Method for manufacturing a non-reusable liquid absorbing article and the article.

The present invention is directed to a process for the continuous production of a disposable article which is intended to absorb liquids, with the aid of a machine comprising a pulp shredding device, a continuous web forming section. defibrillated pulp and a device for cutting said tape in a succession of absorbent masses.

The present invention also relates to disposable articles intended to absorb liquids, in particular body fluids such as blood or urine.

These can be dressings, sanitary towels, diapers or complete remittances for incontinent babies or adults.

Generally, such articles have a stratified structure formed by a pad of cellulosic fibers, which allows to absorb and retain liquids, placed between a liquid permeable sheet and a synthetic film that plays the role of barrier to said liquids.

The permeable sheet is, in most cases, a non-woven cloth made of artificial and / or synthetic fibers. In recent years there has been a great deal of research into the structure of this non-woven cloth: according to the mode of manufacture and the nature of the fibers used, it is possible to obtain non-woven cloths which are allowed to pass quickly through a liquid but retain very little moisture after use. absorption of the liquid by a pad of cellulosic fibers.

Thus, the surface of the absorbent articles, in contact with

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a user's skin is slightly wet: comfort is improved and the risk of irritation is significantly reduced.

The synthetic film, which forms the barrier to liquids, is generally a relief embossed polyethylene film glued to the non-woven cloth along the longitudinal edges of the article and protects clothing or underwear.

In certain articles, such as full rugs, the polyethylene film is folded over the contour of the article to form a hydrophobic and impermeable narrow tape on the non-woven face side of the cloth; thus, when the article is well applied to the wearer, the liquids to be absorbed remain in the area delimited by the polyethylene tape. The risk of leakage is reduced, but the major drawback is that the wearer's skin is moist on the entire surface of the article.

Other articles, such as sanitary towels, are entirely wrapped in a non-woven cloth and are provided, between the absorbent pad and the non-woven cloth, with a U-shaped synthetic film that protects not only the underside of the article. but also ”¹ the sides. R_PIn most cases, sanitary napkins have appeared on the market comprising a synthetic film whose branches of the U are bent along the longitudinal edges to form a kind of drip: this virtually eliminates the risk of lateral leakage, but the ends of the article do not contain any barrier to liquids.

In order to remedy the drawbacks of the present articles, the present invention proposes a novel structure whereby an impermeable sheet provided between a non-woven cloth which is in contact with a user's skin and an absorbent mass is placed between it. permeable to liquids, said zone being centrally disposed with respect to the upper face of the absorbent mass.

According to the present invention, the manufacturing process is

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characterized by:

(a) unrolling an impermeable sheet from a parent coil which is passed to form two continuous tapes in a device which cuts it in its middle zone along a line formed by a series of straight segments; parallel to the longitudinal axis of the sheet, said segments being

- situated alternately on either side of the said axis,

- offset from each other, the distance between two successive segments on the same side of the leaf axis being greater than the length of the segments, and whose ends are connected by two segments which cut the leaf axis in their area. average.

h) laterally deviating the first tape from a distance slightly less than the distance separating the segments located on either side of the axis of the. leaf.

c) the second strip follows a longer path than the first strip of a length equal to the cutting pitch;

(d) the two strips are then placed over the absorbent masses such that the open areas delimited by said ribbons are situated in the central region of the absorbent masses;

e) sectioning the casing obtained in individual articles.

In one embodiment of the present invention, the two tapes are heat-bonded or glued along the longitudinal edges of the article to a continuous, impermeable film constituting the underside.

In another embodiment of the invention, the impermeable and microperforated foil prior to cutting, for example by means of a spiked roller and a foam counter roller, having both sides

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letes equal the width of the sheet.

r> ff

This embodiment makes it possible to obtain an article which retains liquids in a particularly satisfactory manner, avoiding any maceration phenomena.

In another embodiment of the invention, whether or not in combination with the foregoing, the cutting is provided by a knife describing a sinusoid on the waterproof sheet in displacement, the sinusoid amplitude being half the width of the zone. permeable and the half wavelength being the length of the permeable zone.

The present invention is also directed to an article

disposable liquid-absorbent material comprising an absorbent mass of which at least the upper face is made up of a liquid-permeable nonwoven cloth, characterized in that it is disposed between the absorbent mass and the non-woven cloth a liquid impermeable sheet consisting of at least two cut strips z

and associated to form an obliquely permeable zone which discovers at least 50% of the absorbent mass in its central region.

Another synthetic film forms the liquid barrier on the lower side of the article. The ends of the article are heat-joined or glued to prevent any liquid from passing through the absorbent mass to the upper and / or lower faces. The permeable zone is preferably less than 80% of the total absorbent mass surface.

Thanks to the present invention there are now disposable disposable articles for absorbing liquids in which the liquid is absorbed and enclosed in an impermeable pouch: the rising of liquids from the side or in the vicinity. ds.s ends and impossible.

These articles are generally made with the aid of paper, a continuous shredding tape forming section, a tape cutting device and a series of separate absorbent masses.

According to one embodiment of the invention, the impermeable foil tapes are bonded by heat bonding or by bonding to a non-woven cloth before being applied to the absorbent masses.

Other advantages and features of the invention will become apparent from the description of various embodiments illustrated in the accompanying drawings, the figures of which represent:

Fig. 1 is a top view of an article according to a first embodiment of the invention;

Fig. 2 is a top view of an article whose central absorption zone is delimited by two tapes cut from an impermeable sheet;

Fig. 3? a sectional view of fig. 1, made by line (AA);

Fig. 4 is a sectional view of FIG. 2, made by line (AA);

Fig. 5 is a cross-sectional view of fig. 2, made by line (SB);

Fig. 6 is a sectional view of FIG. 1, made by line (BB);

Fig. 7 is a top view of fig. 1;

Fig. 8 is a top view of fig. 2;

Fig. 9j is a top view of a complete paddle according to the invention;

Fig. 10 is a sectional view of FIG. 9, made by line (AA);

Fig. 11 is a sectional view of FIG. 9, made by line (BB);

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Fig. 12 is a top view of fig. 9;

Fig. 13 is a schematic principle of a machine for making an article according to the invention;

Fig. 14 is a top view of a pre-cut film in a pattern allowing the formation of absorption zones;

and

Fig. 15 is a top view of two tapes cut to a film as shown in FIG. 14 and associated to form open zones.

In the drawings of fig. 1 and 2 there is shown an article according to the present invention comprising an absorbent mass (1) having an upper face (2) and a lower face (3) consisting of a liquid permeable nonwoven cloth (4). A liquid impermeable sheet (5) is placed between the absorbent mass (1) and the nonwoven cloth (4) on the upper side (2).

This sheet (9) is provided with a liquid permeable zone (6) and may consist of two half sheets (5a) and (5b).

article has ends (7) and (8).

drawing of fig. 3 shows a sectional view of fig. 1 made by (AA): sheet (3) comprises a zone (6) having a number of holes (6a). The sheet (5) is covered by a non-woven cloth (4) and its longitudinal edges are glued or heat-joined to (10).

drawing of fig. 4 shows a sectional view of fig. 2, made by (AA): the impermeable sheet (5) consists of two half sheets (5a) and (5b) cut and joined to form an oblong opening (6).

The non-woven cloth-coated half-sheets (5a) and (5b) completely surround the absorbent mass (1) and are bonded or heat-bonded (10) to the underside (3). ) so that the absorbent mass (1) is completely enclosed except zone (6).

Advantageously, the absorbent mass (1) is wrapped in a sheet of cotton wool fabric (9) which ensures good diffusion of the liquid. The cotton wool (9) is placed between the absorbent mass (1) and the impermeable sheet (5a, 5b).

drawing of fig. 5 is a sectional view of FIG. 2, made by line (BB): the two half sheets (5a) and (5b) are, on the upper facet side (2), as well as on the underside side (3), glued or heat-bonded together. completely enclosing the absorbent mass (1) in the vicinity of the ends (7) and (8), at (10a) and (10b).

drawing of fig. 6 is a sectional view of FIG. 1 made by (BB): the sheet (5) completely surrounds the absorbent mass (1), and its longitudinal edges are glued or joined by the action of heat on the underside side (3) of the article.

The drawings of fig. 7 and 8 are top views of the articles represented by FIGS. 1 and 2: the sheet (5) - or the two half sheets (5a) and (5b) - are glued or joined by the heat acting transversely on themselves to close the ends (7) and (8) of the article according to the present invention.

Thus, liquids are absorbed in the absorbent mass (1) through zone (6), diffuse throughout the absorbent mass (1), especially in the parts enclosed in the impermeable sheet (5): the ends (7) and ( 8) are, as stated above, closed so that liquids cannot wet the upper face (2) of the article and the non-woven cloth (4) may only become damp in zone (6).

The drawings of fig. 9 to 12 represent the top view and cross-sectional views of a complete liner whose absorbent mass (11) surrounded by a sheet of cotton wool fabric (19) is fixed to a waterproof film (22). Along the longitudinal edges of the absorbent mass (11), small, tensioned sheets are glued to the film (22).

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Two tapes (15a) and (15b) cut in an impermeable film are disposed in the absorbent mass (11) and delimit a zone (16) for passing liquids.

In the vicinity of the ends of the absorbent mass 11, the tapes 15a and 15b completely cover.

The ends (17) and (18) of the complete liner are closed, with the films (15a), (15b) and (22) being glued or joined by the heat action transversely. On the other hand, the longitudinal edges of the complete liner are glued or joined by the action of heat.

The upper face (12) of the complete liner consists of a liquid-permeable nonwoven cloth (14) which is glued or bonded by heat to its entire surface on the two strips (15a) and (15b).

drawing of fig. 13 is a schematic principle of the manufacturing process of an article according to the invention.

A shredded pulp tape (3I), wrapped in a sheet of cotton wool fabric, passes between the embossing rollers (32) and then a tape cutter in a series of separate absorbent masses (34).

A waterproof sheet (35) θ unwound from a stock reel (36) and passes through a cutting device (37), yielding two half-tapes (35a) and (35b).

The tape 35a follows a longer path than the tape 35b to form the zones 6 (see fig. 2).

Just before being applied to the absorbent masses (34), the tapes (35a) and (35b) are fixed with the aid of a gluing ramp (8) to the non-woven cloth (39).

In a known manner, the separate absorbent masses 34 are conveyed on a film of synthetic material which is intended to constitute the rear face of the complete liner.

The ^ has one. thus a continuous casing consisting of a..QUAFFENT. '^ Ε'βουοοΒ * 4

--:-~_{: Tr}—— Series of absorbent masses enclosed in an impermeable enclosure except in their upper central area: a thermal cutting device, for example, separates the individual articles.

It is also possible to transversely join the articles by heat and then separate them with the aid of a rotary knife.

The drawings of fig. 14 and 1? show how from a sheet 45 one obtains two half-tapes 45a and 45b.

The sheet (45) is cut along a line (T) formed by a series of line segments (T ^, T₂, T ^, - · -) of the same length (£) parallel to the longitudinal axis (XX¹) of sheet (45), situated in a quincy, alternating on one side and the other of (XX¹), offset from each other, the distance between two segments (T ^) and (T ^) being on the same side of (XX¹) greater than (£).

The ends of two segments (T · ^) and (T₂) located on either side of (XX¹) are linked by a segment (T'12) ^ass3rd middle (M12) is on the axis (XX¹).

The tape 45b is laterally offset from a distance slightly greater than (d- ^) Z the distance between the segments (T ^), (T₂) and (T ^) and 0 axis (XX¹ and then longitudinally offset by a length equal to the cutting pitch (T) such that two segments such as (T ^) and (T₂) are symmetrical with respect to the axis (XX ').

Thus, they form a series of open zones 46, overlapping the tapes 45a and 45b only between these zones 46.

By way of example, in order to obtain an area 46 having a larger dimension of 315 mm and a width of 110 mm, the dimensions of the article to be manufactured being 550 x 350 mm, a film is made from of polyethylene with a width of 300 mm.

Cut segments (T- /, (T₂), (T ^),

... with a length_no.

<img file="PT76320B_D0006.tif" />

. 205 mm parallel to the axis (XX¹) and located at a distance of 30 mm from the latter.

The segments (T- ^), (T₂), (T3) ··· are arranged such that the distance (^₁₂M₂^) between two segments (T '^' ^ 23) ^seJ^The lg^{u &amp;}l ^{to 2}≤5 mm.

The pitch of the cutouts is equal to 265 mm.

By laterally deflecting the 50 mm tape (U5b) and longitudinally deflecting it one step, ie 265 mm, a series of open zones (1 + 6) of width 110 mm and maximum length is obtained. equal to 315 mm.

The two strips (5a) and (* + 5b) overlap longitudinally in the vicinity of the axis (XX ') over a distance of 10 mm.