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 rear and front sections. 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 rear and front 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 rear and front sections 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.

The formation of elasticized waist sections involves a high cost both for the machine and for the materials used for manufacturing absorbent sanitary articles. In particular, the elastic films used for manufacturing elastic element have a substantial impact on the cost of the 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. Document <CIT> discloses an absorbent article and method of making the article. It does not disclose that the stretchable elastic film is shorter than the two non-elastic outer layers.

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 absorbent sanitary articles which employ a reduced quantity of elastic films and 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>, and rear and front waist sections <NUM>, <NUM>. The rear and front waist sections <NUM>, <NUM> have respective transverse edges <NUM>, <NUM>. The rear and front waist sections <NUM>, <NUM> may be not elastic. A crotch section <NUM> extends between the rear and front waist sections <NUM>, <NUM>. In use, the rear and front waist sections <NUM>, <NUM> are closed around the user's waist and the crotch section <NUM> is arranged between the user's legs.

The chassis <NUM> may have a rectangular shape, with two straight side edges <NUM> parallel to the longitudinal axis X. In a possible embodiment, the side edges <NUM> may be shaped so as to conform to the legs of the user in the configuration in which the absorbent sanitary article <NUM> is worn, such 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> set between the topsheet <NUM> and the backsheet <NUM>.

The absorbent sanitary article <NUM> comprises at least one gasketing element <NUM> elastically stretchable in a transverse direction Y orthogonal to the longitudinal axis X. In <FIG> the gasketing element <NUM> is shown in an exploded position with respect to the chassis <NUM>. The gasketing element <NUM> is applied on the outer surface of the topsheet <NUM> in at least one of the rear and front waist sections <NUM>, <NUM>. In a possible embodiment, the absorbent sanitary article <NUM> may comprise rear and front gasketing elements <NUM> attached respectively to the rear and front sections <NUM>, <NUM> of the chassis <NUM>.

With reference to <FIG> and <FIG>, the gasketing element <NUM> comprises two non-elastic outer layers <NUM>, <NUM> and at least one transversally stretchable elastic film <NUM> sandwiched between the two non-elastic outer layers36, <NUM>.

The two non-elastic outer layers <NUM>, <NUM> may be joined to the transversally stretchable elastic film <NUM>, by ultrasonic welding, thermocompression welding or by glue. In a possible embodiment, the two non-elastic outer layers <NUM>, <NUM> may be joined to the transversally stretchable elastic films <NUM>, by a pattern of ultrasonic spot welds <NUM>. The spot welds <NUM> may form through holes in the transversally stretchable elastic film <NUM> and the two non-elastic outer layers <NUM>, <NUM> may be fixed to each other through the through holes.

The gasketing element <NUM> may comprise a non-elastic outer layer <NUM> of non-woven material and a non-elastic outer layer <NUM> of impermeable plastic material. The non-elastic outer layer <NUM> of impermeable plastic material may forms the surface of the gasketing element <NUM> facing the outer surface of the topsheet <NUM>. The non-elastic outer layer <NUM> of non-woven material may form the surface of the gasketing element <NUM> which in use is in contact with the user's skin.

With reference to <FIG>, the transversally stretchable elastic film <NUM> is shorter than the two non-elastic outer layers <NUM>, <NUM> both in the direction of the longitudinal axis X and in a transverse direction Y orthogonal to the longitudinal axis X. Therefore, the gasketing element <NUM> has two non-elastic longitudinal portions <NUM> and two non-elastic transverse portions <NUM> forming a non-elastic frame surrounding the transversally stretchable elastic film <NUM>.

With reference to <FIG>, in the non-elastic longitudinal transverse portions <NUM>, <NUM> the transversally stretchable elastic film <NUM> is not present and the two non-elastic outer layers <NUM>, <NUM> are fixed directly to each other, e.g. by the same pattern of spot welds <NUM> that joins the two non-elastic outer layers <NUM>, <NUM> to the transversally stretchable elastic film <NUM>.

With reference to <FIG>, the or each gasketing element <NUM> is attached to the rear and/or front waist section <NUM>, <NUM> the chassis <NUM> along a C-shaped attachment profile <NUM> including two opposite longitudinal portions <NUM> and a transverse outer portion <NUM>.

The C-shaped attachment profile <NUM> may be formed by glue or by welding or a combination thereof. In a possible embodiment, the transverse outer portion <NUM> of the C-shaped attachment profile <NUM> may be formed by glue and the two opposite longitudinal portions <NUM> may be formed by welding, e.g. ultrasonic welding. In a possible embodiment, the two opposite longitudinal portions <NUM> of the C-shaped attachment profile <NUM> may include both glue and welding.

In a possible embodiment the two non-elastic longitudinal portions <NUM> of the gasketing element <NUM> are overlapped to the two opposite longitudinal portions <NUM> of the C-shaped attachment profile <NUM> and the outer non-elastic transverse portion <NUM> of the gasketing element <NUM> is overlapped to the transverse outer portion <NUM> of the C-shaped attachment profile <NUM> so that the portion of the gasketing element <NUM> containing the elastic element <NUM> is not attached to the chassis <NUM>.

With reference to <FIG>, a central inner region <NUM> of the elastic gasketing portion <NUM> is detached from the outer surface of the topsheet <NUM>. The central inner region <NUM> of the gasketing element <NUM> is bordered on three sides by the C-shaped attachment profile <NUM> and is detached from the outer surface of the topsheet <NUM> to form a pocket open toward the crotch section <NUM>.

With reference to <FIG>, in a possible embodiment the gasketing element <NUM> has a width W1 in the transverse direction Y which is less than the width W2 in the transverse direction Y of the corresponding rear or front section <NUM>, <NUM> of the chassis <NUM>.

With reference to <FIG> and <FIG> the absorbent sanitary article <NUM> may comprise 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> may comprise a plurality of elastic wires which are fixed, e.g. by glue, at discrete points to two opposite non-woven layers. The non-woven layers of the elastic leg cuffs <NUM> have respective outwardly facing longitudinal edges which are fixed, e.g. by glue, to the inner surface of the topsheet <NUM>. The elastic leg cuffs <NUM> have respective inwardly facing longitudinal edges detached from the inner 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.

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 between two non-woven layers. The longitudinally tensioned elastic wires are fixed in discrete points to the two non-woven layers by glue or by welds forming mechanical anchoring points, e.g. as disclosed in <CIT> and <CIT>. Between the longitudinally spaced fixing points the elastic wires are free to contract, so that the two non-woven layers assume a pleated shape when the elastic tension of the elastic wires is released. The elastic leg cuffs <NUM> may also be formed 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>.

With reference to <FIG> and <FIG>, the two non-elastic longitudinal portions <NUM> of the gasketing element <NUM> may be fixed to end portions of respective elastic leg cuffs <NUM>.

The absorbent sanitary article <NUM> may comprise pairs of rear and front side panels <NUM>, <NUM> projecting laterally beyond the side edges <NUM> of the rear and front sections <NUM>, <NUM>. The rear side panels <NUM> may carry respective fastening formations <NUM>, formed for example by micro-hook elements. The front side panels <NUM> may have a surface of loop material (e.g. a non-woven material) for connection with the micro-hook fastening formations <NUM> of the rear side panels <NUM>. The rear and/or front side panels <NUM>, <NUM> may be elastically stretchable in the transverse direction Y.

When the absorbent sanitary article <NUM> is worn, the back and front side panels <NUM>, <NUM> close the rear and front sections <NUM>, <NUM> of the chassis <NUM> around the user's waist. The or each gasketing element <NUM> is in contact with the back and/or front waist regions of the user. The outer layer <NUM> of the gasketing element <NUM> is kept in contact with the user's skin. The outer layer <NUM> of the gasketing element <NUM> may be formed by a layer of non-woven material to provide a soft feeling against the user's skin.

The central inner region <NUM> of the gasketing element <NUM> forms an inwardly open pocket between the outer surface of the topsheet <NUM> and the gasketing element <NUM>. Such pocket helps containing liquid, solid or semi-solid body exudates in the back and/or front waist region. The outer layer <NUM> of the gasketing element <NUM> facing the topsheet <NUM> may be of impermeable plastic material to form an impermeable barrier which helps containing body exudates in said pocket.

The elastic leg cuffs <NUM> may draw inwardly the inner edge of the gasketing element <NUM> so as to distance the inner surface of the gasketing element <NUM> from the topsheet <NUM>, which has the effect of opening the pocket.

The gasketing elements <NUM> may be manufactured by an apparatus <NUM> schematically shown in <FIG>.

The apparatus <NUM> comprises a first feeding device <NUM> configured to feed a continuous elastic film <NUM> in a direction parallel to its longitudinal axis.

The apparatus <NUM> comprises a cut-and-slip unit <NUM> which transversely cuts from the continuous elastic film <NUM> individual elastic elements <NUM>. The cut-and slip unit <NUM> spaces longitudinally from each other the individual elastic elements <NUM>. The apparatus <NUM> comprises a transfer wheel <NUM> which picks-up the longitudinally spaced elastic elements <NUM> from the cut-and slip unit <NUM>. The transfer wheel <NUM> may be provided on its outer surface with suction holes to hold the longitudinally spaced elastic elements <NUM>.

The apparatus <NUM> comprises an anvil wheel <NUM> having an outer cylindrical surface <NUM> provided with suction holes pneumatically connected to a source of subatmospheric pressure.

The apparatus <NUM> comprises second and third feeding devices <NUM>, <NUM> configured to feed to the outer cylindrical surface <NUM> of the anvil wheel <NUM> first and second continuous non-elastic layers <NUM>, <NUM>.

The transfer wheel <NUM> applies the longitudinally spaced elastic elements <NUM> on first continuous non-elastic layer <NUM> on the outer cylindrical surface <NUM> of the anvil wheel <NUM>, where they are retained by suction.

The second continuous non-elastic layer <NUM> is overlapped to the first continuous non-elastic layer <NUM> over the longitudinally spaced elastic elements <NUM>, so that the elastic elements <NUM> spaced apart from each other are sandwiched between the first and second continuous non-elastic layers <NUM>, <NUM>. In a transverse direction the first and second continuous non-elastic layers <NUM>, <NUM> are wider than the transversely stretched elastic elements <NUM>.

The apparatus <NUM> comprises a fastening device <NUM> cooperating with the outer cylindrical surface <NUM> of the anvil wheel <NUM>. The fastening device <NUM> may be an ultrasonic welding device, a pressure device for fastening by adhesive, or a thermal or thermomechanical welding device. The fastening device <NUM> joins the individual elastic elements <NUM> to the continuous non-elastic layers <NUM>, <NUM> to form a continuous elastic laminate <NUM> which is then detached from the anvil wheel <NUM>.

With reference to <FIG>, the continuous elastic laminate <NUM> comprises two continuous non-elastic outer layers <NUM>, <NUM> and a plurality of elastic elements <NUM> elastically stretchable in a transverse direction Y and sandwiched between the two non-elastic outer layers <NUM>, <NUM>. The elastic elements <NUM> in the transverse direction Y are shorter than the non-elastic outer layers <NUM>, <NUM> and are spaced apart from each other in the longitudinal direction X.

<FIG> schematically shows a machine <NUM> for manufacturing absorbent sanitary articles.

The machine <NUM> is configured for forming an array of chassis <NUM>. In the machine <NUM> the array of chassis <NUM> may be formed in the form of a continuous composite tape <NUM> which advances in a machine direction MD, on conveyors <NUM>, <NUM>. The continuous composite tape <NUM> may include a pair of continuous elastic leg cuffs <NUM> and pairs of front and rear side panels <NUM>, <NUM>.

With reference to <FIG>, the continuous elastic laminate <NUM> exiting the apparatus <NUM> of <FIG> may be supplied in-line to the machine <NUM> for manufacturing absorbent sanitary articles.

Alternatively, at the exit of the apparatus <NUM> of <FIG> the continuous elastic laminate <NUM> may be collected in reels which are stored and transported to machines <NUM> for manufacturing absorbent sanitary articles. In this case, the continuous elastic laminate <NUM> which supplies the machine <NUM> is unwound from a reel in an unwinding device (not shown).

With reference to <FIG>, in the machine <NUM> the continuous elastic laminate <NUM>, supplied either in-line or unwound from a reel, is transversely cut in a cut-and-slip unit <NUM> to form individual gasketing elements <NUM>. A glue dispenser (not shown) may be provided pstream of the cut-and-slip unit <NUM> for applying a glue pattern on the continuous elastic laminate <NUM>.

The cut-and-slip unit <NUM> comprises an anvil wheel <NUM> cooperating with a rotating knife <NUM>.

With reference to <FIG>, the anvil wheel <NUM> comprises a plurality of gripping elements <NUM> adjacent to respective anvil elements <NUM>. The anvil elements <NUM> cooperate with the rotating knife <NUM> to transversely cut the continuous elastic laminate <NUM>. The individual gasketing elements <NUM> formed by cutting the continuous elastic laminate <NUM> are retained by respective gripping elements <NUM>. The gripping elements <NUM> move with a speed greater than the speed of the continuous elastic laminate <NUM>, so that the individual gasketing elements <NUM> are spaced apart from each other in the longitudinal direction. Each of the gripping elements <NUM> includes two gripping pads <NUM>, <NUM> configured for retaining, e.g. by suction, respective portions of the respective individual gasketing elements <NUM>. The two gripping pads <NUM> of each gripping element <NUM> are movable in the transverse direction Y apart from each other, so as to transversally stretch the respective gasketing elements <NUM>. The transverse movement of the two gripping pads <NUM>, <NUM> may be controlled by a cam.

With reference to <FIG>, the anvil wheel <NUM> applies the transversely stretched gasketing elements <NUM> on the continuous composite tape <NUM> moving in the machine direction MD in positions longitudinally spaced from each other.

A glue dispenser <NUM> may be provided for intermittently dispensing glue layers on the continuous composite tape <NUM> upstream of the anvil wheel <NUM>.

The individual gasketing elements <NUM> are attached to the array of chassis <NUM> such that the gasketing elements <NUM> extends between the two side edges <NUM> of the respective chassis <NUM>. Each gasketing element <NUM> is attached, e.g. by glue, to the outer surface of the topsheet <NUM> of a respective chassis along a C-shaped attachment profile as disclosed with reference to <FIG> and <FIG>, so that a central inner region <NUM> of the gasketing element <NUM> is detached from the outer surface of the topsheet <NUM> to form a pocket open toward the crotch section <NUM>.

Claim 1:
An absorbent sanitary article comprising:
- a chassis (<NUM>) having a longitudinal axis (X), two side edges (<NUM>), rear and front waist sections (<NUM>, <NUM>), and a crotch section (<NUM>) intermediate between the rear and front waist sections (<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>) set between the topsheet (<NUM>) and the backsheet (<NUM>), and
- at least one gasketing element (<NUM>) applied on the outer surface of the topsheet (<NUM>) in at least one of said rear and front waist sections (<NUM>, <NUM>), wherein said at least one gasketing element (<NUM>) has a width in the transverse direction (Y) which is less than the width in the transverse direction (Y) of the respective rear or front waist section (<NUM>, <NUM>) of the chassis (<NUM>), wherein the at least one gasketing element (<NUM>) includes two non-elastic outer layers (<NUM>, <NUM>) and a transversally stretchable elastic film (<NUM>) sandwiched between said two non-elastic outer layers (<NUM>, <NUM>), wherein the transversally stretchable elastic film (<NUM>) is shorter than the two non-elastic outer layers (<NUM>, <NUM>) both in the direction of said longitudinal axis (X) and in a transverse direction (Y) orthogonal to the longitudinal axis (X), so that the gasketing element (<NUM>) has two non-elastic longitudinal portions (<NUM>) and two non-elastic transverse portions (<NUM>) forming a non-elastic frame surrounding the transversally stretchable elastic film (<NUM>), and wherein the at least one gasketing element (<NUM>) is attached to the chassis (<NUM>) along a C-shaped attachment profile (<NUM>) including two opposite longitudinal portions (<NUM>) and a transverse outer portion (<NUM>), wherein a central inner region (<NUM>) of the gasketing element (<NUM>) is detached from the outer surface of the topsheet (<NUM>) to form a pocket open toward said crotch section (<NUM>).