A shut-off valve is described for controlling a flow of molten material from an injector gate towards a mold cavity. The valve comprises a channel, for the molten material, which extends along a first axis up to the gate; a shutter member mounted movably along a respective second axis and so that a free end of the shutter member can move towards, and reach, a point inside the channel to throttle and/or close the channel, thus regulating said flow; and an actuating member having a portion coupled to the shutter member so that a rotation of the actuating member causes a translation of the shutter member along the second axis from and/or towards said point. The actuating member comprises an annular stator fixed on the mold, and an annular rotor rotatably placed inside or outside the stator and coupled to the shutter member.

An injection molding system includes a supplying unit configured to supply a flowable mixture; an injection unit communicable with the supplying unit, wherein the injection unit includes an outlet configured to discharge the flowable mixture; a molding device configured to receive the flowable mixture from the outlet and includes a mold cavity and a feeding port communicable with the mold cavity and engageable with the outlet; and a supporting device disposed between the injection unit and the molding device and configured to facilitate an engagement of the injection unit and the molding device. The supporting device includes a first element connected to the injection unit and a second element disposed on the molding device. The second element includes a slot configured to receive a protruding portion of the first element, the protruding portion of the first element is slidable within and along the slot of the second element.