摘要 |
PURPOSE:To secure a grid base plate for a storage battery excellent in lightness and quality stabilization, by using a composite plate making a synthetic resin film stick fast to both surfaces of a lead or lead alloy sheet carrying numerous small holes. CONSTITUTION:A perforated lead sheet 3 is produced by the way of boring a lot of small holes 2 of about 0.7mm.phi through regularly in a continuously cast and rolled plate 1 of 1.5mm. in thickness, composed of Ca 0.08wt%, Sn 0.8wt% and the remnant of Pb. A polyethylene film 4 of 0.2mm. in thickness is stretched over both surfaces of this perforated sheet 3 and, after being heated and compressed, a composite plate 5 is produced. This composite plate 5 obtained in this way is punched to make square holes, and a storage battery grid base plate 6 which has an empty space 8 to be charged with active material made up by a grid frame 7 is thus secured. |