Tufted area rugs are made without knots. They have a canvas backing glued on to the cut or cut and looped piles. Loops of yarn are pulled through the rug's backing.  These loops are then sheared to create the smooth surface of the rug. The process is less skill and labor intensive than hand knotting. It takes a much shorter amount of time to complete tufted rugs compared to that of hand-knotted rugs. That is why even the highest-quality tufted rugs can be produced relatively quickly and less expensively than hand-knotted rugs. Wool tufted rugs require frequent vacuuming because they tend to shed more than other rugs.  This shedding is not a defect but rather a common characteristic of this type of tufted rug.  Short fibers within the pile work themselves loose and might be most evident in high traffic areas.  Although, your vacuum bag may fill with this surplus fiber, the total fiber loss during use is relatively small.  Shedding will gradually decrease.  The length of time required to eliminate shedding is dependent upon the type and amount of vacuuming performed.