Method for making pet containers with enhanced silicon dioxide barrier coating

Patent metadata

Field	Value
Publication number	US-9725802-B2
Application number	US-201414538298-A
Country	US
Kind code	B2
Filing date	Nov 11, 2014
Priority date	Nov 11, 2014
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A process for applying a silicon oxide barrier coating to a PET container, wherein the PET container comprises a wall having an inner surface and an outer surface, the process comprising the steps of: (a) heating a PET container such that at least the outer surface is at a temperature of from about 200° F. to about 383° F.; (b) forming a coated PET container by applying at least one silicon oxide barrier layer on at least the inner surface of the PET container while the temperature of at least the outer surface of the PET container is at a temperature of from about 200° F. to about 383° F.; and (c) cooling the coated PET container after step b.

First claim

We claim:

1. A process for applying a silicon oxide barrier coating to a PET container, wherein the PET container comprises a wall having an inner surface and an outer surface, the process comprising the steps of:
a. heating a PET container such that at least the outer surface is at a temperature of from 225° F. to about 383° F.;
b. forming a coated PET container by applying at least one silicon oxide barrier layer on at least the inner surface of the PET container while the temperature of at least the outer surface of the PET container is at a temperature of from 225° F. to about 383° F.; and
c. cooling the coated PET container after step b, wherein the heating step comprises the use of a heating tunnel through which the PET containers travel, and wherein the heating tunnel comprises from two to six heat zones of different temperatures located along a vertical axis of the containers.

2. The process of claim 1 wherein the heating step comprises heating the PET container to a surface temperature of from about 250° F. to about 383° F. throughout the wall.

3. The process of claim 1 wherein the forming step comprises:
i. forming a vacuum in a chamber in which at least one PET container is situated;
ii. adding a silicon oxide forming monomer reaction gas to at least the inner surface of the wall of the PET container; and
iii. exposing the PET container to plasma energy to deposit the at least one layer of silicon oxide on at least the inner surface of the wall of the PET container.

4. The process of claim 1 wherein the heating tunnel comprises rotary elements to rotate the containers to ensure even heat exposure circumferentially.

Assignees

• Graham Packaging Co

Inventors

• Bobrov Sergey B
• Schneider Mark D

Classifications

• C23C16/46

  characterised by the method used for heating the substrate (C23C16/48, C23C16/50 take precedence) · CPC title

• C23C16/045

  Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates · CPC title

• C23C16/0209 Primary

  by heating · CPC title

• B65D23/02 Primary

  Linings or internal coatings · CPC title

• C23C16/513

  using plasma jets · CPC title