HK1163485A - A device and a method for making absorbent pads used in personal sanitary items - Google Patents

Description

Device and method for manufacturing absorbent pads for use in personal hygiene products

Technical Field

The present invention relates to a device and a method for manufacturing absorbent pads included in personal hygiene articles, and to a machine for manufacturing personal hygiene articles equipped with such a manufacturing device.

The invention is preferably suitable for the manufacture of personal hygiene products with high absorption capacity, such as diapers for babies (diapers), incontinence pads for adults and the like.

Background

Conventionally, the manufacture of these products involves the preparation of an absorbent pad, which is usually sandwiched between a permeable inner layer of non-woven fabric and an impermeable outer layer of polyethylene.

In the case of diapers and incontinence pads (baby diapers and adult diapers), the pads comprise a plurality of cellulose fibres and are suitably shaped and preformed and then placed between the two aforementioned layers.

More precisely, a manufacturing device of the traditional type for manufacturing said mats uses a compacted cellulose strip previously wound into a roll. These strips of material are fed to a suitable comminuting device and the compacted cellulose is broken up into loose cellulose fibres or fluff by the comminuting device.

The fibres produced in this way are conveyed towards the aspirating cavity which negatively reproduces the desired shape of the mat and are held together by the aspirating means, and a partial vacuum is created in the same cavity by means of the aspirating means.

The shape of the aspirating cavity is specific due to the fact that the pads of said infant and adult sanitary products must have a precise geometric shape. In these products, more precisely, the central part of the pad must have an absorption capacity which is significantly higher than the absorption capacity of the surrounding parts. Alternatively, the pad must be shaped such that the central portion will be significantly thicker than the surrounding portions.

Once the pad has been prepared in this manner, the pad is placed between the inner and outer layers.

Disadvantageously, the manufacturing devices and methods used to date to manufacture such pads are rather complex and do not always give correct and reliable results.

In fact, the preparation of the mat by the above method involves holding together a large number of loose fibres, which tend to disperse, causing shape defects in the mat.

This creates serious problems from the large amount of fluff dust generated and the need for extensive precautions to keep the mat stable.

Furthermore, it is not uncommon for the suction cavity to be incompletely or irregularly filled during formation of the mat, and therefore a large number of defective articles must be discarded.

Prior art methods of making other related articles, such as feminine sanitary napkins, now include the use of pads prepared from strips of material made from a shaped and stable getter material that are wound into rolls. In this case, the mat is prepared by cutting portions of the desired shape from a continuous strip of material.

However, said strips of material have a constant thickness and they cannot be used in the manufacture of baby diapers and incontinence pads for adults, since they do not ensure a suitable poor absorption capacity at the centre and at the periphery of the pad.

Disclosure of Invention

It is therefore an object of the present invention to provide a manufacturing device and a method for manufacturing absorbent pads for use in personal hygiene articles, and a machine for manufacturing personal hygiene articles comprising such a manufacturing device, wherein the above-mentioned drawbacks associated with the prior art are overcome.

In particular, it is an object of the present invention to provide a manufacturing device and a method for manufacturing absorbent pads for use in personal hygiene articles, and a machine for manufacturing personal hygiene articles comprising such a manufacturing device, from which absorbent pads can be manufactured quickly and conveniently.

It is a further object of the present invention to provide a manufacturing device and a method for manufacturing absorbent pads for use in personal hygiene articles, and a machine for manufacturing personal hygiene articles comprising such a manufacturing device, which, for example, will significantly reduce the production of waste products.

The stated objects are achieved substantially in a manufacturing device for manufacturing absorbent pads for use in personal hygiene articles, a machine for manufacturing personal hygiene articles comprising the manufacturing device, which is characterized by one or more of claims 1 to 13, the machine is characterized by claim 14, and the method is characterized by one or more of claims 15 to 21.

Drawings

The invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows in perspective view a manufacturing apparatus of the present invention for manufacturing an absorbent pad for inclusion in a personal hygiene article;

FIG. 2 is a side view of the manufacturing apparatus shown in FIG. 1;

FIG. 3 illustrates a detail of the manufacturing apparatus shown in FIG. 1 in a side sectional view;

FIG. 4 shows, in a schematic side view, a machine for manufacturing personal hygiene articles comprising the manufacturing device of FIG. 1;

fig. 5 to 8 show details of the manufacturing apparatus shown in fig. 1, schematically illustrating successive operating steps.

Detailed Description

In the accompanying drawings, reference numeral 1 generally designates a device for making absorbent pads of the invention for use in personal hygiene articles, in particular baby diapers (known as diapers) and/or adult incontinence products.

The manufacturing device 1, as will become clearer in the context of the present description, comprises at least one pick-up head 2, which pick-up head 2 receives a first discrete portion 4a and a second discrete portion 4b, which in combination constitute an absorbent pad 4 for personal hygiene articles.

The first and second discrete portions 4a, 4b of the pad 4 are made using a continuous absorbent material, previously prepared and stabilized, and wound into rolls or onto reels.

The absorbent material may also be previously treated with chemical additives for enhancing its absorbent capacity.

The pick-up head 2 is movable along a feed path P (see fig. 2), preferably circular, for which purpose the manufacturing apparatus 1 further comprises a drum 3 rotatable about a central axis of rotation a, with which the pick-up head 2 is associated.

Advantageously, the manufacturing device 1 comprises a plurality of pick-up heads 2 associated with the drum 3, and the pick-up heads 2 are preferably equally angularly spaced around the circumference of the same drum 3.

The manufacturing apparatus 1 further comprises a first application unit 5 by means of which the first portions 4a of the pads 4 are prepared and placed successively on the pick-up head 2, and a second application unit 6 by means of which the second portions 4b of the pads 4 are prepared and placed successively on the pick-up head 2, each second portion being positioned above a relative first portion 4 a.

In the embodiment described so far, the first application unit 5 is similar in every respect to the second application unit 6, and both are positioned adjacent to the drum 3 and the pick-up head 2, in particular each at a position substantially tangential to the aforementioned feed path P.

As shown, the second application unit 6 occupies a position downstream of the first application unit 5 with respect to the feed path P followed by the pick-up head 2.

The manufacturing device 1 also comprises movement-inducing means operating on the pick-up head 2 and/or on the first application unit 5 and/or on the second application unit 6, which are designed to produce a relative displacement of the first portion 4a and of the second portion 4b, so that the second portion 4b will only partially cover the first portion 4 a.

In short, the effect produced by the motion-inducing means, directly or indirectly, on the two portions 4a and 4b of the pad 4 is to position said portions 4a and 4b obliquely with respect to each other.

In this way, the central portion of the pad 4 comprises two portions 4a and 4b superimposed on each other, while the peripheral portion comprises only the first portion 4a or only the second portion 4 b. It is self-evident that this means that the central part of the pad 4 is substantially twice as thick as the surrounding parts and therefore has a greater absorption capacity than said surrounding parts.

In the embodiments described so far, the pick-up heads 2 are each rotatable about a corresponding axis of rotation B and actively cooperate with motion-inducing means, which will cause them to rotate through a predetermined angle.

As shown, the single axis of rotation B extends transversely to the feed path P. In practice, the axis of rotation B of each pick-up head 2 is arranged substantially transversely to the axis of rotation a of the drum 3, and more precisely the axes of rotation B of all the pick-up heads 2 radiate substantially perpendicularly to the axis of rotation a of the drum 3.

In practice, the movement-inducing means actively cooperate with the pick-up head 2 at least when it is positioned between the first application unit 5 and the second application unit 6.

In operation, as each pick-up head 2 moves along the feed path P, rotating about the central rotation axis a of the drum 3, it passes near the first application unit 5 and receives the first portion 4a of the pad 4 from this same unit.

The same pick-up head 2 then travels towards the second application unit 6 and causes it to pivot about its axis of rotation B through the aforementioned predetermined angle.

In this way, when the pick-up head 2 reaches the second application unit 6, the second portion 4b of the pad 4 will be positioned above the first portion 4a, but only partially above the first portion 4a, which has been rotated through the aforesaid predetermined angle.

As best shown in fig. 3, each pick-up head 2 comprises a carrier element 7 and a rotatable shaft 8, on which carrier element 7 the portions 4a and 4b of the pad 4 rest, while the rotatable shaft 8 is connected to the carrier element 7 so as to be able to induce angular movements in the same element as described above. The rotatable shaft 8 is connected to motion-inducing means (not shown in the figures) and each pick-up head 2 further comprises a sleeve 9, which sleeve 9 is rigidly associated with the drum 3 by means of threaded fasteners (not shown); the shaft 8 is inserted through the sleeve 9 and concentrically aligned with the sleeve 9.

The drum 3 has a cylindrical wall 10 and a base wall 11, the pick-up head 2 being attached to the cylindrical wall 10, and the base wall 11 being connected to the cylindrical wall 10. Thus, the cylindrical wall 10 and the base wall 11 define, in combination, a space inside which the movement inducing means are advantageously arranged at least partially.

For example, the movement-inducing means comprise a cam follower profile (not shown) and a cam (not shown) associated with the pick-up heads 2, so as to enable said pick-up heads 2 to be selectively rotated according to their angular position with respect to the central rotation axis a of the drum 3.

The manufacturing apparatus 1 also comprises vacuum means operating at least via the pick-up head 2 and for holding the portions 4a and 4b of the pad 4 on the head.

The vacuum device includes, for example, a system (not shown) that generates an inspiratory flow. The carrier element 7 of the single pick-up element 2 has a plurality of through holes 12 and the suction flow is generated through these through holes. To this end, the rotatable shaft 8 of each head is hollow, so that the generated suction flow can be received and conveyed through the carrying element 7.

In the example shown, the carrying element 7 of each pick-up head 2 has a substantially convex and preferably spherical profile. Advantageously, this type of geometry allows the portions 4a and 4b of the pad to be placed on the head more easily and more accurately. Furthermore, this same feature is advantageous for making the step of distancing the pads 4 formed on each pick-up head 2 more precise.

The first application unit 5 comprises a belt conveyor 13 for conveying a continuous strip of absorbent material unwound from a reel positioned upstream.

A cutting mechanism 14 is located at one end 13a of the conveyor 13 by which the first portion 4a of the continuous mat 4 is cut and released to a transport roller 15.

In more detail, the cutting mechanism 14 comprises a rotating shaft 16 and a plurality of blades 17 rigidly associated with the shaft 16 and driven in rotation by the shaft 16. Causing the rotating blade 17 to strike against the conveyor roller 15 and cut the strip.

Preferably, at least the conveyor 13 and the transport rollers 15 will be vacuum components. The conveyor roller 15 rotates substantially tangentially to the feed path P and is designed to accelerate the portions 4a along the feed path so that they are spaced one after the other.

Similarly, the second application unit 6 comprises a belt conveyor 18 for conveying a continuous strip of absorbent material unwound from a reel positioned upstream.

A cutting mechanism 19 is located at one end 18a of the conveyor 18 by which the second portion 4b of the continuous mat 4 is cut and released to a delivery roller 20.

In more detail, the cutting mechanism 19 comprises a rotary shaft 21 and a plurality of blades 22 rigidly associated with the shaft 21 and driven in rotation by the shaft 16. Causing the rotating blade 22 to impinge on the feed roller 20 and cut the strip.

Preferably, at least the conveyor 18 and the transfer roll 20 will be vacuum components. The conveyor roller 20 rotates substantially tangentially to the feed path P and is designed to accelerate the portions 4b along the feed path so that they are spaced one after the other.

The continuous strip from which the first and second portions 4a, 4b of the mat 4 are cut can be unwound from separate drums.

In contrast, in the illustrated embodiment, two strips are obtained from a single strip of absorbent material and the single strip is cut longitudinally to produce individual strips.

To this end, the manufacturing device 1 also comprises a cutting device 23 by means of which the continuous strip of absorbent material is taken up at a feed station and cut longitudinally in a direction substantially coinciding with the longitudinal direction of the strip (fig. 4).

The cutting device 23 is positioned both upstream of the first application unit 5 and upstream of the second application unit 6 and comprises a rotating disc-type blade 24 interacting with an anvil roll 25. The band of absorbent material is fed to the cutting device 23 between the blade 24 and the anvil roll 25.

The manufacturing apparatus 1 further comprises an unloading unit 26, by means of which unloading unit 26 the pads 4 formed on the pick-up head 2 are spaced from said head 2. Said unloading unit 26 is positioned substantially tangential to the feed path P at a position downstream of the second application unit 6.

In more detail, the pad 4 formed on the pick-up head 2 is taken up, accelerated and released by the unloading unit 26 onto a strip of material such as polyethylene used in the manufacture of diapers or incontinence pads (baby or adult diapers).

As shown in fig. 4, the present invention also relates to a machine 27 for making personal hygiene articles, typically diapers for infants and/or incontinence pads for adults.

The machine 27 comprises at least one manufacturing device 1 for manufacturing absorbent pads included in personal hygiene articles as described above and a device 28 for forming and assembling the hygiene articles.

The invention also relates to a method of manufacturing an absorbent pad for use in personal hygiene articles, typically diapers for infants and/or incontinence pads for adults.

The method comprises an initial step of preparing the first portion 4a of the pad 4 (fig. 5), and a similar parallel step of preparing the second portion 4b of the pad 4.

The first part 4a is rotated (fig. 6), whereby the prepared second part 4b, which is at least partly placed on the first part 4a, is also rotated (fig. 7).

More precisely, the method comprises the step of displacing or tilting the first part 4a relative to the second part 4b such that the second part 4b will only partially cover the first part 4 a.

An alternative variant of the method may comprise the step of displacing or tilting the second portion 4b relative to the first portion 4 a.

Needless to say, the step of placing the second part is only performed after the first part has been displaced.

Once the step of positioning the second portion 4b has ended and the first portion 4a is partially covered, the pad 4 is formed.

With the disclosed method, the central portion of the pad 4 comprises two superposed portions 4a and 4b, while the peripheral portion comprises only the first portion 4a or only the second portion 4 b. It is self-evident that this means that the central part of the pad 4 is substantially twice as thick as the surrounding parts and therefore has a greater absorption capacity than the surrounding parts.

In the preferred embodiment illustrated, the step of displacing the first portion 4a is achieved by rotating said portion 4a (fig. 6).

More precisely, said step is carried out by rotating the first portion 4a about a central axis substantially perpendicular to the plane occupied by the first portion 4 a.

Finally, the pad 4 prepared in this way is again rotated, this time into symmetrical alignment with the sanitary products in production (fig. 8).

The step of preparing the first portion 4a of the pad 4 comprises the steps of: preparing a corresponding continuous strip of absorbent material and repeatedly cutting the continuous strip to produce a continuous discrete first portion 4 a. The cutting step is preferably performed by cutting the continuous strip transversely to its longitudinal direction.

Similarly, the step of preparing the second portion 4b of the pad 4 comprises the steps of: preparing a corresponding continuous strip of absorbent material and repeatedly cutting the continuous strip to produce continuous discrete second portions 4 b. The cutting step is preferably carried out by severing the relative strip transversely to its longitudinal direction.

Advantageously, the step of preparing the strip comprises the steps of: a continuous strip of absorbent material is prepared and cut in a direction substantially parallel to the longitudinal direction of the strip to produce two distinct strips.

The stated objects are achieved by the present invention which provides significant advantages.

In fact, with the manufacturing device and method described above, it is possible to manufacture the pad simply and quickly by joining two portions of absorbent material one partially superposed on the other, thus making the central portion of the single pad have an absorbent capacity that is greater than that of the peripheral portions.

In short, a pad suitable for baby diapers or adult incontinence pads can be manufactured quickly and simply, while avoiding the use of loose and unstable fluff material which is difficult to handle.

Moreover, thanks to the extreme simplicity achieved, the number of defective or inappropriate articles produced is significantly reduced, with obvious advantages from a production and economic point of view.

Claims (21)

1. A manufacturing device for manufacturing absorbent pads for use in personal hygiene articles, comprising at least one pick-up head (2) and at least one first application unit (5), said pick-up head (2) being movable along a feed path (P), while a discrete first portion (4a) of an absorbent pad for personal hygiene articles is placed on said pick-up head (2) by said first application unit (5);

it is characterized in that the preparation method is characterized in that,

the manufacturing apparatus further includes:

a second application unit (6) by which discrete second portions (4b) of the pad are placed on the pick-up head (2);

-motion-inducing means operating on the pick-up head (2) and/or on the first application unit (5) and/or on the second application unit (6) and designed to induce a relative displacement between the first portion (4a) and the second portion (4b) so that, when the second portion (4b) is placed on the pick-up head (2), the second portion (4b) will only partially overlap and cover the first portion (4 a).

2. A manufacturing device as in claim 1, wherein the pick-up head (2) is rotatable about a relative rotation axis (B) which preferably extends in a direction transverse to the feed path (P), and the motion-inducing means actively cooperate with the pick-up head (2) to induce such rotation.

3. The manufacturing device according to claim 1 or 2, characterized in that the motion-inducing means actively cooperate with the pick-up head (2) at least when the pick-up head (2) is located between the first application unit (5) and the second application unit (6).

4. A manufacturing device as in any claim hereinbefore, characterized in that said feed path (P) is substantially circular.

5. A manufacturing apparatus as claimed in claim 4, characterized in that it comprises a drum (3) rotatable about a central rotation axis (A) and supporting the pick-up head (2).

6. A manufacturing apparatus as claimed in any one of the foregoing claims, characterized in that said pick-up head (2) comprises a carrying element (7) and a rotatable shaft (8), said first portion (4a) and said second portion (4b) of the pad being positionable on said carrying element (7), while said rotatable shaft (8) is connected to said carrying element (7).

7. The manufacturing device according to claim 6, characterized in that the pick-up head (2) further comprises at least one sleeve (9) rigidly associated with the drum (3), and in that the rotatable shaft (8) is inserted through the sleeve (9) and concentrically aligned with the sleeve (9).

8. A manufacturing device according to any one of claims 6 and 7, characterized in that the carrier element (7) has a plurality of through holes (12) which enable an aspiration flow through the carrier element (7).

9. A manufacturing apparatus as claimed in any one of claims 6 to 8, characterized in that the carrying element (7) of the pick-up head (2) is substantially convex.

10. A manufacturing device as claimed in any one of claims 5 to 9, characterized in that said movement-inducing means are at least partially housed inside said drum (3).

11. The manufacturing device according to any one of the preceding claims, characterized in that it comprises a plurality of pick-up heads (2), said plurality of pick-up heads (2) being connected to said drum (3) and preferably being equally angularly spaced one after the other.

12. The manufacturing device according to any one of the preceding claims, wherein the first application unit (5) and/or the second application unit (6) comprise a conveyor (13, 18) and a cutting mechanism (14, 19), the conveyor (13, 18) being intended to convey the corresponding continuous strip of absorbent material, while the cutting mechanism (14, 19) is located downstream of the conveyor (13, 18), and the discrete first portions (4a) and/or second portions (4b) are separated from the corresponding continuous strip of absorbent material by the cutting mechanism (14, 19).

13. The manufacturing apparatus according to any one of the preceding claims, characterized in that it further comprises an unloading unit (26) located downstream of the second application unit (6), the formed mat (4) being transferred by the unloading unit (26) onto a continuous web for manufacturing the personal hygiene articles.

14. Machine for manufacturing personal hygiene articles, characterized in that it comprises a manufacturing device for manufacturing absorbent pads according to one or more of claims 1 to 13.

15. A method for manufacturing an absorbent pad for use in personal hygiene products, characterized in that the method comprises the steps of:

preparing at least one discrete first portion (4a) of an absorbent pad for personal hygiene articles;

preparing discrete second portions (4b) of the mat;

-placing the second portion (4b) on the first portion (4a) such that the first portion (4a) will be partially covered by the second portion (4 b).

16. A method according to claim 15, characterized in that it comprises a step of displacing the first part (4a) before placing the second part (4b) on the first part (4 b).

17. A method according to claim 16, characterized in that it comprises the step of displacing the first part (4a) by rotating the first part (4 a).

18. A method as claimed in claim 17, characterized in that it comprises the step of rotating said first portion (4a) by causing a rotational movement about a central axis substantially perpendicular to the plane occupied by said first portion (4 a).

19. The method according to any one of claims 15 to 18, wherein the step of preparing the first portion (4a) and/or the second portion (4b) of the absorbent pad comprises the steps of: -preparing a corresponding strip of absorbent material, and-cutting said strip to obtain said discrete first portions (4a) and/or second portions (4 b).

20. The method of claim 17, wherein the step of preparing the strip comprises the steps of: preparing a continuous band of absorbent material and cutting said band of material in a direction substantially parallel to the longitudinal direction of said band to divide said band into corresponding distinct strips.

21. The method according to claim 19 or 20, wherein the step of cutting the strip to obtain the discrete first portions (4a) and/or second portions (4b) is carried out by cutting the strip in a direction substantially transverse to the longitudinal direction of the strip.