| 摘要 |
<p>Absorbent nappy/diaper pads composed of a first absorbent base material, and a second absorbent material consisting of superabsorbent polymer powders, are made by a unit (3) that comprises a conveyor (11) carrying the first absorbent material along a predetermined feed path (P), and a feed system (24) by which the superabsorbent polymer powders are released onto the feed path (P); the feed system (24) comprises a fixed duct (27) with an outlet (45) directed at the feed path (P), and a valve (34), positioned along an intermediate segment of the duct (27), by which the superabsorbent polymer powders are dispensed intermittently and controllably. The valve (34) comprises a rotating disc (41), set transversely to the duct (27), with an annular region (51) that revolves through a gap (43) in the duct (27) and presents at least one slot (42) delimited longitudinally, in the direction of rotation of the disc (41), by a leading edge (52) and a trailing edge (53); the radial dimension of the slot (42) increases progressively, at least along a part of the distance from the leading edge (52) toward the trailing edge (53).</p> |
