A positive-pressure packaging system is provided to seal a product within an open package. The system includes a pressure chamber which encloses the product and package and is configured to expel atmosphere gases initially present within the package. The system includes a seal assembly for straitening the opening of the package so as to prevent the passage of particulate and other matter from within the open package. The system also includes a pressure source configured to increase pressure within the pressure chamber so as to expel the atmosphere gases by compression of the open package. A method of using the positive-pressure packaging system is also disclosed.