| 摘要 |
A method of forming envelope blanks from a length of material with a rotary knife, comprising the steps of: streaming the length of material; providing a rotary knife; arranging the rotary knife so that an axis of rotation of the rotary knife is at a first acute angle to a transverse axis of the length of material; and bringing the knife into contact with the length of material to form an envelope blank, wherein the knife has at least one cutting protrusion extending along an outer surface thereof for contacting the length of material, the at least one protrusion arranged in at least a partial outline corresponding to cuts to be made on the length of material to form the envelope blank, the outline being offset on the surface of the knife by an offset amount corresponding to said first angle so as to be generally aligned with a longitudinal axis of the length of material. |
