| 摘要 |
1510006 Metal sheeting SOC LORRAINE DE LAMINAGE CONTINU 5 Nov 1975 [6 Nov 1974 9 Oct 1975] 45921/75 Heading E1K [Also in Division B3] A metal, e.g. aluminium, sheet intended to be subjected to a drawing operation, e.g. deep drawing, for the fabrication of a shaped metal part, has its surface formed with a roughness consisting of plateau portions in relief and intervening recessed valley portions, wherein the average ratio of the dimension of the valley portions to that of the plateau portions in any direction on the surface of the sheet is from 1:1 to 3:1, the average dimension of the plateau portions is from 40 to 200 micrometres and the height of the plateau portions is more than 6 micrometres. Preferably, the above ratio is from 3:2 to 5:2, and the average dimension of the plateau portions is from 60 to 120 micrometres. The height of the plateau portions is preferably from 10 to 25 but could be 50 micrometres. The roughened sheet is preferably coated with a softer metal e.g. tin, the weight of the coating not exceeding 15 grams/square metre. |
