Device and apparatus for selective deposition of molten plastic material and method of manufacture by selective deposition

1. A device for selective deposition of molten plastic material, which comprises a melting chamber communicated with a passage for feeding plastic material and at least one outlet opening for supplying molten plastic material dropwise or continuously, said chamber housing a portion susceptible to vibration of a sonotrode of an ultrasonic transducer, an elongated casing enveloping said sonotrode and said sonotrode vibrating in a longitudinal direction with respect to said casing, wherein

said passage for feeding plastic material includes a feeding mechanism configured to transport said plastic material to the chamber;

said feeding mechanism comprises a spindle governed in a controlled manner and located in an annular cavity delimited between an outer cylindrical wall provided by the inner face of the casing and the sonotrode wherein the annular cavity and the spindle are coaxial to the longitudinal axis of the sonotrode,

said melting chamber is located in an end portion of said elongated casing enveloping said sonotrode, and

one end of the melting chamber being opposite the tip of the sonotrode.

2. The device according to claim 1 , further comprising means for providing a limited run movement of the sonotrode, thus adjusting the volume of plastic material of said melting chamber delimited by the tip of the sonotrode.

3. The device according to claim 1 wherein said ultrasonic transducer is associated with the spindle through bearing supports.

4. The device according to claim 1 , wherein said feeding of plastic material comprises at least one side feeding mouth of the casing communicated with a distal area of said annular cavity of the melting chamber.

5. The device according to claim 1 , wherein said melting chamber is located in an end portion of a casing enveloping said sonotrode, opposite to an open end of said enveloping casing, for the access of the material in a direction which is substantially aligned with the sonotrode, and said outlet opening is a side opening of the casing.

6. The device according to claim 5 , further comprising a controlled unit for feeding by pushing plastic material into the melting chamber through the open end of the casing.

7. The device according to claim 1 , wherein said sonotrode is controlled to provide, depending on the plastic material to be melted, an amount of ultrasound energy sufficient to melt the plastic material fed to the melting chamber almost instantaneously.

8. The device according to claim 1 , wherein said plastic material is any polymeric material and can be supplied in any morphology comprising at least pellets, powder, filaments, sheets and gel.

9. The device according to claim 1 , wherein said outlet opening of said melting chamber is associated with a dispensing body having one or more oriented nozzles.

10. The device according to claim 1 , wherein said melting chamber is located in an end portion of an elongated casing enveloping said sonotrode, which vibrates in a longitudinal direction with respect to said casing, the melting chamber being opposite the tip of the sonotrode, and it has a control system for the deposition of the material, assuring a correct drip or operation of the deposition as well as the width of the layer in question.

11. The device according to claim 10 , wherein said control system is integrated in the outlet opening and its function is to control the amount of deposited material according to the molten volume in the chamber in question.