I believe molding two halves with a vacuumpump to provide pressure will produce a better structure and allow me to better control wall thickness.
我认为两半的模具加上真空泵来提供压力能使结构更好，我也能更好的控制壁厚。
2
Sprinkler pump shell cracks, or impeller, leaf damage, or seal damage, will affect the degree of vacuum, water pumping, water pressure is too small or the phenomenon.