Ultrasonic joining method and ultrasonic joining device

1. An ultrasonic joining method for connecting paper material ( 5 ), comprising the following steps:

introducing the paper material ( 5 ) into a gap ( 4 ) between a sonotrode ( 2 ) and an anvil ( 3 ), and

causing the sonotrode ( 2 ) to oscillate ultrasonically for the ultrasonic welding of the paper material ( 5 ),

wherein the paper material ( 5 ) is moistened with demineralized water ( 9 ) during the ultrasonic welding.

2. The ultrasonic joining method according to claim 1 , characterized in that the paper material ( 5 ) is moistened with water vapor.

3. The ultrasonic joining method according to claim 2 , characterized in that the water vapor has a temperature of at least 80° C. during the moistening of the paper material ( 5 ).

4. The ultrasonic joining method according to claim 1 , characterized in that the paper material ( 5 ) is moistened with liquid water ( 9 ), the water having a temperature of 50° C. during the moistening of the paper material ( 5 ).

5. The ultrasonic joining method according to claim 1 , characterized in that water ( 9 ) with a conductivity of at most 100 μS/cm is used for the moistening.

6. The ultrasonic joining method according to claim 1 , characterized in that water ( 9 ) with a conductivity of at most 50 μS/cm is used for the moistening.

7. The ultrasonic joining method according to claim 1 , characterized in that water ( 9 ) with a conductivity of at most 20 μS/cm, is used for the moistening.

8. The ultrasonic joining method according to claim 1 , characterized in that a joining force is applied to the paper material ( 5 ) in the gap ( 4 ) in a joining force direction ( 6 ), ultrasonic friction welding being carried out in which the joining force direction ( 6 ) is not parallel to an oscillation direction ( 7 ) of the ultrasonic oscillation.

9. The ultrasonic joining method according to claim 1 , characterized in that the joining force direction ( 6 ) is perpendicular to an oscillation direction ( 7 ), with a maximum deviation of +/−10°.

10. The ultrasonic joining method according to claim 1 , characterized in that no adhesive and no thermoplastic is used for the ultrasonic joining of the paper material ( 5 ).

11. The ultrasonic joining method according to claim 1 , characterized in that no adhesive, no thermoplastic and no printing ink is used for the ultrasonic joining of the paper material ( 5 ).

12. The ultrasonic joining method according to claim 1 , wherein the paper material ( 5 ) is moistened with demineralized water ( 9 ) on inner sides of joining points.

13. A method for producing a package made of paper material ( 5 ), the method comprising an ultrasonic joining method according to claim 1 .

14. An ultrasonic joining device ( 1 ) for connecting paper material ( 5 ), comprising

a sonotrode ( 2 ) configured to oscillate ultrasonically, and

an anvil ( 3 ), with a gap between the sonotrode and the anvil,

the ultrasonic joining device being configured to weld the paper material ( 5 ) in the gap ( 4 ) by ultrasonic oscillation of the sonotrode ( 2 ),

and further comprising a moistening device ( 18 ) for moistening the paper material ( 5 ) with demineralized water ( 9 ) during ultrasonic welding of the paper material.

15. The ultrasonic joining device according to claim 14 , wherein the paper material ( 5 ) is moistened with demineralized water ( 9 ) on inner sides of joining points.

16. The ultrasonic joining method according to claim 1 , wherein the paper material ( 5 ) is also moistened with water before ultrasonic welding of the paper material.

17. The ultrasonic joining device according to claim 14 , wherein the moistening device ( 18 ) also moistens the paper material ( 5 ) with water before ultrasonic welding of the paper material.

18. The ultrasonic joining method according to claim 1 , wherein the gap ( 4 ) is formed between a flat surface of the ultrasonic horn ( 2 ) and a flat surface of the anvil ( 3 ), and wherein the flat surface of the ultrasonic horn ( 2 ) and the flat surface of the anvil ( 3 ) are parallel to the direction of vibration ( 7 ).

19. The ultrasonic joining method according to claim 8 , wherein the joining force is applied with the anvil ( 3 ).

20. The ultrasonic joining device ( 1 ) according to claim 14 , wherein the gap ( 4 ) is formed between a flat surface of the sonotrode ( 2 ) and a flat surface of the anvil ( 3 ), wherein the flat surface of the sonotrode ( 2 ) and the flat surface of the anvil ( 3 ) are parallel to an oscillation direction ( 7 ) of the ultrasonic oscillation, and wherein the anvil ( 3 ) is configured to be moved in a direction of the sonotrode ( 2 ) in order to generate a joining force ( 6 ).