Blow molded polyester container with an over-molded thermoplastic layer
Polyester containers that are produced from polyester preforms, the preforms preferably having a thermoplastic over-mold layer on at least a part of the exterior surface of the preform. In one aspect the invention can be a perform that is made by over-molding the thermoplastic layer onto the preform surface in one or more over-molding operations. In a single over-molding embodiment the preform has a body layer of a first color and the over-molded layer of a second color. The over-mold layer can have a thickness gradient varying in thickness from one end of the preform to adjacent another end of the preform. This will give the blow molded container a unique appearance where there the container will be substantially transparent or of a first color and the over-mold layers of differing colors.
1. A preform having a first end and a second end, the preform having a preform body layer having an outer surface and a plurality of thermoplastic over-mold layers overmolded directly to the outer surface of the preform body layer, the outer surface being smooth and continuous, the plurality of thermoplastic over-mold layers being of different colors from one another, a portion of the outer surface of the preform body layer without an over-mold layer, and at least one of the plurality of thermoplastic over-mold layers having a thickness gradient.
2. A preform as in claim 1 wherein the preform body layer is of a first color and at least one of the plurality of thermoplastic over-mold layers is of a second color.
3. A preform as in claim 1 wherein the at least one of the plurality of thermoplastic over-mold layers on the preform body layer has a color gradient from the first end to the second end.
4. A preform as in claim 1 wherein the at least one of the plurality of thermoplastic over-mold layers on the preform body layer has a color gradient from the second end to the first end.
5. A preform as in claim 1 wherein the preform body layer is a first color, the preform body layer visible in a portion with no over-mold layer, the color of the preform body layer and the at least one of the plurality of thermoplastic over-mold layers blending in an area of thickness gradient.
6. A preform as in claim 1 wherein the thermoplastic body layer is selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate.
7. A preform as in claim 1 wherein each of the plurality of thermoplastic over-molded layers is selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene polymers, polyethylene copolymers, polypropylene polymers, polypropylene copolymers and vinyl copolymers.
8. A preform as in claim 1 wherein the thickness of the at least one of the plurality of thermoplastic over-mold layers varies from one of the first end toward the second end and the second end toward the first end.
9. A preform as in claim 8 wherein the thickness of the at least one of the plurality of thermoplastic over-mold layers is greater at the second end, the color of the preform being darker at the second end.
10. A preform as in claim 1 wherein the plurality of thermoplastic over-mold layers are separate layers.
11. A preform as in claim 1 wherein the preform body layer is of a different color from at least one of the thermoplastic over-mold layers.