PURPOSE: To maintain th concn. of aq. treating liquid in a specified range by adding a specified ratio of a soluble fluorescent dye to the water soluble chemical and lubricant to be added to said liquid, measuring the concn. of the fluorescent dye in the treating liquid and adding the controlled amt. of the chemical and lubricant thereto.
CONSTITUTION: A specified ratio of soluble fluorescent dye is added to the water soluble chemical and lubricant or a concn. soln. of the water soluble chemical and lubricant to be added to aq. treating liquid contg. the water soluble chemical and lubricant for treating metallic material in said aq. treating liquid. The concn. of the fluorescent dye in the water soluble treating liquid is measured and the water soluble chemical and lubricant as well as a specified ratio of the fluorescent dye are added and replenished successively to said liquid by controlling the amts. thereof to be added in accordance with said concn. The aq. treating liquid is alkali defatting and cleaning liquid, aq. cutting fluid, etc. and fluorescein salt, etc. are used for the soluble fluorescent dye. Said dye is added at about 0.01W0.005pts.wt. based on 100pts.wt. water soluble chemical and lubricant.
SUGAWARA KIMIHISA
MIZUNO YUTAKA
NEGI KAZUHIKO
TOYODA CHUO KENKYUSHO KK