Unwinder for web material and method for controlling the unwinding of web material

Method for controlling the unwinding of web material, comprising:

• pulling, by means of an actuator, a web material unwound from a first reel along a feeding path and in sequence through a junction device and a dynamic storage device located between said first reel and said actuator;
• wherein, in the dynamic storage device, the web material is arranged to zigzag around at least a first return roller and around at least a second return roller, mounted idle on a carriage free to move towards or away from the first return roller;
• decreasing a speed of the web material unwound from the first reel in a portion placed at the junction device and splicing an end portion of the web material running low on the first reel to an initial portion of a web material of a second reel maintaining a constant delivery speed of the web material downstream of the dynamic storage device by approaching the carriage to the first return roller caused by the traction exerted by said strip material;
• conferring to the web material unwound from the second reel a speed greater than the delivery speed to move away the carriage from the first return roller under the weight of the carriage;
• wherein it is also envisaged to rotate, through at least one motor and in a direction consistent with a feed direction of the web material, at least one motorized shaft on which said at least one first return roller is idly mounted.

Apparatus for the production of sanitary articles, having at least one feeding path of at least one web material carried by at least one reel, wherein the apparatus comprises at least one guide device of the web material, wherein said at least one guide device is arranged along the feeding path and comprises:

• a frame;
• at least one motorized shaft, mounted on the frame;
• at least one motor coupled to said at least one motorized shaft to make it rotate about its own main axis;
• at least one return roller rotatably coupled to said at least one motorized shaft through at least one bearing, and free to rotate on said at least one motorized shaft.