Why and where Vacuum are used?
One of the usage of vacuum is used in material handling, for holding and transfering the parts.
if you need some design asist,you can check the FESTO and Aventics sites.
Another usage is sealing of machine and lubrication elements from the enviromental effects like dust .
A vacuum is used In a flash evaporator to lower the boiling point of water.
We used vacuum chambers to degas urethane and silicone materials before injecting them into molds. Vacuuming removed air which may have been mixed into the material and could have formed bubbles or voids in the casting process.