INJECTION MOLDING MACHINE FOR PREFORM

PROBLEM TO BE SOLVED: To provide an injection molding machine of a preform, capable of improving the productivity or the like by reducing the generation of cold slag in the injection molding of the preform.SOLUTION: The injection molding machine 1 for the preform has a bottom insert 3, a nozzle insert 4 and a needle valve 5. The needle valve 5 has, on a tip side thereof, a cylindrical straight part 51 and a truncated cone-shaped taper part 52 having a taper angle corresponding to a taper hole 41 of the nozzle insert 4. When the injection of a molten resin 109 is closed, the tip side part of the taper part 52 is inserted into a hole 31 for a gate of the bottom insert 3, and the tip side part of the straight part 51 is inserted into the taper hole 41 of the nozzle insert 4.