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. <EOS>