Clamping device for transversal cutting machines of logs of paper

A method for transversally cutting a log of tissue paper for making rolls of tissue paper, said log of tissue paper having a longitudinal axis, said method comprising the steps of:

• providing a sawing station comprising a blade;
• feeding said log of tissue paper towards a cutting zone of said sawing station;
• blocking a part of said log of tissue paper using a clamping device;
• said clamping device comprising a first part upstream from said blade, and a second part downstream from said blade;
• driving said blade into the paper and cutting in turn the log of tissue paper into rolls;
• wherein said step of blocking provides blocking by said first part of the clamping device said log of tissue paper and blocking by said second part of the clamping device a roll being cut, and wherein said step of cutting provides cutting the log of tissue paper by penetration of a triangular cutting edge of the blade;
• and
• during the cut, when clamping the log of tissue paper by said first part and clamping said roll being cut by said second part, moving said first and second parts relative to each other such that said blade driven in the log of tissue paper forms a cutting slit that progressively opens as the cutting action of the blade proceeds causing a minimum friction of the blade with and wherein said relative movement of said first and second parts of said clamping device produce a flexional action on said log of tissue paper suitable for creating an opening having a size substantially equal to the thickness of said blade.