Ultrasonic device for a polymer injector apparatus

An ultrasonic device for a polymer injector apparatus including:

• a fusion chamber with a sonotrode bore;
• an ultrasonic head including a distal portion, housed in cantilever in the fusion chamber and inserted through the sonotrode bore, a proximal portion disposed outside the fusion chamber, the distal portion and at least part of the proximal portion constituting a sonotrode;
• an ultrasonic transducer connected to the proximal portion of the ultrasonic head;
• a first nodal plane disposed coplanar with an annular-shaped first surface of the ultrasonic head, the first nodal plane defined between the distal portion and the proximal portion and a second nodal plane coplanar with a second surface of the ultrasonic head, parallel to the annular-shaped first surface of the ultrasonic head, and included in the proximal portion away from the first nodal plane;
• a ring seal disposed around the sonotrode bore of the fusion chamber and comprising a first annular surface disposed coplanar to the first nodal plane, and an anchoring device attached to the second surface of the ultrasonic head, and
• a pressure device connected at least to the anchoring device and configured to compress at least part of the proximal portion of the ultrasonic device between the first and second nodal planes, the pressure device further configured to press the annular-shaped first surface of the ultrasonic head against the first annular surface of the ring seal and to press the ring seal against the surrounding of the sonotrode bore in a direction perpendicular to the annular-shaped first surface of the ultrasonic head, producing a tight sealing of the sonotrode bore of the fusion chamber.