Mold making allows us to create multiple copies of the same part to duplicate prototypes or create prototypes with many parts of the same size and shape. Once the master part is created and carefully finished, parts can be duplicated with minimal finishing needed creating greater efficiency and consistency. With the mold making process, we are able to create parts with different properties; whether soft and flexible, dense and strong or crystal clear. Due to the quality of parts that can be cast, we can utilize this process for short run production when needed.
First, the master part is created with 3D printing or CNC machining then refined and finished. To make the mold, a box is cut from acrylic or MDF large enough to fit the master part. Molds can either be created as monolithic or two-pour. For a monolithic mold, the master is suspended by wire in the box and the part line is taped off. The box is filled with silicone and set overnight. Once set, the box is removed and the silicone is cut to the tape to remove the part.
For a two-pour mold, the part is secured within the box by clay and a part line is created. Silicone is poured in, filling the first half of the mold. Once the silicone sets overnight, the box is flipped upside down and the clay and tape is removed. Next, the second half of the mold is filled with silicone and set. To remove the master, the
mold is peeled apart and the part is removed.
For both monolithic and two-pour molds, once the mold has been set and the master removed, gates or channels are cut into the silicone for the resin to flow through. The mold is now ready to be used for urethane casting or vacuum casting.
