RU2413488C1 - Absorbent product containing elastic laminate - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to disposable absorbent products, such as pull-up diapers, hygienic panty and incontinence panty, and can be used in child, patient or invalid care. An absorbent panty-like product (55) contains a basic structure comprising a front panel (56), a back panel and a perinea panel (58) located between the front and back panels (56, 57), and front and back waist panels (61a, 61b), located at the front and back panels (56, 57) respectively. Herewith, at least one of the front and back panels (56, 57) contains an activated three-layer elastic laminate (68) containing a first canvas of a fibrous non-woven material and a second canvas of said fibrous non-woven material and an elastic film between the first and second canvases of the fibrous non-woven material. At least one of the first and second canvases of the fibrous non-woven material represents a canvas of a crepe non-woven material.

EFFECT: designing the absorbent panty-like product containing the activated three-layer elastic laminate of much higher transverse tensile strength and higher prick resistance.

18 cl, 1 ex, 1 tbl, 4 dwg

Description

FIELD OF THE INVENTION

The invention relates to a coward-type absorbent article comprising at least partially an elastic base structure, the base structure comprising a front panel, a rear panel and a crotch panel located between the front and rear panels. At least one of the front and rear panels comprises an activated three-layer elastic laminate that comprises a first canvas of fibrous nonwoven material and a second canvas of fibrous nonwoven material and an elastic film between the first and second canvases of fibrous nonwoven material.

State of the art

Panty-type absorbent articles include a panty-shaped base structure and an absorbent core component combined with it. When creating products such as underpants, the main goal is to make them look like ordinary underwear as much as possible. Therefore, absorbent articles, such as diaper pants, hygiene pants and panties used for incontinence, are made with the possibility of their convenient and tight fit to the carrier. It is desirable that the products were made with the possibility of pulling them up and pulling them down the hips of the wearer in order to enable the wearer or someone who is caring for a child, patient, person with a disability, etc., to easily remove the stained product and replace it with a new one clean product. For these reasons, the base part of the product is usually made of a material that lends itself to elastic stretching, at least in areas intended to be “overlaid” over the hips of the wearer. In addition, it is desirable that the base portion surrounding the absorbent parts of a coward-type product be permeable to air and steam, that is, to be breathable. A breathable product prevents a situation in which moisture remains on the skin of the wearer and is more comfortable and less warm to wear than an airtight product. It is also preferable if the product is soft, smooth and similar to textiles so that it does not rub the skin of the wearer and that it looks like ordinary underwear as much as possible.

In addition, it is important that it is possible to stretch an absorbent article such as underpants over the thighs of the wearer without breaking. A common problem is that the wearer or caregiver tears up the underpants by inadvertently poking the material with their fingers while trying to provide a good grip for pulling on or off the underpants.

The previously used elastic material for pant-type articles is a laminate comprising an elastic film located between two layers of inelastic non-woven material. To give the laminate the ability to stretch elastically, it is subjected to an activating treatment. A three-layer activated laminate is disclosed in international patent application No. WO 03/047488. The activated laminate is obtained by stepwise stretching a layer of elastic film between two inelastic fabric-like layers. Step-by-step stretching is performed by passing a laminate between the engaged gear rollers. The activation of elastic laminates by means of stepwise stretching is also disclosed in US Pat. the elasticity of the layer of elastic film. In the three-layer laminate in WO 03/047488, the inelastic layers are completely torn, so that the elasticity of the activated laminate is essentially the same as the elasticity of the elastic film layer.

Open laminates have good properties in terms of comfort and are soft, textile-like, breathable and elastic. However, the main disadvantage associated with the known laminates is that the activation process leads to at least partial tearing and destruction of the tissue-like layers, which results in a material having a reduced tensile strength and reduced puncturing resistance. When used as a component of the base part in a disposable product such as underpants, the material is easily torn when exposed to the forces arising from putting on or removing a product such as underpants. This tearing problem is especially evident for those female carriers or women who care for a child, a sick person, a disabled person, etc., who often have long nails that can pierce and tear panty material.

In order to overcome the problem of low load resistance arising from the use of an absorbent article including an elastic laminate, it was proposed in US 2005/0101216 A1 to form an elastic laminate from an elastic film and creped nonwoven material. Through the use of creped non-woven material, the laminate will have the softness and fluffiness of a creped, bulk non-woven material. In addition, it is also claimed that creped non-woven material gives the laminate elasticity, since the non-woven material is extensible in the creping direction. The use of creped nonwoven fabric is proposed as an alternative to activation by step stretching. Therefore, in document US 2005/0101216 A1, it is indicated that by using creped non-woven material, “coarse” activating treatment can be avoided with its attendant negative effect on the strength of the non-woven canvas.

However, although the creped nonwoven used in US 2005/0101216 A1 allows laminates to be obtained with some degree of elasticity, the elastic properties of the laminates are still severely limited by the extensibility of the creped nonwoven.

Therefore, there is still a need for an elastic laminate that has in combination high tensile strength, softness, flexibility and puncturing resistance. In addition, there is a need for an absorbent article such as underpants having a base part with sections of elastic panels having high tensile strength, softness, flexibility and puncture resistance.

Accordingly, an object of the invention is to provide an improved elastic stretch laminate for use in disposable absorbent articles such as underpants. Another object of the invention is to provide a textile-shaped, disposable absorbent article such as a coward having increased tensile strength and increased puncturing in combination with softness and flexibility. An additional object of the invention is to provide a simple and economical method of manufacturing a stretchable laminate having a high tensile strength and an appearance similar to textiles.

SUMMARY OF THE INVENTION

In accordance with the invention, a coward-type absorbent article is provided comprising a base structure, the base structure comprising a front panel having a front end edge and first and second side edges, a rear panel having a rear end edge and first and second side edges, and a crotch panel located between the front and rear panels, and the front and rear waist panels located respectively at the front and rear panels, and an absorbent core included in the base structure with the formation of one whole with it, while the first and second side edges of the front panel are connected via edge connections to the corresponding first and second side edges of the rear panel, and at least one of the front and rear panels contains an activated three-layer elastic laminate containing the first canvas non-woven fibrous material and a second canvas of fibrous nonwoven material and an elastic film between the first and second canvas of fibrous nonwoven material. At least one of the first and second webs of fibrous nonwoven fabric is a creped nonwoven fabric canvas, and the three-layer elastic laminate has a first tensile strength (MD) of at least 20 N / 25 mm, and preferably strength tensile in the first direction (MD) of at least 25 N / 25 mm and tensile strength in the second direction (CD) perpendicular to the first direction (MD) of at least 15 N / 25 mm, and preferably strength Tensile s in the second direction (CD), of at least 20 N / 25 mm.

The first direction is usually the production direction, that is, the direction MD of the canvas movement of the activated elastic laminate in the machine, and the second direction is usually the transverse direction CD. The three-layer elastic laminate is preferably included in the absorbent article, such as underpants, so that the MD direction is parallel to the waist edge of the article, so that the waist opening can elastically stretch.

Preferably, at least one of the waist panels of a pant-type product according to the invention comprises an elastic waist element.

The waist panels can be attached to the front and rear panels as separate components during the formation of underpants. The waist panels may contain an elastic waist element in the form of an elastic tape of any suitable kind, such as elastic laminates, strips of elastic foam material, elastic non-woven materials, non-elastic materials that have been elasticized by elastic threads or cords, etc. The widely used elastic waist element is made by attaching elastic elements, such as threads, ribbons or narrow strips, in a pre-stretched condition between two layers of non-woven, inelastic material. All commonly used elastic materials, such as natural or synthetic rubber, flexible foam, etc., can be used. A belt element of this type may be formed from two separate layers of nonwoven material, or may be formed from one layer of nonwoven material that has been folded to form a two-layer structure. In addition, you can use the activated laminate in accordance with the invention to create an elastic waist element. The elastic waist element in the waist panels preferably has a greater ability to stretch elastically than the stretch elastic sections in other parts of the base portion. When forming the elastic waistband from an activated laminate according to the invention, it is preferable to use at least two layers of the laminate, for example, by folding the laminate in half.

In an alternative embodiment, the elastic waist member is an integral part of the base portion. In this embodiment, the elastic waist member can be formed by folding the edge portion of the inelastic canvas of the base portion and attaching the elastic members between the folded portions of the canvas of the base portion. There is also the possibility of attaching elastic elements to the canvas layer of the base part and leaving the elastic elements unclosed or closed with a separate canvas. An additional possibility is to create an elastic waist element by bending the edge portion of the elastic front and / or back panel, as a result of which a waist panel will be created having a greater ability to stretch elastically than the uncomplicated parts of the elastic panels. Elastic waist elements suitable for use in an absorbent article such as underpants according to the invention are disclosed in PCT / SE 205/000309 (PCT / SE 2005/0000309).

The elastic waist panel preferably extends continuously over the entire length between the edge joints. In a particularly preferred embodiment, both the front and rear waist panels are elastic waist panels forming a continuous elastic waist.

The elastic laminate used in accordance with the invention preferably forms the front and back panels of an absorbent article such as underpants. However, there is the possibility of performing only portions of the respective front and rear panels of elastic laminate. In such embodiments, at least 20%, preferably at least 25%, more preferably at least 30%, and most preferably at least 40% of the total surface area of the base portion, measured when the base part is in a flat state, formed by an elastic laminate. As an example, an elastic laminate can be used only in those parts of the front and rear panels that are designed to be placed over the thighs of the wearer and thus form elastic side panels. In addition, it may be desirable to avoid overlapping between the elastic laminate and the core structures occupied by the absorbent core.

The absorbent core is preferably part of a separately manufactured core component or “central kit” that has been included in the base structure. The core component comprises an absorbent core sandwiched between the top sheet and the liquid impermeable back sheet. Needless to say, the core component may comprise additional components, such as a liquid transporting sheet, elastic elements, shape stabilizing elements, shaping elements or the like.

Although forming a core component alone is a preferred method of incorporating an absorbent core into a base structure, alternative embodiments in which portions of the base structure are used as a top sheet and / or back sheet are also contemplated within the scope of the invention.

A stretchable laminate can be obtained by a method comprising attaching an elastic film between a first canvas of a nonwoven fabric and a second canvas of a nonwoven fabric by laminating, wherein at least one of the first and second canvas of the nonwoven fabric is a creped nonwoven fabric canvas and the laminate is elasticized by stepwise stretching the laminate in at least one direction. In accordance with the invention, the activation of the laminate by means of stepwise stretching occurs after lamination, that is, after the layers in the laminate are attached to each other.

In a laminate used in an absorbent article such as underpants according to the invention, at least one of the nonwoven webs is a creped nonwoven. Crepe nonwovens tend to have greater elongation and flexibility than non-creped nonwovens. By choosing a creped nonwoven fabric for one or both of the layers of nonwoven fabric, an elastic laminate can be obtained that has better properties in terms of fit, flexibility and extensibility than when using non-creped nonwoven materials. The creped nonwoven fabric facilitates retraction of the elastic laminate after elongation, resulting in increased elasticity compared to a corresponding laminate having only layers of uncreated nonwoven fabric.

By creped nonwoven material is meant any nonwoven material in which the fibers have been crimped or bulky thermally or mechanically to shorten the fibers in the creping direction, whereby the material becomes stretchable and preferably elastically stretchable in the direction of the creped fiber. The nonwoven webs used in the invention can be creped both in the manufacturing direction, that is, the direction of movement of the material in the machine (MD), and in the transverse direction CD. The creped nonwoven webs are preferably stretchable, more preferably elastically or elastically stretchable, at least in the direction of movement of the material in the machine, which means that the canvases recover at least some of their original dimensions after being stretched. If it is desired that the canvas has the ability to stretch both in the direction of movement of the material in the machine and in the transverse direction, this can be achieved either by selecting a canvas of non-woven material, which by its nature is stretchable in the transverse direction, or by bi-directional creping. Recovery after stretching is highly dependent on the orientation of the fibers. Therefore, the canvas, which is stretchable in the direction of movement of the material in the machine and has the majority of fibers oriented in this direction, will have better ability to recover than the canvas with fibers arranged in a more random manner.

Through the use of canvases that have been given extensibility by creping, any conventional nonwoven canvas having high tensile strength in the transverse direction can be selected. This is a great advantage, since nonwoven webs that are stretchable due to their fibrous composition usually have low transverse tensile strengths. Such canvases are also relatively expensive, which makes them less suitable for use in disposable products.

In addition, it has now been found that when using at least one canvas of creped nonwoven material in the laminate, the laminate can be activated by step-by-step stretching and can still retain its tensile strength to a much greater extent than when using non-creped non-woven materials. The stretchable canvas of the creped nonwoven fabric is not destroyed during the activation process, but remains largely unbroken.

The activation operation involves the stepwise stretching of a two-layer laminate. The activation can be carried out by means of heated or unheated gears engaged with gears having teeth located on the circumferential periphery that engage and thereby allow the laminate to stretch. The activation operation provides the possibility of subsequent stretching of the laminate without any noticeable limitation due to the canvases of the nonwoven material.

The layers in the laminate can be attached to each other by any suitable bonding method, for example, by adhesion bonding, thermal bonding or ultrasonic welding. However, in accordance with one particularly suitable embodiment of the invention, the elastic film is applied as an extrusion coating to at least one of the first and second webs of the fibrous nonwoven material.

The elastic film is preferably perforated to provide breathability. This can be achieved directly during lamination, if at least one of the nonwoven webs is attached to the elastic film by extrusion coating. The punching operation can be performed by passing the connected elastic film and the nonwoven fabric web over the vacuum lamination drum while the elastic film is in a molten or semi-molten state. A similar method is disclosed in US patent No. 5733628 and leads to the fact that the elastic film is converted into a three-dimensional layer of the laminate with holes.

Alternatively, the elastic film may be a prefabricated perforated film that is attached to the nonwoven webs by any suitable means, such as adhesive adhesion, thermal bonding, or ultrasonic welding.

The elastic film may have a surface density of from 10 to 120 g / m ² , preferably from 15 to 60 g / m ² , and can be obtained from any suitable elastic polymer, natural or synthetic. Some examples of suitable materials for the elastic layer are low crystallinity polyethylene, metallocene-catalyzed low crystallinity polyethylene, ethylene vinyl acetate (EVA) copolymers, polyurethane, polyisoprene, butadiene and styrene copolymers, styrene block copolymers such as styrene and isoprene copolymers alternating blocks (SIS), a styrene butadiene copolymer with alternating blocks (SBS), or a block alternating styrene-ethylene / butadiene block copolymer. Mixtures of these polymers can also be used, as well as other modifying elastomeric or non-elastomeric materials. One example of a suitable elastic film is a three-layer elastomeric film with holes made with a composition of polyethylene - a copolymer of styrene and ethylene / butadiene with alternating blocks - polyethylene (PE-SEBS-PE).

In this context, an elastic material is defined as a material having a residual elongation after relaxation of less than 10% after subjecting the material to an elongation of 30% when tested for elasticity as described.

An inelastic material is a material that does not fall within the definition of an elastic material. Accordingly, an inelastic material, as used herein, is a material that may be extensible or inextensible. In the case of a tensile material, the material has a residual elongation after stretching and relaxation of more than 10% after subjecting the material to an elongation of 30%, as determined in accordance with the elasticity test.

The laminate used in the panty type absorbent article according to the invention is preferably made continuously from canvases extending in the MD direction of movement of the material in the machine, and the laminate is preferably activated by stepwise stretching at least in the MD direction of movement of the material in the machine. By exposing the activation laminate only in the direction MD of the movement of the material in the machine, the creped nonwoven in the activated laminate will retain maximum tensile strength in the transverse direction CD, perpendicular to the direction MD of the movement of material in the machine and to the direction in which the activated laminate can be elastically stretched. However, it is usually desirable to have some degree of extensibility also in the transverse direction of the CD. As mentioned above, transverse extensibility of the CD can be obtained by selecting a material that is extensible in nature and / or by creping the canvas also in the transverse direction of the CD. The creped nonwoven material serves as a reinforcing means for the laminate in the transverse direction of the CD, imparting tear resistance to the laminate and making the laminate particularly suitable for use as an elastic panel material in an absorbent article such as underpants.

The laminate canvases can have the same width to obtain a three-layer laminate, which can subsequently be continuously introduced into the manufacturing process of a disposable product such as underpants and form elastic sections of the base part of the product. Alternatively, the laminate may be cut, and it may be shaped into individual elements, which may subsequently be used to make a disposable absorbent article such as underpants.

According to one embodiment of the invention, one of the first and second nonwoven webs has a width equal to the width of the elastic film, and the other of the first and second nonwoven webs has a width greater than the width of the elastic film. Such a three-layer laminate is accordingly continuously introduced into the process in the manufacture of disposable products such as underpants, and the specified laminate can form both elastic and inelastic sections of the base part of the product. For example, a portion of a canvas of nonwoven material that protrudes outward from the canvas of the laminate can be used to create a waist panel on an item such as underpants. The waist panel is preferably an elastic waist panel, which means that the canvas of the inelastic non-woven material should be provided with elastic elements such as ribbons, cords, etc.

One or both of the fibrous nonwoven webs in the elastic laminate may preferably contain thermoplastic fibers. Examples of polymers suitable for use in nonwoven webs are polyethylene, polyesters, polypropylene and other polyolefin homopolymers and copolymers. Particularly well-suited nonwoven webs are those that contain thermoplastic fibers, which are a mixture of polypropylene and polyethylene fibers. Preferred canvases have a high content of thermoplastic fibers and contain at least 50% thermoplastic fibers and preferably at least 80% thermoplastic fibers. Nonwoven webs will generally be used in joints and seams in a disposable item such as underpants. Therefore, it is highly desirable that nonwoven webs can be welded by heat sealing or ultrasonic welding processes.

The fibrous layers are preferably selected so as to give the laminate the ability to create a soft feeling and the appearance and feel of a fabric-like material. Examples of suitable materials are meltblown nonwovens or spunbond nonwovens. However, any soft, flexible, and preferably extensible nonwoven materials and nonwoven laminates, such as laminates formed from a nonwoven fabric of a spunbond production method, a nonwoven fabric obtained by an aerodynamic method from a melt, and a nonwoven fabric of a spunbond production method can be used ( SMS - Spunbond-Meltblown-Spunbond), bonded canvases obtained by carding, and non-woven materials obtained by exposure to liquid jets.

The density of the creped nonwoven webs used in the laminate is suitably from 10 to 80 g / m ² and preferably from 13 to 50 g / m ² . Examples of suitable polymers used in the fibrous material are polyethylene, polyesters, polypropylene and other polyolefin homopolymers and copolymers. Natural fibers, such as cotton, can also be used, provided that they provide the desired properties. A mixture of polymers can contribute to higher flexibility of the nonwoven layer and thereby give the nonwoven material a greater elongation at maximum load. It has been proven that a mixture of polyethylene and polypropylene polymers provides good results in this regard. A mixture of fibers from different polymers is also possible.

Brief Description of the Drawings

The invention will be described hereinafter in more detail with reference to the attached drawings,

where figure 1 shows the lamination process in accordance with the invention,

figure 2 shows a three-layer laminate in accordance with the invention,

figure 3 shows a plan view of a diaper-panties with open side connections; and

figure 4 shows the diaper of figure 3 with closed side connections.

Embodiments of the invention

Figure 1 schematically shows a method of manufacturing a stretchable three-layer laminate in accordance with the invention. The first nonwoven fabric web 1 is fed from the storage roll 2 to the first joint gap between the rubber roller 3 and the metal roll 4. The molten elastic film forming polymer 6 is extruded through the die 7 into this gap, and the first inelastic nonwoven web 1 and the elastic film form the first laminate 8, which is removed from the roller 9.

In the second lamination operation, the film side 14 of the first laminate 8 is coated with glue or glue is sprayed onto the film side 14 of the first laminate 8 and subsequently passed through the second joint gap between the two fastening rollers 16, 17 together with the second nonwoven web 18. Adhesive is preferably a thermoplastic adhesive, although other types of adhesives can be used if desired. According to the invention, one of the first and second nonwoven webs 1, 18 is a creped nonwoven.

The three-layer laminate 19 is subsequently activated by passing the laminate between the gear rollers 10, 11 engaged with each other, so that the three-layer laminate 19 undergoes stepwise stretching. There are a number of different stretching methods, as described in EP 0714351. Depending on the design of the gear rollers engaged with each other, stepwise stretching can be carried out to stretch the laminate diagonally, in the MD direction of movement of the material in the machine or in the transverse direction CD. The degree of tearing of the canvases of the nonwoven material caused by stepwise stretching can be controlled by adjusting the “depth” of meshing of the teeth or gearing elements introduced into the meshing. Stepwise stretching leads to the "release" or activation of the elasticity of the elastic film and provides the possibility of elastic stretching of the three-layer laminate 19.

The metal roller 4 in the first joint gap is preferably a vacuum roller with holes, so that the three-dimensional molding of the extruded elastic film 6 and the formation of holes on the extruded elastic film 6 are carried out simultaneously with the film 6 being attached to the first canvas 1 of the nonwoven material.

The second lamination operation can alternatively be performed by heat welding or ultrasonic welding.

Figure 1 is a very schematic illustration of a method in accordance with the invention. However, all individual process steps are well known and have been described previously in the prior art. In addition, figure 1 does not show the width of individual canvases. A multilayer material can be formed with all the canvases having the same width or length in the transverse direction of the CD. Alternatively, the second canvas 18 of nonwoven fabric may have a greater width than the elastic film 6 and the first canvas 1 of nonwoven fabric, and may extend beyond the first laminate on one or both of its sides.

The three-layer laminate 19 shown in FIG. 2 comprises a first layer 1 of fibrous nonwoven material, a second layer 18 of nonwoven material and an elastic film 6 between the first and second layers 1, 18 of nonwoven material. Holes are formed in the elastic film 6, and it has a plurality of holes 20 made therethrough. The holes 20 may be holes formed with a three-dimensional shape, as disclosed in WO 03/047488, or may be simple two-dimensional holes passing through the film 6.

The elastic film 6 is elastically extensible in at least a first direction MD. For a laminate obtained in a continuous process, the first direction MD is the direction of movement of the material in the machine, that is, the direction of movement of the laminate canvas during the manufacture of the canvas. Laminate 19 is preferably elastically extensible in the first direction MD and preferably is extensible or elastically extensible in the second direction, namely the transverse direction CD, perpendicular to the first direction MD. The layers of the laminate 19 can be attached to each other by any suitable means, such as bonding by extrusion, adhesive bonding, or by heat bonding using heat or ultrasound.

According to the invention, at least one of the first and second layers 1, 18 of the nonwoven fabric is a creped nonwoven fabric.

The activated three-layer laminate 19 is soft and drapable, has high tensile strength and high puncturing resistance and is extremely well suited for use in various types of disposable articles such as underpants. The creped nonwoven fabric provides reinforcement of the laminate, especially in a direction perpendicular to the direction of stretching. Therefore, the laminate has resistance to puncturing and can be subjected to tensile forces and tensile forces arising when donning and removing products such as underpants, without breaking or tearing.

In addition, by selecting non-woven materials having thermoplastic properties, it is possible to obtain a laminate that can easily be incorporated into a disposable product by heat sealing methods. Since bonds formed by heat sealing and used in side joints usually “penetrate” into the materials to be welded, the orientation of the laminate with respect to the first and second layers of nonwoven materials is usually not key to obtaining the joint formed by heat welding, provided that, at least one of the layers is predominantly formed of thermoplastic fibers or the combination of two layers contains a sufficient amount of thermoplastic material to provide sufficient bond strength tions.

The panty diaper 55 shown in FIGS. 3 and 4 is intended to encompass the lower part of the wearer's body like a normal underwear item. In Fig. 3, the diaper 55 is shown from the inside, that is, from the side facing the wearer when the product is worn, and in Fig. 4, the diaper is shown from the outside, or from the side facing the garment, which is the side facing away from the wearer when wearing a diaper.

The diaper has a front panel 56, a rear panel 57 and a crotch panel 58 extending between the front and rear panels 56, 57 and having a relatively small width compared to the front and rear panels 56, 57. The front and rear panels 56, 57 are made so that they covered the wearer's thighs and extended over the abdomen and back of the wearer to cover the lower part of the wearer's body.

The diaper 55 further comprises a central zone 59 extending from the crotch panel 58 to the front panel 56 and the rear panel 57. The front and rear panels 56, 57 form part of the base portion 60, which extends from the garment side of the diaper 55 and closes and surrounds the central zone 59. The base part 60 includes a front panel 56, a rear panel 57, a crotch panel 58 and an elastic waistband 61 attached to the front and rear panels 56, 57. Each of the front and rear panels 56, 57 has a waist edge 62, a crotch edge 63and accordingly a pair of side edges 64.

The term “panel” is used here to indicate the functional part of the base part of the diaper, while the terms “zone” and “part (section)” are used to indicate the location of a particular element of the diaper in the base part or to describe the intended location of a specific part of the diaper relative to the user's body . The panel may be a separate component or part integrally with the base part. The zone or section may have a length in which they fully or partially cover one or more panels.

When the components are connected, attached or attached to each other, they are separate parts that have been bonded by any suitable means, for example by adhesive adhesion, by stitching or by ultrasonic welding or heat welding. The term “connected” also encompasses separable (openable) joints, such as separable side joints and re-closable joints, such as hook and loop joints, re-fastenable ribbons, button fasteners, etc. The components that were placed on top of each other need not be bonded, although in the sense used here, the term "located" should be understood in a broad sense as also encompassing bonded components.

The front and rear panels 56, 57 are connected to each other along their side edges 64 by means of heat bonding, ultrasonic welding, adhesive cords (strips) or the like to form side seams 65, as best shown in FIG. 4. The elastic waistband 61 consists of a front waist panel 61a and a rear waist panel 61b, which are attached respectively to the front panel 56 and the rear panel 57. The front and rear waist panels 61a, 61b are also connected to each other along the side seams 65. By connecting the front and rear panels 56, 57 and waist panels 61a, 61b of the diaper-panties 55 will be formed with a hole 66 for the waist and two holes 67 for the legs.

Figure 3 shows the diaper 55 in a flat state, with all the elastic components that were attached to the base portion 60 in the state when they were under tensile load, stretched to the full dimensions of the base portion 60 in its unstretched state. Figure 4 shows the diaper-panties 55 as it looks when the side seams 65 were formed, and it was possible to relax the stretched elastic elements and assemble the base material into assemblies to form elastic [zones] of the leg openings 67, 66 and waist.

The front and rear panels 56, 57 are formed of a hardened elastic laminate 68 made in accordance with the invention and containing at least one layer of creped non-woven material. The front and rear panels 56, 57 lend themselves to elastic stretching, at least in the direction of the waist edges 62.

The crotch panel 58 is formed from a crotch non-woven material 69 that has been attached to the front and back panels 56, 57 in the crotch seams 70. Therefore, the crotch part material 69, which is preferably an inelastic material, such as an inelastic non-woven material, is located in the central zone 59 of the product and overlaps the elastic front and rear panels 56, 57 to a small extent. The crotch material 69 is joined along its transverse edges 71, 72 to the front and rear panels 56, 57 in overlapping portions. The connection can be made in any suitable way, for example by ultrasonic welding, by means of adhesive adhesion or the like. In alternative embodiments, the outer nonwoven fabric may extend continuously along the front and rear panels 56, 57 and the crotch panel 58, so that no seams or joints between panels 58, 56, 57 are required.

In the example shown, elastic waistband 61 comprises first and second layers of a substantially inelastic nonwoven material that is elasticized by one or more elongated elastic members 73, such as elastic threads or tapes. The first and second layers can be formed from one layer of material that has been bent onto it itself, or can be formed from two separate strips of material. The elastic elements 73 are placed in the belt 61 in a stretched state so that they are pulled together and provide for the collection of non-woven material in the folds in the belt 61, when it is possible to weaken them, as shown in Fig.9.

An elastic belt 61 is attached to the front and rear panels 56, 57 with elastic elements 73 in a stretched state and with front and rear panel material located between the nonwoven layers in the belt. Alternatively, the elastic waistband 61 may be a component that is prefabricated and attached to the outer side or inner side of the front and rear panels 56, 57, respectively. The waist connection 74 between the waistband 61 and the front and rear panels 56, 57 can be made in any suitable manner for example by ultrasonic welding, heat sealing or by adhesive adhesion. An additional option is to form a belt 61 from one or more layers of inelastic non-woven material, which also represent parts of the front and rear panels 56, 57 and form their continuous protruding parts. It is also possible to form an elastic waist element by doubling the sections along the waist edges 62 of the elastic front and back panels 56, 57 and optionally adding additional elastic elements to the folded sections. Suitable elastic belts are also disclosed in document PCT / SE205 / 000309 (PCT / SE2005 / 0000309).

Elastic elements 75 are also located at the edges of the leg openings 67 and serve to give elasticity to the leg openings. The elastic elements at the leg openings can be conventional elastic elements of any type, such as elastic threads, tapes, strips of foam or the like. One example of a suitable method for accommodating leg elastic members is disclosed in WO 2004/078083.

The extension of the central zone 59 in the plane is formed by a liquid-tight barrier sheet 76 located between the absorbent core 77 and the base portion 60.

The liquid impermeable barrier sheet 76 has a rectangular shape, and the absorbent core 77 has an hourglass shape. A liquid-permeable topsheet 78 is located on top of the core 77 and a liquid-impermeable barrier sheet 76. Therefore, a liquid-impervious barrier sheet 76 is located below the absorbent core 77 and adjacent areas located directly outside the absorbent core 77.

A liquid-permeable topsheet 78 may consist of any material known to be used for this purpose, such as a nonwoven layer, a perforated plastic film, a mesh material, a tow or the like. The top sheet 78, of course, can also consist of a laminate of two or more sheets of the same material or different materials.

The liquid impermeable barrier sheet 76 may consist of a liquid impermeable plastic film, a sheet of nonwoven material that has been coated with a liquid barrier material, or a sheet of some other flexible material that is capable of preventing the penetration of liquids. However, it may be preferable if the liquid impermeable barrier sheet 76 is breathable, that is, allows water vapor to pass through the sheet 76.

The absorbent core 77 may be made of absorbent material, such as fluff pulverized pulp, tissue paper, absorbent foam, etc. The absorbent core may also contain superabsorbents, that is, polymeric materials that are capable of absorbing the fluid released by the body in an amount many times greater than their own weight, and form a hydrogel. Such superabsorbents are usually present in particulate form, but fibers, flakes, granules and films are also possible. In addition, the absorbent core 77 may contain non-absorbent components, such as stiffening elements, shaping elements, binders, etc. Various types of receiving fluids, porous structures, such as fiber wool, canvases of resilient nonwoven fabric, open porous foam material or the like, can also be included in the core. It goes without saying that absorbent cores 77 may also be used having shapes other than that shown in FIGS. 3 and 4.

The top sheet 78, the barrier sheet 76 and the absorbent core 77 can be formed as a separate component or “core pack”, which was subsequently integrated into the base of the diaper. The various components included in the central kit can be connected to each other in any conventional manner, for example by adhesive adhesion, ultrasonic welding or heat sealing. It goes without saying that the central kit may contain additional components in addition to the components described here, such as a liquid transporting sheet, elastic elements, elements for stabilizing the shape, elements for shaping, or the like.

The nonwoven material 69 in the crotch panel 58 is placed on the side of the liquid-tight barrier sheet 76 facing the garment. The central zone 59 extends into the front and rear panels 56, 57 so that the elastic laminate 68 in these panels overlaps the liquid-tight barrier sheet 76 in the outer parts of the Central zone 59, as can be seen in figure 3. The elastic laminate 68 is placed on the side of the liquid-tight barrier sheet 76 facing the garment.

As shown in FIGS. 3 and 4, the elastic reinforced laminate 68 preferably forms the front and rear panels 56, 57 of the panty diaper 55. However, it is only possible to make portions of the corresponding front and rear panels 56, 57 of the elastic laminate 68 with creped nonwoven fabric. In such embodiments, at least 20%, preferably at least 25%, more preferably at least 30%, and most preferably at least 40% of the entire surface area of the base portion, which is visible in a flat the state shown in figure 3, is formed by an elastic laminate in accordance with the invention. As an example, an elastic laminate can only be used in those parts of the front and rear panels 56, 57 that are designed to be placed over the thighs of the wearer and thus form elastic side panels. In some cases, it may be desirable to avoid any overlap between the central zone 59 and the elastic laminate in the front and rear panels 56, 57.

Therefore, the invention relates to a coward-type absorbent article (55) comprising a base structure, the base structure comprising a front panel (56), a rear panel and a crotch panel (58) located between the front and rear panels (56, 57), and front and rear waist panels (61a, 61b), located respectively at the front and rear panels (56, 57), and at least one of the front and rear panels (56, 57) contains an activated three-layer elastic laminate (68), containing the first canvas non-woven fibrous material and a second canvas of fibrous nonwoven material and an elastic film between the first and second canvas of fibrous nonwoven material. As indicated above, at least one of the first and second fibrous nonwoven webs is a creped nonwoven webs.

Description of test methods

Tensile Strength (Ref: ASTM D 882 (ASTM - American Society of Testing Materials))

The method allows to determine the tensile strength and elongation of various elastic materials. The tensile strength and elongation of a well-defined test piece are determined by testing with a tensile tester.

Device: Instron 456

A tensile tester connected to a computer

Slider Speed: 500 m / min

Clamp distance: 50 mm

Sample preparation: Test samples are cut from the entire width of the material. The width of the specimen should be 25.4 mm and the length should be at least 50 mm greater than the distance between the clamps, if possible. It is important that the edges of the sample are flat and free from tears and incisions. Samples are incubated for at least 4 hours at a relative humidity of 50% ± 5% and a temperature of 23 ° C ± 2 ° C before testing.

Procedure: The tensile tester is calibrated in accordance with the instructions for the device and set to zero. The specimen is secured and ensured that it is not secured obliquely or unevenly. Prevent slipping of material by using clamps coated with galun or similar material. The tensile tester is started and stopped after the material ruptures (in the absence of automatic control). Measurement data obtained as a result of premature rupture (i.e. the sample ruptures in the clamp or is damaged during preparation) are ignored, if possible.

The following results are displayed using a tensile tester / computer:

- Maximum effort, N / 25,4 mm

- Elongation at maximum effort,%

- Breaking force, N / 25,4 mm

- Relative elongation at tearing force,%

- Bend Point [Characteristics] N /%

Elasticity test

The method allows to determine how the elastic material behaves with repeated loading and unloading cycles. The sample is stretched to a predetermined elongation and a cyclic motion from 0 to the specified, predetermined elongation is performed. Target forces during loading and unloading are recorded. The residual, that is, the remaining elongation of the material subjected to relaxation is measured.

A tensile tester, Lloyd LRX, with the ability to perform cyclic movements and equipped with a printer / plotter or software for presenting data, is used. A sample is prepared by cutting it with a width of 25 mm and a length that is preferably 20 mm greater than the distance between the clamps in the tensile testing apparatus.

The tensile tester is calibrated in accordance with the instructions for the device. The parameters required for the test (efforts under loading and unloading) are adjusted to the following values:

Slider Speed: 500 mm / min Clamp distance: 50 mm Preload: 0.05 N

The sample is placed in the clamps in accordance with the marks and ensure that the sample is centered and fixed perpendicular to the clamps. The tensile tester is started and three cycles are performed from 0 to a predetermined elongation corresponding to the largest given first load. Before the last cycle, the sample is kept in an unstressed state for 1 minute, then the residual elongation is measured by stretching the sample until a force of 0.1 N is determined, and the elongation is recorded.

An elastic material is defined as a material having a residual elongation after relaxation of less than 10% after subjecting the material to an elongation of 30% in the above test. Elongation of 30% means elongation to a length that is 30% more than the original length of the sample.

The inelastic material has a residual elongation after relaxation of more than 10% after subjecting the material to an elongation of 30%.

Puncture strength

Puncture resistance is measured in accordance with ASTM Designation D3763-02. From the shock type penetration tests by this method, the data of the load versus displacement are obtained. The maximum load for each sample is calculated.

Examples

The transverse tensile strength (CD) and the puncture strength were determined for two samples.

Sample A was an activated three-layer laminate containing an inner three-layer elastomeric film with holes made of polyethylene - a copolymer of styrene and ethylene / butadiene with alternating blocks of polyethylene (PE-SEBS-PE) having a surface density of 36 g / m ² and two the outer layer of uncreated non-woven material BB Sofspan 200 with a surface density of 22 g / m ² on each side of the film.

Sample B was a three-layer laminate containing an inner three-layer elastomeric film with holes made of polyethylene - a copolymer of styrene and ethylene / butadiene with alternating blocks of polyethylene (PE-SEBS-PE) having a surface density of 36 g / m ² and the first outer a BB Sofspan 200 nonwoven layer with a surface density of 22 g / m ² on one side of the film and a second outer layer of creped nonwoven fabric of a spunbond production method having a surface density of 20 g / m ² on the other side of the film . The creped nonwoven was sealed up to 50% when creped.

The test results are shown below in Table 1.

Table 1 Sample Transverse tensile strength CD, N / 25 mm Piercing force, N BUT 10 40 AT eighteen 48

As can be seen in table 1, the laminate B in accordance with the invention has a significantly higher transverse tensile strength CD and higher puncturing resistance than the three-layer laminate of the prior art.

Claims (18)

1. A panty-type absorbent article (55) containing a base structure, the base structure comprising a front panel (56) having a front end edge (62) and first and second side edges (64), a rear panel having a rear end edge ( 62) and the first and second side edges (64), and the crotch panel (58) located between the front and rear panels (56, 57), and the front and rear waist panels (61a, 6lb) located respectively at the front and rear panels (56, 57), and the absorbing core (77), included in the base structure with the formation of a single integer with it, while the first and second side edges (64) of the front panel (56) are connected via edge connections (65) to the corresponding first and second side edges (64) of the rear panel (57), and at least one of the front or rear panels (56, 57) contains an activated three-layer elastic laminate (68) containing a first canvas of fibrous nonwoven material and a second canvas of fibrous nonwoven material and an elastic film between the first and second canvases of fibrous nonwoven material, characterized in that, at least , one of the first and second webs of fibrous nonwoven fabric is a creped nonwoven fabric canvas, and in that the three-layer elastic laminate (68) has a first tensile strength (MD) of at least 20 N / 25 mm, and preferably, a tensile strength in a first direction (MD) of at least 25 N / 25 mm and a tensile strength in a second direction (CD) perpendicular to the first direction (MD) of at least 15 N / 25 mm, and preferably strength p and stretching in the second direction (CD), of at least 20 N / 25 mm. 2. A panty-type absorbent article according to claim 1, wherein at least one of the waist panels (61a, 61b) is an elastic waist panel (61a, 61b). 3. An absorbent article such as underpants according to claim 2, in which the elastic waist panel (61a, 61b) extends continuously over the entire length between the edge joints (65). 4. An absorbent article of the type of panties according to any one of claims 1 to 3, in which at least 20%, preferably at least 25%, more preferably at least 30%, and most preferably at least at least 40% of the entire surface area of the base part, visible in a flat state, is formed by an activated elastic three-layer laminate (68). 5. An absorbent article such as underpants according to any one of claims 1 to 3, in which the absorbent core (77) is part of a component (32) with a core, while the component (32) with a core contains a top sheet (78), a barrier sheet ( 76) and an absorbent core (77) located between the top sheet (78) and the barrier sheet (76). 6. The panty-shaped absorbent article according to claim 4, wherein the absorbent core (77) is part of a component (32) with a core, the component (32) with a core comprising a top sheet (78), a barrier sheet (76) and an absorbent a core (77) located between the top sheet (78) and the barrier sheet (76). 7. An absorbent article of the type of panties according to any one of claims 1 to 3, in which the elastic film (6) in the activated three-layer elastic laminate (68) is attached to at least one of the first and second fibrous nonwoven webs (1, 18) material by extrusion coating. 8. An absorbent article of the type of panties according to claim 6, in which the elastic film (6) in the activated three-layer elastic laminate (68) is attached to at least one of the first and second canvases (1, 18) of the fibrous non-woven material by coating extrusion method. 9. An absorbent product such as underpants according to any one of claims 1 to 3, in which at least one of the first and second canvases (1, 18) of the nonwoven material is attached to the elastic film (6) by adhesive adhesion, thermal bonding or ultrasonic welding . 10. An absorbent article of the type of pants according to claim 8, in which at least one of the first and second canvases (1, 18) of the nonwoven material is attached to the elastic film (6) by adhesive adhesion, thermal bonding or ultrasonic welding. 11. An absorbent article of the type of pants according to any one of claims 1 to 3, in which the elastic film (6) in the activated three-layer elastic laminate (68) is perforated. 12. An underwear type absorbent product according to claim 10, wherein the elastic film (6) in the activated three-layer elastic laminate (68) is perforated. 13. An absorbent article of the type of pants according to any one of claims 1 to 3, in which the activated three-layer elastic laminate (68) was made by a continuous process of canvases (1, 6, 18) extending in the direction (MD) of movement of the material in the machine, and the activated three-layer elastic laminate (68) was activated by stepwise stretching, at least in the direction (MD) of the movement of the material in the machine. 14. An absorbent article of the type of pants according to claim 12, in which the activated three-layer elastic laminate (68) was made by a continuous process from canvases (1, 6, 18) extending in the direction (MD) of movement of the material in the machine, and the activated three-layer elastic the laminate (68) was activated by incrementally stretching at least in the direction (MD) of the movement of the material in the machine. 15. An absorbent article of the type of pants according to any one of claims 1 to 3, in which the first and / or second canvas (1, 18) of the fibrous nonwoven material in the activated three-layer elastic laminate (68) contains thermoplastic fibers. 16. An absorbent article of the type of pants according to claim 14, in which the first and / or second canvas (1, 18) of the fibrous nonwoven material in the activated three-layer elastic laminate (68) contains thermoplastic fibers. 17. The panty-type absorbent article of claim 15, wherein the first and / or second canvas (1, 18) of the fibrous non-woven fabric contains at least 50% thermoplastic fibers and preferably at least 80% thermoplastic fibers. 18. The panty-type absorbent article of claim 16, wherein the first and / or second canvas (1, 18) of the fibrous nonwoven fabric contains at least 50% thermoplastic fibers and preferably at least 80% thermoplastic fibers.

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