Abstract: A filtering device for filtering a thermoplastic material by passing a continuous filter across a passage through which the material is caused to flow at an elevated temperature and pressure. The filter is passed through entry and exit ports flanking the passage. Seals on the filter cooperate in sealing engagement with the walls of the entry port to prevent the flowable thermoplastic material from escaping therethrough. The exit port is larger than the entry port, and is sealed off by a solidified plug of the thermoplastic material bonded to the filter. The pressure of the thermoplastic material in the filter passage forces the plug out of the exit port into contact with an external stop, with that portion of the plug in contact with the stop being selectively heated to accommodate controlled emergence of the plug and the filter bonded thereto.