Ultrasonic joining method and ultrasonic joining device

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

introducing the paper material ( 5 ) into a gap ( 4 ) between an ultrasonic horn ( 2 ) and an anvil ( 3 ), wherein the gap ( 4 ) is formed between a flat surface of the ultrasonic horn ( 2 ) and a flat surface of the anvil ( 3 );

applying a joining force with the anvil ( 3 ) in a joining force direction ( 6 ) to the paper material ( 5 ) in the gap ( 4 ); and

setting the ultrasonic horn ( 2 ) into an ultrasonic vibration in order to join the paper material ( 5 ) in an ultrasonic frictional welding operation, in which the joining force direction ( 6 ) is not parallel to a direction of vibration ( 7 ) of the ultrasonic vibration, 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 ).

2. The ultrasonic joining method according to claim 1 , characterized in that the joining force direction ( 6 ) is perpendicular to the direction of vibration ( 7 ), with a maximum deviation of ±10°.

3. The ultrasonic joining method according to claim 1 , characterized in that an ultrasonic vibration frequency of the ultrasonic horn ( 2 ) lies between 10 and 80 kHz.

4. The ultrasonic joining method according to claim 1 , characterized in that an ultrasonic vibration amplitude of the ultrasonic horn lies between 10 and 50 μm.

5. The ultrasonic joining method according to claim 1 , characterized in that the paper material ( 5 ) is moistened prior to and/or during the ultrasonic frictional welding operation.

6. The ultrasonic joining method according to claim 1 , characterized in that no adhesive and no thermoplastic resin is used in order to ultrasonically join the paper material ( 5 ).

7. A method for producing a packaging from paper material ( 5 ), wherein an ultrasonic joining method is used according to claim 1 .

8. An ultrasonic joining device ( 1 ) for bonding paper material ( 5 ), comprising:

an ultrasonic horn ( 2 ) configured to be set into ultrasonic vibration, the ultrasonic horn ( 2 ) having a flat surface, and

an anvil ( 3 ) having a flat surface,

wherein the device is configured such that a joining force acts on the paper material ( 5 ) in a joining force direction ( 6 ) in a gap ( 4 ) between the flat surface of the ultrasonic horn ( 2 ) and the flat surface of the anvil ( 3 ) as a result of applying a force to at least one of the ultrasonic horn ( 2 ) and the anvil ( 3 ),

wherein the ultrasonic joining device ( 1 ) is configured to perform an ultrasonic frictional welding operation in which the joining force direction ( 6 ) is not parallel to a direction of vibration ( 7 ) of the ultrasonic vibration,

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 ), and

wherein the anvil ( 3 ) is configured to be moved in a direction of the ultrasonic horn ( 2 ) in order to generate the joining force ( 6 ).

9. The ultrasonic joining device according to claim 8 , characterized in that the joining force direction ( 6 ) is perpendicular to a direction of vibration ( 7 ) with a deviation of up to ±10°.

10. The ultrasonic joining device according to claim 8 , characterized in that the ultrasonic horn ( 2 ) is configured to be moved in a direction of the anvil ( 3 ).

11. The ultrasonic joining method according to claim 1 , characterized in that an ultrasonic vibration frequency of the ultrasonic horn ( 2 ) lies between 20 and 70 kHz.

12. The ultrasonic joining method according to claim 1 , characterized in that an ultrasonic vibration amplitude of the ultrasonic horn lies between 20 and 40 μm.

13. The ultrasonic joining method according to claim 1 , characterized in that the paper material ( 5 ) is moistened on inside surfaces of joints prior to and/or during the ultrasonic frictional welding operation.

14. The ultrasonic joining method according to claim 1 , characterized in that no adhesive, no thermoplastic resin and no printing ink is used in order to ultrasonically join the paper material ( 5 ).