Bring Your Product to Market Faster
with Urethane Casting

Overmolding // It’s easy to mold an elastomeric urethane over a metal or plastic part to create a rigid product with a soft surface, such as an armrest. Another common application is press fitting and gluing inserts into urethane parts.

Clear Parts // Urethane parts can be cast in a material that can be polished to a water-clear finish.

Flame Retardant Parts // One rigid urethane material is flame retardant. It’s hard to find additive materials with a UL94V0 rating.

Greater Design Freedom than Injection Molding // Injection molded parts need to follow strict design rules, such as avoiding undercuts and thick-to-thin wall transitions, and designing draft into parts so they can be released from the tool. Because the silicone molds used in urethane casting are flexible, design engineers don’t need to worry as much about these rules and can design more complex features into their parts.

Many Finishing Options // Urethane parts can be painted to match any Pantone color. A variety of textures and finishes are also available.

Exceptional Detail // Urethane casting can be used to produce parts with complex geometries and fine detail.

Hard or Soft // Urethane materials can be used to create both rigid and flexible, elastomer-like parts.

Fast to Market // In the production range of 50-100 parts, urethane casting is often faster and less expensive than additive manufacturing. Whether you’re seeking bridge production or want to get consumer feedback on a new product, urethane casting can help you bring products to market faster,

Test Multiple Hardness Levels from a Single Mold // One silicone mold can be used to produce the same part in a variety of durometers, so they can be tested side-by-side to determine which one works best.

Lead Time // It takes an average of two weeks for silicone tooling to be created. Once it’s done, however, parts can be produced quickly.

Short Tool Life // Silicone tooling can only produce an average of 20-25 parts. After that, new tooling must be built to produce additional castings. This also means that urethane casting isn’t practical for large-scale part production.

Limitations for Prototyping // Additive manufacturing is ideal for rapid prototyping because it enables designers to quickly iterate a series of designs. In contrast, the silicone tooling used for urethane castings tends to lock engineers into a single design. New tools can be built to accommodate design changes, but each one takes an average of two weeks to build.

Impractical for 1-2 Prototype Parts // Compared to CNC machining or additive manufacturing, the cost to produce silicone tooling to produce one or two prototype urethane parts can be cost-prohibitive on a per-part basis. The sweet spot for producing urethane castings is in the 50-100 range.

Overmolding enables designers to create parts with rigid and flexible parts, such as armrests and door handles, consumer products with two-tone designs and products with grippable surfaces. It’s also commonly used in the medical industry to create components that are easier to clean for use.

Polyurethane is easy to bond to other materials, such as plastic, metal and wood.

Many design engineers don’t realize that urethane casting is a viable and affordable alternative to producing small quantities of parts using injection molding. It produces parts with a surface finish and mechanical properties that are similar to injection-molded parts, making it ideal for late-stage prototyping and bridge production.

It’s also well-suited to parts with complex geometries and fine details.