Whisper Loaders are self-contained vacuum conveying systems which operate automatically to maintain a constant material level in day bins or a receiving hopper, which can be located above injection, extrusion or blow molding machines. Each self-contained system operates on a batch principle. They come with an adjustable timer for conveying, and with a proximity switch to initiate the process. With 0.25 to 4.25 cubic ft. capacities, Whisper Loaders can also be outfitted for Gravimetric operations. Adding a high-level probe and slide gate with allow you to refill with a signal from a feeder.