Patent ID: 8277277

Claim:
A blasting method used in a blasting process including an abrasive circulatory system from a blasting gun to an abrasive-recovery tank, in which: an abrasive is ejected together with a compressed gas from the blasting gun in a blasting chamber in a cabinet, the blasting chamber having a lower part thereof formed in a hopper shape; negative pressure is caused in the abrasive-recovery tank by the effect of an air flow generated by a ventilator for sucking air in the abrasive-recovery tank communicating with a bottom of the blasting chamber; the abrasive in the blasting chamber is recovered into the abrasive-recovery tank by the effect of the negative pressure; and the abrasive recovered into the abrasive-recovery tank is supplied to the blasting gun by using abrasive-supply means, the blasting method comprising the steps of: providing a plurality of workpieces with the same material, the same shape, and substantially the same processed surface; spraying liquid in an air flow for transporting the abrasive by using liquid-supply means in the abrasive circulatory system; blasting one workpiece with an abrasive containing a certain amount of the liquid by ejecting the abrasive sprayed with the liquid onto a surface of a workpiece at an acute incident angle; acquiring a surface reflectance, serving as a reference surface reflectance, after the blasting is completed; blasting the other workpiece with an abrasive containing an unknown amount of liquid; measuring a surface reflectance after the blasting is completed and comparing the measurement with the reference surface reflectance; and controlling an amount of the liquid sprayed so that the surface reflectance measured on the other workpiece becomes close to the reference surface reflectance, wherein the abrasive contains a certain amount of liquid to exhibit desired elasticity.