Core for a product in sheet form wound around this core, and roll formed with such a core

A tearable core, comprising:

• a tearable cylindrical wall around which a product in sheet form may be wound to form a roll having a length in a longitudinal direction of the cylindrical wall, the tearable core having a length at least equal to half the length of the roll, and having to be torn in order to access the sheet-form product from inside the roll;
• wherein the cylindrical wall is made up of at least two superposed strips including an outer strip disposed to be in contact with the product and an inner strip, the strips being wound in a helix on one another and attached to one another with an overlapping section, said overlapping section made of a section extending from a longitudinal edge of the inner strip to a longitudinal edge of the outer strip;
• wherein said overlapping section comprises a first part and a second part, said first part forming a tab, said tab being not attached over a defined width from said longitudinal edge of the inner strip in order to be free and accessible from the inside of the tearable core, the second part forming an attachment region of the strip and being disengageable when submitted to an axially directed force of between 1000 cN and 3000 cN;
• wherein a first attachment region and a second attachment region are created between the two strips at least on each side of a join between turns, at least one of said attachment regions being released when submitted to said axially directed force of less than 3000 cN;
• and
• wherein a width (L2) of the inner strip and a width (L1) of the outer strip are defined, with windings of the inner and outer strips being wound at a same pitch, so that the free and accessible tab of the inner strip is formed adjacent to the join between turns of two facing longitudinal edges of the helically wound outer strip.