Patent Application
20080099593
This application claims priority to copending French patent application number 06 09510, filed Oct. 30, 2006, the disclosure of which is incorporated herein by reference.
The present invention relates to the field of paper for sanitary or domestic use. Its subject is a roll of paper comprising an annular groove formed in at least one end thereof and its method of manufacture.
In this field, the invention is aimed particularly at toilet paper, tissue paper used especially as a household towel or hand-wipe. These papers are presented to the user for example in the form of rolls consisting of one sheet, where appropriate pre-cut into sections, rolled about a central axis. The rolls may be of a type with or without a spindle and in the latter case, with or without a central hole. To make them convenient to use, the rolls are usually placed in an appropriate dispenser.
When the intended use falls outside the domestic circle, in collective establishments, particularly such as hotels, restaurants, hospitals or other establishments, the dispensers are produced to perform a plurality of functions. These are storing the paper, maintaining the hygiene of the product, controlling the consumption of the paper or else preventing the use of non-compliant rolls; as paper manufacturers often supply dispensers at prices substantially below full price to users who agree to dispense only that paper manufacturers' products through the dispenser; but some users neglect to use that paper manufacturers' products in these dispensers.
For the latter case and also to provide continuous guidance throughout the consumption of the roll and satisfactory dispensing of the sheet, when the roll has a spindle in particular, systems have been proposed that comprise protrusions or lugs that protrude relative to one of the lateral faces of the roll support. These protrusions or lugs are annular or off-centre relative to the axis of the roll and interact with a groove of matching shape made on the adjacent lateral face or end of the roll.
To produce this groove on the roll, a known means consists in cutting out the sheet appropriately while it is rolled about the axis of the roll or else of a spindle. Patent EP 380 438 describes a method with cutting of a sheet of great width into several sheets of smaller width matching that of the rolls to be manufactured. Use is made of a plurality of blades parallel with one another which make a continuous cut of the wide sheet. Retractable blades cut additional strips of a width corresponding to the depth of the groove over a determined length depending on the width of the groove to be formed.
According to another known method, after the roll is formed, the groove is cut by means of a cutting tool. It is observed that all the known methods are limited to a solution in which the groove is obtained by removing material.
The applicant has sought to enhance the technique of forming the groove. One objective has been the development of a method that is simpler to apply than cutting the strip of material while it is rolled. Specifically, the latter method is disadvantageous when it involves manufacturing products at a high rate as is required on modern production machines.
The applicant has also sought to enhance the quality of the product. Even though the groove is of reasonable depth, the result thereof is a lack of material on the sections level with the groove.
According to the invention, the roll of absorbent paper for sanitary or domestic use, comprising a continuous sheet rolled about an axis and forming a plurality of helical coils forming layers about the axis, provided, on at least one of its ends or lateral faces, with a groove defining a closed contour about this axis, is characterized in that the width of the sheet forming the coils level with, or aligned with, the groove is reduced by deformation and/or by compression of the coil in a direction parallel to the axis.
Reduction by deformation makes it possible, when the sheet is unrolled at the groove, to retrieve, by opening out, virtually the whole width. This is possible because the paper for sanitary or domestic use is an absorbent paper, the wadding being made of cellulose, of low basis weight, whose feature is to be extremely flexible.
An advantage that stems from the foregoing is that it allows a deeper groove to be formed. A protrusion of greater height interacting with a deeper groove provides more effective guidance.
Another advantage is that it allows varied shapes of groove, polygonal, for example, or simply circular.
Preferably, the groove has a U-shaped cross section with two edges extending parallel to the axial direction and parallel with one another, and more particularly the bottom of the groove is curved.
The applicant is aware of patent U.S. Pat. No. 3,038,598 which mentions the formation of a V-section groove by compression. It should be noted that an axial movement of a V-section punch whose branches are inclined relative to this direction leads to a lateral crushing of the coils. This is possible because the absorbent paper is flexible and of low density. However, the maintenance of such a shape over time is not guaranteed because the paper, due to its elasticity, tends to resume its initial shape. In addition, the guidance is not satisfactory compared with a U-section groove.
The present invention applies to any type of roll of absorbent paper, especially with a central hole and in this case preferably with a cylindrical spindle.
The invention also relates to a manufacturing method according to which, after having formed the roll, one end or lateral face of the roll is deformed by compression by means of a punch or tool comprising a rib of a shape matching that of the desired groove.
When the roll has a central hole, the punch advantageously comprises a central cylindrical boss with a diameter matching that of the hole.
Other features and advantages will emerge from the following description of a non-limiting embodiment with reference to the drawings in which:
The roll shown in
The roll comprises, on at least one lateral face, a circular groove close to the central hole 3.
This groove is obtained by pressing a tool as shown in
The layout of the groove may be of any shape; it depends on the shape of the guide lug or protrusion that has been chosen on the roll support.
In all cases, the aim is to obtain a groove 7 defining a closed contour about the axis XX.
On the face comprising the groove 7, the plug 32 comprises an annular rib 32′ of a radius and width suitable for fitting in the groove 7.
The invention is not limited to the embodiment represented in the figures. It embraces all the equivalents within the scope of those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 06 09510 | Oct 2006 | FR | national |
