disclosed is a method and apparatus that uses uv energy to seal articles in plastic clamshell packages , and which employs a portable tray that can hold a plurality of packages to be sealed , each package having a bottom piece shaped to hold an article and a top piece with a periphery which nests within the periphery of a bottom piece supplied with uv curable adhesive . the tray is mountable on a loading platform which is operative to position the tray within an enclosure below a raised pressure plate having uv transparent portions , and below a uv light source and a shutter mechanism for controlling exposure of the transparent portions of the pressure plate by the uv source . when a loaded tray is positioned below the plate it is lowerable to press top and bottom clamshell pieces together , and the shutter is opened and closed to expose the adhesive for a predetermined period of time as pressure is maintained , after which the pressure plate is returned to its raised position and the tray of cured packages removed from the enclosure .