Vacuum casting is a low-pressure injection moulding or vacuum duplication manufacturing process that allows the manufacturing of a customised plastic part in small and medium quantities. Vacuum casting is particularly suitable for the manufacture of a prototype or very small quantities. In plastics processing A very small quantity lays between 1 – 30 pieces per year. The medium run starts at about 5 pieces per year and goes up to 2,000, 5,000 or 10,000 pieces per year, depending on the size, shape and complexity of the part. The large series lay normally above a requirement of 10,000 per year.
Vacuum or vacuum casting or bagging is a process for shaping parts made of composite materials by moulding. (Wikipedia) These materials are based on thermosets.
In contrast to mouldless plastics processing, vacuum casting machines require a mould. This mould makes it possible to produce several parts with the same mould. The mould is made from a master model. This is mainly produced by stereolithography (3D printing) or digital cutting (CNC). The master model is the part to be manufactured.
For example: I want to make a custom-made Tool A.