| 摘要 |
PURPOSE:To prevent adhesion of dust based on electrification at the time of manufacturing of a plastic base material for an optical disc, by making use of air or gas passed through an electrostatic dust collector provided in a charging course of mold releasing air or gas as the mold releasing air. CONSTITUTION:An electrostatic dust collector 18 which can collect dust of ultrafine particles which is not collected by air filters 19a, 19b, 19c is provided on a charging course of mold releasing air 20a, 20b and dust of fine particles from course particles is collected and removed by the air filters 19a, 19b, 19c and the dust of the ultrafine particles is collected and removed by the electrostatic dust collector 18. Then as an article whose cleanness is high is obtained as the mold releasing air 20a, 20b, a large quantity of ions is generated by the electrostatic dust collector 18 by applying high direct voltage between electrodes, ionized air or gas is kept including within the mold releasing air 20a, 20b in quantities and possesses function to eliminate static electricity of a molded article of a plastic base material for an optical disc electrified at the time of molding, adhesion of the dust based on electrification through the circumference is prevented. |
