An edge-gated injection molding apparatus comprising: an injection manifold assembly for distributing a melt stream of moldable material to a plurality of mold cavities that are aligned on opposing sides of the injection manifold assembly, the injection manifold assembly having exterior side surfaces including a plurality of melt outlets with each melt outlet suitable for being in fluid communication with a respective mold cavity of the plurality of mold cavities, a plurality of nozzle seals for receiving the melt stream from the plurality of melt outlets of the injection manifold assembly and delivering the melt stream to the plurality of mold cavities; a plurality of biasing components secured to the injection manifold assembly with each biasing component being disposed between a pair of melt outlets for biasing the nozzle seals outward from a centerline of the injection manifold assembly toward its respective mold cavity; and wherein an upstream end of each nozzle seal is slidably disposed against a respective exterior side surface of the injection manifold assembly so as to accommodate thermal expansion of the injection manifold assembly; and the outward biasing of the exterior side surface by its respective biasing component applies a preload to the nozzle seal, characterized in that the injection manifold assembly includes an injection manifold and a plurality of diverter blocks that are attached to a downstream surface of the injection manifold, and wherein each of the plurality of diverter blocks defines one of the plurality of melt outlets of the injection manifold assembly and the exterior side surface against which a respective nozzle seal is slidably disposed and includes an interior side surface that contacts a corresponding contact surface (249a, 249b) of the biasing component associated with the melt outlet. an injection manifold assembly for distributing a melt stream of moldable material to a plurality of mold cavities that are aligned on opposing sides of the injection manifold assembly, the injection manifold assembly having exterior side surfaces including a plurality of melt outlets with each melt outlet suitable for being in fluid communication with a respective mold cavity of the plurality of mold cavities, a plurality of nozzle seals for receiving the melt stream from the plurality of melt outlets of the injection manifold assembly and delivering the melt stream to the plurality of mold cavities; a plurality of biasing components secured to the injection manifold assembly with each biasing component being disposed between a pair of melt outlets for biasing the nozzle seals outward from a centerline of the injection manifold assembly toward its respective mold cavity; and wherein an upstream end of each nozzle seal is slidably disposed against a respective exterior side surface of the injection manifold assembly so as to accommodate thermal expansion of the injection manifold assembly; and the outward biasing of the exterior side surface by its respective biasing component applies a preload to the nozzle seal, characterized in that the injection manifold assembly includes an injection manifold and a plurality of diverter blocks that are attached to a downstream surface of the injection manifold, and wherein each of the plurality of diverter blocks defines one of the plurality of melt outlets of the injection manifold assembly and the exterior side surface against which a respective nozzle seal is slidably disposed and includes an interior side surface that contacts a corresponding contact surface (249a, 249b) of the biasing component associated with the melt outlet.