| 主权项 |
1. A machine for making filter bags (1) for infusion products formed from lengths of filter material,
characterized in that it comprises at least:
a station (2) for feeding a first continuous strip (3) of thermoformable filter material movable along a working path (P);a station (4) for heating the first continuous strip (3), located along the working path (P) and including means (22) for heating the first continuous strip (3) of thermoformable filter material at a predetermined temperature;a drum (5) for forming a first portion (3P) of the filter bag (1) disposed downstream of the station (4) for heating along the working path (P); said drum (5) having two mutually concentric circular parts (6,7) continuously rotating in phase about a single axis (X) of rotation so as to configure an annular zone (8) where the first continuous strip (3) is interposed; a first circular part (6) of the drum (5) being provided with a series of radial dies (9), and a second part (7) having a corresponding series of forming punches (10) for forming the first strip (3) of filter material and adapted to plastically deform a portion of the first strip (3) of filter material inside a corresponding die (9) at least for a predetermined arcuate stretch (T) of a circular path followed by the drum (5), so as to form an open three-dimensional chamber (C) of filter material;a station (11) for dosing a dose (12) of infusion product and configured for placing, the dose (12), in phase with the drum (5), inside the open three-dimensional chamber (C) of filter material;a station (13) for feeding a second continuous strip (14) of filter material and configured for placing the second continuous strip (14) above the first continuous strip (3) with the three-dimensional chambers (10) with the dose (12) of infusion product, so as to define a flat base that closes the filter bags (1);a station (15) for joining/closing the second continuous strip (14) of filter material onto the first continuous strip (3) of filter material and located along the working path (P), downstream of the station (13) for feeding the second continuous strip (14) of filter material;a cutting station (16) for making a sequence of single, flat-based filter bags (1) by cutting the first and the second continuous strip (3, 14) of filter material; the cutting station (16) being located downstream of the joining/closing station (15) along said working path (P). |
