Disclosed are embodiments of a vessel configured to contain a secondary magnetic induction field therein for melting materials, and methods of use thereof. The vessel can be used in an injection molding apparatus having an induction coil positioned along a horizontal axis and adjacent to the vessel. The vessel can have a tubular body configured to substantially surround and receive a plunger tip. At least one longitudinal slot extends through the thickness of the body to allow and/or direct eddy currents into the vessel during application of an RF induction field from the coil. The body also includes temperature regulating lines configured to flow a liquid within. The temperature regulating lines can be provided to run longitudinally within the wall(s) of the body between its inner bore and outer surface(s). A flange may be provided at one end of the body to secure the body within an injection molding apparatus.