BLOW MOLDING OF HOLLOW SYNTHETIC RESIN PRODUCT

摘要

PURPOSE:To mold even a hollow molded product of complicated shape without generating breaks by spraying a fusion bond preventing agent from the vicinity of an upper blowing opening into the inner surface of a parison when the parison is discharged. CONSTITUTION:A discharge nozzle 5 for a fusion bond preventing agent is installed in the vicinity of an upper blowing opening 2 of a die 1 and a solenoid valve 6 is installed at the root of said nozzle 5, and the solenoid valve is connected with a fusion bond preventing agent surge tank 7 through a feed pump 8 and said solenoid valve 6 is opened and closed by a parison controller 14 through a step output selector unit 13. When a parison 3 is discharged out of the upper blowing opening 2 of the die 1, the fusion bond preventing agent is discharged out the nozzle 5 and said fusion bond preventing agent is sprayed to the inner surface of the parison 3.