Through the implementation process of the bead selection

pre-foaming

dry curing

model making

model drying

combined drying

dipping

split

combination of dry sand compaction

negative pressure suction

vacuum casting

clean out

it is not only be solved for the un-rational bead choose of EPC pattern in the process of casting surface friction disc and insufficient strength of particle model

as well as large volume and large deformation caused by the gap size and due to substandard problems such as deformation

but also be solved for slag hole

shrinkage and other problems in the EPC friction disc as a result of incomplete combustion of foam pattern

instability and imbalance of iron liquid filling

iron solidification pressure holding time caused by the lack of internal casting formation.The variable negative pressure EPC process was adopted to produce the friction disc products

which has high quality and high yield.