Urethane casting has several advantages over other plastic manufacturing processes such as injection molding and additive manufacturing (3D printing). It is fast, inexpensive, and produces high-quality parts. However, it has the limitation of only being capable of producing a limited number of parts, so it may not be the best process for a particular project.
The urethane casting process is very quick because the silicone molds used to make the parts in this process are created very quickly, especially compared to injection molding. It is ideal for low-quantity production – when volumes do not justify investment in injection mold tooling – so first-run production parts can be made weeks before production tooling is ready. It’s excellent for testing product design, for one-off products, or for testing market or consumer responses to a new product. With such a quick turnaround time, urethane casted parts can bring a project to its next level for end-user testing or short-run production, and give a company a first-to-market advantage.
The liquid poured and cured silicone molds used for casting urethane are much cheaper to produce compared to creating injection mold tooling. To put it in perspective, a casting project might be hundreds of dollars, compared to the thousands of dollars it would be for a comparable injection molding project. Again, and as always, the best method will be determined by part quantity. For low-volume part quantities, urethane casting provides a very good value because the cost is very low, yet the quality of the parts is very high.
The cast urethane process can use a variety of materials to produce parts that are rigid to flexible (rubber-like), colored or transparent. The silicone molds provide excellent surface finish detail and can accurately mimic production colors and textures. The urethane casting process can actually provide equal or better physical properties than injection molded parts, and are significantly stronger than their 3D printed counterparts. In addition, parts can be over-molded, have inserts incorporated into them, and have secondary process treatments like painting.