EP0564319A1 - New embossed multiply papers, apparatus and process for making the same - Google Patents

Abstract

The invention relates to multi-ply embossed papers, more particularly multi-ply papers containing an embossed sheet (1) of paper exhibiting protuberances of different depths produced during its embossing, characterised in that deeper protuberances (11) called large protuberances alternate with protuberances so that the small protuberances (12) can be placed in a point-to-point position with the protuberances (22) of a second sheet of embossed paper (2) and in that the large protuberances (11) fit between the protuberances (22) of the second sheet (2). The invention also relates to a process and a device for the production of these multi-ply embossed papers. <IMAGE>

Description

The present invention relates to new multilayer papers, a device and a method for manufacturing them.

The invention relates more particularly to papers usable in the household and domestic field, in particular embossed papers based on crepe paper of the cellulose wadding type. In this area, papers are particularly sought after having good absorption qualities associated with great softness and good mechanical resistance properties.

In this field, we have been oriented for many years towards papers having several layers, in general two or three, previously embossed, then glued slightly together, glue being deposited on the ends of the protuberances produced during the embossing operation.

Two different systems of embossing, assembly and bonding are currently used leading to two different types of structure. A first type consists of making two identical embossings on two separate plies of paper so as to produce protuberances on the sheets, to form a laminate from these two sheets, the protuberances of the two sheets being directed towards the internal part of the laminate and glued together by their ends. This system achieves what we would call a "point-point" assembly. Such a process, as well as the laminates obtained, is described in patent US-A-3,414,459. Such a system essentially makes it possible to make two-layer papers with the structure shown in FIG. 6 of patent US-A-3 414 459. Another variant described in this patent consists, as it appears in FIG. 7, of inserting before gluing the tips an unembossed sheet between the two embossed sheets.

Another method described in particular in US Pat. No. 3,867,225 consists in also producing a laminate between two embossed sheets also placed so that the protuberances are directed towards the interior of the laminate, by gluing the ends of the protrusions one of the two sheets and to make the bonding in a position such that the protrusions of one of the sheets come to fit between two protrusions of the other sheet. We will call the structure "nested" or "nested" the structure obtained.

US Pat. No. 4,320,162 has proposed a method for producing sheets of multilayer paper having two series of embossings of different depths and in which the bonding between the two sheets is carried out only between the most embossing deep. The goal sought with the product obtained is an improvement in softness, water retention, bulk and aesthetics.

Thus, in general, we are looking for assemblies of sheets of embossed paper essentially combining softness, improved feel, good absorption properties with good mechanical resistance. The Applicant has continued work in this direction and has now found a new embossed structure making it possible to make laminates, for example three-sheet complexes having both improved qualities of softness due to the fact that a greater quantity of air is enclosed between the layers at the same time as increased mechanical strength due, in particular, to better rigidity of the structure due in particular to the fact that bonding is carried out at different levels.

The present invention provides a new structure of embossed paper making it possible to produce multilayer complexes combining qualities hitherto never combined. It also proposes a method and a device for producing these multilayer complexes.

The present invention provides a new structure of embossed paper sheet having protrusions of different depths, characterized in that the deepest protrusions called large protrusions alternate with shallow protrusions said small protrusions so that the small protrusions can be brought into play coincidence in point-to-point position with the protuberances of a second sheet which is itself embossed and that the large protuberances of the first sheet are interposed between two protuberances of the second sheet.

According to another characteristic, the present invention relates to multilayer complexes containing the two layers of embossed paper defined above in which the ends small protuberances of the first sheet and protuberances of the second sheet are glued in a point-to-point position and the ends of the large protuberances of the first sheet come to fit between two protuberances of the second sheet.

According to another characteristic of the invention, the sum of the heights of the small protrusions of the first sheet and the protrusions of the second sheet is at least equal to the height of the large protrusions of the first sheet. According to a particular embodiment, said sum is equal to the height of the large protuberances.

According to another characteristic of the invention, the small protrusions of the first sheet have the same height as the protrusions of the second sheet.

According to another characteristic, the invention relates to complexes further comprising a third sheet having protuberances whose pitch corresponds to that of the large protuberances of the first sheet and which are glued in point-to-point position relative to the large protuberances of the first leaf.

The invention also relates to complexes formed by four sheets in which the first two have the configuration described above and further comprising a third sheet having an embossing identical to that of the second sheet and a fourth sheet comprising an embossing identical to that of the first sheet with protuberances and large protrusions, the small protrusions of the fourth sheet being located in point-to-point position relative to the protrusions of the third sheet and the large protrusions of the fourth sheet coming to fit between the protrusions of the third sheet, the bonding between the sheets being ensured at least at the level of the large protuberances of the first and fourth sheets.

• on crée par gaufrage d'un premier pli des petites et des grandes protubérances sur ce pli.
• on crée par gaufrage séparé d'un deuxième pli des protubérances sur ce pli, ces protubérances étant séparées entre elles par la même distance que les petites protubérances du premier pli et ayant une hauteur telle que la somme de leur hauteur et de la hauteur d'une petite protubérance du premier pli soit de préférence au moins égale à la hauteur d'une grande protubérance du premier pli,
• on encolle les extrémités des protubérances du deuxième pli,
• on réalise un matelas entre les premier et deuxième plis en collant les extrémités des petites protubérances du premier pli avec les extrémités des protubérances du deuxième pli en position pointe-pointe, les grandes protubérances du premier pli venant s'emboîter entre des protubérances du deuxième pli.

The invention also relates to a process for preparing the complexes described above, in particular a process in which:

• small and large protrusions on this fold are created by embossing a first fold.
• protrusions on this fold are created by separate embossing of a second ply, these protrusions being separated from one another by the same distance as the small protrusions of the first ply and having a height such that the sum of their height and the height of a small protrusion of the first fold is preferably at least equal to the height of a large protrusion of the first fold,
• we stick the ends of the protrusions of the second fold,
• a mattress is produced between the first and second plies by gluing the ends of the small protrusions of the first ply with the ends of the protrusions of the second ply in the point-to-point position, the large protrusions of the first ply coming to fit between protuberances of the second ply .

• on réalise le gaufrage séparé d'un troisième pli, ce gaufrage présentant un pas identique à celui des grandes protubérances du premier pli,
• on encolle les extrémités des protubérances réalisées sur ce troisième pli,
• on réalise le collage du troisième pli et du matelas formé entre les deux premiers plis de façon que les extrémités des protubérances créées sur le troisième pli viennent se coller en position pointe-pointe sur le deuxième pli au niveau des grandes protubérances du premier pli.

According to another variant of the present invention, it relates to a method in which:

• embossing is carried out separately from a third ply, this embossing having a pitch identical to that of the large protuberances of the first ply,
• the ends of the protuberances made on this third fold are glued,
• the third ply and the mattress formed between the first two plies are bonded so that the ends of the protuberances created on the third ply stick in the point-to-point position on the second ply at the level of the large protrusions of the first ply.

• on réalise un matelas comme précédemment décrit entre les deux premiers plis,
• un troisième pli est gaufré pour avoir une configuration identique à celle du deuxième pli,
• un quatrième pli est gaufré pour avoir une configuration identique à celle du premier pli,
• les troisième et quatrième plis sont réunis entre eux pour former un matelas dans lequel les protubérances formées sur le troisième pli viennent en position pointe/pointe par rapport aux petites protubérances formées sur le quatrième pli alors que les grandes protubérances du quatrième pli viennent s'intercaler entre deux protubérances du troisième pli,
• puis on réalise un encollage du matelas, ainsi formé entre les troisième et quatrième plis, au niveau des grandes protubérances du quatrième pli,
• les deux matelas constitués par les premier et deuxième plis respectivement et les troisième et quatrième plis sont collés entre eux pour former un complexe constitué de quatre feuilles gaufrées et à deux niveaux de collage.

According to a variant of the invention, it relates to a process for preparing a complex comprising four plies in which:

• a mattress is produced as previously described between the first two folds,
• a third fold is embossed to have a configuration identical to that of the second fold,
• a fourth fold is embossed to have a configuration identical to that of the first fold,
• the third and fourth plies are joined together to form a mattress in which the protuberances formed on the third ply come in point / tip position relative to the small protuberances formed on the fourth ply while the large protuberances of the fourth fold are inserted between two protrusions of the third fold,
• then a gluing of the mattress, thus formed between the third and fourth plies, is made at the level of the large protrusions of the fourth ply,
• the two mattresses formed by the first and second plies respectively and the third and fourth plies are glued together to form a complex consisting of four embossed sheets and with two levels of gluing.

According to other characteristics finally, the invention relates to a device making it possible to produce the various multilayer complexes of the present invention or the implementation of the method of the invention.

• la figure 1 représente un exemple de complexe formé de trois feuilles gaufrées obtenu dans un procédé de gaufrage et collage pointe-pointe de l'art antérieur ;
• la figure 2 représente un autre exemple de complexe formé de trois couches gaufrées et collées selon un procédé "nested" de l'art antérieur ;
• la figure 3 représente un exemple de papier multicouche composé de trois couches selon la présente invention ;
• la figure 4 représente schématiquement un dispositif permettant de réaliser le papier à trois couches de la figure 3 ;
• la figure 5 représente un exemple de papier à quatre couches selon la présente invention ;
• la figure 6 représente schématiquement un dispositif pour réaliser le papier de la figure 5.

Other objects and characteristics of the invention will appear in the description which follows, given with reference to the drawings:

• FIG. 1 represents an example of a complex formed from three embossed sheets obtained in an embossing and point-to-point bonding process of the prior art;
• FIG. 2 represents another example of a complex formed from three embossed layers and bonded according to a "nested" method of the prior art;
• FIG. 3 represents an example of multilayer paper composed of three layers according to the present invention;
• Figure 4 schematically shows a device for making the three-layer paper of Figure 3;
• Figure 5 shows an example of four-layer paper according to the present invention;
• FIG. 6 schematically represents a device for producing the paper of FIG. 5.

FIG. 1 represents a laminate obtained in a conventional process of the prior art of embossing and gluing in point-to-point position where two sheets a, b were embossed simultaneously and glued in point-to-point position with a third sheet c embossed according to same pattern. In this complex, bonding is carried out at the points e, all located at the same level.

FIG. 2 represents a laminate composed of three embossed sheets and glued in the "nested" position according to the prior art. In this embodiment, two sheets a ', b' have been embossed simultaneously, the ends e ′ of the protuberances of these two sheets are stuck in an interposed position between the protuberances produced in a third sheet c ′. Again, the association points between the three sheets are all at the same level.

FIG. 3 represents a complex according to the invention composed of three embossed sheets 1, 2 and 3: the first sheet 1 has protuberances of two different depths, protuberances 12 of shallow depth alternating regularly with deeper protuberances 11.

The ends of the protrusions 12 are glued at e1 to the ends of the protrusions 22 of a second layer 2, also embossed, while the ends of the protrusions 11 are interposed between two protrusions of the sheet 2. A third layer constitutes the complex in FIG. 3: this layer has an embossing with a pitch not identical to that of layer 1 with regard to the protrusions 11 and the ends of the protrusions 33 are glued in e2 to the layer 2 in the point-to-point position relative to the ends of the protrusions 11 of sheet 1.

It is preferable, as regards the height of the different protrusions, that the height of the protrusions 11 is at most equal to the sum of the heights of the protrusions 12 and 22.

Advantageously, the folds 1 and 3 will be made of a particularly soft material, the fold 2 which, for its part, is not in contact with the outside, may consist of a sheet which is less soft to the touch, therefore more resistant without that it affects the touch of the whole.

If we compare the structure according to the invention shown in Figure 3 with the structures shown in Figures 1 and 2, we see that the complex according to the invention has the advantage of having points of association located on two levels distinct, which allows better stiffening and strengthening of the structure.

• une augmentation de l'absorption (sachant que l'absorption d'un complexe en ouate de cellulose est due en partie aux fibres, et en partie au volume enfermé par les feuilles),
• une augmentation du phénomène de moelleux,
• une augmentation de l'épaisseur.

Furthermore, still by comparing the complexes according to the invention of FIG. 3 with those of the prior art represented in FIGS. 1 and 2, it can be seen that in the products of the invention, has an increase in the volume enclosed by the three sheets, compared to a conventional process, which leads to:

• an increase in absorption (knowing that the absorption of a cellulose wadding complex is partly due to the fibers, and partly to the volume enclosed by the leaves),
• an increase in the softness phenomenon,
• an increase in thickness.

Furthermore, the product in FIG. 3 has an external surface similar to that of a point-to-point product (with the embossing point situated inward), therefore a good feeling of touching on the surface.

An embodiment has been described in which the small protrusions regularly alternate with the large protrusions and are in equal number. The invention also includes cases where groups of at least two small protrusions alternate with the large protrusions.

The invention also includes the embodiment where the third fold is omitted.

FIG. 4 schematically represents an embossing and bonding unit making it possible to produce the product of FIG. 3. It consists of three embossing groups (A1, C1), (A2, C2) and (A3, C3) each consisting of a cylinder of etched non-deformable material, for example of steel A1, A2, A3 and a cylinder of elastic material, for example of rubber C1, C2, C3 and two conventional gluing groups E1 and E2. The engraving carried by the cylinder A1 has the particularity of being made up of alternating heights of different heights.

The cylinder A2 carries reliefs of the same pitch as the small protrusions of the cylinder A1 and the cylinder A3 reliefs of the same pitch as the large protrusions of the cylinder A1.

The device of FIG. 4 allows the production of a complex between a first fold of paper 1 and a second fold 2 and the production of a complex structure further comprising a third fold 3.

• le pli 1 en provenance du dévidoir D1 non représenté est gaufré entre A1 et C1 avec une gravure à deux niveaux,
• le pli 2 en provenance du dévidoir D2 non représenté est gaufré entre A2 et C2, avec une gravure à un seul niveau, la pointe formée par la gravure sur le pli 2 vient au contact du cylindre encolleur E1, qui dépose une quantité de colle sur le pli 2,
• les plis 1 et 2 sont ensuite associés en position pointe-pointe en appliquant A2 et C2 contre A1, de façon que la petite pointe de gaufrage de 1 soit en contact avec la pointe de 2, la pression de A2 sur A1 et la colle déposée sur la pointe de 2 assurent l'association des 2 plis, réalisant une sorte de matelas entre les plis 1 et 2,
• le pli 3 en provenance du dévidoir D3 non représenté sera gaufré entre A3 et C3 et, comme 2, il recevra un dépôt de colle sur les pointes formées par le gaufrage,
• le matelas formé par 1 et 2 pourra s'associer avec le pli 3, par pression de A3 sur A1 entre les pointes formées par A3 et la grande pointe de A1, la colle étant déposée sur les pointes de 3,
• à la sortie de A3 et A1, le deuxième niveau est réalisé, ainsi que la structure complète.

During operation, the different cylinders rotate in the direction indicated by the arrows:

• fold 1 from the reel D1 not shown is embossed between A1 and C1 with a two-level engraving,
• the fold 2 coming from the reel D2 not shown is embossed between A2 and C2, with an engraving on a single level, the point formed by the engraving on the fold 2 comes into contact with the gluing cylinder E1, which deposits a quantity of glue on fold 2,
• folds 1 and 2 are then associated in point-to-point position by applying A2 and C2 against A1, so that the small embossing point of 1 is in contact with the point of 2, the pressure of A2 on A1 and the glue deposited on the tip of 2 ensure the association of the 2 folds, making a sort of mattress between folds 1 and 2,
• the fold 3 coming from the dispenser D3 not shown will be embossed between A3 and C3 and, like 2, it will receive a deposit of glue on the points formed by the embossing,
• the mattress formed by 1 and 2 can be associated with the fold 3, by pressing A3 on A1 between the points formed by A3 and the large point of A1, the glue being deposited on the points of 3,
• at the end of A3 and A1, the second level is completed, as well as the complete structure.

The device represented in FIG. 4 can be implemented by replacing one or more folds of paper with several superimposed layers of paper, which will lead to complexes similar to that of FIG. 3, but having four or more layers of paper.

FIG. 5 represents a complex composed of four sheets of embossed paper and glued together as in the case of FIG. 3 at two levels, e1 and e'2. The layers 1 and 2 have a structure identical to that of the sheets 1 and 2 of FIG. 3. The sheet 4 'has an embossing with protrusions of different heights, identical to that of the layer 1. The sheet 3' has an embossing with only one level of protuberances, identical to that of layer 2.

The protrusions 33 'of the layer 3' are located in the point-to-point position relative to the small protrusions 42 'of the layer 4' and the large protrusions 41 'of the layer 4' are located in the point-to-point position relative to the large protrusions 11 of layer 1.

Bonding is carried out at two levels in the complex: at the points of the protrusions 41 ′ and 11 and between the sheets 1 and 2 between the points of the protrusions 12 and 22.

FIG. 6 represents a device making it possible to produce a product consisting of 4 layers of embossed and glued paper as shown in FIG. 5. This device consists of four embossing groups (A1, C1), (A2, C2), ( A'3, C'3) and (A'4, C'4) each consisting of a cylinder of non-deformable material, for example of engraved steel A1, A2, A'3, A'4 and a cylinder of elastic material, for example rubber, C1, C2, C'3, C'4. The groups (A1, C1) and (A2, C2) are identical to those in FIG. 4. The cylinder A'3 has protuberances of two different dimensions, similar to those of the cylinder A1. The cylinder A'4 has protrusions similar to those of A2.

In operation, the different cylinders rotate in the direction indicated by the arrows. A first fold 1 is embossed between the two cylinders A1 and C1.

A second fold 2 is embossed between the two cylinders A2 and C2 and the protrusions formed on this fold then come into contact with a gluing device E1.

Then, the small protrusions formed on the fold 1 are then glued in point-to-point position with the protrusions of the fold 2 by passing these two folds between the cylinders A1 and A2.

A third fold 3 'is embossed by passage between the cylinders A'4 and C'4.

A fourth fold 4 'is embossed by passage between the cylinder C'3 and the cylinder A'3.

The folds 3 'and 4' are then brought together between the cylinders A'3 and A'4 to form a mattress in which the protuberances formed on the fold 3 'come in point-to-point position relative to the small protuberances formed on 4', while the large protrusions formed on 4 'are interposed between two protrusions of 3'.

Then a bonding of the mattress thus formed is made between 3 'and 4' at the large protrusions of 4 '.

The two mattresses thus formed respectively between the folds 1 and 2 and 3 'and 4' are then glued together by passage between cylinders A1 and A3 to form a complex consisting of four embossed sheets having two levels of bonding.

Claims (11)

1) sheet (1) embossed with paper having protuberances of different depths made during its embossing, characterized in that deeper protuberances (11) called large protuberances alternate with shallower protuberances (12) called small protuberances so that the small protrusions (12) can be placed in point-to-point position with the protrusions (22) of a second sheet of embossed paper (2) and in that the large protrusions (11) come to fit between two protrusions (22 ) from the second sheet (2). 2) Multilayer complex, characterized in that it comprises the first and second sheets (1) and (2) as defined in claim 1 and in that the ends of the small protrusions (12) of the first sheet (1) and the protrusions (22) of the second sheet (2) are glued in a point-to-point position and the ends of the large protrusions (11) of the first sheet (1) come to fit between two protrusions of the second sheet (2) . 3) Complex according to claim 2, characterized in that the sum of the heights of the small protrusions (12) of the first sheet (1) and the protrusions (22) of the second sheet (2) is at least equal to the height of the large protrusions (11) of the first sheet (1). 4) Complex according to claim 2 or 3, characterized in that the small protrusions (12) of the first sheet (1) are the same height as the protrusions (22) of the second sheet (2). 5) Complex according to one of claims 2 to 4, characterized in that it further comprises a third sheet (3) having protrusions (33) whose pitch corresponds to that of the large protrusions of the first sheet (1) and which are glued in point-to-point position relative to said large protrusions (11) of the first sheet (1). 6) Complex according to one of claims 2 to 4, characterized in that it further comprises a third sheet (3 ') having an embossing with protrusions (33') identical to that of the second sheet (2) and a fourth sheet with a embossing identical to that of the first sheet (1) with small protrusions (42 ') and large protrusions (41'), the small protrusions of the fourth sheet (4 ') being located in point-to-point position relative to the protrusions (33 ') of the third sheet (3') and the large protrusions (41 ') of the fourth sheet (4') coming to fit between the protrusions (33 ') of the third sheet and the bonding being carried out at least at the level of the large protuberances (11) and (41 ') of the first and fourth sheets (1) and (4'). 7) Process for preparing the complex according to one of claims 2 to 5, characterized in that: - small (12) and large protrusions (11) are created by embossing a first fold (1) on this fold, - We create by separate embossing of a second fold (2) protrusions (22) on this fold, these protrusions being separated from each other by the same distance as the small protrusions of the first fold (1) and having a height such that the sum of their height and the height of a small protuberance of the first fold (1) is at least equal to the height of a large protuberance of the first fold (1), - the ends of the protrusions of the second fold (2) are glued, - a mattress is produced between the first and second plies (1) and (2) by gluing the ends of the small protrusions of the first ply (1) with the ends of the protrusions of the second ply (2) in the point-to-point position, the large protrusions of the fold (1) fitting between the protrusions of the second fold (2). 8) Process according to claim 7 for the preparation of the complex according to claim 5, characterized in that: the separate embossing of a third ply (3) is carried out, the embossing having a pitch corresponding to that of the large protuberances of the first ply (1), - the ends of the protuberances made on this third fold (3) are glued, - The third ply (3) and the mattress formed between the first two plies (1) and (2) are bonded so that the ends of the protrusions created between the third ply (3) are stuck in point-to-point position on the second ply (2) at the level of the large protrusions of the first ply (1). 9) Process according to claim 7 for the preparation of a complex according to claim 6, characterized in that: - a third fold (3 ') is embossed to have a configuration identical to that of the second fold (2), - a fourth fold (4 ') is embossed to have a configuration identical to that of the first fold (1), - the third and fourth plies (3 ') and (4') are joined together to form a mattress in which the protuberances formed on the third ply (3 ') come in point-to-point position relative to the small protuberances formed on the fourth fold (4 ') while the large protrusions of the fourth fold (4') are inserted between two protrusions of the third fold (3 '), - the two mattresses formed by the first and second plies (1) and (2) respectively and the third fourth plies (3 ') and (4') are glued together to form a complex consisting of four embossed sheets and at two levels lift-off. 10) Device for producing a complex according to one of claims 2 to 5 or implementing the method according to claim 8, characterized in that it comprises: - three embossing groups (A1, C1), (A2, C2) and (A3, C3) each consisting of two cylinders, a first cylinder being of etched non-deformable material (A1, A2, A3) and a second cylinder of elastic material (C1, C2, C3), the first cylinder (A1) having alternating protrusions of two dimensions, - two gluing groups (E1, E2). 11) Device allowing the production of complex according to claim 6 or the implementation of the method according to claim 9, characterized in that it comprises four embossing groups (A1, C1), (A2, C2), (A ' 3, C'3), (A'4, C'4) each consisting of two cylinders, one of which (A1, A2, A'3, A'4) is made of a non-deformable material engraved with the other (C1 , C2, C'3, C'4) made of elastic material, two of the cylinders (A1) and (A'3) having two different etching levels and at least two sizing groups (E1 and E2).

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