Characteristics of EPC
1. Flexible design
It provides enough freedom for the structural design of castings. Highly complex castings can be cast by the combination of foam modules.
2. Reduce investment and production costs
Reduce the weight of casting blank and have small machining allowance. (1) casting batch number (2) casting material (3) casting size (4) casting structure
3. The traditional casting has no sand core.
Therefore, there will be no uneven wall thickness of castings caused by inaccurate size of sand core or inaccurate position of lower core in traditional sand casting.
4. High casting precision
Lost foam casting is a new technology with almost no allowance and precision forming. This process does not need to take the mold, parting surface and sand core, so the casting has no flash, burr and draft angle, which reduces the dimensional error caused by the combination of cores. The surface roughness of the casting can reach ra 3.2 ~ 12.5 micron; The dimensional accuracy of castings can reach CT7 ~ 9；; The machining allowance is at most 1.5 to 2mm, which can greatly reduce the machining cost and reduce the machining space by 40% to 50% compared with the traditional sand casting method.
5. Cleaner production
There is no chemical binder in the molding sand, and the foamed plastic is harmless to the environment at low temperature, and the recovery rate of used sand is over 95%.
Like other casting processes, the equipment and technology of EPC also have its shortcomings and limitations. Not all castings are suitable for production by EPC process, which needs specific analysis.
Whether to adopt this process is mainly based on the following factors.
1. The order of applicability of casting materials is roughly as follows: gray cast iron-non-ferroalloy-ordinary carbon steel-nodular cast iron-low carbon steel and alloy steel; Through necessary preparation, the process experiment and debugging cycle will not be too long.
2. The larger the casting batch, the more considerable the economic benefits.
3. Casting structure The more complex the casting structure, the better the advantages and economic benefits of EPC process. For the case that there are narrow inner cavity channels and interlayers in the structure, it is necessary to carry out experiments in advance before the EPC process can be put into production.
4. The casting size mainly depends on the applicable scope of corresponding equipment (such as vibrating table and sand box).