First, the plastic resin is inserted into the mold through the sprocket. The task of the sprocket bush is to keep the mold in front of the nozzle of the injection cylinder so that the molten material is then inserted into the mold from the cylinder. The sprocket bus leads the molten material through the channel to the mold quettes. The molten material can circulate through the channels, and hence the canals or channels are also referred to. After passing through the mosquito, the melt material passes through special designed gates or gates and ultimately enters Quetta space to form an injectable piece. The amount of resin needed to fill the sprout, mold, and quetta of the mold is called a shot. Naturally, the molten material that cooled inside the racks is connected to the body of the piece at the exit of the piece from the mold and should therefore be separated from it. However, sometimes the shelves are heated by a special system and as a result, the residual material in them is melted again and separated from the body of the main piece.