Method of forming a coreless roll of web material

Abstract: A method of forming a coreless roll of web material comprises feeding a web material (P) to a mandrel (26). The mandrel (26) has a plurality of axially extending projections (26a) at spaced intervals. The free end of the web material (P) is then pressed against the mandrel (26) by a pressure roller (28) for the initial winding of a roll (R). Affixing means is applied to the pressure roller (28), and the web material (P) is pressed between the pressure roller (28) and the projections (26a) of the mandrel (26) to transfer the affixing means from the pressure roller (28) to at least first two windings of the roll (R) whereby they are releasably affixed together. The web material (P) is wound about the mandrel (26) to provide a fully wound roll. The roll (R) is thereafter severed from the remainder of the web material (P). The mandrel (26) is then removed from the roll (R) to render the roll coreless.

Description: The present invention relates to a method of forming a web material into a coreless roll. A conventional roll of toilet paper typically includes a core made of cardboard, while a toilet roll holder typically includes a pair of support bars which are inserted into the core to hold the roll in the toilet roll holder. There has recently been proposed a coreless roll of toilet paper. Such a coreless roll, however, tends to be collapsed when the toilet paper is almost exhausted from the roll. Referring specifically to Fig. 1, a conventional toilet roll holder 2 includes a rear wall 4 adapted to be secured to the wall of a bathroom, a pair of side walls 6, 6 extending forwardly from opposite sides of the rear wall 4, and a cover 8 pivotably mounted to the side walls 6, 6. A space 10 is defined by the rear wall 4 and the side walls 6, 6 to receive a coreless roll of toilet paper 12. A pair of opposite support bars 14, 14 are so biased as to normally extend horizontally from the respective side walls 6, 6 of the toilet roll holder 2. The coreless roll of toilet paper 12 has a central through bore 16. In use, the coreless roll 12 is inserted into the space 10 from below the toilet roll holder 2 so as to move the support bars 14, 14 from their horizontal position toward their vertical position against the bias of springs (not shown). At this time, the support bars 14, 14 are inserted into the bore 16 of the coreless roll 12. After the support bars 14, 14 have been inserted, the coreless roll 12 is lowered to return the support bars 14, 14 to their horizontal position so as to hold the coreless roll 12 in place in the toilet roll holder 2. When a desired length of toilet paper is withdrawn from the coreless roll 12, transverse forces act on the coreless roll 12. These forces tend to cause the coreless roll to collapse particularly when the toilet paper is exhausted from the coreless roll 12. In such a case, the roll drops from the toilet roll holder 2. FR-A-2 351 901 discloses a coreless roll of web material comprising a number of windings with a central bore, at least first two windings adjacent to said central bore including affixing means, said affixing means extending in a direction transversely of the web material for releasably affixing said at least first two windings. US-A-1 868 115 discloses a roll of paper having the adhesive distributed according to points aligned along transversal lines. US-A-4 487 378 was used as a basis for the preamble of method claim 1 and discloses a coreless roll of a toilet paper with a bore having a polygonal cross section. First several windings of the toilet paper are moistured with water containing an adhesive or glue to facilitate maintaining of the shape of the bore and as a result, those windings are adhesively attached to each other to thereby prevent the roll from collapsing under the action of transverse forces. However, a disadvantage with this coreless roll is that those first several windings can not be withdrawn from the roll as they are firmly secured together. Accordingly, it is an object of the present invention to provide a method of forming a coreless roll of web material which will not collapse under the action of transverse forces and which is able to be withdrawn until it is completely exhausted. According to the present invention, there is provided a method of forming a coreless roll of web material comprising the steps of Claim 1. The coreless roll obtained by this method comprises a number of windings with a central through bore. At least the first two windings, for example, first 6 to 10 windings, adjacent to the central bore includes a plurality of circumferentially spaced lines of affixing means. These lines of affixing means extend in a direction transversely of the web material for releasably affixing at least the first two windings of the roll. Advantageously, the lines of affixing means resist transverse forces which act on the coreless roll when the web material is withdrawn from the roll. These lines of affixing means are spaced from each other along the circumference of the roll to facilitate release of the first two windings and enable complete withdrawal of the web material. In a preferred embodiment of the invention, the web material is a toilet paper. The coreless roll has a diameter of approximately 110 mm, and the central bore has a diameter of approximately 30 to 35 mm. The affixing means includes water. Alternatively, a glue in a diluted state may be used. According to the present invention, there is provided a method of forming a web material into a coreless roll, which comprises the steps of Claim 1, whereby the at least first two windings of the roll are releasably affixed together. The other objects of the present invention will become clear from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings. Fig. 1 is a perspective view of a toilet roll holder and a conventional coreless roll of toilet paper; Fig. 2 is a schematic view of a winding machine, showing the manner in which a web material is wound about a mandrel; Fig. 3 is a view similar to Fig. 2, but showing the manner in which a cutter is actuated to sever a fully wound roll from the remainder of the web material; Fig. 4 is a view showing the manner in which a jet of air is directed to the free end of the web material to initiate the winding of a roll; Fig. 5 is a perspective view showing the manner in which affixing means is evenly distributed on the pressure roller by means of a blade; Fig. 6 is a view similar to Fig. 5, but showing the manner in which affixing means is evenly distributed on the pressure roller by means of an air nozzle; and Fig. 7 is a perspective view of a coreless roll of toilet paper which has almost been exhausted. Referring now to Figs. 2 to 4, there is shown a winding machine suitable for forming a web material into a coreless roll. Specifically, a winding machine 18 comprises a pair of drive or contact rollers 20, 22 against which a substantially cylindrical mandrel 26 bears as shown in Fig. 4. A web material P is supplied from a supply roll 27 and wound into a roll about the mandrel 26 to a predetermined thickness. To initiate winding of the roll, a pressure roller 28 is lowered to press the leading end of the web material P against the mandrel 26. A double-acting piston and cylinder assembly 30 is provided above the contact rollers 20, 22 and includes a piston rod 32. The pressure roller 28 is rotatably mounted to the lower end of the piston rod 32 and lifted as the roll increases in diameter. When a predetermined length of the web material is wound onto the mandrel 26 to form a roll R, a push rod 35 is extended from a pusher 36 so as to move the roll R to the left in Fig. 2 and onto a pair of roll receiving rollers 38, 38. The pressure roller 28 is then lifted (as shown in Fig. 3) to allow for the placement of a new mandrel between the contact rollers 20, 22. Thereafter, a cutter 40 is actuated to sever the roll from the remainder of the web material. As shown in Fig. 3, the free or leading end of the continuous web material from the supply roll 27 is rolled onto the new mandrel by means of an air nozzle 42. The pressure roller 28 is again lowered to press the free end of the web material against the mandrel for initial winding of the roll. This mode of operation of the machine is well known in the art. According to one feature of the present invention, the mandrel 26 has a gear-shaped cross section and includes a plurality of axially extending projections 26a. These projections 26a have a width of approximately 2.0 mm and are spaced approximately 3.0 mm from each other. Each roll R has a diameter of approximately 110 mm and has a hollow axial bore of about 30 to 35 mm in diameter. An affixing means is applied to at least first two windings of the roll, for example, first 6 to 10 windings, to releasably affix them together. Referring specifically to Fig. 5, a plurality of spray nozzles 42 are arranged, at spaced intervals, above the pressure roller 28 and connected to a feed water line 44. The feed water line 44 is, in turn, mounted to the bracket 34 and connected to a source 56 of water. A blade 46 is swingably attached to the bracket 34 and urged against the pressure roller 28 under the influence of a spring (not shown). Water as an affixing means is supplied from the water source 56 and applied to the surface of the pressure roller 28 through the spray nozzles 42. The water is evenly distributed on the pressure roller 28 by means of the blade 46. As the web material is pressed between the pressure roller 28 and the axially extending projections 26a of the mandrel 26, the water is transferred from the pressure roller 28 to the web material to wet at least the first two windings of the roll. The water serves to loosen the arrangement of fibers of the web material while the fibers are interwound under the pressure of the pressure roller 28. As the water is dried, the interwound fibers firmly affix these first two windings together. The first two windings of the roll can, of course, be released when the web material is pulled. In accordance with the present invention, a plurality of lines L of affixing means are provided on the first 6 to 10 windings of a roll and extend in parallel to each other at spaced intervals. As shown in Fig. 6, an air nozzle 50 may alternatively be used to evenly distribute the affixing means on the pressure roller 28. The air nozzle 50 extend along the pressure roller 28 and is connected to a source 51 of air under pressure. The air nozzle 50 has an opening 52 through which air under pressure is directed to the pressure roller 28. The affixing means may alternatively include glue. The glue is preferably diluted about 10 to 20 times by means of a suitable diluent such as water.

Claims: A method of forming a coreless roll of web material, comprising the steps of: feeding a web material (P) to a substantially cylindrical mandrel (26) with a plurality of axially extending projections (26a) arranged in a circumferentially spaced relationship; pressing a free end of the web material (P) against said mandrel (26) by a pressure roller (28) for initial winding of a roll; winding the web material (P) about said mandrel (26) to provide a fully wound roll (R); severing said fully wound roll (R) from the remainder of the web material (P); and removing said mandrel (26) from the fully wound roll (R) to render the fully wound roll coreless, characterized in that said pressing step for initial winding of the roll comprises: applying affixing means to said pressure roller (28); pressing the web material (P) between said pressure roller (28) and said axially extending projections (26a) of said mandrel (26) to transfer said affixing means from said pressure roller (28) to at least first two windings of the roll so that a plurality of lines (L) of affixing means are provided on said windings and extend, in a direction transversely to said web material (P), in parallel to each other at circumferentially spaced intervals, whereby said at least first two windings of the roll are releasably affixed together. The method of claim l, wherein the web material (P) is a toilet paper, and wherein the fully wound roll (R) rendered coreless has a diameter of approximately 110 mm, and its central bore diameter of approximately 30 to 35 mm. The method of claim 1, wherein said plurality of lines of affixing means have a width of approximately 2.0 mm and are spaced approximately 3.0 mm from each other. The method of claim 1, wherein said affixing means includes water. The method of claim 1, wherein said affixing means includes glue. The method of claim 1, wherein said mandrel has a gear-shaped cross section. The method of claim 1, wherein said step of applying affixing means comprises the steps of arranging a plurality of spray nozzles (42) so as to apply said affixing means to said pressure roller (28), said spray nozzles (42) being spaced from each other in a direction axially of said pressure roller (28), and urging a blade (46) against said pressure roller (28) so as to uniformly distribute said affixing means on said pressure roller (28). said blade (46) extending along said pressure roller (28). The method of claim 10, wherein said step of applying affixing means comprises the steps of arranging a plurality of spray nozzles (42) so as to apply said affixing means to said pressure roller (28), said spray nozzles (42) being spaced from each other in a direction axially of said pressure roller (28), and arranging an air nozzle (50) with a nozzle opening (52) extending along and directed to said pressure roller (28) so as to apply a jet of air to said pressure roller (28) through said nozzle opening (52) to uniformly distribute said affixing means on said pressure roller (28).

Inventors: YAMAZAKI TOKUSHICHI, YAMAZAKI, TOKUSHICHI
Applicants: YAMAZAKI TOKUSHICHI, YAMAZAKI, TOKUSHICHI
Application year: 1993
Main classification: B65H18
IPC codes: B65H19, B65H18