Extraction assembly of a core from a log, converting line having said assembly and method for producing a coreless log

A converting line comprising a final edge gluer and a closed log accumulator, and having an extraction assembly comprising:

• a rectilinear transporter of a log wound about a disintegrable core;
• and
• a gripping device for a portion of the core projecting from the log,
• wherein:
• the rectilinear transporter has a transverse transport direction with respect to a log advancement direction of the log along a converting line, and has an alternating transport direction back and forth in opposite directions;
• the rectilinear transporter comprises a first portion and a second portion aligned with respect to the first portion along the transverse transport direction;
• and
• the first portion of the rectilinear transporter is situated in series with units along a supplying log direction (F1).

A method for producing a coreless log, the method comprising:

• forming a log by winding one or more tissue paper plies on a disintegrable core, wherein the disintegrating core is projected with respect to the paper plies wound at least from a log side;
• extracting the log from a supply path along a transverse direction;
• clamping the disintegrable core in a set point of a projecting perimeter portion;
• reintroducing the log in the supply path along a transverse direction that is in an opposite direction with respect to the extracting;
• and
• maintaining a core projecting portion tightened during the reintroducing of the log, thereby causing disintegration of the core to obtain at least one strip that is extracted from the log.