METHOD OF STERILIZING WATER-SOLUBLE CUTTING OIL

PURPOSE:To provide the title method which enable repeated use of cutting oil through sterilization of the oil by a simple method, is economical and can prevent the emission of offensive odor and improve the working environment, by applying ultrasonic waves to a putrid water-soluble cutting oil placed in a sterilizing vessel. CONSTITUTION:A putrid water-soluble cutting oil 2 is placed in a sterilizing vessel 1. Ultrasonic waves 4 are applied from an ultrasonic generator 3 provided in the sterilizing vessel 1 to the putrid oil 2 to sterilize the same. The bactericidal effect is increased in proportion to the intensity of the applied waves. However, the upper limit of the intensity is 50kHz from the viewpoint of the effect on a human body. The lower limit of the intensity is pref. 15kHz since the sterilization time is prolonged when the intensity is 15kHz or less. This method enables a water-soluble cutting oil to be repeatedly used through simple sterilization. Therefore, this method is economical and can prevent emission of offensive odor and improve the working environment.