Method and apparatus for automatically supplying a molding material

摘要

A method and apparatus are provided which can automatically and securely supply a molding machine with natural resin pellets and masterbatch pellets at a predetermined mixture ratio, and which is excellent in performance and costs. A natural resin feeder and a masterbatch feeder are connected to a chute of the molding machine via respective tubes. The amount of the natural resin pellets and the amount of the masterbatch pellets which are air-transferred through the respective tubes are controlled such that they are transferred in accordance with the predetermined mixture ratio. The chute and the raw material supply port of the molding machine is connected by a pipe whose cross-sectional area at the upper portion is substantially equal to or smaller than that at the lower portion thereof. The natural resin feeder and the masterbatch feeder are intermittently operated in accordance with signals from an upper limit level meter and a lower limit level meter provided on the pipe.