| 摘要 |
<p>PURPOSE:To form a uniform coat film by blowing a powder binder and a base material independently to the surface of a metal mold in an electrostatically charged state. CONSTITUTION:Three holes are pierced longitudinally into, for example, a nozzle base 6, and conductive earth rings 10 are fitted to the central part. Corona discharge pins 12 are provided to the inside walls of the respective holes 9 and the nozzle base 6 is connected to an electric power source 13. A metal die 2 is placed on a table 3 and is preheated to a predetermined temperature, thence a parting agent 26 is blown thereto. While passing a conveyor 8 suspending the nozzle base 6 over the metal die 2, a binder 27 is charged by the base nozzle 6 discharged from a feeder 16 and is then blown to the metal die 2 by way of a pipe 22. Similarly, a base material 28 and an adhesive agent 29 are blown. Thereby, a uniform coat film is made. Next, a shell sand discharging device 25 passes over the metal mold 2 to back up shell sand 30. The shell sand is sintered by the heat retained in the metal mold 2 and the sintered shell mold 31 is taken out.</p> |
