Dürkopp Adler 755 B Operating Instructions Manual page 68

Operation
Important
The incision device for piping ends must be cleaned regularly.
Depending on the material, the knives may have to be replaced as well.
For a detailed description, refer to the maintenance instructions
( p. 291).
66 Operating Instructions 755 B, 756 B/F - 00.0 - 02/2021