A vacuum packaging machine includes a vacuum chamber and a sealing mechanism within the chamber. A product-filled package can be supported within the chamber with its open end disposed between sealing bars of a sealing mechanism. At least one of the sealing bars is continuously heated including as the package is placed within the chamber, as a vacuum is drawn in the chamber, as the sealing bars are closed around the open end of the package and as the package is removed after sealing is complete.
A prosthetic implant made of polyethylene is packaged in a sterile manner by being placed in a flexible, gas-impermeable sachet after which a vacuum is created in the sachet and it is hermetically closed. The sachet is subsequently placed in a gas-impermeable envelope and an inert gaseous atmosphere is established in the envelope and the envelope is closed hermetically. The assembly formed by the implant, the sachet and the envelope is then exposed to radiation.