Container preform assembly and method of manufacture
View Patent ↗A preform assembly for blow molding a container includes a molded plastic preform having a body and a neck with an external surface. At least one circumferential channel is molded into the external surface of the preform neck for removing the preform from the forming mold. A plastic finish ring separate from the preform is externally secured to the preform neck over the external surface of the neck.
1. A preform assembly for blow molding a container, which includes:
a molded plastic preform having a body and a neck with an external surface, and having an open mouth at one end of said neck,
first and second external circumferential channels molded into said neck external surface for removing said preform from a forming mold, wherein said first circumferential channel is adjacent to said mouth and said second circumferential channel is adjacent to said body, such that the space on said neck between said first and second circumferential channels has no additional circumferential channels, and wherein said neck has at least one external axial channel extending between said circumferential channels on said external surface of said neck; and
a plastic finish ring molded separately from said preform and externally secured to said neck over said surface, and wherein said second circumferential channel is at least partially uncovered by said finish ring.
2. The preform assembly set form in claim 1 wherein said preform has an external flange surrounding said mouth, said first circumferential channel being adjacent to said flange.
3. The preform assembly set forth in claim 1 wherein said finish ring has at least one external thread and an external capping flange at one axial end of said ring.
4. The preform assembly set forth in claim 1 wherein said finish ring is externally secured to said neck by interference fit, adhesive, or welding.
5. The preform assembly set forth in claim 1 wherein said plastic finish ring is of different material construction from said plastic preform.
6. The preform assembly set forth in claim 1 wherein said plastic finish ring is of material construction selected from the group consisting of: PET, PP, PE, PEN, REG, PCR, and wholly or partially crystallized polyester.