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

FINLAND-FINLAND (Fl)

Patent * and the National Board of Registers Patent- och registerstyrelsen

ANNOUNCEMENT _ _. __Λ[Β] (11) UTLÄGGNINGSSKRIFT 7 5 4 8 8 ^C (45) (51) Kv.lk.Vlnt.CI * A 61 F 13/00 (21) Patent application - Patentansökning (22) Filing date - Ansökningsdag (23) Starting date - Giltighetsdag (41) Made public - Blivit offentlig (44) and hear the date of publication. Ansökan utlagd och utl.skriften publicerad (86) Kv. application - Int. trap (32) (33) (31) Privilege claimed - Begärd priority France-France (FR) 8203409

833692 11.10.83 03.02.83 11 .10.83 31.03.88

PCT / FR83 / 00023

02.03.82 (71) Beghin-Say, Thumeries, France-France (FR) (72) Marcel Holvoet, Louviers, Sem Mitrani, Ris Orangis,

Raymond Rigneul, Durrenentzen, France-Frankfurt (FR) (74) Oy Kolster Ab (54) Method for the manufacture of a disposable product for the absorption of liquids and a disposable product prepared by the method For the manufacture of liquid products for the absorption of other products ) Summary

The invention relates to a method for manufacturing disposable articles and a disposable article for absorbing liquids, for example a baby diaper or a sanitary napkin. In this method, a liquid-impermeable film (35) is cut so as to form two strips (35a) and (35b) from the central region along a line forming a series of successive equal length segments parallel to the longitudinal axis of the film and alternating diagonally on either side of said axis. The strip (35a) is phase shifted laterally by a distance slightly smaller than the distance between the segments on different sides of the axis XX '. The strip (35b) follows a path longer than the path of the strip (35a) at a distance equal to the cutting distance. The strips (35a) and (35b) are then placed on the suction layers (34) in such a way that the permeable area enters their central region.

The resulting tube is cut into individual objects.

T'l2Ϊ2^{T <}23

45a dl_ —45 '45b (57) Abstract

The application of a fender for the manufacture of an engagement device and an appendix for the engagement of an engagement device, eg, ex.ex. a baby diaper or a sanitary napkin.

In the case of a film (35), which is not included in the genome, a picture of the band (35a) and (35b) is shown in the middle of the line, in which the picture is shown in the first line segment of the line 1 direction as the film's longitudinal axis and located obliquely intersecting alternately pi Bida the sides of said axis. The band (35a) is made up of 1 band attached to the strings of the three strings of axle XX. * The band (35b) is attached to the strings of the band (35a) as Ling as the cutting distance. The band (35a) and (35b) then siliconize the absorbent sketch (34) to show a genomic flap of the ligand.

The aid will be granted on a first-come, first-served basis.

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Method of making a disposable liquid absorbent ar ticle and a disposable article of the method

The present invention relates to a method for continuously manufacturing a disposable article for absorbing liquids on a machine comprising a pulp defibering device, a compartment for forming a continuous strip of defibered pulp, a device for cutting said strip into a series of absorbent layers.

This invention also relates to disposable products for the absorption of fluids, especially human body secretions such as blood or urine.

These products can be wound dressings, sanitary napkins, diapers for babies or incontinent adults.

In general, such products are layered in structure and formed of a cellulosic fibrous mattress capable of absorbing and retaining liquids and sandwiched between a liquid-permeable layer and a synthetic film that acts as a barrier to liquids.

The permeable layer is most often a nonwoven fabric made of artificial and / or synthetic fibers. In recent years, numerous studies have focused on the structure of this nonwoven fabric: depending on the method of manufacture and the fibers used, it is possible to produce nonwovens that pass liquid rapidly but retain very little moisture after the liquid is absorbed into the cellulosic fiber mattress.

In this way, the surface of the absorbent articles in contact with the wearer's skin remains slightly moist: comfort is better and the risk of irritation is substantially lower.

A synthetic film that acts as a liquid barrier is usually an embossed polyethylene film that is glued to a nonwoven fabric along the longitudinal edges of the article: it protects clothing or underwear.

In some products, such as diapers, the polyethylene film is bent around the product to form a narrow water-repellent and non-woven impermeable tape: thus, when the product is tightly against the wearer, the absorbent liquids remain in the area bounded by the polyethylene tape. The risk of leakage is lower, but the biggest drawback is that the wearer's skin is moist over the entire surface of the object.

Some other products, such as sanitary napkins, are completely wrapped in a nonwoven fabric and have a U-shaped synthetic film between the absorbent layer and the nonwoven fabric that protects not only the underside of the product but also its edges. Recently, sanitary napkins have entered the market with a synthetic membrane with U-prongs bent along longitudinal edges to form a kind of trough: the dangers of leakage are thus virtually eliminated from the sides, but there is no barrier to liquids at the ends of the product.

To overcome the disadvantages of the products currently in use, the present invention proposes a new structure in which an impermeable film having a liquid-permeable region is arranged between the nonwoven fabric and the absorbent layer in contact with the skin of the wearer, said region being centered relative to the upper surface of the absorbent layer.

The production method according to the invention is characterized in that

(a) after the liquid-impermeable film is wound open from the machine roll, it is passed to form two continuous strips in a device which intersects its center along a line consisting of a series of successive straight segments parallel to the longitudinal axis of the film and forming a zigzag shape alternately on both sides; the longitudinal axis of the film and which are phase shifted relative to each other, wherein the distance between successive straight segments on the same side of the longitudinal axis of the film is longer than the length of the straight segment, and the ends of which are connected to each other by straight segments intersecting the longitudinal axis of the film at their centers,

II

b) the first continuous strip is phase shifted laterally at a distance slightly shorter than the distance between the straight segments on different sides of the longitudinal axis of the film,

(c) the second continuous strip follows a path which is one interval longer than the path of the first continuous strip;

d) the first and second continuous strips are then arranged on and around the suction layers so that the open areas delimited by said strips are in the middle of the suction layers;

(e) the tube thus obtained is cut into individual products.

According to a variant of the invention, both strips are heat-sealed or glued along the longitudinal edges of the article to a continuous impermeable film forming its inner surface.

According to another variant of the invention, either in combination with the above or separately, the cutting is performed with a blade which cuts the sinusoidal film into the transitioning impermeable film, the extent of the sinusoid being half the width of the transmissive region and half the wavelength equal to the length of the transmissive region.

The invention also relates to a disposable article for absorbing liquids, comprising an absorbent layer having at least an upper surface of a liquid-permeable nonwoven fabric.

The disposable product according to the invention is characterized by what is stated in claim 7.

The second synthetic film forms a barrier to the flow of liquids from the inner surface side of the product. The edges of the product are heat-sealed or glued in such a way that any flow of liquid from the suction layer to the upper and / or lower surfaces is prevented. The permeable area is preferably less than 80% of the total female surface area of ​​the suction layer.

Thanks to the present invention, disposable products for absorbing liquids are now obtained, in which the absorbed liquid is sealed in an impermeable pocket: it is impossible for liquids to rise to the edges or near the ends.

These products are generally made on machines comprising a pulp defibering device, a compartment for forming a continuous strip of defibered pulp, a device for cutting said strip into a series of separate absorbent layers.

According to one embodiment of the invention, the impermeable film strips are heat-sealed or glued to the nonwoven fabric before being applied to the absorbent layers.

Other advantages and features of the invention will become apparent from the description of several embodiments in which:

Fig. 1 is a top plan view of a product having a central suction area bounded by two strips cut from an impermeable well, Fig. 2 is a sectional view taken along line AA of Fig. 1, Fig. 3 is a sectional view taken along line BB of Fig. 1, Fig. 4 is a view taken from the end of Fig. 1, Fig. 5 is a top view of the sheath according to the invention, Fig. 6 is a sectional view taken along line AA of Fig. 5, Fig. 7 is a sectional view taken along line BB of Fig. 5, Fig. 8 is a view taken from the end of Fig. 5, Fig. 9 is a schematic diagram of a machine for manufacturing an object according to the invention, Fig. 10 is a top view of a film pre-cut along a line allowing the formation of suction areas, Fig. 11 is a top view of two strips cut from the film of Fig. 10 and joined together to form open areas.

Figure 1 shows a product according to the invention with an absorbent layer 1 having an upper surface 2 and a lower surface 3 formed of a liquid-permeable nonwoven fabric 4. A liquid-impermeable film is placed between the absorbent layer 1 and the nonwoven fabric 4 on the upper surface 2 side.

Said film 5 is provided with a liquid-permeable region 6 and consists of two film halves 5a and 5b. The product has ends 7 and 8.

The drawing of Fig. 2 shows a sectional view of Fig. 1 along the line AA: the impermeable film consists of two film halves 5a and 5b which are cut and joined so as to form an elongate opening 6.

The film halves 5a and 5b coated with the nonwoven fabric 4 surround the suction layer 1 and are glued or heat-sealed (from point 10) on the underside side 3 so that the suction layer 1 is completely encapsulated except for the area 6.

The absorbent layer 1 is preferably wrapped in a layer 9 of cotton fabric, which ensures good spreading of the liquid. A layer 9 of wadding is placed between the absorbent layer 1 and the impermeable film 5a, 5b.

The drawing of Fig. 3 shows a sectional view of Fig. 1 along the line BB: the two film halves 5a and 5b are glued or heat-sealed on both the upper surface 2 and the lower surface 3 so that the suction layer 1 is completely pressed between the ends 7 and 8 near the ends 10a and 10b.

The drawings of Figure 4 show the end of the product shown in Figure 1: the film halves 5a and 5b - are glued or heat-sealed transversely on top of each other so as to close the ends 7 and 8 of the product according to the invention.

Thus, the liquids are absorbed into the suction layer 1 through the region 6, spread throughout the suction layer 1, especially into the parts inside the impermeable membrane 5a, 5b: when the ends 7 and 8 are closed, the liquids cannot wet the upper surface 2 and the nonwoven 4 only possibly moist.

Figures 5-8 show top views and sectional views of a sheath having an absorbent layer 11 surrounded by a layer 19 of wadding attached to an impermeable groove 22. The strips are glued in a stretched condition along the longitudinal edges of the absorbent layer 11.

Two strips 15a and 15b cut from the impermeable membrane are arranged on the suction layer 1 and delimit the area 16 for the passage of liquids.

Near the ends of the suction layer 11, the strips 15a and 15b completely cover each other.

The ends 17 and 18 of the sheath are closed when the films 15a and 15b are glued or heat sealed in the transverse direction. On the other hand, the longitudinal edges of the sheath are glued or heat-sealed.

The upper surface 12 of the sheath consists of a liquid-permeable nonwoven fabric 14 glued or heat-sealed over its entire surface to the strips 15a and 15b.

The drawing of Figure 9 is a schematic diagram of a method of manufacturing a product according to the invention. The strip 31 of fibrous mass wrapped in the cotton fabric layer passes between the embossing rolls 32 and then to a device where the strip is cut into a series of separate suction layers 34.

The impermeable film 35 is wound from a machine roll 36, passes to a cutting device 37: two strip halves 35a and 35b are obtained. The strip 35a follows a longer path than the strip 35b to form the regions 6 (see Figure 1). Immediately before the strips 35a and 35b settle on the suction layers 34, they are attached to the nonwoven fabric 39 by means of a gluing ramp 38.

The separate suction layers 34 are conveyed in a manner known per se to a synthetic film intended to form the back surface of the sheath.

This results in a continuous tube consisting of a series of suction layers wrapped in an impermeable cover, with the exception of their upper central region: for example, a heat cutting device separates the individual products.

It is also possible to heat-seal the products transversely and then separate them with a rotating cutting blade.

The drawings of Figures 10 and 11 show how two strip halves 45a and 45b are obtained from the film 45. The film 45 is cut along a line T consisting of a series of strands T1, T2, etc. of the same length / parallel and parallel to the longitudinal axis of the film 45 and located in zigzag form relative to each other alternately on both sides of the axis XX 'and phase shifted with respect to two at the same time. a segment on the side of the axis XX '^T1 3^{a T}2 with a distance greate r than L.

Two segments on different sides of the axis XX ' ^T1 3^{a T}2 The ends are connected to each other by a segment T '^₂with center M ^₂ is on the axis XX '.

The strip 45b is phase shifted laterally by a distance slightly greater than d ^ (segments T ^, T₂ and Τβ and the distance between the axis XX ') and then phase shifted longitudinally by a length equal to the distance of the section T so that two segments such as Tj and T₂ become symmetrical about the axis XX '.

Thus, a series of open areas 46 are formed, with the strips 45a and 45b overlapping only between these areas 46.

For example, to provide a region 46 with a maximum dimension of 315 mm and a width of 110 mm, with a product size of 550 x 350 mm, starting from a 300 mm wide polyethylene film.

Cut thirst Τβ, T₂, Τβ, etc., which are 205 mm long, parallel to the axis XX 'and situated at a distance of 30 mm from the latter.

Janat Tj, T₂, Τβ is fitted such that for two segments ^T*12' ^T'l3 is the distance Μβ₂Μ₂β is 275 mm. The cutting distance is 265 mm. By phase shifting the strip 45b laterally by about 50 mm and phase shifting it longitudinally by one axis which is 265 mm, a series of successive open areas 46 which are 110 mm wide and have a maximum length of 315 mm are obtained.

The two strips 45a and 45b overlap in the longitudinal direction close to the axis XX 'by a distance of 10 mm.