Abstract: A method for injection molding a material involving bringing the interior of a tightly sealed injection mold under a high vacuum, then injecting the material into the interior of the injection mold at an ultrahigh speed in the vicinity of a speed at which adiabatic change is exerted on the material in accordance with a predetermined pattern of internal pressure so as to fill the interior of the injection mold with the material, and molding the material under low pressure. An injection molding apparatus used for carrying out the aforementioned method is capable of bringing the interior of the injection mold to a high vacuum.

Abstract: A straight-hydraulic mold clamping system for use in a molding machine has a bearing portion for a rod of a mold clamp cylinder provided with a plurality of annular oil grooves within which an oil functions, and utilizes the rigidity of the rod so as to horizontally support a movable platen and a molding die attached to the movable platen in a cantilever manner and maintain the horizontality of the movable platen and the molding die.