continuous manufacture of nappy-pants in accordance with the present invention comprises, for the accurate guidance of each elastic member, a guiding means mounted in the immediate proximity of the supporting and driving member over which 35 the impervious sheet passes to receive the elastic members, so that it can'be'freely oriented around an axis substantially perpendicular to the surface of the said member, preferably by means of a frictionless bearing, on a trolley driven in translation transversely to the 240 1 75' direction of movement of the supporting and driving member. This trolley may be driven by a linear or rotary motor, preferably controlled, with index-linking to the movement of the supporting and driving member, by an electronic control unit commanded by a computer.

The said guiding means may advantageously comprise a guiding head with closed holding means for the elastic members, for example in the form of parallel drilled holes or channels into which the elastic members are threaded, so that the elastic members do not run the risk of escaping from the holding means during the translational movements of the guiding means.

Furthermore, the variable stretching tensions of the elastic members may be produced by rotary feeding instruments which exert a clamping effect on the elastic members and whose variable-speed drive is controlled by the same computer-commanded electronic control unit.

The trajectories for positioning the elastic members on the impervious sheet may be preferably followed and controlled by a computer program, as can the shape of the crotch indentations cut out of the impervious sheet, for example by a device incorporating water jets, permitting an accurate adjustment of the outer edge of the elastic members in relation to the edge of the indentations.

A number of illustrative embodiments of the invention will be described below in greater detail with reference to the attached drawings and without any limitation being implied. In the drawings: Figure 1 is a diagrammatic side view of the main components of a plant for the continuous manufacture of nappy-pants in accordance with the invention; Figure 2 is a top view of only a part of the means for feeding, tensioning and guiding the elastic members of Figure 1; Figure 3^ is a. .diagrammatic side view of an alternative form of the plant of Figure lj Figure 4 is a view illustrating a number of stages of manufacture of a first embodiment of 240 1 7 5 nappy-pants according to the invention; Figure 5 is a top view, with partial cutaway, of a pair of nappy-pants manufactured according to Figure 4; Figure 6 is a view illustrating a number of 5 stages of manufacture of a second embodiment of nappy-pants according to the invention; Figure 7 is a top view, with partial cutaway/ of a pair of nappy-pants manufactured according to Figure 6.

As shown very diagraramatically in Figures 1 and 10 2, the plant for the continuous manufacture of nappy-pants according to the invention comprises a rotary drum 1 onto which is being wound a continuous flexible sheet 2 of a moisture-impervious heat-weldable material such as polyethylene. The drum 1 is driven in rotation in the direction of the arrow F1 so that the sheet 2 fits the rotary drum 1 closely over approximately one half of its periphery. The drvun is maintained at a relatively low temperature of between 30 °C and 100°C, obtained optionally by forced artificial cooling inside the drum. 20 Two groups or bundles 4 of four parallel individual elastic strands 5 which may be, for example, elastic threads of the Lycra type or textured threads, or any other suitable elastomeric material, unwound from reels 6, are driven between two sets of tensioning 25 rollers 7 driven in rotation so that the linear speed of travel of the elastic strands 5 leaving the tensioning rollers 7 is lower than the peripheral speed of the impervious sheet 2 on the rotary drum 1.

By adjusting the difference in speed in an 30 appropriate manner, the desired elongation of the elastic strands 5 is obtained and can be varied at regular intervals as the latter move past.

An adhesive material 8 which is liquefied by melting (of hot-melt type) is delivered by a device of 35 the nozzle type 9 for applying adhesive, which extrudes it continuously .over . the-whole .width the. impervious sheet 2 which moves past under this nozzle 9, with the exception of a middle region 10/ of small area, situated on the lengthwise axis 11 of the said sheet 2, and which 24 01 7 9" is repeated according to a step corresponding to the length of the future nappy-pants to be formed.

The four elastic strands 5 of each bundle 4 then run over a first stationary guiding instrument 12 and 5 then over a guiding head 13 provided with holes or channels for guiding and holding the strands parallel to each other, and mounted so as to rotate freely with a frictionless bearing, for example of the air cushion type, on a movable trolley 14 which can slide on a slide 10 rail 15 in the directions shown by the double arrow F2.

The trolley is driven by a rotary motor 17 or optionally by a linear motor driven as a function of the rotation of the drum 1 and hence of the travelling position of the impervious sheet 2, by an electronic 15 control unit 18, driven by a computer program 19. This same electronic control device allows the motors 20 actuating the tensioning rollers 7 to be driven.

After passing over the guiding heads 13, (only one of which is shown in Figure 2), the elastic strands 20 come into contact at 21 with the impervious sheet 2 on its adhesive-coated face, at the periphery of the rotary drum 1, the guiding heads being arranged in the immediate proximity of the point of contact 21. The elastic strands 5 are directed between the guiding head 13 and the point 25 of contact 21 with the impervious sheet which is at the periphery of the rotary drum 1, in a direction tangent to the profile of the rotary drum 1.

The frictionless rotation of the guiding head 13 about an axis perpendicular to the axis of the drum 1, 30 that is to say in a plane tangent to the peripheral surface of the drum 1 in the region of the point of contact 21 allows the direction of the elastic strands at the entry of the guiding head to be kept permanently on the axis of the trajectory according to which the said 35 strands are adhesively bonded to the impervious sheet 2, avoiding exposing them- to high.transverse forces which would be detrimental to their correct positioning and their proper adhesive bonding to the said impervious sheet 2. 24017 5 The characteristics of the plant, in particular of the rotary drum, and the nature of the adhesive are optimised in order that an immediate bonding of the elastic strands to the impervious sheet should take place immediately after the points of contact 21, allowing the elastic strands to be bonded along a double curved outline which is symmetrical in relation to the lengthwise axis (11), as can be seen in the following figures.

The plant according to Figure 3 reproduces most of the components of the plant of Figure 1, with the difference that the rotary drum 1 which is used as a supporting and driving member for the impervious sheet 2 is replaced here by a rotary endless conveyor belt, preferably applying suction, driving the sheet 2 which is flattened.

Figure 2 and the description given on this topic also apply to the plant of Figure 3, taking into account the fact that the belt la drives the sheet 2 with a translational motion and not with a rotary motion like a drum.

The main advantage in using a conveyor belt la applying suction, instead of a rotary drum, is the more accurate positioning of the elastic strands 5 of each bundle 4 on the impervious sheet 2. In fact, on a drum, the impervious sheet 2 undergoes, after application of the elastic strands under tension, a transverse retraction causing an undulation of the sheet, that is to say a distortion which is detrimental to the parallel position of the strands in the bundle. Moreover, because of the curvature of the surface of the drum, the distance between the various strands of a bundle varies when these strands are deposited onto the impervious sheet 2 during the transverse movements of the guiding head 3.3, that is to say when the latter pivots about its axis of rotation. On the other hand, when the elastic strands 5 are deposited onto an impervious sheet 2 supported and driven flat by a conveyor belt la which applies suction, this sheet is held perfectly until the elastic strands are definitively attached and cannot therefore be distorted, - 11 240 1 7 and the geometrical conditions in which the deposition of the elastic strands onto the sheet 2 conveyed flat by the belt la takes place ensure that the distance between the strands does not vary, that is to say that the strands 5 are parallel on the impervious sheet 2.

In a first embodiment, illustrated in Figure 4, the continuous impervious sheet 2, which unwinds in the direction of the arrow F3 arranged along the lengthwise axis 11 of the said sheet 2, and which has received an 10 application of adhesive 8, receives along its two lengthwise edges two bundles 4 of four continuous parallel individual elastic strands, shown as a single thick line for greater clarity. These two bundles cross each other at regular intervals, forming a repetitive closed outline 15 pattern whose length along the axis 11 corresponds to that of the nappy-pants.

The concave curved portions 4a between the points C and D, corresponding to the central crotch region of the future nappies, are adhesively bonded in the highly 20 stretched state according to the process which was described with reference to Figures 1, 2 and 3, the elongation of the elastic strands being close to 180% in value, whereas the convex curved portions 4b between the points D and E, and 3 and C, have undergone only a very 25 small stretching", corresponding to an elongation of only 5 to 10%; finally, the rectilinear portions 4c between the points A and B, and E and F, which connect the above curved portions 4b of two successive patterns, have been stretched slightly more strongly, so that the elastic 30 strands here exhibit an elongation of approximately 50%.

It should be noted that these rectilinear portions 4c of the elastic strands cross each other in an X, in a region 10 centred on the lengthwise axis 11 of the sheet 2, and which is devoid of any adhesive 35 material, with the result that in this place the elastic strands are not attached .to the impervious sheet 2.

The deposition of absorbent pads 22, of an anatomical shape or of any other shape, and of a moisture-permeable veil 23 (which is not shown in 240 1 7 Figure 4 but can be seen in Figure 5)/ which are adhesively bonded to the impervious sheet 2 using the adhesive material 8, and then of adhesive fastenings 24 on the lengthwise edges of the sheet 2, take place in a 5 subsequent stage of the process. After the stage of cutting out the indentations 25, the final stage of manufacture takes place, consisting in sectioning the composite strip obtained transversely along the lines 26 so as to form the nappy-pants like those illustrated in 10 Figure 5.

During the transverse sectioning the rectilinear portions 4c of the elastic' strands are sectioned at their intersection, and their ends retract over a small length corresponding to the region 10 which is devoid of any 15 adhesive material 8, that is to say as far as points A and F.

Finally, as can be seen in Figure 5, a pair of nappy-pants is obtained, in which the crotch indentations 25 have a concave curved outline adjoined on the inside 20 by a set 4 of curved elastic strands placed in a highly stretched state, the outermost strand of which is arranged close to the outline of the indentation, ensuring suitable leakproofing against the risks of transverse leakages from the absorbent pad at this spot. 25 The two sets of elastic strands 4 extend continuously and symmetrically in relation to the lengthwise axis 11, forming an outline of practically closed perimeter around the absorbent pad 22. These two sets of elastic strands therefore make it possible both to ensure the lengthwise 30 elasticity in the crotch region 27 and also to form, in the front 28 and rear 29 end regions of the nappy-pants, elasticated belts which facilitate the adjustment to the user's waist and which greatly limit the risks of a leakage along the transverse edges of the nappy-pants. 35 In a second embodiment illustrated in Figures 6 and 7/ where identical, components _bear . the same references, the essential difference from the preceding embodiment lies in the fact that the two bundles 4 of continuous parallel individual elastic strands are 240175 deposited onto the impervious sheet 2 moving past along the arrow F3, along its lengthwise edges, without crossing each other at regular intervals.

The rectilinear portions 4c which are symmetrical 5 in relation to the axis 11 approach each other as far as the points A, but then the heads guiding the two bundles 4 of elastic strands, which may, furthermore/ be mounted on trolleys sliding on the same slide rail, are driven in opposite directions and the bundles 4 move apart after 10 the points F. Between the points A and F of two successive patterns, the elastic strands which are applied onto the sheet 2 in the regions 10 which are devoid of any adhesive material will be able to retract during the stage of transverse sectioning along the lines 26. 15 A pair of nappy-pants which is very close to that of Figure 5 is therefore obtained, as shown in Figure 7, but in which the two sets 4 of elastic strands form an elasticated outline around the absorbent pad, the perimeter of which has, at the two ends (28 and 29) of 20 the nappy-pants along their lengthwise axis 11, an opening 30 whose width can be adjusted, as a function of the instructions for moving the heads guiding the elastic strands and/or the area of the nonadhesive region 10, possibly to an extremely small value so as to approach 25 the embodiment of Figures 4 and 5.

It should be noted that the "window" or non-adhesive region 10 on the impervious sheet 2 may be advantageously replaced by spraying an antiadhesive solution onto the end parts of the rectilinear portions 30 4c of the elastic strands, in all the embodiments envisaged.

To prevent the ends of the elastic members 4 from adhering to the impervious sheet 2 it would also be possible to keep an adhesive-free strip in the middle of 35 the width of the impervious sheet, over the whole length of the latter, during the application 8 of the adhesive to this sheet. This would make it possible in particular to position a moisture indicator, for example by printing with a water-soluble ink, directly on the inner face of 240175 the impervious sheet.

Furthermore, although in the examples illustrated the various portions of variable tension of the elastic strands have the values determined above, it will be understood that the invention is not limited to the use of these precise values. Moreover, it will be possible to envisage, without considerable modification, producing a continuous variation in the tension of the elastic members over the whole length of each pair of nappy-pants .

Finally, within the scope of the invention, the absorbent pad, instead of being of an anatomical hourglass shape, could also be, for example, rectangular in shape, without side indentations, in which case the elastic members could follow a substantially rectilinear path over the whole crotch region. 0 H o ^ 7 5

Claims (29)

WHAT WE CLAIM IS:

1 . Nappy-pants, to be disposed of after use, comprising a liquid-impervious outer sheet, a liquid-permeable inner sheet, the two sheets being of a substantially rectangular overall shape with opposed median indentations cut out in their lengthwise edges to allow legs to pass through and defining in the lengthwise direction of the nappy-pants a narrower crotch region between two wider end or belt regions, an absorbent pad whose dimensions are smaller than those of the two sheets, which is arranged between the two sheets so that its edges are set back in relation to the corresponding edges of the two sheets, the two sheets being joined together by adhesive bonding at their edges, around the absorbent pad, fastening members adhered to the inner face of the impervious sheet in the two end or belt regions for closing the nappy-pants around the user's waist, and elastic members attached under tension by adhesive bonding to the inner face of the impervious sheet on both longitudinal sides of the absorbent pad, substantially over the whole length of the impervious sheet, with a higher tension in the crotch region than in the end regions, the elastic members being arranged on the opposite longitudinal sides of the absorbent pad so as to have, in the two end regions, sections converging in the direction of the transverse edges of the impervious sheet, characterised in that the convergent sections of the elastic members approach one another towards each transverse edge of said nappy-pants so that the maximum distance separating the convergent sections at or near the transverse edges is smaller than a maximum width of the absorbent pad, whereby the elastic members form a practically closed elastic barrier around the absorbent pad and provide the impervious sheet both with a lengthwise elasticity in the crotch region and a transverse elasticity in the end regions. -lb- *;O *• ^ "l 1 / 3

2. Nappy-pants according to Claim 1, characterised in that the converging sections of the elastic members are substantially rectilinear in outline and are inclined by at least 45° in relation to the lengthwise direction of the nappy-pants.

3. Nappy-pants according to Claim 2, characterised in that the converging sections of the elastic members are inclined by at least 60°.

4. Nappy-pants according to any one of Claims 1 to 3, characterised in that the length of the converging sections of the elastic members is such that the length of projections of the sections onto the transverse edges of the nappy-pants corresponds to at least 40% of the length of the transverse edges of the nappy-pants.

5. Nappy-pants according to Claim 4, characterised in that the length of said projections corresponds to more than 50% of the length of the transverse edges of the nappy-pants.

6. Nappy-pants according to any one of the preceding claims, characterised in that the converging sections of the two elastic members join each other or are separated from each other near each transverse edge of the nappy-pants by a distance corresponding to less than 20% of the length of the transverse edges.

7. Nappy-pants according to Claim 6, characterised in that said distance separating said converging sections is less than 15% of the length of the transverse edges.

8. Nappy-pants according to any one of the preceding claims, characterised in that the converging sections of the two elastic members are separated from each other near each transverse edge of the nappy-pants by a distance of less than 50% of said maximum width of the absorbent pad.

9. Nappy-pants according to Claim 8, characterised in that said distance separating said convergent sections is less than 30% of said maximum width of the absorbent pad.

10. Nappy-pants according to any one of the preceding claims, characterised in that in the converging sections, the elastic members have a tension which is at least 50% lower than the tension of the elastic members in the crotch region.

11 . Nappy-pants according to any one of the preceding claims, wherein said absorbent pad is of rectangular overall shape with two opposite side indentations in the crotch region, characterised in that the elastic members have, in the median part of the crotch region, substantially rectilinear sections followed on both sides by outwardly concave curved sections, themselves followed in the end regions by outwardly convex curved sections to which the converging sections are joined, the outwardly convex sections having a lower tension than the converging sections, themselves having a lower tension than the tension of the elastic members in the crotch region.

12. Nappy-pants according to Claim 11, characterised in that the elastic members are extended between substantially 100 and 200% in the crotch region, between substantially 5 and 10% in the outwardly convex sections and between substantially 40 and 60% in the converging sections.

13. Nappy-pants according to any one of the preceding claims, characterised in that each elastic member comprises a plurality of individual elastic strands arranged mutually in parallel. - 18 - i 75

14. A process for the continuous manufacture of nappy-pants according to any one of the previous claims, each comprising a crotch region and two end regions, consisting in passing a continuous impervious sheet over a supporting and driving member, bringing continuous elastic members into contact with the sheet, on the member, while varying at regular intervals the tension of the elastic members at their points of contact with the sheet, and in moving the points of contact at regular intervals transversely to the lengthwise direction of the sheet so as to attach the elastic members by adhesive bonding onto the sheet so that the elastic members form, on the sheet, two repetitive continuous outlines which are symmetrical in relation to the lengthwise axis of the sheet, and which have, in the regions corresponding to the end regions of the nappy-pants, a tension which is lower than in the regions corresponding to the crotch regions of the nappy-pants, in depositing onto the impervious sheet absorbent pads, a liquid-permeable continuous sheet and adhesive fastenings located in the two end or belt regions for closing the nappy-pants around the user's waist, and in cutting the composite strip thus obtained transversely between the absorbent pads to obtain said nappy-pants, characterised in that the transverse movement, at regular intervals, of the points of contact between the elastic members and the impervious sheet is controlled so that, in the regions corresponding to the end regions of the nappy-pants, the two outlines at regular intervals cross each other or are separated from each other by a distance which is smaller than the maximum width of the absorbent pads thereby forming a practically closed elastic barrier around the absorbent pad of the thus obtained nappy-pants.

15. The process according to Claim 14, characterised in that adhesive is applied to the impervious sheet on its face - 19 - 24 o 1 7 receiving the elastic members, with a view to the adhesive bonding of the latter onto the sheet.

16. The process according to Claim 15, characterised in that an adhesive-free strip is left in the middle of the width of the impervious sheet during the application of the adhesive.

17. The process according to Claim 15, characterised in that the application of adhesive to the impervious sheet is interrupted intermittently in a region situated in the middle of the width of the sheet, so as to form at regular intervals an adhesive-free window where the paths of the elastic members cross or are separated from each other.

18. The process according to Claim 15, characterised in that adhesive is applied to the impervious sheet continuously over its whole width and that an antiadhesive material is sprayed at regular intervals onto the elastic members.

19. A plant when used for the continuous manufacture of nappy-pants according to any one of Claims 1 to 13, by implementing the process according to any one of Claims 14 to 18, characterised in that it comprises, for guiding each said elastic member, a guiding means, mounted on a trolley in the immediate proximity of a supporting and driving member over which the impervious sheet passes, to receive the elastic members, said guiding means being freely rotatable about an axis substantially perpendicular to the axis of the member by means of a frictionless bearing, said trolley being driven in translation transversely to the direction of movement of the supporting and driving member, and, in order to give variable stretching tensions to the elastic members, rotary feeding instruments which exert a clamping effect on the elastic members and whose variable-speed drive is controlled by an electronic control unit commanded by a computer.

20. The plant according to Claim 19, characterised in that the trolley is driven by a linear or rotary motor controlled, with index-linking to the movement of the supporting and driving member, by the electronic control unit commanded by the computer.

21. The plant according to Claim 20, characterised in that the trajectories for positioning the elastic members on the impervious sheet are mapped out and controlled by a computer program, as is the shape of the crotch indentations cut out of the impervious sheet.

22. The plant according to Claim 19, characterised in that the guiding means comprises a guiding head with closed holding means for the elastic members.

23. The plant according to Claim 22, characterised in that said holding means are in the form of parallel drilled holes or channels into which the elastic members are threaded.

24. The plant according to any one of Claims 19 to 23, characterised in that the supporting and driving member consists of a rotary drum.

25. The plant according to any one of Claims 19 to 23, characterised in that the supporting and driving member consists of a conveyor belt which applies suction.

26. Nappy-pants substantially as herein described with reference to any embodiment disclosed in Figures 4-7. - 21 - 2'> 0 175

27. A process for the continuous manufacture of nappy-pants substantially as herein described with reference to any embodiment disclosed in the accompanying drawings.

28. A plant for the continuous manufacture of nappy-pants substantially as herein described with reference to any embodiment disclosed in Figures 1-3.

29. Nappy-pants whenever manufactured by the process of any one of Claims 14-18 and 27. OATED THIS"$ DAY OF A. J. PARIk & SON PER AGENfi FOR THE APPLICANTS