| 摘要 |
A method and an apparatus for producing openings in sheet metal material being provided in band form as well as a perforated sheet material produced by said method. The method comprises providing notches in the sheet material and stretching partial areas of the notched sheet material by a thickness-reducing processing step, whereby the notches which lie between the stretched partial areas of the notched sheet material are enlarged to form openings. The apparatus for producing openings in sheet metal material comprises roller means for producing notches in the sheet material and roller means for stretching partial areas of the notched sheet material by thickness reduction. The resulting perforated sheet metal material combines the advantages of punched sheet metal, i.e., mechanical stability, and expanded metal mesh, i.e., no loss of material during production of the openings in the sheet material. |
