Methods to prevent backspray in lost foam casting

Lost foam casting is one of the casting processes, and there will be various casting defects in the casting process, resulting in defects in castings, and lost foam casting is no exception. Respray is a common phenomenon in lost foam casting, when the respray is serious, it may endanger the personal safety of the pouring worker, must be paid attention to, in order to reduce the spray phenomenon, the following measures can be taken:
First, the density of the foam model should be small, under the premise of ensuring the surface quality of the foam and ensuring the strength of the model, the lighter the foam should be made as possible to reduce the amount of gas during pouring. Second, the foam model must be dried before coating, and each batch of foam model should be sampled to check the weight change of its drying process, make a baking weight change curve, and only when the weight no longer changes can it be painted. Third, the pouring system, especially the straight runner and the cross runner, should not be painted, so that the gas generated during pouring can be quickly and fully pumped away, and there is no coating, saving the consumption of coating. Finally, a baffle is covered with a baffle on top of the gate cup, which can block the molten steel sprayed back, so that it cannot splash out and endanger the on-site operators.
The use of the above methods can effectively prevent the phenomenon of respraying in the process of lost foam casting, better prevent the defects of castings, improve the quality of castings, and improve the safety of production.