EP1893513B1 - Roller comprising a means for holding coils - Google Patents

Abstract

The invention relates to a roll including a sheet (F) made of a flexible material, such as an absorbent fibrous material, formed by winding the sheet around a winding axis while creating a hole in the center and that presents a first set ( 10 ) of windings bonded to each other. The roll is characterized by the fact that it includes a second set ( 20 ) of windings that are not bonded to each other, between the center hole and the first set ( 10 ). The roll, according to the invention, holds up well throughout its use and is easily placed into service, in particular in the case of a roll of the center pull type.

Description

The invention relates to the field of absorbent paper products, cellulose wadding, or other similar material such as a nonwoven, presented in the form of rollers and intended for wiping. It relates in particular to the field of products for sanitary or domestic use, such as wiping rolls, towels or toilet paper.

For these applications, the rolls consist of a continuous sheet which comprises one or more plies. The sheet is optionally precut in consecutive coupons in the direction of the winding, and is wound axially, preferably around a support, a pin for example, which may or may not support a mandrel; the roll can thus comprise a central mandrel or not.

The sheet of the outer turn can be unwound from the periphery of the roll, in the direction of the winding. In this case it is said that the roll is tangential feeding. After having removed the mandrel, if necessary, the sheet of the inner turn can be unwound from the center, in the axial direction, perpendicular to the winding direction of the roll. In the latter case, it is said that the roll is centrally rewind.

For chuckless rollers, collapsing the walls of the central hole can be a problem. Indeed, because of the more or less strong pull exerted on the sheet during the winding and the elasticity thereof, there is a tightening that tends to relax in the central area at the time when the the roller is extracted from the support which was used for the winding. This collapse can also occur when cutting by saw or when handling the roller. This phenomenon is also known on the coils from which the mandrel has previously been extracted.

This makes the product particularly difficult to use when it is a central reel, because after collapse there is little room to grab the first sheet. We are thus led to take several sheets, which is a source of waste for the user. In the case of a roll with tangential unwinding, the absence of central hole makes mounting difficult on the support axis of the distributor.

In the case of a product without central mandrel, a solution has been proposed by the applicant in the patent applications WO2005005295 and FR0405022 . It consists in forming a primer by moving laterally the free end of the sheet, so that it protrudes from one of the sides of the roll.

However, this solution may be ineffective if the roll has been defined with fragile pre-cuts and the central hole is deformed or worse, completely collapsed. Indeed, the first coupon can then be detached during the extraction of the opening, the subsequent sheets then becoming difficult to access or inaccessible.

In addition, when using the reel in central reeling in a suitable distributor, and in the absence of maintenance of the walls of the reel, a collapse thereof can occur at any time and cause the formation of a plug at the dispensing orifice, thus preventing its continued use.

Other solutions are for the use of a bonding agent: water, adjuvant, glue, or any other material to maintain the hole formed after removal of the coil from its winding support, and until its use. However these solutions are not entirely satisfactory either.

A bonding agent applied to the first turns of the spool makes it possible to form a well-formed hole, the appearance of which depends on the profile of the spindle. For example, pins of polygonal, grooved or cylindrical section are used. These pins lead to the formation of a hole of the corresponding profile. However, these first turns being associated with each other, it is not possible to extract the first sheet alone. It can not be avoided often to remove all at the same time; it inevitably generates waste. Moreover, beyond these first associated turns, the walls are no longer maintained; they can collapse during use or at any other time.

It has been envisaged to deposit a liaison agent on the first turns, but only in the middle zone of the sheet, leaving the edges free of glue. The gripping of the first sheet is facilitated, but the question of collapse is not completely resolved, especially when it is used.

As the patent teaches US 6,179,235 a binding agent may be applied to at least one of the two slices of the roll or on at least one of the edges of the sheet. However, these means can not effectively avoid collapse during distribution, especially for large products.

The invention proposes a solution that avoids the disadvantages of the previous solutions.

According to the invention, the mandrel-free roll is composed of a sheet of flexible material, such as an absorbent fibrous material, formed by winding the sheet around a winding axis forming a hole in the center, and presenting a first group of interconnected turns, is characterized in that it comprises a second group of non-interconnected turns between said hole in the center and the first group.

A turn corresponds to a turn in the roll. Linked turns are turns which are associated with each other by any means of connection, including water, but whose separation from each other remains easy under the usual conditions of use of unwinding.

The solution of the invention has the advantage of being able to be implemented very simply, by arranging the means ensuring the connection, for example the spraying of a liquid substance, appropriately during the winding of the sheet. No additional devices are expected. Preferably, the liquid substance is water or an aqueous adhesive substance.

Advantageously, the number of non-interconnected turns of the second group is greater than or equal to 2. It is preferably less than the number of turns corresponding to 10% of the length of the roll.

The solution of the invention applies in particular to the rollers of the type with tight winding allowing the realization of dense rollers, said compact. Such rolls can be made for use in central reeling, preferably with a free end of the first turn from the central hole, and offset relative to one of the sidewalls of the roll, or for use in tangential unwinding.

According to another characteristic of the invention, the roll comprises at least one additional group of interconnected turns, between said first group of connected turns and the periphery of the roller, these groups of connected turns being separated from each other by non-coils. linked. This succession of unbonded turns and groups of connected turns can be repeated at will according to need, and according to the ability to not collapse of the wound material and the more or less significant dimension of the coil. This solution also has the advantage of avoiding the collapse of the walls when the roll is already widely started and that the hole has become consequent.

The application of the bonding agent may vary between each roll, between each bound turn of the same roll, both in terms of the deposited agent, the covered surface, the quantity, the length, and the position of the this liaison agent.

The invention also relates to a method of manufacturing a roll, according to which a sheet is wound around a winding axis and a bonding agent is applied to bond the turns together, after formation of a predetermined number spirals unrelated to each other. Unbound turns are the first turns formed around the winding axis.

• la figure 1 représente de façon schématique un rouleau de papier conforme à l'invention,
• les figures 2 à 4 montrent un mode de fabrication de rouleaux à partir d'une bobine mère,
• la figure 5 montre un moyen pour former une amorce de dévidage central.

The invention will be better understood and additional advantages will appear on reading the description which follows. It details an embodiment with reference to the appended drawings, in which:

• the figure 1 schematically represents a paper roll according to the invention,
• the Figures 2 to 4 show a way of making rolls from a reel,
• the figure 5 shows a way to form a central unwinding leader.

We see on the figure 1 a roll 1 placed on one of the lateral faces forming one of the sides of the roll. This is for example a roll of wiping paper central reeling, which was removed if necessary the mandrel. The sheet F is wound continuously from the center. The inner end of the roll is shown with the first partially extracted sheet F1. In the absence of maintaining the turns at the axis, the central hole will have a natural tendency to close. It then becomes difficult to grasp alone, the end of the first leaf. It is already known to glue the leaves together at the first turns. But if we consolidate the turns forming the periphery of the central hole, it remains however in this bound area, the difficulty of individually grasp the sheet constituting the first turn.

According to the invention, the risk of collapse is reduced by producing a bonded zone, but leaving the leaves of the very first turns free to bond, to allow the user easy priming of the coil. The bonded area is defined so as to ensure sufficient cohesion between the turns to ensure good holding of the roller while allowing easy separation of these turns under the usual unwinding conditions. In the example of the figure 1 there is shown in thick lines a first group 10 where the turns are interconnected.

Between the central hole and this first group 10, there are turns of unbonded sheets. They form a second group 20.

With this particularly simple solution, the walls of the central hole are strengthened by binding a number of turns together, but also the first sheet (s) constituting the first two turns at least remain ) free and can therefore be entered without difficulty.

At the extreme, only the first two turns are not associated; all the other turns of the roll are linked together, thus forming a single group of linked turns.

According to another possibility, to overcome the risks of seeing the central hole close, the walls of the coil are consolidated by at least one, or preferably, additional and non-contiguous groups (11, 12) of linked turns; their number depends essentially on the dimensions of the roll. The groups of non-contiguous linked turns (10, 11, 12) are separated from each other by non-bound turns (21, 22).

In particular, the group (s) of linked turns comprise a number of turns between 4 and 20.

Even more particularly, for a wiper product with a diameter of 20 cm, the first 20 turns will be kept free and only one first group of 15 linked turns will be necessary.

A mode of manufacture, of the discontinuous type usually called "stop &go" by those skilled in the art, in relation to the Figures 2, 3 and 4 .

The figure 2 shows the diagram of a roll making process. A mother reel 103, of cellulose wadding for example, is unwound from its support. Sheet F is driven to the roll forming station. The mother reel is of width 2.60 m for example. The sheet is cut longitudinally with respect to its direction of travel by means of knife blades 105. Thus, a sheet of 2.60 m width can be cut into 13 strips 100 of 20 cm width. The strips 100 are guided to come on a pair of cylinders 107 and 109 arranged side by side. When the downstream ends 100A have passed the cylinder 109, a pin 111 with or without mandrels is placed on the strips 100, at the hollow formed between the two cylinders 107 and 109, upstream of the downstream ends 100A. A means 115 moves the ends 100A of the strips 100 over the pin 111 with or without a mandrel. It is advantageously air jets properly oriented. We see on the figure 3 that the end is being pulled down. Then, a support cylinder 113 is lowered, whose function is to maintain the ends 100A on the spindle 111 equipped or not with mandrels, as well as the spindle 111 equipped or not with mandrels on the two cylinders 107 and 109, and to compress the sheet during winding. The drive in rotation of at least one of the cylinders 107, 109 or 113 is controlled; This leads to the pin 111 and the strips 100. The winding begins and the rollers 110 'are formed.

In accordance with the invention, an applicator means 118 of a coil bonding agent is placed on the path of the strips 100 therebetween. This agent may be water, but an adhesive substance may also be used. This means is for example disposed upstream of the cylinders 107 and 109 and applies the bonding agent to the surface of the sheets 100. For a liquid agent, it is advantageously a sprayer. The surface of the sheet receiving the sprayed liquid, the quantity applied, the continuous or discontinuous application mode, in particular, are determined as required. Due to the pressure exerted on the sheet during the winding, the water for example, allows in the areas of contact turns between them, the formation of bonds between the cellulosic fibers. These connections allow the association of turns. Nevertheless, this association is made in such a way as to guarantee easy distribution of the bound turns during a usual unwinding, either by the center or in tangential.

The application of the bonding agent is interrupted or not until the rolls are formed.

According to another characteristic of the invention, the application of the binding agent is temporarily interrupted, to resume it thereafter and thus to form another group of linked turns, separated from the first by a group of unbonded turns. This succession of groups of unrelated and linked turns can be repeated at will. It is understood that the choice of the number of groups of linked turns depends on the objective, their frequencies and the dimensions of the roller. A large roll with a large diameter will include several areas to accompany the unwinding and prevent the walls from collapsing during use or at any other time.

According to another characteristic of the invention, the application of the bonding agent varies between each roller or between each tied coil of the same roller, according to at least one of the following parameters: nature of the bonding agent deposited, its quantity, its position relative to the sheet, the surface or the covered form.

When the desired diameter is reached, the assembly formed by the spindle and the rollers is evacuated. The plurality of strips 100 is cut by means of a transverse knife. After winding the end of the strips 100, the rolls are extracted. In the case of roll without mandrel, this operation will be facilitated by the use of a conical pin, or, as is known, by the use of a mechanized pin with adjustable diameter. To allow easier extraction, these pins may or may not be coated with a coating reducing their coefficient of friction.

According to another method of manufacture, a cylinder is formed without longitudinal cut 105 upstream of the winding. After extraction of the winding support, this cylinder is sawed into individual rolls.

According to another characteristic of the invention, the technique set forth in the two patent applications in the name of the applicant is applied. WO2005005295 and FR0405022 . According to this technique, it is a matter of creating a gripping primer by displacing, laterally with respect to the direction of travel, the end of the sheet 110A constituting the first turn. This portion then exceeds the roll and ensures that the sheet will be extracted without problems.

Another way of forming a wire feed primer is shown on the figure 5 . A cylinder 200 of smaller diameter than the central hole comprises perforations 210. It is connected to a vacuum source not shown in the figure. After having formed the rollers according to the invention and, if necessary, removed the mandrel, cylinder 200 is introduced into the central hole and the inside of the cylinder is drawn into suction. The first turn of the winding being free, it comes to press against the cylinder 200 because of aspiration. The cylinder 200 is then rotated by a fraction of a turn on itself in a predetermined direction, and then extracted from the roll. The leaf is then driven by the movement. When it is out of the desired length with respect to the side of the roll, the vacuum is cut and the cylinder is moved away. The roll is thus ready for use.

Claims (13)

1. A roll consisting of a sheet (F) of flexible material, such as an absorbent fibrous material, which roll is formed by winding the sheet around a winding axis while creating a hole in the center and which presents a first set (10) of windings bonded to each other, characterized by the fact that it includes a second set (20) of windings that are not bonded to each other, between said center hole and the first set (10).
2. A roll according to the preceding claim whose number of windings of the second set (20) is greater than or equal to 2.
3. A roll according to either of claims 1 and 2 whose number of windings of the first group (10) is greater than or equal to 2.
4. A roll according to any of the preceding claims that presents a succession of sets of noncontiguous bonded windings(10,11,12), which sets are separated from each other by non bonded windings.
5. A roll according to any of the preceding claims, wherein the bonded windings incorporate a bonding agent.
6. A roll according to the preceding claim whose bonding agent is a liquid substance, preferably water or an adhesive substance.
7. A roll according to claim 5 or 6 whose bonding agent, between each bonded winding of the same roll, varies according to at least one of the following parameters: nature of the bonding agent deposited, its quantity, its position, or the surface or shape covered.
8. A roll according to any of the preceding claims whose embodiment is of the tight winding type.
9. A roll according to any of the preceding claims whose embodiment is of the center pull type.
10. A roll according to the preceding claim whose free end of the first winding from the central hole is laterally staggered.
11. A roll according to any of claims 1 to 8 of the tangential unwinding type.
12. A manufacturing process for a roll according to any of the preceding claims wherein a sheet (F) is winded around a winding axis and a bonding agent is applied in order to bond the windings to each other, after the forming of a specific number of windings that are not bonded to each other.
13. A process according to the preceding claim whose bonding agent application is accomplished by projecting a liquid substance, preferably water or an adhesive substance.

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