ITMI990294A1 - DISPOSABLE DIAPER OF THE PUT AND APPARATUS TYPE AND METHOD FOR ITS MANUFACTURE - Google Patents

Description

DESCRIPTION . THE

The present invention relates to the sector of absorbent diapers for children and adults of the disposable type.

More specifically, the present invention relates to disposable absorbent nappies, of the type with panties closed around the waist with an elasticated belt and to the equipment and method for manufacturing such disposable panty nappies.

The disposable type absorbent nappies have now met with widespread favor with the consumer and are now used both by children during the first years of life, and by adults with different incontinence problems. The typical disposable product, well known in the state of the art, is composed of a structure with three main layers such as an internal liquid permeable layer that is in contact with the body, an external liquid impermeable coating, and a absorbent pad interposed between the inner and outer layers. The materials now generally employed for the three main elements of disposable diapers include various types of non-woven fabric, a thin sheet of plastic for the outer lining, and defibrated pulp called fluff for the absorbent pad. Nonwoven is a comfortable non-irritating material suitable for direct contact with the skin which allows liquids to seep up to the absorbent pad. The typical absorbent pad is made of defibrated cellulose pulp mixed with superabsorbent polymers.

The waterproof outer layer is generally a thin sheet of plastic that does not allow the urine and feces that are deposited inside the diaper during normal use to go outside the diaper itself.

These three basic layers that make up the absorbent diaper are generally glued to each other by hot melt glue, which, distributed in various ways on the inner faces of the various layers, brings them together in a single product.

Nowadays, disposable absorbent nappies are built with various features such as: two elasticated zones in correspondence of the passage for the legs, elasticized lateral containment barriers to prevent the escape of liquid and solid substances from the lateral passages for the legs, elasticized barriers containment placed at the front and back of the diaper to prevent leakage of substances in the belt area, various types of elastic bands placed at the waist belt to increase the comfort and wearability of the diaper, various types of side closures mechanical elasticated by tear or through conventional adhesive tapes placed on the back of the diaper that attach in a repositionable way on the tape placed in the front position on the diaper, external elasticized covers to increase the fit, one or more sheets of hydrophilic material placed between the non-woven fabric and cushions o absorbent with the task of quickly distributing the liquids received to the entire surface of the absorbent pillow, various types of anatomical conformation in the area between the legs both on the absorbent pillow and on the plastic and non-woven layers, these are some of the main features which can be found on today's absorbent nappies and which are well known by all experts in the field.

All these innovations have been made to absorbent nappies over the course of several years of development with the aim of making absorbent nappies more and more comfortable to wear and suitable for carrying out their main task of absorbing and containing the liquid and solid substances produced by the body.

Generally, the market for disposable absorbent nappies is divided into products for children and products for adults, in turn divided into various sizes or dimensions to be able to adapt to the various sizes of users.

Products for children are divided into three main categories: normal absorbent nappies open on the sides, absorbent nappies type panties closed on the sides very similar to normal panties and with low absorbency generally called in the diaper industry with the name of Training Pants, and absorbent nappies like panties very similar to Training Pants also closed on the sides but with high absorption power generally called in the diaper sector with the name of Pant Diaper.

Normal open absorbent nappies are more common than panty type nappies; they are generally used from the birth of the child until the child has complete control of urinary and fecal functions.

Panty diapers called Training Pants with low absorbency are used for relatively short periods while the baby is starting to have control over his bodily functions.

Panty diapers called Pant Diaper with high absorbency are generally used instead of normal absorbent diapers open on the sides during the various stages of growth.

Normal diapers are generally flat, open-sided items that wrap around the baby by overlapping portions of the sides that are secured together, for example with a piece of pressure-sensitive adhesive or other conventional mechanical fastening systems well known in the art, to put on or take off this type of diaper you have to act on the two side closure systems.

The Training Pants and Pant Diaper panty diapers have closed sides to form a closed and elastic waistband that thanks to this elastic function allows the diaper to be worn and removed like a normal underpants without having to act on side closures, and to adapt independently to the baby's waist size.

The Training Pants were designed thinking, in the psychology of toilet training, that the child is more easily accustomed to go to the toilet if he wears panty-type diapers similar to the undergarments used by adults.

The Pant Diaper have been designed thinking of a very comfortable product easy to wear that adapts independently to the child's body and to be used not only during the last period of use of diapers such as Training Pants but to replace the normal diapers open on the sides.

Generally, the adult incontinence market features three main types of disposable diapers in various sizes and dimensions in relation to the size of the people they are intended for.

One type is a flat diaper, open on the sides, to be wrapped around the person; quite similar in construction technology to normal baby diapers, the sides are kept closed, for example by adhesive labels, after wrapping around the person's waist.

This type of open-sided adult diaper is typically used for inpatient adults.

Another type is the disposable absorbent underpants nappy: it is similar in construction technology and functional features to the Pant Diaper for children clearly proportioned in size to be worn by adults.

This diaper is worn and carried like a normal underpants, has closed sides to form a closed and elastic waistband which thanks to this elastic function allows the diaper to be worn and removed effortlessly like a normal underpants and to adapt independently to the size of the waistline. Absorbent adult diapers of this type are generally called Adult Pants or Incontinence Pants.

Another type of disposable adult diaper consists of a central absorbent body generally of elongated shape that goes between the legs of the incontinent person and is folded in a U shape with the front close to the belly and the back close to the waist. this diaper is kept close to the body with two applied and detachable lateral eiastical belts that connect the two lateral parts of the diaper.

This absorbent diaper for adults with belt is less expensive than the closed panty diaper, but has the disadvantage of being less comfortable than the Adult Pants and being more conspicuous when wearing it.

Generally, the belts are applied and can be detached from the front and rear panels of the covering either with buttons and eyelets or with fastening with Velcro or other known systems.

It is thought that toilet habits for children can be psychologically aided by the fact that the child feels that the throw-away panty-type undergarment is more like the adult's non-throw than normal. disposable diaper open and therefore encouraged to break away from the use of common disposable diapers and to master the functions of his body.

Basically, the pant type diapers for adults, "Adult Pants", have been designed both to promote a better fit and functionality of the product but above all to psychologically help adults to endure the discomfort of incontinence, in the least traumatic way possible, making them feel as normal as possible; from this reasoning emerges the fact that for incontinent adults it is thought preferable to have a disposable absorbent diaper that is as similar as possible to normal non-disposable underwear.

Generally, it is not normal for an adult to wrap around a garment open at the sides and fasten it with adhesive tape or to have a pant to be fastened with a belt and buttons or other similar systems.

With regard to the functional aspect, the absorbent diapers of the traditional type open on the sides and the diapers of the type closed on the sides perform substantially the same basic functions, that is to absorb and contain the urine and feces of the body for a certain period of time.

However, the fit, comfort, and similarity to normal underpants make the disposable nappy closed at the sides much better and preferred than the traditional open nappy.

Unfortunately, the production cost of closed panty nappies is considerably higher than the cost for traditional nappies, this means that closed panty nappies for both children and adults represent niche products and given the high cost not accessible to most people.

The higher cost is due to several factors.

Underpants-type closed diapers have stretch sections in the areas of the passage for the legs substantially perpendicular to the stretch sections of the belt: therefore during the manufacturing process, at least one of these orientations is in contrast with the normal direction of construction of the diaper, consequently the manufacturing operations must first coincide with one of the orientations to make a part of the diaper, then, with a complex physical manipulation, the manufacturing operations must aim at the transverse orientation to complete the product.

The transversal movement and the positioning of components of flexible products at high production speeds, confers considerable complexity to the manufacturing operations.

It is necessary that all diapers are the same in construction within a limited degree of tolerances, therefore the more the complexity of the process increases, the more waste products are produced to maintain a constant level of quality, consequently the production costs are higher compared to costs of normal diapers.

Furthermore, the typical production speed for diapers closed at the waist, such as underpants, is lower than the production speed of diapers of the normal open type, again due to the fact that the diaper with closed underpants requires much more complicated manufacturing technologies.

Furthermore, the costs of special elasticized materials used in the underpants-type diaper to ensure a good fit for the user contribute to considerably increase the cost of the latter compared to the cost of current open diapers.

Based on these considerations, there is a need to provide improved disposable nappies of the type with closed underpants, with an elasticated area in the belt that allows them to be worn easily like a normal underpants and at the same time manages to lower the costs for their production. levels that make them accessible to the majority of people.

It is for this purpose that the present invention aims.

The present invention responds to the need of the industry by providing improved disposable underpants nappies closed with elastic waist belts, and an apparatus and method for making such underpants type nappies.

This new nappy includes an outer liquid impermeable sheet, an inner layer permeable to liquids, an absorbent pad inserted between the outer layer and the inner layer, a series of elastic elements applied in tension in the area of the passage for the legs, and a pair of elastic belts applied in tension longitudinally with respect to the working direction of the machine, longitudinally with respect to the absorbent pad, longitudinally with respect to the elastic threads applied at the passage for the legs, above the inner layer and securely fixed at the opposite ends of the same, the all held together through the application of hot glue in certain bonding areas

During the use of the diaper, the elastic waist belts, which during manufacture are longitudinal to the absorbent pad, mark the closed upper limit of the diaper and are placed transversely to the absorbent pad.

The present invention provides an apparatus for the production of a disposable panty-type diaper closed at the waist by two elastic elements: it includes a section for forming the main mat composed of several materials which receives a long and continuous layer of external protection impermeable to the which a series of elastic elements under tension have been applied by means of hot glue, these elastic elements, generally threads, are applied continuously in the two internal lateral parts of the external waterproof tape, by a long and continuous layer of permeable internal protection, by a continuous series of absorbent pads separated and spaced from each other always by the same distance which are inserted between the inner layer and the outer layer. These are bonded together by hot-melt adhesive to form a consecutive diaper tape.

A pair of tensioned elastic belts are located longitudinally over the inner layer on opposite sides of the carpet. The elastic belts comprise at least one sheet of material on which elastic elements are applied in tension, the release of the elastic elements delineates the pleated and elasticized areas in the belt.

A fastening device integrally attaches the elastic belts to the carpet at predetermined intervals near the end areas of each diaper on the line.

A cutting device cuts the carpet at predetermined intervals to separate each diaper from the solid line.

When the belts with their tensioned elastic are released from tension, the elastic elements return to their initial length before being tensioned, this causes the two lateral elastic bands to move in a transverse position with respect to the central belt with the absorbent pad, delimiting the elasticated areas of the belt; closing transversely to the absorbent pad, the two elastic bands together with the central tape to which they have been attached, delimit the special passages for the legs, which are also elasticized.

The present invention provides a method for manufacturing absorbent panty diapers including: the step of forming a continuous liquid-impermeable outer covering carpet. an internal layer permeable to liquids, a series of absorbent pads interposed between the two layers, all made adherent together rn urr sol carpet, the overlapping phase on the upper layer in the carpet of a pair of tensioned elastic belts positioned longitudinally to the carpet, stretched , separated and arranged on opposite sides of the same, the integral attachment phase of a pair of elastic belts tensioned to the carpet at predetermined intervals, to delimit the joint between elastic belts and the carpet, the cutting phase of the carpet and the elastic belts along a spaced line on the outside of the attachments, and the stage of dividing the carpet into discreet disposable absorbent panties.

The elasticated belts, applied longitudinally to the carpet, delimit a substantially cup-shaped and panty-type diaper in which the elasticated belts delimit the upper area of the open end of the diaper, which elasticized areas are substantially transverse with respect to the absorbent pad and jointly with the side areas of the mat, they delimit the opposite passages for the legs of the diaper.

Objects, advantages and characteristics of the present invention will become clear by reading the following description of the invention and its claims with reference to the attached drawings, in which:

figure 1 represents the perspective detail of the disposable panty diaper according to the present invention;

figure 2 is a schematic illustration of a production line of the disposable diaper shown in figure 1 according to the present invention;

Figure 3 is a detailed schematic drawing of a sealing roller and a contrast roller for manufacturing the disposable panty diaper illustrated in Figure 1, according to the present invention;

Figure 4 is a detailed schematic drawing of a knife and counter knife for manufacturing the disposable panty diaper illustrated in Figure 1, according to the present invention;

Figure 5 is a partially sectioned top view of a carpet portion adjacent to the sealing roller for manufacturing the disposable panty diaper illustrated in Figure 1, according to the present invention;

Figure 6 is a top view of a portion of the carpet of Figure 2 to illustrate the operation of the cutting roller for making the disposable panty diaper illustrated in Figure 1, according to the present invention.

With reference to the drawings in which like parts have equal identifications, Figure 1 is a partially sectioned perspective view of the panty-type diaper 10, according to the present invention.

The panty diaper 10 comprises a body formed by an external waterproof layer 12, an internal permeable layer 14, an absorbent pad 16 interposed between the two, and two opposite elasticated belts 18, 20.

The body defines a front panel 22 and a rear panel 24 joined by the two opposite elasticated belts 18, 20 which define the elasticized side panels and delimit the appropriate opposite openings for the legs 30, 32, where elasticized threads are present.

In the illustrated version, the longitudinal opposite sides of the absorbent pad 16 define two arcuate recesses 17 (see Figure 2) between the front and rear ends of the pads 16.

The recesses 17 in practice delimit the openings for the legs 30, 32 for a better anatomical fit of the diapers 10.

The joining lines, consisting for example of welds 34, 36 at the sides of the front part of the panel 22 and the joining lines, consisting, for example, of welds 38, 40 at the sides of the rear part of the panel 24, join the elastic belts 18 , 20 at the front and rear of the absorbent panel.

As indicated in partially sectioned figure 5, the belts 18, 20 include a series of elastic elements 42 tensioned, to substantially form continuous elastic pleated portions when, after the construction process, they are released from the working tension and return to their initial size. thus creating an elasticated area in the waistband of the underpants.

Furthermore, a series of elastic threads 44 are provided on the peripheral area of the openings for the passage of the legs 30, 32 to substantially form continuous elasticized portions around the openings for the passage of the legs in the underpants 10.

Figure 2 is a schematic illustration in perspective of a production line 50 of the diaper 10 illustrated in Figure 1.

The webs of the material for the waterproof layer 12 and the permeable layer 14 are supplied continuously by the respective coils.

The belts of the outer 12 and inner 14 layers pass adjacent the respective gluing head 56, 58 and pass on the respective feed roller 60, 62 up to a pair of joining rollers 64.

A continuous series of separate and spaced absorbent pads 16 are inserted between the lower band 12 and the upper band 14.

The waist belt assembly station 70 forms the elasticated waist belts 18, 20 starting from a tape 72 of material.

Preferably the material is non-woven fabric, but it can be a fabric or other fabric suitable for coupling or joining the carpet 89 of the waterproof 12 and permeable layer 14 and forming elastic sections therein, as mentioned below.

Station 70 comprises a gluing head 74 and a feed roller 76 for the elastic elements 42.

The feed roller 76 receives a group of elastic elements 42 longitudinally tensioned and spaced apart from a feeder.

The feed roller 76 is externally covered with non-stick material to avoid being soiled by the glue.

The tensioning of the elastic elements 42 is done with mechanisms conventionally known in the field.

A pair of opposite folding bars 78 receive the side parts 77 of the carpet 72.

The bending bars 78 fold the side parts 77 over the middle parts 79 forming an elastic sandwich 81.

The elastic sandwich tape 81 then advances towards the dividing roller 80.

Knife 82 is mounted adjacent to roller 80.

By the action of the knife 82, the elastic sandwich tape 81 splits in two to form the elastic belts 18, 20.

A pair of deflection bars 84, 86 directs the belts 18, 20 to the feeding roller 88. The feeding roller 88 transfers the elastic belts 18, 20 to the insertion roller 87 and to the carpet 89 formed by the lower outer layer 12, the upper inner layer 14 and between the two layers the separate absorbent pads 16 and the elastic threads in tension 44.

The return bars 84, 86 also perform the function of aligning the outer edges of the belts 18, 20 with the respective outer edges of the belt 89.

The belts 18, 20, which are tensioned so as to stretch the elastic elements, are stretched over the upper inner layer 14 of the carpet 89 and form a composite carpet 90.

A sealing roller 92 and a contrast roller 93 receive the composite carpet 90.

The roller 92 comprises a pair of sealing elements 94 which protrude from the surface of the roller (better illustrated in Figure 3).

The sealing elements 94 make joints in the carpet 90 at selected intervals to secure the belts 18, 20 to the carpet as mentioned below.

A cutting roller 95 and a counter knife 97 are positioned after the sealing roller 92 and its counter roller 93.

The cutting and counter-knife rollers 95, 97 receive the belt 90 with the belts 18, 20 already secured by the unions performed by the welding rollers 92 and the contrast roller 93.

In the version illustrated in figure 5, the joints are the welds 34, 36 and 38, 40.

The cutting roller 95 comprises the knives 120 for cutting the carpet 90 outside the welds 34, 36 and 38, 40 while making a central transverse cut between the welds.

The action of the knives separates the single panty-shaped diapers 10a from the carpet 90.

The extractors 98 are positioned on opposite sides of the line 50 to remove the scraps 100.

A separation belt 102 on the suction side receives the finished diapers 10a and transports them to a stacker (not shown).

Figure 3 is a detailed illustration of the weld and contrast rollers 92 and 93 of the preferred version.

The sealing roller 92 comprises the two sealing elements 94 which have the sealing surface 106 outside the roller.

In the illustrated version, the sealing elements 94 each have supports 108 and 110 arranged at oblique angles with respect to the longitudinal axis 112 from roller 92.

The supports 108, 110 are preferably oriented at angles of 45 ° with respect to the longitudinal axis 112. The supports 108, HO therefore substantially define a right angle 114 between the two.

A layer of soft rubber 115 generally covers the roller 92 except on the welders 94.

The rubber layers 115 cooperate by keeping the carpet 90 stretched during welding.

Figure 4 is a detailed illustration of the knife and counter knife rollers 95 and 97.

The cutting roller 95 includes a knife 120 formed of two V-shaped mirror sections 122 and a cross section 124.

The knife 120 protrudes from the cutting roller 95.

The two sections 122 correspond to the shape of the sealing elements 94, so that the sections 122 in the illustrated version are each oriented to define a substantially right angle 125.

The blades 122 of the knife 120 cut the carpet 90 outside the welds formed by the rollers 92, 93 so as to separate the scraps 100 from the carpet 90, at the same time during the rotation of the knife 95 and counter-knife rollers 97, the blade section 124 completely separates the individual diapers 10 from the continuous belt 90.

A layer of soft rubber 126 generally covers the roller 95 except on the knife 120-124 and helps to keep the carpet 90 stretched during cutting.

Figure 5 is a sectional top view of a portion of the carpet 90 adjacent the fusing roller 92 and the contrast roller 93 (which are not shown in the figure).

The carpet 90 comprises the lower layer 12 with a series of elastic threads 44 which extend longitudinally to the length, and in the direction of work of the machine line 50.

The upper web 14 covers the separate absorbent pads 16 and the elastic threads 44 overlapping the lower web 12.

The tapes that define the elastic waist belts 18, 20 are separated from each other so as to determine a distance 130 along the longitudinal axis of the carpet 90.

The spacing width 130 can range from 0.00m for small size baby diapers to 300mm or more for large size adult diapers.

In large diapers, a conventional rotating cutting system consisting of a knife and counter-knife (not shown in the drawings) positioned between the pressing rollers 64 and the roller 87 for inserting elastic belts 18, 20 cuts two side sections of the carpet 89 formed by the upper web 14 and the lower web 12 on the outside of the elastic threads 44.

The cut takes place only in the external central area, preferably in correspondence with the recesses 17 on the absorbent pad 16, the two cut parts are at the same time removed by suitable scrap extractors.

In this way a carpet 89 will be created which, instead of being with the two straight external sides, will assume an hourglass shape in correspondence with the recesses 17 on the absorbent pad 16.

The sequence of lateral cuts along the edges of the carpet 89 must not coincide with the part of the carpet 89 dedicated to the welding of the elastic waist belts 18, 20, this operation is done to make the product more comfortable in the openings for the passage of the legs especially for diapers with panties of larger sizes or for adult incontinence.

The elastic belts 18, 20 are located above the upper band 14 β include the elastic elements 42.

The sealing roller 92 and the contrast roller 93 form the welds 34, 36 and 38, 40, which welds join the elastic belts 18, 20 to the belt 90.

Figure 6 is a top view of a portion of the carpet 90 adjacent to the cutting roller 95 and its relative counter-knife roller 97 (which are not shown in the figure).

Figure 5 shows the cuts made in the carpet 90 by the knife roller 95 and its relative counter knife 97 to separate the diapers 10 from the continuous belt 90.

With respect to the welds, the cuts are parallel, spaced apart and outside the welds 34, 36, and 38, 40 in order to maintain the union of the elastic belts 18, 20 to the part of the belt 90 which corresponds to the front and rear panels. 22, 24.

The cuts also separate the scraps 100 from the carpet 90.

A disposable underpants nappy 10a according to the present invention is illustrated distinct by the solid line 90, as are the scraps 100.

The manufacture of the disposable nappies 10 of the present invention will now be described, with particular reference to Figure 2 and other figures as stated below.

The external coating tape 12 supplied by its own reel (not shown) moves in the working direction of the line, maintained at the correct working tension by suitable systems well known in this sector, passes adjacent to the gluing head 56 which distributes hot-melt glue on the inner side of the belt.

The tape 12 can be a plastic film, a laminate consisting of a plastic film and an external non-woven fabric or a composite laminate, a microperforated but liquid impermeable film with an external non-woven surface, materials conventionally used in the sector.

The elastic threads 44 are applied continuously in the working direction of the tape 12 to the inner part of the tape 12 and fixed thereto with hot adhesive, keeping them under tension.

The web 12 moves past the feed roller 60 longitudinally of the working direction of the machine towards the press rollers 64.

The absorbent pads 16 are deposited longitudinally on the tape of the outer covering 12 equally spaced in a continuous and constant manner in relation to the speed of the line.

The absorbent pads 16 are preferably obtained with a traditional forming apparatus commonly found in diaper manufacturing lines, systems well known in the art.

The internal coating tape 14 supplied by its own reel (not shown) moves in the working direction of the line, maintained at the correct working tension by suitable systems well known in this sector, passes adjacent to the gluing head 58 which provides to distribute hot-melt glue on the inner side of the belt.

The carpet moves beyond the feed roller 62 longitudinally to the working direction of the machine towards the pressing rollers 64, which press together the external belt 12, with the relative elastic threads 44 applied, the absorbent panel 16 the internal belt 14.

Thanks to the hot glue previously applied to the belts 12, 14, the composite intermediate carpet 89 is formed.

As mentioned above, the larger diapers can comprise recesses in the layer 12 and in the layer 14 of the carpet 89. Said cavities correspond in shape and longitudinal position to the cavities 17 of the absorbent pads 16 with respect to the transverse position with respect to the carpet 89 are positioned outside elastic threads 44 to allow a comfortable fit of the diaper to panties.

The tapes defining the elastic belts 18, 20 kept at the correct working tension are then positioned continuously and longitudinally to the working direction of the machine on the intermediate composite belt 89 by the insertion roller 87.

In the illustrated version, the elastic belts 18, 20 are formed simultaneously in the elastic belt assembly station 70.

However, it falls within the present invention that the belts 18, 20 are constructed separately by means of two belts already separated from the beginning of the formation of the elastic belts and then supplied separately to the belt 89.

To put it briefly, in the illustrated version the base belt 72 for the construction of the elastic belts is preferably supplied in reels, with a width of the starting belt 72 four times that of one of the belts 18, 20.

The system folds the two opposite lateral parts of the tape 72 to the extent of a quarter each, over the two middle parts also of a quarter each and then cuts the material into the two elastic belts 18, 20.

However, in order to save material, the two lateral parts 77 of the belt can be folded, covering only the elastic elements 42 rather than the entire width of the belt.

Describing more particularly the formation of the elastic belts 18, 20, the tape 72 of the elastic belts 18, 20 receives the adhesive on one of the surfaces, which will then be the internal surface of the sandwich, from the gluing head 74.

The stretched elastic elements 42 move beyond the feed roller 76 depositing on the belt 72 to which they are fixed by means of hot glue.

The folding bars 78 cause the opposite side parts 77 of the web 72 to fold over the middle parts 79.

The adhesive on the surfaces of the folded sides 77 and the middle parts 79 secures the carpet with the elastic elements 42 inserted under tension in the middle.

The sandwich 81 thus formed passes between the dividing roller 80 and the knife 82 which cuts the sandwich strip 81 on the longitudinal axis, forming the separate elastic belts 18, 20.

The deflection bars 84, 86 return the separated elastic belts in a spaced manner as they travel towards the insertion roller 87 passing through the roller 88.

The insertion roller 87 lays the elastic belts 18, 20 longitudinally on the carpet 89, thus forming the composite carpet 90.

The outer edge of the belts 18, 20 is aligned with the respective outer edges of the carpet 90, by means of transmission bars 84, 86.

The so composed carpet 90 moves towards the heated sealing rollers 92, 93, passes through their tangency line and is welded in the predetermined areas.

The sealing roller 92, and its counter-roller 93 also cooperate in maintaining the tension of the carpet 90 composed of the various layers of tapes and the elastic elements 42, 44.

With reference to Figures 3 and 5, the sealing rollers 92, 93 join the elastic belts 18, 20 to the belt 90 only in the predetermined areas.

By turning, the sealing roller 92 and its counter-roller 93 cause the sealing faces 106 to come into contact with the carpet 90 which, being interposed between the sealing roller 92, and its counter-roller 93 receives a strong pressure in correspondence with the sealing faces 106.

Then, the heat and the strong pressure between the rollers 92, 93 attach the belts 18, 20 to the belt 90 along the seams 34, 36 and 38, 40.

The elastic belts 18, 20 can be attached by other means, such as adhesives, ultrasonic, thermal systems or other fasteners known in the art.

For example, a shaped layer of adhesive or a targeted spray of adhesive or a series of separate lines, spirals or dots of adhesive can be used to secure the belts 18, 20 along lines 34, 36 and 38, 40.

Furthermore, it falls within the scope of the present invention that the attachments, welds or joining lines that join the elastic belts 18, 20 and the front and rear panels 22, 24 can be of an arched shape, with discontinuous points or at minor or major angles. approximately 45 ° with respect to the longitudinal axis, provided that the fastening secures the ends of the elastic belts 18, 20 to the panels 22, 24 in such a way that the elastic belts form an elastic belt ring for the diaper 10.

Additionally, glue, ultrasonic, heat or other bonding mechanisms may equally provide spaced attachment points between the elastic belts 18, 20 and the front and rear panels 22, 24.

Thus, the welds 34, 36 and 38, 40 can be continuous sequences as illustrated or arcuate, curvilinear, irregular, formed by joining segments, and other geometries.

With reference to Figures 4 and 6, the carpet 90 with the belts 18, 20 attached at predefined intervals to the welds 34, 36 and 38, 40, moves towards the cutting roller 95 and the respective counter roller 97 to be separated into individual diapers panties 10 from the solid line.

The cutting roller 95 rotates bringing the knife 120 into contact against the counter-knife roller 97, the carpet 90 to be cut passes between the cutting roller 95 and its counter-knife 97.

While the rollers 95, 97 rotate, the blade 120 cuts the carpet 90 on the outside of the welds 34, 36, 38, 40 thus separating the side scraps 100, during rotation, it also transversely supplies, through the central section of the blade 124, dough with respect to the direction of the machine, to separate the diapers panties 10 from the carpet 90.

The blade 120 then cuts both the diaper 10 and the scraps 100 from the carpet 90.

The extractors 98 are normal suction extractors by means of which they remove the scraps of the cut 100 from the carpet 90.

The vacuum separating belt 102 then carries the panty diaper 10 to a folding station (not shown) where the diapers are folded and packaged.

The method of the present invention facilitates high production speeds and minimum number of production rejects, because in a simple way it allows to apply the elastic waist belt 18, 20 on the carpet 89 in the same working direction of the machine longitudinally to the absorbent panels 16, longitudinally to the elastic threads 44 to elasticise the opening of the legs without transfers, rotations or cross positioning.

It is noted that the assembly station 70 is arranged substantially across the longitudinal line of the machine, and the return bars 84, 86 position the belts 18, 20 for a longitudinal application to the carpet.

In an alternative embodiment, the assembly station 70 is also longitudinally aligned and arranged vertically to the line 50.

In the illustrated version, the rollers 92 and 93 are heated by electrical resistances and by means of the heat and pressure between the roller 92 and the contrast roller 93 they join together belts 18, 20 and carpet 90 along the welds 34, 36 and 38, 40.

The fixing takes place only in the welding area, from the sealing surface 106 through the mat 90 against the contrast roller 93.

In the preferred version, the two rollers 92, 93 have a circumference equal to the length of the diaper 10. The two rollers 92, 93 make one revolution per diaper.

The elastic elements 42 and 44 are preferably made of Lycra or other similar elastic material, natural or synthetic rubber, materials already currently used in the sector.

The feeding of the elastic elements 42 to the roller 76 is carried out by stretching and then stretching and keeping the elastic threads under tension, so that the elastic elements 42, at the moment of being fixed by glue to the tape 72, have a predefined elongation.

The amount of elongation of the elastic elements 42 is in the range from about 50 percent to about 350 percent of elongation, the percentage of elongation is determined with respect to the measurement of a stretch of elastic thread in the rest condition before application under tension in belts 18, 20.

In a preferential version, the elastic elements 42 are elongated by about 280%.

The elastic threads 44 are preferably made of Lycra or other similar elastic material, natural or synthetic rubber, materials already currently used in the sector.

The elastic yarns 44 are fed by stretching and then stretching and keeping the elastic yarns under tension, so that the elastic yarns 44 at the moment of being fixed by glue to the tape 12, exhibit a predefined elongation.

The elongation is preferably from 50 percent to 120 percent, the percentage of elongation is determined with respect to the measurement of a stretch of elastic thread in the rest condition before the application under tension in the outer web 12.

The number of elastic elements 42, 44, the size and the distance between them, can be selected and adjusted to obtain the required results of strength and wearability, as is well known in the art.

The elastic elements can be configured to provide satisfactory elasticity in the elastic belt portions 18, 20 as well as the contours of the shanks 30, 32 to act as a leak barrier, to also avoid excessive irritation or marks on the skin.

Once the panty nappy 10 is thus finished and cut from the carpet 90, and there is no longer any force that keeps it tensioned and relaxed, the elastic elements 42 which had been applied in a tensioned manner return to their original size creating in the elastic belts 18, 20 of the pleats.

The return of the elastic elements 42 to their original length causes the flat underpants 10a to assume the cup shape like a pair of underpants which can be quickly raised and lowered, as would be done with normal underpants.

During the manufacturing process the elastic belts 18, 20 in the carpet 90 are arranged in a flat and extended position, longitudinally with respect to the absorbent panel 16, the elastic threads 44 and the working direction, when the complete diaper 10 is cut from the carpet 90, and the diaper is left free to return to the rest position, it passes from a substantially flat shape to a three-dimensional shape, the elastic belts 18, 20 move around their welding line 34 36 and 38, 40, and move into a second substantially transverse position with respect to the central body of the panty diaper and its components.

The lower edge of the elastic belts 18, 20 defines the upper elasticized part of the legs 30, 32.

In a preferential version, some of the elastic elements 42 are placed on lateral parts of the elastic belts 18, 20.

Releasing the tension, the lower contour of the belts 18, 20 outlines the pleating for the upper part of the legs 30, 32.

The elastic threads 44 also return to their original length. This forms elastic pleated sections on the contour of the legs 30, 32.

The diaper 10 folds along the transverse median axis thus bringing the opposite ends of the diaper together.

The belts 18, 20 are oriented substantially transversely to the absorbent pad 16 and define the parts of the open end of the panty diaper which embraces the person's waist.

The resilience of the resilient belts 18, 20 permits resilient movement as the person lowers or raises the diaper 10 as needed.

The same elasticity ensures a comfortable fit of the diaper. The non-woven 72 in the preferred version of the belts 18, 20 allows the passage of air to the skin and is a soft surface in contact with the skin at the waist.

Other typical characteristics of disposable nappies are easily incorporated into the underpants type nappy 10 of the present invention and the manufacturing line 50 is easily modified to incorporate accessories for the construction of the elasticized lateral anti-escape barriers called in the sector (upstanding lag gather) or the application of a fast liquid acquisition tape called "surge" or acquisition layer, and other conventional applications used in current disposable diapers.

It is envisaged that the belts 18, 20 made of material with suitable elastic properties can give sufficient elasticity without the need to use elastic elements 42.

The principles, the preferred embodiments, the operating modes of the present invention have been described in the preceding description. The invention is not to be understood as being limited to the particular forms explained, because they are intended as indicative and not restrictive.

Furthermore, variations and modifications can be made by those skilled in this art without departing from the spirit of the invention as described in the following claims.

Claims (15)

CLAIMS I. Disposable diaper comprising a liquid impermeable outer cover; a liquid permeable inner lining; a plurality of elastic threads in the passage areas for the legs interposed between the external and internal lining, an absorbent pad interposed between the external and internal lining; characterized in that it comprises a pair of elastic waist belts placed longitudinally above the inner layer and fixedly joined to the opposite ends of the diaper, in which the elastic waist belts define lateral cross sections to the absorbent pad. 2. Disposable diaper, according to claim 1, characterized in that said belts are fastened with reinforced joints. 3. Disposable diaper, according to the preceding claims, characterized in that said elastic belts comprise non-woven fabric with adhesive on the first surface; and a plurality of elastic elements pulled from a released to a tensioned position and secured to the nonwoven with the adhesive where the elastic elements return to the released position to determine pleating and elasticity in the elastic waist belts. 4. Disposable diaper, according to one or more of the preceding claims, characterized in that said elastic belts comprise non-woven fabric with adhesive on the first surface; and a plurality of elastic elements pulled from a released position to a tensioned one remaining secured to the first surface of the non-woven fabric with the adhesive where the non-woven fabric, folded along the longitudinal axis, determines a first layer and a second layer with the elastic elements interposed between them, which elastic elements return to the released position to determine the pleating and elasticity in the waist belt. 5. Disposable diaper, according to one or more of the preceding claims, characterized in that said elastic waist belts comprise: a first layer of non-woven fabric with adhesive on the first surface; a second layer of non-woven fabric with adhesive on the first surface; and a series of elastic elements pulled from a released position to a tensioned position interposed between the first and second layer, remaining secured to the first surface of the non-woven fabric with the adhesive where the non-woven fabric, folded along the axis longitudinal, determines a first layer and a second layer with the elastic elements interposed between them, which elements return to the released position to determine the elasticity in the waist belts. 6. A method of making an absorbent diaper in the form of underpants which includes the following steps: (a) forming a continuous carpet of liquid impermeable layer, liquid permeable layer, and a plurality of absorbent pads interposed between the outer and inner lining and adhered together; (b) overlapping on the permeable layer at the top of the carpet longitudinally a pair of elastic belts at the waist, in tension, arranged on opposite sides of the same; (c) attach the pair of elastic waist belts to the mat at predetermined intervals to determine the fastenings between the elastic waist belts and the mat; (d) cut the carpet and belts along a line extending out of the attachments, thereby separating the carpet into distinct panty diapers, where the elastic waist belts, which have been inserted and attached longitudinally to the carpet, substantially determine a cup-shaped panty diaper, in which the elastic waist belts define the lateral sections of an open end of the diaper, which features they are substantially transverse with respect to the absorbent pad and, integrally with the lateral parts of the carpet, determine the elasticized passages for the legs in the diaper. 7. Method according to claim 6, characterized in that said attachment step comprises forming joints at oblique angles relative to the longitudinal axis of the carpet. 8. Method, according to one or more of the preceding claims, characterized by the fact that said step of attaching comprises the joining of a belt section to the carpet substantially at an angle of 45 degrees, relative to the longitudinal axis of the carpet. Method according to one or more of the preceding claims, characterized in that said attachment step comprises welding a portion of the elastic waistband to the carpet. 10. Method of making an absorbent diaper in the form of underpants, which includes the steps of: (a) forming a multi-layered carpet with a liquid impermeable layer, a liquid permeable layer, at least one absorbent pad interposed between the outer and inner lining, and secured together with adhesive; (b) apply a pair of elastic waist belts in tension on the permeable layer overlying the mat, the elastic waist belts being arranged on opposite sides of the mat; And (c) firmly attach the pair of elastic waist belts to the top layer of the carpet along defined and spaced joints that determine oblique angles relative to the longitudinal axis of the carpet, where the carpet and elastic waist belts attached to it form a disposable nappy type underpants with the sides closed with the elastic belts at the waist which determine pieces of ring transversely to the absorbent pad and which determine the opposite openings integrally with the carpet for the legs in the same. 11. Method of manufacturing a disposable absorbent diaper in the form of underpants, which includes the steps of: (a) provide a carpet composed of several layers with a first width comprising a liquid impermeable layer, a liquid permeable layer, a plurality of elastic threads in the passage areas for the legs and at least one absorbent pad interposed between the outer and inner lining , and secured together with adhesive; (b) providing a pair of elastic waist belts in tension above the permeable layer overlying the mat, the elastic waist belts being arranged on opposite sides of the mat and each having a second width less than one-half of the first width; And (c) secure by attaching the pair of elastic waist belts to the respective edges of the mat along joining lines that determine oblique angles relative to the longitudinal axis of the mat, where the carpet and the elastic waist belts attached to it form a disposable nappy type underpants with closed sides, with elastic belts at the waist which, when the elastic tension is released, determine pleated and elasticized side parts of a ring transversal to the absorbent pad and which, in collaboration with the carpet, determine the opposite openings for the elasticized legs in it. 12. Disposable baby diaper in the form of panties which includes: {a) a mat composed of several layers with a liquid impermeable layer underneath, a liquid permeable layer above, a series of elastic elements in the passage areas for the legs and an absorbent pad inserted between the two, and secured together with adhesive ; (b) a pair of elastic waist belts tensioned above the permeable layer overlying the mat, the elastic waist belts arranged on opposite sides of the mat; And (c) fixings that secure the pair of elastic belts at the waist at the respective ends of the carpet along lines that determine oblique angles relative to the longitudinal axis of the carpet, where the elastic waist belts, being thus attached to the mat, determine lateral portions of an open end of the diaper, which portions are substantially transverse with respect to the absorbent pad and integral with the mat define the opposite elasticized passages for the legs in the diaper. 13. Disposable panty diaper as defined in claim 12, where the seams comprise attachments joining the elastic waist belts to the carpet. 14. Apparatus for making a disposable panty diaper, which comprises: a mat forming station receiving a long strip of a liquid impermeable layer, a long strip of a liquid permeable layer, a plurality of elastic threads in the passageways for the legs and a quantity of absorbent pads separated and inserted between the two layers, which are secured together with adhesive to form a carpet of consecutive diapers; the means for providing a pair of elastic belts which overlap the permeable upper layer in the opposite lateral parts of the carpet, the elastic waist belts comprise at least one layer with elastic elements, where the release of the tension of the elastic elements establishes the pleats and the elasticity in the elastic waist belts; a fastening system which operates to securely attach elastic waist belts to the carpet at predetermined intervals near the ends of each diaper in the carpet; and a cutting device for cutting the carpet at predetermined intervals to separate each diaper from the carpet, where the elastic waist belts, when their elastic is released, determine side parts thickly pleated transversely to the absorbent pad for the diaper to panties and integrally with the carpet determine the opposite elasticated openings for the legs in it. 15. Apparatus for making a disposable panty diaper as defined in claim 13, wherein the means for providing the belts comprises: providing an amount of material in a long strip; an adhesive applicator for placing the adhesive on the first surface of the material in a long strip; means for placing two separate sets of a number of elastic elements on the adhesive on the material; a pair of opposite folding flaps for folding at least the opposite side parts of the material onto the respective central zone to overlap the elastic elements in the middle, where the side and middle parts join together with the adhesive to form a long intermediate belt; a knife to separate the intermediate long belt along the longitudinal axis to form a pair of long belts; and guide rollers to convey the pair of long belts on the carpet.