Various embodiments provide apparatus and methods for injection molding. In one embodiment, a constraining plunger may be configured in-line with an injection plunger to transfer a molten material from a melt zone and into a mold. The constraining and injection plungers are configured to constrain the molten material there-between while moving. The constrained molten material can be controlled to have an optimum surface area to volume ratio to provide minimized heat loss during the injection molding process. The system can be configured in a longitudinal direction (e.g., horizontally) for movement between the melt zone and mold along a longitudinal axis. A molded bulk amorphous object can be ejected from the mold.