3D Printing is a revolutionary technique for creating prototypes and parts in very low volumes. But it can also be used in combination with another technique to cost-effectively make parts in quantities up to 250 or more.
That other technique is casting parts out of silicone or urethane using 3D printed molds. This is opening up new possibilities for companies to make high quality parts at a very low per-unit cost, with a minimum fixed cost investment.
If you need to make products in very low quantities, between one and five, 3D Printing is typically a good choice. But if you need larger quantities, or if the parts you need to create are larger than eight inches in length, or if they require intricate surfaces or extremely smooth surfaces, the per-unit cost starts to rise. It can also be time-consuming.
3D printing a mold can be a viable alternative, depending on the requirements of the project. For example, certain grades of silicone and urethane bond to (and therefore can’t be removed from) 3D printed molds which are porous. If a 3D printed molded isn’t viable, often molds can be machined from aluminum, which cost a bit more to make but can produce hundreds of parts in almost any grade of silicone or urethane.
The process starts with a 3D model, which is either existing, created from scratch, or derived from a 3D laser scan of an existing part. We can then use a “negative” of that image to design a mold to make that part.
We’re then ready to make the mold. The material we use depends on the needs of the project, particularly the hardness/flexibility and durability as well as the desired finish on the part.
For projects that require quantities of approximately 5 to 20 parts, we typically make the molds from 3D printed plastic. But for greater quantities, for parts that need a smoother finish, or for materials that would bond to porous 3D printed molds, we machine molds from aluminum. Aluminum molds are more expensive to create than 3D printed molds, but casting into aluminum molds with manual injection of a 2-part material that cures at room temperature is still way less expensive than injection molding, which melts the plastic and injects it under pressure using expensive machines.
In either case, the result is significant cost savings for creating the parts in low volume. A piece that could cost several hundred dollars per unit on a 3D printer can be made much faster and less expensively with a urethane casting process. The per-unit cost could be as low as a few dollars, depending on the requirements of the project. And the molds cost in the hundreds of dollars, even in aluminum, where molds for injection molding start at several thousand dollars, quickly getting into tens of thousands of dollars.
Using this approach to combine 3D printing and urethane casting, companies can produce high-quality, low-volume parts, for prototyping, initial demand testing, or other needs, at a fraction of the cost of 3D printing individual parts.
For more information on 3D Printing molds for low and medium-volume parts, contact us.
6100 Emmanuel Dr., SW
Atlanta, GA 30336.
(470) 231-PART (7278)