PURPOSE: To provide a mold, which can cast lead grid without using lubricant, by using a porous metal material having no alloying with the lead and specifying thermal conductivity, hole diameter, thickness and permeability.
CONSTITUTION: Mold material for casting lead uses the material having no alloying with the lead and 3Kcal/m/hr/°C-15Kcal/m/hr/°C thermal conductivity. Further, the porous metal material having hole diameter distribution of ≤10% void vol. of ≤50μm the max. fine hole diameter and ≥0.2 ml/sec.cm2 permeability under condition of 0.02kg/cm2 pressurizing in 10mm thickness, is used. By this material, the grid for lead battery can be cast without using the ordinary lubricant. This mold has no change with the lapse of time to carving depth caused by deterioration of a cork and as carved working surface is tranferred to the product grid as it is, the aimed product size and wt. are obtd.
ITO MASAHIRO
YOSHIDA KOKEI
SHIBATA HIROYOSHI
KOBE CAST IRON WORKS