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.

Abstract: A slide plate screen changer has a housing defining a material flow passage and a transverse slide plate passage in which is mounted a movable screen plate. Seal rings on the upstream and downstream sides respectively of the screen plate prevent leakage of material from the flow passage. One of the seals is adjusted by means of a threaded bushing which surrounds the flow passage and which protrudes axially from one end of the housing where it is fully accessible to torque exerting tools.

Abstract: A filter element for use in a filter for pressurized material in flowable form is disclosed. The filter element includes an elongated perforate web adapted to move longitudinally across the flow axis of the material being filtered and to accommodate filtered flow therethrough of the material. A plurality of seal members are fixed to the perforate web transversely to and at spaced intervals along the longitudinal axis thereof. The perforate web extends continuously and uninterruptedly across the seal members to thereby provide the sole and exclusive means of interconnection therebetween. The seal members preferably have a thickness at least as great or greater than the thickness of the perforate web, and preferably the ends of the seal members protrude laterally beyond the side edges of the perforate web.

Abstract: A filter system includes a path of flow for a flowable material to be filtered and a continuous filter element moveable transversely to such flow. The continuous filter element passes through a channel of predetermined and uniform cross section and carries a plurality of seal members at intervals along its length, each seal member being of the same cross sectional size and shape as the channel so as to form moving seals within the channel. The filter member is moved continuously or on demand through the channel, presenting a continuously renewed filter area to the flowable material. The new filter system is illustrated for filtering in the plastics industry.