Coreless roll of absorbent sheet and method for manufacturing the same

Abstract

A coreless roll of an absorbent sheet product, such as napkins, toilet paper, towels, etc., is provided made of a spirally wound continuous web of absorbent material having a first end and a second end, wherein a coating composition comprising a specific polymer is coated onto the continuous web. The coreless roll has excellent resistance to collapsing, as well as excellent flexibility, elasticity and resiliency. Moreover, the coreless roll has excellent disintegrability in water and can be used up over its whole length. A process for the manufacture of the coreless roll is also provided.

What is claimed is: 
     
         1 . A coreless roll of an absorbent sheet product made of a spirally wound continuous web of absorbent material having a first end and a second end, the web of absorbent material being wound such as to define an axial hollow passageway centrally positioned relative to the coreless roll and extending from one edge to another edge of the coreless roll and such that the first end is located on the outer side of the roll and the second end is located at the axial hollow passageway;
 wherein the spirally wound continuous web of absorbent material has a density of from 50 to 140 mg/cm 3 , preferably of 60 to 130 mg/cm 3 , more preferably of 70 to 120 mg/cm 3 ;   wherein at least a last turn located at the second end of the continuous web of absorbent material comprises a coating composition comprising a polymer including oxygen and/or nitrogen atoms, a turn being one circumvolution of the spirally wound continuous web about the axial hollow passageway; and   wherein at least 20%, preferably at least 25%, more preferably at least 30%, more preferably at least 35%, more preferably at least 40%, more preferably at least 50%, more preferably at least 70% of the entire length of the continuous web of absorbent material in the machine direction comprises a coating composition comprising a nonionic polymer including oxygen and/or nitrogen atoms.   
     
     
         2 . The coreless roll of  claim 1 , wherein the coating composition is applied to only one side of the continuous web of absorbent material. 
     
     
         3 . The coreless roll of  claim 1 , wherein the polymer including oxygen and/or nitrogen atoms comprised in the coating composition applied to at least the last turn located at the second end is a nonionic polymer. 
     
     
         4 . The coreless roll of  claim 1 , wherein a maximum intersheet adhesion between the coated portions of the continuous web of absorbent material and the portions of the continuous web being in contact therewith is of from 0.3 to 1.7N. 
     
     
         5 . The coreless roll of  claim 1 , wherein the coating composition that is applied to the continuous web of absorbent material has an ionic demand of −1000 to +100 μeq/g, preferably of −500 to +50 μeq/g, more preferably of −50 to 0 μeq/g. 
     
     
         6 . The coreless roll of  claim 1 , wherein the nonionic polymer comprises at least one repeating unit comprising one or more oxygen and/or one or more nitrogen atoms. 
     
     
         7 . The coreless roll of  claim 6 , wherein the nonionic polymer comprises at least one repeating unit comprising one or more ether oxygen atoms and/or one or more hydroxyl groups. 
     
     
         8 . The coreless roll of  claim 6 , wherein on average at least 50%, preferably at least 80%, of all repeating units constituting the nonionic polymer comprise one or more oxygen and/or one or more nitrogen atoms. 
     
     
         9 . The coreless roll of  claim 1 , wherein the nonionic polymer is a nonionic cellulose ether. 
     
     
         10 . The coreless roll of  claim 9 , wherein the nonionic cellulose ether has a number-average molecular weight of 1,000 to 1,000,000, preferably of 2,000 to 500,000, more preferably of 3,000 to 200,000, more preferably 5,000 to 100,000. 
     
     
         11 . The coreless roll of  claim 9 , wherein the nonionic cellulose ether is an alkyl cellulose ether such as methylcellulose or ethylcellulose, a hydroxyalkyl cellulose ether such as hydroxyethyl cellulose or hydroxypropyl cellulose, or a combination thereof. 
     
     
         12 . The coreless roll of  claim 1 , wherein the nonionic polymer is a polyether polyol, preferably a polyether polyol selected from polyethylene glycol, polypropylene glycol, and mixtures thereof, more preferably polyethylene glycol, and wherein preferably at least 40%, more preferably at least 50%, more preferably at least 70% of the entire length of the continuous web of absorbent material in the machine direction comprises a coating composition comprising the polyether polyol. 
     
     
         13 . The coreless roll of  claim 12 , wherein the nonionic polymer has a number-average molecular weight of 800 to 250,000, preferably of 1,000 to 50,000, more preferably of 1,500 to 15,000, more preferably of 1,500 to 10,000, more preferably of 2,000 to 7,500, e.g. 2,500 to 4,000. 
     
     
         14 . The coreless roll of  claim 1 , wherein the coating composition comprises:
 (a) at least 50 wt.-%, preferably at least 65 wt.-%, more preferably at least 80 wt.-% of the nonionic polymer;   (b) not more than 50 wt.-%, preferably not more than 35 wt.-%, more preferably not more than 20 wt.-% of further additives such as plasticizers, reinforcing agents, fragrance, and dyes;   each based on the total solids content of the coating composition.   
     
     
         15 . The coreless roll of  claim 1 , wherein the coating composition is applied in molten form or, after the addition of water, as an aqueous solution, wherein the aqueous solution preferably contains the nonionic polymer in an amount of at least 0.1 wt.-%, more preferably at least 0.5 wt.-% based on the total weight of the coating composition. 
     
     
         16 . The coreless roll of  claim 1 , wherein at least the last two, preferably at least the last three turns, preferably at least the last five turns, more preferably at least the last ten turns located at the second end of the continuous web of absorbent material comprise the coating composition. 
     
     
         17 . The coreless roll of  claim 1 , wherein the coating composition is applied such that, with respect to the length portion or length portions of the continuous web that comprise(s) the coating composition, the area covered by the coating composition is at least 50%, more preferably at least 60%, more preferably at least 70%, more preferably at least 80%, more preferably at least 90% of the total area of said length portion(s). 
     
     
         18 . The coreless roll of  claim 1 , wherein if the coating composition has been applied continuously in the machine direction, the resulting coated portion starts at the second end and includes at least the last turn of the second end. 
     
     
         19 . The coreless roll of  claim 1 , wherein if the coating composition has been applied intermittently in machine direction, thereby providing two or more coated portions, (i) one coated portion includes at least the last turn of the second end and (ii) the amount of nonionic polymer applied to the half of the continuous web including the second end is preferably equal to or greater than the amount of nonionic polymer applied to the half of the continuous web including the first end. 
     
     
         20 . The coreless roll of  claim 1 , wherein the total amount of nonionic polymer is from 0.001 to 40 g/roll, preferably 0.005 to 10 g/roll, more preferably 0.005 to 5 g/roll, in particular 0.01 to 2 g/roll. 
     
     
         21 . The coreless roll of  claim 1 , wherein the web of absorbent material is composed of at least 1 tissue paper ply. 
     
     
         22 . A coreless roll of an absorbent sheet product made of a spirally wound continuous web of absorbent material having a first end and a second end, the web of absorbent material being wound such as to define an axial hollow passageway centrally positioned relative to the coreless roll and extending from one edge to another edge of the coreless roll and such that the first end is located on the outer side of the roll and the second end is located at the axial hollow passageway;
 wherein the coreless roll has a resiliency at 30 seconds of at least 75%, preferably at least 80%, more preferably at least 85%, even more preferably at least 90%.   
     
     
         23 . The coreless roll of  claim 22 , wherein the roll has a diameter of 50 to 500 mm, preferably of 80 to 200 mm, more preferably of 100 to 155 mm. 
     
     
         24 . (canceled) 
     
     
         25 . The coreless roll of  claim 1  being in a compressed form. 
     
     
         26 . The coreless roll of  claim 1 , which is an absorbent product selected from the group consisting of napkins, towels household towels, kitchen towels or hand towels, toilet papers, wipes, handkerchiefs, and facial tissues. 
     
     
         27 . A manufacturing method for manufacturing a coreless roll of an absorbent sheet product comprising:
 conveying a continuous web of absorbent material having a first end and a second end, which is composed of at least 1 tissue paper ply;   optionally severing the continuous web of absorbent material substantially transversally to the machine direction to produce single but coherent sheets;   applying a coating composition as defined in  claim 1  to the continuous web;   spirally winding the continuous web of absorbent material so as to produce a log of web of absorbent material, the web of absorbent material being wound such as to define an axial hollow passageway centrally positioned relative to the log and extending from one edge to another edge of the log and such that the first end is located on the outer side of the log and the second end is located at the axial hollow passageway; and   cutting the log into multiple coreless rolls.   
     
     
         28 . The manufacturing method of  claim 27 , further comprising
 subjecting the coreless roll to compression in a direction perpendicular to the axial hollow passageway to produce a coreless roll in a compressed form.   
     
     
         29 . (canceled) 
     
     
         30 . (canceled) 
     
     
         31 . The coreless roll of  claim 2 , wherein the coating composition is applied to the side of the continuous web of absorbent material oriented towards the axial hollow passageway. 
     
     
         32 . The coreless roll of  claim 21 , wherein the at least 1 tissue paper ply comprises 2 to 6 superimposed tissue paper plies. 
     
     
         33 . The coreless roll of  claim 8 , wherein the at least 50%, preferably 80%, of all repeating units comprise one or more ether oxygen atoms and/or one or more hydroxyl groups. 
     
     
         34 . The manufacturing method of  claim 27 , wherein the at least 1 tissue paper ply comprises 2 to 6 superimposed tissue paper plies.