Lost foam casting process is different from other casting methods. Lost foam casting process is a new casting method formed by the integration of full mold casting and vacuum seal casting. It improves the defects and shortcomings of vacuum seal casting and full mold casting, extracts their respective advantages, and is a new breakthrough and development of full mold casting technology and vacuum seal casting technology. According to different casting profiles, Lost foam casting can be divided into dry sand (dry mold without binder) and self hardening lost foam casting (i.e. wet mold with binder). According to the pouring conditions of lost foam casting, it can be divided into lost foam casting under ordinary atmospheric pressure and vacuum lost foam casting. Compared with sand casting under gravity, lost foam casting has the following advantages;
- Simplify the production process, no sand core, no parting surface, simple modeling, shorten the production cycle, use dry sand modeling, and the casting has no burr and flash, which can effectively improve the production efficiency;
- The working conditions are good, the labor intensity of operators is reduced, and the environment of molding process and modeling process is purified;
- The dimensional accuracy of the casting is improved, and the design of the workpiece is not limited by the lost foam casting process (no splitting or parting);
- When designing the lost foam casting process, it is convenient to design the gate and riser. According to the size and shape of the casting, the gate can be placed in the ideal position. The best riser shape can be selected without the limitation of mold retraction, and the utilization rate of liquid metal is high;
- Good casting quality, less machining allowance, high surface smoothness and low scrap rate;
- The lost foam casting technology is easy to master, the requirements for workers’ skills are low, and the production process is easy to standardize;
- The input cost is low. Compared with sand casting, the production cost of the same output can be reduced by 35% ~ 55%. Diversified production lines, different kinds of products can be produced on the same production line, and the effect is fast.