NASER Plastic Hopper Loader Suction feeders are widely used in the injection molding of raw materials, can be automatically fed to the injection molding machine. When there is a lack of material in the barrel of the injection molding machine, the suction machine signal will be given. The suction machine uses the principle of ventilation to convey the plastic materials to the barrel of the injection molding machine. When the material reaches a certain level, the suctioning opportunity is stopped, and when the material is not enough, it can be conveyed again.