Patent Description:
The present invention also relates to a method for producing absorbent sanitary articles.

An absorbent sanitary article typically has a structure that comprises a central body or chassis having a front section and a rear section. The chassis normally includes a permeable topsheet intended to come into contact with the user's skin when the article is worn, an impermeable backsheet and an absorbent core sandwiched between the topsheet and the backsheet. The front and rear sections of the chassis are normally closed around the user's waist by means of hook-and-loop fasteners, better known as Velcro© fastening devices.

The front section and rear section may be elasticized. <CIT> and <CIT> disclose methods for bonding elastic parts under tension to an advancing carrier, which may be used for elasticizing the waist sections of absorbent sanitary articles. The methods disclosed in these documents provide: advancing a carrier substrate, advancing a continuous elastic substrate, cutting an elastic part from the continuous elastic substrate, stretching the elastic part in a cross direction, positioning the elastic part on the carrier substrate, and adhesively bonding a stretched central region of the elastic part with the carrier substrate, and mechanically bonding end regions of the elastic part with the carrier substrate. <CIT> discloses an absorbent sanitary article; <CIT> and <CIT> represent relevant prior art in the technical field.

The formation of elasticized waist sections involves a high cost both for the machine and for the materials used for manufacturing absorbent sanitary articles.

Although it would be desirable to avoid applying elastic elements in the waist regions to reduce the costs of absorbent sanitary articles and of the machines for manufacturing the same, without elastic elements in the waist regions the absorbent sanitary articles might have reduced capacity to contain leakage of body exudates in the crotch region, especially solid and semi-solid body exudates.

The object of the present invention is to provide an absorbent sanitary article which overcomes the problems of the prior art.

More specifically the object of the present invention is to provide low cost absorbent sanitary articles which maintain good capacity of retention of body exudates.

According to the invention, this object is achieved by an absorbent sanitary article having the features of claim <NUM>.

According to another aspect, the invention relates to a method for manufacturing absorbent sanitary articles having the features of claim <NUM>.

The claims form an integral part of the technical disclosure provided here in relation to the invention.

The present invention will now be described with reference to the attached drawings, provided purely by way of non-limiting example, wherein:.

It should be appreciated that the attached drawings are schematic and not to scale with respect to real products. Various figures may not be represented in the same scale. Also, in various figures some elements may not be shown to better show other elements.

With reference to <FIG> and <FIG>, numeral <NUM> indicates an absorbent sanitary article according to the present invention. <FIG> shows the absorbent sanitary article <NUM> in the configuration in which it is worn, and <FIG> shows the absorbent sanitary article <NUM> in a flat configuration.

The absorbent sanitary article <NUM> comprises a chassis <NUM> elongated along a longitudinal axis X. The chassis <NUM> has two side edges <NUM>, a front section <NUM> and a rear section <NUM>. The front section <NUM> and the rear section <NUM> in use are closed around the user's waist. The front section <NUM> and the rear section <NUM> may be not elastic. A crotch section <NUM> extends between the front section <NUM> and the rear section <NUM>. In use, the crotch section <NUM> is arranged between the legs of the user.

The side edges <NUM> may be cut so that they conform to the legs of the user in the configuration in which the absorbent sanitary article <NUM> is worn. The side edges <NUM> may be shaped so that in a flat configuration the absorbent sanitary article <NUM> has substantially an hourglass shape.

The chassis <NUM> comprises a topsheet <NUM> made of a permeable material having an outer surface which, in use, is in contact with the user's skin, an impermeable backsheet <NUM>, and an absorbent core <NUM> sandwiched between the topsheet <NUM> and the backsheet <NUM>.

The absorbent sanitary article <NUM> comprises a fastening device <NUM> configured for fastening the front section <NUM> and the rear section <NUM> to each other. The fastening device <NUM> may comprise two back side panels <NUM> attached to the rear section <NUM> of the chassis <NUM> and extending laterally beyond respective side edges <NUM>. The back side panels <NUM> may be elastically stretchable in a transverse direction Y orthogonal to the longitudinal axis X. The back side panels <NUM> may have distal portions provided with micro-hook elements <NUM> which form a releasable surface connection with a micro-loop front panel <NUM> attached in the front section <NUM> of the chassis <NUM>.

With reference to <FIG>, in a possible embodiment the chassis <NUM> may have a rectangular shape, with two straight side edges <NUM> parallel to the longitudinal axis X. The absorbent sanitary article <NUM> may comprises a pair of front side panels <NUM> projecting laterally from opposite sides of the front section <NUM>. The front side panels <NUM> may have a surface of loop material (e.g. a non-woven material) for connection with the micro-hook elements <NUM> of the back side panels <NUM>. In this case the micro-loop front panel <NUM> may not be present.

Both in the embodiment of <FIG>, <FIG> and in the embodiment of <FIG>, at least one of the transverse edges of the chassis <NUM> may be shaped instead of straight. For instance, the front edge may have a central substantially semi-circular concave portion to contour the umbilical cord of the user.

The absorbent sanitary article <NUM> comprises two elastic leg cuffs <NUM>. The leg cuffs <NUM> are sometimes also referred to as leg bands, side flaps, barrier cuffs, elastic cuffs or gasketing cuffs. The elastic leg cuffs <NUM> may be formed as disclosed in <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>.

The elastic leg cuffs <NUM> comprise a plurality of elastic wires <NUM> which are fixed, e.g. by glue, at discrete points to two opposite non-woven layers <NUM>.

The non-woven layers <NUM> of the elastic leg cuffs <NUM> have respective outwardly facing longitudinal edges <NUM> which are fixed, e.g. by glue, to the outer surface of the topsheet <NUM>. In the crotch section <NUM> the outwardly facing longitudinal edges <NUM> of the elastic leg cuffs <NUM> may be adjacent to the respective side edges <NUM> of the chassis <NUM>.

The non-woven layers <NUM> of the elastic leg cuffs <NUM> have respective inwardly facing longitudinal edges <NUM> detached from the outer surface of the topsheet <NUM> which in use are in contact with the legs of the user to form barriers which help reduce the leakage of liquid, solid or semi-solid body exudates in the leg regions. At least some of the elastic wires <NUM> may extend along the inwardly facing longitudinal edges <NUM> of the elastic leg cuffs <NUM>.

The elastic leg cuffs <NUM> have respective non-elastic end portions <NUM>, <NUM>. At the non-elastic end portions <NUM>, <NUM> the outwardly facing longitudinal edges <NUM> and the inwardly facing longitudinal edges <NUM> are both fixed to the outer surface of the topsheet <NUM>. The non-elastic end portions <NUM>, <NUM> may be rendered non-elastic by not providing the elastic wires <NUM> at these portions or by not fixing the elastic wires <NUM> to the non-woven layers <NUM> at these portions.

The elastic leg cuffs <NUM> may be configured in various ways. In a possible embodiment the elastic leg cuffs <NUM> may be formed separately from the topsheet <NUM> by sandwiching longitudinally stretched elastic wires <NUM> between two non-woven layers <NUM>. The longitudinally tensioned elastic wires <NUM> are fixed in discrete points to the two non-woven layers <NUM> by glue or by welds forming mechanical anchoring points, as disclosed in <CIT> and <CIT>. Between the longitudinally spaced fixing points the elastic wires <NUM> are free to contract, so that the two non-woven layers <NUM> assume a pleated shape when the elastic tension of the elastic wires <NUM> is released.

It should be appreciated that the elastic leg cuffs <NUM> may be formed in various ways, such as for example, by folding portions of the topsheet <NUM> laterally inward, i.e., toward the longitudinal axis X, to form both the leg cuffs <NUM> and the side edges <NUM> of the chassis <NUM>. In another example, the leg cuffs <NUM> may be formed by attaching an additional non-woven layer or layers to the chassis <NUM> at or adjacent to each of the respective side edges <NUM> of the chassis <NUM>. The leg cuffs <NUM> may extend to the same longitudinal extent as the chassis <NUM> or alternatively the leg cuffs <NUM> may have a longitudinal extent that is less than that of the chassis <NUM>.

The absorbent sanitary article <NUM> may comprise leg elastic elements <NUM> which may be formed by stretched elastic wires fixed between the topsheet <NUM> and the backsheet <NUM> and extending along the side edges <NUM> of the chassis <NUM>, which impart a pleated form to the side edges <NUM> in the crotch section <NUM>.

The absorbent sanitary article <NUM> comprises at least one gasketing element <NUM> elongated in a transverse direction Y orthogonal to the longitudinal axis X.

The at least one gasketing element <NUM> is attached to the outer surface of the topsheet <NUM> in at least one of the front and rear waist sections <NUM>, <NUM>. In a possible embodiment the absorbent sanitary article <NUM> may comprise two gasketing elements <NUM> attached to the outer surface of the topsheet <NUM> in the front waist section <NUM> and in the rear waist section <NUM>, respectively.

The or each gasketing element <NUM> is not stretched in the transverse direction Y and has a length in the transvers direction Y which is less than the length in the transverse direction of the chassis <NUM>. This simplifies and reduces the cost of the machine for manufacturing the absorbent sanitary articles in that a device for stretching transversally the gasketing elements <NUM> is not required.

The or each gasketing element <NUM> has two opposite lateral portions <NUM> overlapped and fixed to elastic end portions <NUM> of the respective elastic leg cuffs <NUM>. The two opposite lateral portions <NUM> of the gasketing element <NUM> extend partially on the non-elastic end portions <NUM>, <NUM> and partially on the elastic end portions <NUM> of the elastic leg cuffs <NUM>. The two opposite lateral portions <NUM> of the gasketing element <NUM> may be fixed to the corresponding portions <NUM>, <NUM>, <NUM>, of the leg cuffs <NUM> by glue or by welding, e.g. ultrasonic welding or thermocompression welding.

The or each gasketing element <NUM> has a central outer portion <NUM> extending between the two opposite lateral portions <NUM> and fixed to the outer surface of the topsheet <NUM>, e.g. by glue, ultrasonic welding or thermocompression welding.

The or each gasketing element <NUM> has a central inner portion <NUM> extending between the two opposite lateral portions <NUM> and detached from the outer surface of the topsheet <NUM>.

When the absorbent sanitary article is worn, the or each gasketing element <NUM> is in contact with the back and or front waist region of the user. The elastic leg cuffs <NUM> draw elastically inwardly the central inner portion <NUM> of the or each gasketing element <NUM>. The central inner portion <NUM> forms an inwardly open pocket between the outer surface of the topsheet and the or each gasketing element <NUM>. Such pocket helps containing liquid, solid or semi-solid body exudates in the back and/or front waist region.

In the preferred embodiment, said at least one gasketing element <NUM> is made of a non-elastic material. At least one gasketing element <NUM> may comprise a layer of impermeable plastic material forming an impermeable barrier in the back and/or front waist region which helps containing body exudates. At least one gasketing element <NUM> may comprise a layer of non-woven material on a surface opposite the outer surface of the topsheet <NUM> to provide a soft feeling against the skin of the user. In a possible embodiment at least one gasketing element <NUM> may be formed by a non-elastic laminate including a layer of impermeable plastic material and at least one layer of a non-woven material.

In a possible embodiment, at least one gasketing element <NUM> is made of an elastic material not stretched in the transverse direction Y. In a possible embodiment at least one gasketing element <NUM> may be formed by an elastic laminate including an elastic film and at least one layer of a non-woven material.

In a possible embodiment, at least one gasketing element <NUM> has a transverse outer edge aligned to a corresponding transverse edge of the respective front or rear waist section <NUM>, <NUM>.

Since the or each gasketing element <NUM> is not stretched in the transverse direction, it may have a surface with a printed pattern including writings, and/or images.

The absorbent sanitary articles <NUM> according to the present invention may be manufactured by a machine <NUM> schematically shown in <FIG>.

The machine <NUM> comprises an inlet conveyor <NUM> which feeds in a machine direction MD a continuous absorbent tape <NUM>. A first cutting unit <NUM> transversally cuts the continuous absorbent tape <NUM> to form individual absorbent cores <NUM> moving in the machine direction MD.

A first web feeding device <NUM> feeds a continuous backsheet web <NUM> in the machine direction MD. A first glue dispenser <NUM> applies glue on an upper surface of the continuous backsheet web <NUM>.

The individual absorbent cores <NUM> moving in the machine direction MD are applied on the upper surface of the continuous backsheet web <NUM>.

Continuous elastic wires <NUM> intended to form leg elastic elements <NUM> are applied on the upper surface of the continuous backsheet web <NUM>. A second glue dispenser <NUM> applies glue to the continuous elastic wires <NUM>.

A second web feeding device <NUM> feeds a continuous topsheet web <NUM> in the machine direction MD. A third glue dispenser <NUM> applies glue on a first surface of the continuous topsheet web <NUM>.

Two continuous elastic leg cuffs bands <NUM> are applied to the first surface of the continuous topsheet web <NUM>, where they are retained by glue.

A third web feeding device <NUM> feeds a continuous gasketing web <NUM> in the machine direction MD. A fourth glue dispenser <NUM> applies glue on a surface of the continuous gasketing web <NUM>.

A cut-and-slip unit <NUM> transversally cuts the continuous gasketing web <NUM> to form individual gasketing elements <NUM> elongated in a transverse direction and spaced apart from each other in a longitudinal direction. The individual gasketing elements <NUM> are applied on the first surface of the continuous topsheet web <NUM> not stretched in the transverse direction Y. The gasketing elements <NUM> are retained by glue on the first surface of the continuous topsheet web <NUM>.

A fifth glue dispenser <NUM> applies glue on a second surface of the continuous topsheet web <NUM>.

The continuous topsheet web <NUM> with the two continuous elastic leg cuffs bands <NUM> and the individual gasketing elements <NUM> applied to the first surface continuous topsheet web <NUM> is then overlapped to the continuous backsheet web <NUM>, with the second surface of the continuous topsheet web <NUM> facing the upper surface of the continuous backsheet web <NUM>.

A compression unit <NUM> compresses together the continuous topsheet web <NUM> and the continuous backsheet web <NUM> with the individual absorbent cores <NUM> sandwiched therebetween, to form a continuous chassis chain <NUM>.

Pairs of side panels <NUM> may be attached to the continuous backsheet web <NUM>, to the continuous backsheet web <NUM> or to the continuous chassis chain <NUM>.

The continuous elastic leg cuffs bands <NUM> and the individual gasketing elements <NUM> spaced apart from each other in the machine direction MD may be applied to the first surface of the continuous topsheet web <NUM> after the continuous topsheet web <NUM> is overlapped to the continuous backsheet web <NUM>.

A second cutting unit <NUM> cuts the continuous chassis chain <NUM> to form individual absorbent sanitary articles <NUM>. The second cutting unit <NUM> may also cut the side edges of the continuous chassis chain <NUM> to form shaped side edges <NUM>.

A method for producing absorbent sanitary articles according to the present invention comprises:.

The step of attaching the two continuous leg cuffs bands <NUM> to the first surface of the continuous topsheet web <NUM> may be carried out before or after sandwiching the array of absorbent cores <NUM> between the continuous topsheet web <NUM> and the continuous backsheet web <NUM>.

The method may comprise forming on the two continuous leg cuffs bands <NUM> non-elastic portions <NUM>, <NUM> spaced apart from each other in a longitudinal direction, and overlapping and fixing the opposite lateral portions <NUM> of the gasketing elements <NUM> partially on the non-elastic portions <NUM>, <NUM> and partially on elastic portions <NUM> of the continuous elastic leg cuffs bands <NUM>.

Claim 1:
An absorbent sanitary article comprising:
- a chassis (<NUM>) having a longitudinal axis (X), a front and a rear waist section (<NUM>, <NUM>), and a crotch section (<NUM>) intermediate between the front and rear waist section (<NUM>, <NUM>), the chassis (<NUM>) including a topsheet (<NUM>) having an outer surface which in use is in contact with the user's skin, a backsheet (<NUM>), and an absorbent core (<NUM>) disposed between the topsheet (<NUM>) and the backsheet (<NUM>),
- a pair of elastic leg cuffs (<NUM>) extending at least in part along directions parallel to said longitudinal axis (X) and attached to said outer surface of the topsheet (<NUM>),
- at least one gasketing element (<NUM>) having a longitudinal axis oriented in a transverse direction (Y) orthogonal to said longitudinal axis (X), wherein the at least one gasketing element (<NUM>) has a length in the transverse direction (Y) which is less than the length in the transverse direction of the chassis (<NUM>), wherein the at least one gasketing element (<NUM>) is attached to said outer surface of the topsheet (<NUM>) in at least one of said front and a rear waist section (<NUM>, <NUM>), wherein said at least one gasketing element (<NUM>) is not stretched in said transverse direction (Y) and has two opposite lateral portions (<NUM>) overlapped and fixed to elastic end portions (<NUM>) of said elastic leg cuffs (<NUM>), a central outer portion (<NUM>) extending between said two opposite lateral portions (<NUM>) and fixed to the outer surface of the topsheet (<NUM>) and a central inner portion (<NUM>) extending between said two opposite lateral portions (<NUM>) and detached from the outer surface of the topsheet (<NUM>), wherein said central inner portion (<NUM>) of the gasketing element (<NUM>) is raised from the outer surface of the topsheet (<NUM>) and forms a pocket open toward said crotch section (<NUM>),
characterized in that said at least one gasketing element (<NUM>) is made of a non-elastic material, and that said two opposite lateral portions (<NUM>) of the gasketing element (<NUM>) extend partially on non-elastic end portions (<NUM>, <NUM>) and partially on elastic end portions (<NUM>) of the elastic leg cuffs (<NUM>).