ROLLER COMPRISING A MEANS TO SUPPORT ROLLS FIELD OF THE INVENTION The invention relates to the field of products made of absorbent paper, tissue paper or silk, or other similar materials such as nonwovens, products that are presented as rolls and have as an end the drying. The invention relates in particular to the field of products for sanitary or home use, such as rolls of paper for drying, rolls of hand towels, or rolls of toilet paper. BACKGROUND OF THE INVENTION For these applications, the rolls are composed of continuous sheets that include one or several layers or folds. The blades optionally are pre-cut into successive sections in the winding direction, and are rolled axially, preferably around a support, a winch for example, which may or may not support a core; therefore the roll may or may not include a central core. The outer winding sheets can be unrolled from the periphery of the roll, in the winding direction. In this case, it is said that this is a roll for tangential unwinding. After having removed the core, if applicable, the inner winding blade can be unrolled through the interior, from the center, in the axial direction, perpendicular to the winding direction of the roll. In the latter case, the roll is a roll of the central extraction type. As for the rolls without a core, the collapse of the walls of the central hole can create a problem. In fact, due to the more or less strong force exerted on the sheet during rolling and due to the elasticity of the sheet, a tightening occurs which tends to lighten in the central area by extracting the roll from the support that was used for the winding This collapse can also occur in the case of sawing or during roll handling. It is known that this also occurs with the rolls from which the core was previously extracted. This makes the product particularly difficult to use in the case of central extraction rolls, since after the collapse, which gives little space to take the first sheet. Therefore the user is taken to several leaves, which is a source of waste. In the case of a roll for tangential unwinding, the lack of a central hole makes it difficult to mount it on a support shaft of a dispenser. In the case of a central extraction product, a solution was proposed by the applicant in patent applications O2005 / 005295 and FR04 050200. The solution includes forming a guide for capture purposes by laterally moving the free end of the sheet, so that it protrudes from the sides of the roll. However, this solution may be insufficient if the roll was defined with bad pre-cuts and if the central hole is deformed, even worse, if it collapses completely. In fact, the first pre-cut sheet can be detached during the removal of the guide, with the following sheets becoming difficult if not impossible to access. In addition, during the use of the roll for central extraction in a suitable dispenser, and if the walls of the roll are not held in place, the walls may collapse at any time and result in the formation of a binding around the supply opening, thus avoiding its continuous use. Other solutions relate to the use of an adhesion agent, water, additives, glue, or any other material, to maintain the orifice formed after the removal of the spool from its winding support, until it is used. However, these solutions are not completely satisfactory either. An adhesion agent applied to the first windings of a reel makes it possible to create a well formed hole, whose appearance is dependent on the profile of the spindle.
For example, spindles with polygonal, grooved or cylindrical sections are used. These spindles lead to the formation of a hole with a corresponding profile. However, when these first coils are joined together, it is not possible to extract the first sheet in isolation. It is often impossible to avoid extracting them all at once, which generates waste. In addition, beyond these united curls, the walls are no longer held in place; therefore they may collapse during use or at any other time. It has been considered the placement of an adhesion agent on the first coils, but only in the middle area of the sheet, while leaving the edges free of glue. The capture of the first sheet is therefore facilitated, but the problem of collapse is not completely resolved, particularly during its use. As taught in US Pat. No. 6,179,235, an adhesion agent may be applied on at least one of the two vertical sides of a roll, or on at least one of the edges of a sheet. However, these means do not efficiently prevent collapse during distribution, particularly for large products. The invention proposes a solution that avoids the disadvantages of the previous solutions. BRIEF DESCRIPTION OF THE INVENTION According to the invention, a roll without a core, comprising a sheet of flexible material, such as a fibrous, absorbent material, formed by winding the sheet around a winding shaft that creates a hole in the core. the center and presenting a first set of curls glued together, is characterized by the fact that this includes a second set of windings not adhered between the central hole and the first set. A winding corresponds to a rotation inside the roll. Adhered curls are curls that are joined together by any means of adhesion, including water, but whose separation from one another is easily achieved under normal conditions of use for unwinding. The solution under the invention has the advantage that it can be implemented in a very simple manner, by placing the adhesion means, for example, by spraying a liquid substance, in an appropriate manner during the winding of the sheet. No need to provide additional arrangements. Preferably, the liquid substance is water or an aqueous adhesive substance. Advantageously, the number of unbonded windings of the second set is greater than or equal to two. This is preferably less than the number of windings corresponding to 10% of the length of the roll.
The solution under the invention is applied in particular to rolls of the tightly wound type, which allows the manufacture of dense rolls called compact rolls. Such rolls can be made to be used under conditions of central extraction, preferably with a free end of the first winding from the central hole that exceeds the roll side, or to be used under tangential unwinding conditions. According to another feature of the invention, the roll comprises at least one additional set of windings adhered to each other, between the first set of adhered windings and the periphery of the roll, these sets of adhered windings that are separated from each other by unbonded windings . This succession of non-adhered coils and adhered coil sets can be repeated based on needs, and depending on the non-collapsibility of the wound material and on the larger or smaller size of the coil. This solution also has the advantage of avoiding the collapse of the walls when a large part of the roll has already been used and when the hole has become large. The application of the adhesion agent may vary between each roll and between each adhered winding of the same roll, both for the nature of the adhesion agent, the area covered, the amount, the length and for the position of the adhesion agent. An object of the invention is also a roll manufacturing process, wherein a sheet is wrapped around a winding shaft, and an adhesion agent is applied to bond the rolls together, after forming a specific number of windings which are rolled up. do not stick together. The unbonded windings are the first windings formed by winding around the winding axis. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and additional advantages will arise from reading the following description. The description details a modality with reference to the accompanying drawings, wherein: FIGURE 1 represents, in diagram form, a roll as claimed by the invention. FIGURES 2 to 4 show a manufacturing process for rolls based on a main roll. FIGURE 5 shows a means for forming a central extraction guide. DETAILED DESCRIPTION OF THE INVENTION FIGURE 1 shows a roll 1 resting on one of the side faces forming one of its "flanks". For example, this may be a roll of drying paper for central extraction, from which the core was removed, if any. Sheet F is rolled up continuously starting at the center. The FIGURE represents the inner end of the roll with the first leaf Fl extracted partially. In the absence of a means to maintain the windings on the shaft, the central hole will have a natural tendency to close. This makes it difficult to then take the end of the first sheet in isolation. It is already known in the prior art that the sheets can be adhered to one another close to the first coils. However, although the windings forming the periphery of the central hole are consolidated, here remains, in this unattached area, the difficulty of individually taking the leaves constituting the first winding. According to the invention, the risk of collapse is reduced by forming an adhered area, but leaving the sheets of the first coils free of adhesion, so that the user will find it easy to take off the reel. The adhered area is defined to ensure sufficient adhesion between the coils to ensure that the roll holds well while allowing easy separation of these coils under normal unwinding conditions. In the example of FIGURE 1, an initial set 10 is shown in thick lines, where the coils adhere to each other. Between the central hole and the first assembly 10, there are no coils adhered. These form a second assembly 20. Thanks to this particularly simple solution, the walls of the central hole are reinforced by adhering a number of coils to each other, however, the first sheet (s) constituting at least the first two coils remain free and can therefore be taken without any difficulty. In the end, only the first two windings are untied; all the other coils of the roll adhere to each other, thus forming a unique set of adhered coils. According to another possibility, in order to lower the risk of observing that the central hole is closed, the reel networks are consolidated with at least one, or preferably several, additional and non-contiguous sets (11, 12) of adhered coils , its number depends essentially on the dimensions of the roll. The adjoining non-contiguous winding assemblies (10, 11, 12) are separated from each other by unbonded windings (21, 22).
In particular, the one or more sets of adhered coils comprise a number of coils ranging from 4 to 20. Even more particularly, for a drying product with a diameter of 20 cm, the first 20 coils will remain free and will require a first unique set of 15 attached curls. A manufacturing process of the discontinuous type, commonly referred to by the experts as "stop and follow", is described in connection with FIGURES 2, 3 and 4. FIGURE 2 shows the diagram of a manufacturing process for rolls. A main roll 103, made of tissue paper for example, is unwound in its support. The sheet F is led to the roll forming station. The main roll 103 has a width of 2.60 m for example. The blade is cut longitudinally in relation to its direction of travel by means of blades 105. Therefore, a blade with a width of 2.60 m can be cut into 13 strips 100 that are 20 cm wide, the strips 100 are led to make them reach a set of two cylinders 107 and 109 that are placed side by side. Once the downstream ends 100A have passed the cylinder 109, a spindle 111, which may or may not be equipped with cores, is placed on the strips 100, near the gap created between the two cylinders 107 and 109, upstream of the cylinders. 100A ends downstream. A means 115 displaces the ends 100A of the strips 100 above the spindle 111 which may or may not be equipped with a core. Preferably, this means comprises air jets which are directed in a suitable manner. It can be seen from FIGURE 3 that the end is in the process of being inverted. Then, here it is lowered to a support cylinder 113, whose function is to fasten the ends 100A on the spindle 111 which may or may not be equipped with cores, as well as the spindle 111 which may or may not be equipped with cores, on the two cylinders 107 and 109, and compress the sheet during winding. The rotary drive of at least one of the cylinders 108, 109, or 113 is commanded, this drives the spindle 111 as well as the strips 100. The rewinding of the reel begins and the rolls 110 are formed. According to the invention, it is placed in the path of the strips 100 a means 118 for application of adhesion agent, to join the coils together. This adhesion agent can be water, but an adhesive substance can also be used. This means is placed, for example, upstream of the cylinders 107 and 109, and applies the adhesion agent on the surface of the sheets 100. In the case of a liquid agent, the application means is preferably a sprayer. The surface of the sheets receiving the sprayed liquid, the amount applied, the continuous or discontinuous application mode, in particular, are determined according to the needs. Due to the pressure exerted on the sheets during the winding, water, for example, allows, in the contact areas between the windings, the formation of joints between the fibers of the fabric. These unions allow the association of the curls. However, this association is achieved in such a way as to ensure easy separation-extraction of the bound coils, during the normal unwinding operation either through the center or tangentially.
The application of the adhesion agent may or may not be uninterrupted until the rolls are formed. According to another feature of the invention, the application of adhesion agent is temporarily interrupted and subsequently re-started to form another set of adhered windings, separated from the first by a set of non-adhered windings. This succession of unbonded and adhered curls can be repeated at will. It is understood that the selection of the number of sets of adhered windings depends on the objective sought, their frequencies, and the roll dimensions. A wide roll with a large diameter will incorporate several areas to accommodate the curls and to prevent the walls from collapsing when in use or at any other time. According to another characteristic of the invention, the application of the adhesion agent varies between each roll or between each adhered winding of the same roll, according to at least one of the following parameters: the nature of the adhesion agent deposited, its quantity, its position in relation to the sheet, the surface, or the shape covered. After reaching the desired diameter, the spindle and rolls assembly is removed. The plurality of strips 100 is cut by means of a transversal knife. After winding the end of the strips 100, the rolls are removed. In the case of a coreless roll, this operation will be facilitated by the use of a conical spindle, or as is known from the prior art, by the use of a machined spindle with an adjustable diameter. In order to allow easier removal, these spindles may or may not be coated with a coating that reduces their coefficient of friction. According to another manufacturing process, a cylinder without any longitudinal section 105 is formed upstream of the winding. After the extraction of the winding support, this cylinder is cut into individual rolls.According to another feature of the invention, the detailed technique is applied in the two patent applications filed in the name of this applicant WO2005 / 002592 and FR04 05022. According to this technique, the objective is to create a guide for capture purposes to the displacing, laterally in relation to the running direction, the end of the sheet 110A constituting the first winding. This portion then barely protrudes from the roll and ensures that the sheet will be removed without any problems. Another process for forming a guide for unwinding purposes is shown in FIGURE 5. A cylinder 200 with a diameter smaller than that of the central hole has perforations 210. This is connected to a vacuum source not shown in FIGURE. After the rolls have been formed according to the invention and after the core has been removed, if any, the cylinder 200 is inserted into the central hole and the inside of the cylinder is placed in the suction mode. Since the first winding is free, it is absorbed against the cylinder 200 due to suction. The cylinder is then rotated by a fraction of a rotation on itself in a predetermined direction, this is then removed from the roll. The blade is then driven by movement. When the extracted sheet exceeds the desired length of the roll side the vacuum is turned off and the cylinder is removed. The roll is then ready for use. Example 1 A main roll of tissue paper or silk for 2-ply cloth Reflex of GP having a basis weight of 2x20 grams per square meter was prepared. After rewinding, a spray of 7 cc of water per square meter was applied on a specific area to a section of the cloth, separated 200 cm from the inner end of the cloth roll, extended over a length of 210 cm corresponding to a set of 11 windings joined together After removal of the winding shaft, a cloth roll was carefully examined and the strength of the adhesion between the coils adhered together allowed a winding of central extraction distribution by winding, without any collapse. A roll of tissue paper or silk without a core, where the coils were not joined, is placed in a conventional Reflex dispensed as shown in USP 6,109,473. But since the collapse of the walls of the central hole occurred, the cloth can not be distributed through the distributor funnel. It was also observed that the force required to extract the cloth through the funnel does not vary very significantly if the adhered curls were being extracted or the unbonded curls were being extracted. In fact, the adhesion force is such that the cloth is distributed winding by winding.