Preform for blow molding and blow molding method of integral plastic vessel by said preform

Abstract

Abstract PURPOSE: To make a container resist to inversion of the base having a specified thick wall and an inward sloping base from internal pressure without any complex ribs by forming an integral reinforcing ring which is incorporated into the base and running horizontally in the hoop direction. CONSTITUTION: An inflatable part 20 is preformed thick enough to form the reinforced annular ring 44 connected to the base 46. The reinforced ring 44 is formed as an integral portion to prevent inversion radially of the base and inversion of the inward sloping portion from internal pressure. The part 52 of forming wall of the preform 26' is uniformly thick and the outer surface 56 preform 26' and the surface 58 of a stretch rod in the preform slightly taper downward for easy exhausting of the finished bottle. The base forming part 54 includes a thick part 62 to form the reinforced ring 44 and outer surface 64 of the part 54 tapers sharply and the surface 66 of the stretch rod also tapers downward. The annular projection 67 is formed on the portion where the wall forming part 52 and the base forming part 54 meet.

Inventors

• 👤 Harii Betsuku Maachin

Bibliographic Details