Device for replacing a reel in an unwinder and related method

An unwinder for unwinding reels of web material to be fed to a converting line, comprising an unwinding station, in which to arrange a reel to be unwound and in which are arranged:

• a series of guide rollers, defining a feed path of the web material;
• a cutting member adapted to cut web material coming from an exhausted reel;
• splicing members to splice a trailing edge of a first web material coming from the exhausted reel to a leading edge of a second web material coming from a new reel;
• a pick-up device adapted to pick up the leading edge of the second web material from a temporary retaining element, carried by a transfer unit adapted to transfer reels to the unwinding station.

A method for replacing a first reel onto which a first web material is wound in an unwinder, with a second reel onto which a second web material is wound, comprising steps as follows:

• hooking the second reel to a transfer unit;
• engaging a leading edge of the second web material to a temporary retaining element carried by the transfer unit;
• severing the first web material by a cutting member, forming a trailing edge of the first web material upstream of a portion of the first web material that remains in a feed path;
• removing the first reel from an unwinding station of the unwinder and transferring the second reel by the transfer unit into said unwinding station;
• by a pick-up device arranged in the unwinder, engaging the leading edge of the second web material, separating the leading edge from the pick-up device and inserting the leading edge into a feed path.