Method and machine for producing bags containing fiber material

A machine for producing bags containing fiber material, comprising:

• at least one device for feeding fiber material for forming a relative continuous flat layer of fiber material;
• at least one dispensing section for separating in succession portions of fiber material from the continuous layer and moving the portions of fiber material along a predetermined path;
• a first transfer conveyor including compacting receptacles for receiving each portion of fiber material inside respective containment and compaction elements;
• a second transfer conveyor equipped with supporting elements for receiving and holding a bag for containing a portion of fiber material;
• a transfer mechanism for transferring the portions of fiber material from the containment and compaction elements of the first transfer conveyor inside respective housings of a third transfer conveyor, for transferring the portions of fiber material from the housings of the third transfer conveyor inside respective containment bags carried by supporting elements of the second transfer conveyor, and for transferring the containment bags housing respective portions of fiber material from the respective supporting elements of the second transfer conveyor to a fourth transfer conveyor;
• and
• a conveyor mechanism for moving in succession the bags housing respective portions of fiber material to a folding unit at which the bags are closed;
• a supplemental feeding device, for adding predetermined quantities of fiber material to the portions of fiber material;
• the amount of the predetermined quantity of fiber material being established by at least one weighing device for weighing the portions of fiber material;
• a control unit programmed and arranged to determine each time the at least one weighing device detects that a portion of fiber material is underweight and momentarily activate the supplemental feeding device for a length of time that varies as a function of a difference between a weight detected by the at least one weighing device and a reference weight value.