Coreless rolls of a tissue paper product and methods of manufacturing coreless rolls
A coreless roll of a tissue paper product has a first end and a second end, and a web of tissue paper product being wound such as to define a central inner hole with the first end located on the outer side and the second end located at the inner hole, the product including a bonded first ply and a second ply, a grammage of the product being 35 to 55 g/m 2 , and having a Geometric Mean Tensile strength of at least 200 N/m, the first ply and the second ply being made of Conventional Wet Press (CWP) paper and embossed to be nested, the coreless roll having an outer diameter of 95 to 150 mm, an inner hole diameter of 20 to 50 mm, and a density of the coreless roll of 70 to 90 kg/m 3 , a caliper ratio of the roll of 40% to 70%.
1 . A coreless roll of a tissue paper product comprises:
a spirally wound continuous web of tissue paper product having a first end and a second end, the web of tissue paper product being wound to define an axially extending inner hole centrally positioned relative to the coreless roll such that the first end is located on the outer side of the coreless roll and the second end is located at the inner hole,
wherein the tissue paper product comprises two plies, being a first ply and a second ply, the first ply and the second ply being ply-bonded,
wherein a grammage of the tissue paper product is in a range of 35 to 55 g/m 2 ,
the tissue paper product has a Geometric Mean Tensile strength of at least 200 N/m, and wherein:
the first ply and the second ply are made of Conventional Wet Press (CWP) paper,
the first ply and the second ply have been embossed to be nested,
the coreless roll has an outer diameter in the range of 95 to 150 mm, a diameter of the inner hole is in the range of 20 to 50 mm, and a density of the coreless roll is in a range of 70 to 90 kg/m 3 , and
a caliper ratio of the roll is in a range of 40% to 70%,
the caliper ratio (c s -c t )/c t being obtained by dividing a difference between a standard caliper c s of the tissue paper product as defined by the standard ISO-12625-3:2014 and a theoretical caliper c t of the tissue paper product by the theoretical caliper c t , and
the theoretical caliper c t being defined as a ratio between a grammage of the tissue paper product and the density of the roll.
2 . The coreless roll of a tissue paper product of claim 1 , wherein the caliper of the tissue paper product is at least 0.7 mm.
3 . The coreless roll of a tissue paper product of claim 1 , wherein at least one of the two plies has been embossed with a heated embossing roll.
4 . The coreless roll of a tissue paper product of claims 3 ,
wherein the first embossments have been formed by a first heated embossing roll and, the third embossments have been formed by the first heated embossing roll,
and/or wherein the second embossments have been formed by a second heated embossing roll,
and/or wherein the third embossments have been formed by a third heated embossing roll,
and/or wherein, the first ply has been moistened, prior to having been embossed, with an amount of liquid in the range of 2% to 12% of the basis weight of the first ply and wherein the liquid is provided with one or several additives, or wherein the first ply has not been moistened with a liquid prior to having been embossed.
5 . The coreless roll of a tissue paper product of claim 1 ,
wherein the first ply comprises first embossments with a first height (h1), the first height being in a range of 0.2 mm to 2.0 mm,
wherein the adhesive includes lamination glue applied to tips of the first embossments of the first ply,
wherein the second ply comprises second embossments with a second height, the second height being in a range of 0.2 mm to 2.0 mm,
at least a part of the second embossments are nested in at least a part of the first embossments, and
wherein the first ply optionally comprises third embossments with a third height smaller than the first height.
6 . The coreless roll of a tissue paper product of claim 1 , wherein the coreless roll has a radial compression strength of 20 N or more.
7 . The coreless roll of a tissue paper product of claim 1 , wherein at least a part of an innermost circumvolution, optionally the entire innermost circumvolution, of the absorbent material of the coreless roll at the second end comprises a stabilizing coating composition.
8 . The method of manufacturing a coreless roll of a tissue paper product according to claim 1 , the method comprising the steps of:
embossing the first ply with a first embossing roll with first embossing protrusions to form first embossments with a first height in a range of 0.2 mm to 2.0 mm;
embossing the second ply with a second embossing roll with second embossing protrusions to form second embossments with a second height in a range of 0.2 mm to 2.0 mm; and
wherein, optionally, the first embossing roll also comprises third embossing protrusions and the step of embossing the first ply forms first and third embossments on the first ply,
or wherein the method optionally comprises a step of embossing the first ply with a third embossing roll with third embossing protrusions to form third embossments with a third height smaller than the first height.
9 . A method of manufacturing a coreless roll of a tissue paper product, the tissue paper product being made of two plies, the method comprising the steps of:
providing a first ply of Conventional Wet Press paper (CWP) and a second ply of Conventional Wet Press paper (CWP);
embossing the two plies such that they are nested and ply-bonding the two plies to form a tissue paper product with a grammage in a range of 35 g/m 2 to 55 g/m 2 , a Geometric Mean Tensile strength of at least 200 N/m, and a caliper ratio in a range of 40% to 70%;
spirally winding up the tissue paper product on a mandrel to form a coreless roll and to define an axially extending inner hole, with a first end of the tissue paper product being located on the outer side of the coreless roll and the second end being located at the inner hole; and
withdrawing the mandrel;
wherein the coreless roll comprises an outer diameter in the range of 95 to 150 mm and a diameter of the inner hole is in the range of 20 to 50 mm, and the density of the coreless roll lies in a range of 70 to 90 kg/m 3 .
10 . The method of manufacturing a coreless roll of a tissue paper product of claim 9 ,
wherein a caliper of the formed tissue paper product is at least 0.7 mm.
11 . The method of manufacturing a coreless roll of a tissue paper product of claim 9 , comprising the step of heat-embossing at least one of the two plies.
12 . The method of manufacturing a coreless roll of a tissue paper product of claim 9 ,
wherein the method comprises the step of coating at least a part of an innermost circumvolution, optionally the entire innermost circumvolution, of the tissue paper product of the coreless roll at the second end with a stabilizing coating composition.
13 . A coreless roll of a tissue paper product manufactured according to the method of claim 9 .