The volumetric principle of solid material in plastic processing is no longer suitable in non-solid material processing. The metal materrial in the form of liquid or semi-solid and such non-solid state

when processing

because of the cooling of material itself

solidification as well as the distortion of the mold and the core under high temperature and the high-pressured and the reason for the squeezing of the head and squeezing core

cause a big change on the volume of the cavity and the material itself

this phenomenon is called the phenomenon of inequality-volume of the material after processing should be smaller than the volume of material pouring into the cavity before processing and its interpolation is the possible compression volume the material are able to compress when processing. Or the initial volume of the cavity must be bigger than the volume of the metal occupies after processing

its interpolation is the sum of the squeezing volume of the squeezing core and the active volume of the squeezing head

and this is called the principle of inequality-volume of non-solid processing.