A packaging apparatus used to produce packaging units, the packaging unit comprising an article arrangement of at least two articles, wherein the articles are partially wrapped in an outer packaging material consisting of paper or cardboard, the packaging apparatus comprising at least - one application device for fitting the outer packaging material to the article arrangement, - one ultrasonic joining device for forming a joint connection between at least two layers of the outer packaging material, which layers at least partially overlap each other, - wherein the ultrasonic joining device comprises at least one anvil tool and a sonotrode, - which anvil tool is designed and equipped to be at least partially inserted and arranged between at least two articles of the article arrangement, which articles are at least partially wrapped in the outer packaging material, and - wherein the sonotrode is designed and equipped to interact with the at least one anvil tool arranged between the articles to form a joint connection with the at least two at least partially overlapping layers of the outer packaging material, - characterised in that at least one contour of the anvil tool is adapted to at least one contour of at least one of the two articles, between which articles the anvil tool is insertable and arrangeable, - wherein the at least one contour that is formed in an adapted manner is formed in an area of the anvil tool, which area is not involved in the production of the joint connection, - wherein the articles have a cylindrical basic shape, and - wherein the contour area of the anvil tool assigned to the particular article has a correspondingly concavely formed curvature, or - wherein the anvil tool has a triangular cross-sectional area, which is advantageously insertable and arrangeable in the space between two adjacent articles with the cylindrical basic shape. - one application device for fitting the outer packaging material to the article arrangement, - one ultrasonic joining device for forming a joint connection between at least two layers of the outer packaging material, which layers at least partially overlap each other, - wherein the ultrasonic joining device comprises at least one anvil tool and a sonotrode, - which anvil tool is designed and equipped to be at least partially inserted and arranged between at least two articles of the article arrangement, which articles are at least partially wrapped in the outer packaging material, and - wherein the sonotrode is designed and equipped to interact with the at least one anvil tool arranged between the articles to form a joint connection with the at least two at least partially overlapping layers of the outer packaging material, - characterised in that at least one contour of the anvil tool is adapted to at least one contour of at least one of the two articles, between which articles the anvil tool is insertable and arrangeable, - wherein the at least one contour that is formed in an adapted manner is formed in an area of the anvil tool, which area is not involved in the production of the joint connection, - wherein the articles have a cylindrical basic shape, and - wherein the contour area of the anvil tool assigned to the particular article has a correspondingly concavely formed curvature, or - wherein the anvil tool has a triangular cross-sectional area, which is advantageously insertable and arrangeable in the space between two adjacent articles with the cylindrical basic shape.