Abstract: The present invention provides a process for hermetically sealing a container having an open top. The process of this invention employs a novel cap liner comprising a backing layer consisting of thermoplastic material, a sealing layer and a bond layer between the backing layer and the sealing layer. The process comprises the steps of: providing a cap adapted to engage the open top of a container; providing a novel cap liner of this invention; inserting the cap liner into the cap; securing the cap to the container such that the sealing layer of the cap liner contacts the container and extends across the open top of the container; and bonding the sealing layer of the cap liner to the container to produce a hermetically sealed container.