How does the lost foam forming machine work?
Casting method according to EPC process first made of foam plastic model of EPC coating, special coating, drying in a sand box, filled with dry sand, three-dimensional vibration compaction, vacuum casting condition, model of gasification disappeared, metal replacement model replicate as global mold casting, vacuum release condensate after removal casting from the loose sand in the next cycle.EPC process flow1, the production of foam plastic gasification mold (manual, mechanical);2, foam plastic gasification, die combination drying;3, foam plastic mold surface brush, spray refractory coating after drying (must dry);4. Place the special sand box on the three-dimensional vibrating table;5. Fill in low sand (dry sand), shake and scrape;6, the drying of plastic foam mold placed on the bottom sand, according to process requirements into sand, automatic vibration after a certain time, scraping the box mouth;7. Cover the sand box with plastic film, insert the gate cup and connect the negative pressure system. After the compaction, the molten steel is poured, the foamed mould is disappeared, and the metal liquid is replaced by the metal liquid;
The molding process consists of two stages, steam heating and cooling molding.After the pre curing beads by steam heating, about 20S-60S of the time, the air can overflow, produced after the expansion of the heated pressure, the pressure is greater than the sum of the vapor pressure bead outside of the heating, the polymer softening, foaming agent after vaporization bubble in pressure is greater than the outside pressure, bead again expansion, and a whole fullness bead gap, the formation of foam products with the same shape of the mold, cooling after molding can polymerization.
Lost foam molding machine has two kinds of automatic and manual, manual operation is controlled by hydraulic valve, so that the molding machine on the template, left and right templates, front and rear templates in accordance with the design of the mold in order to open and close. The aged expandable polystyrene beads are filled into the closed cavity, and the hot steam passes through the air holes of the wall directly into the cavity in a relatively short time, so that the beads expand and soften after being heated. Because of the limitation of the cavity, the expanded bead fills up all the voids and is completely bonded to a whole. After cooling and shaping, the mold is opened and the mold is taken out.The automatic EPC machine adopts the PLC automatic control hydraulic valve according to the order of the manual to complete the opening and closing of the die.
