Features:1) This batch pre-expander has a PLC and touch panel with a fully automatic production cycle controlling filling, electronic weighing, chamber temperature, pressure and level testing2) With screw conveyor and electronic weighing for high efficiency and filling accuracy3) Closed expansion chamber with permanent pressure for high heat and steam efficiency4) With proportional and pressure relief valves to control chamber temperature, ensuring temperature range within +/-1oC and consistency of foam beads5) With light sensor to control material level, ensuring even density of expanded beads, with density tolerances within 3.5%6) With fluidized bed dryer for automatic drying, sieving, de-lumping and transportation to silo