Plastic containers with an external gas barrier coating, method and system for coating containers using vapor deposition, method for recycling coated containers, and method for packaging a beverage

A method for making a coated plastic container possessing a gas barrier, the method comprising the steps of:

• feeding plastic container bodies into a vacuum cell while the vacuum cell maintains a vacuum in the vacuum cell, the plastic container bodies each having an external surface and an interior surface defining an interior space;
• conveying the plastic container bodies through the vacuum cell;
• feeding a reactive gas into the vacuum cell;
• forming a high-energy coating plasma by heating and evaporating an inorganic coating material with an evaporator disposed in the vacuum cell to form a coating vapor and energizing the coating vapor to form the high-energy coating plasma;
• and
• withdrawing the coated plastic containers out from the vacuum cell,
• the steps of conveying the container bodies and forming the high-energy coating plasma conducted such that, as the container bodies are conveyed through the vacuum cell, the high-energy coating plasma reacts with the reactive gas and deposits a thin coating on the external surface of the containers, (b) the thin coating comprises an inorganic compound and bonds to the external surface of the container bodies, and (c) the resulting coated plastic containers, when containing a pressurized fluid sealed in the interior space at a pressure of 60 psig (4.1 bars), possess a gas barrier of at least 1.25× the gas barrier of the containers without the coating, when the containers without the coating contain a pressurized fluid sealed in the interior space at a pressure of 60 psig (4.1 bars).