Silicone and urethane casting is an excellent way quickly manufacture high-quality plastic cast parts in small to medium quantities (~10-1000 parts) with shorter lead times and lower tooling costs than injection molding. In fact, it has some of the lowest unit costs of any manufacturing technology, including 3D printing, while rivaling injection molding for quality and versatility.
Cast plastic parts are durable and inexpensive. They consistently render fine surface details and offer high-quality finishes with the look and feel of consumer products. Because they are significantly less expensive than injection molding, silicone and urethane casting are also useful for quickly creating prototypes for molded parts.
Urethane and silicone casting are a versatile middle ground between 3D printing and injection molding that can offer the best of both worlds. Modern advances in materials have made silicone and urethane cast parts comparable in quality to injection molded parts. At the same time, these cast parts can be produced in small to medium quantities faster and at less cost than with injection molding.
When compared to 3D printing, silicone and urethane casting materials have a wider range of chemical, thermal and mechanical properties than 3D printed plastics.. Because they are not restricted by the size of a printing bed, cast parts also offer better value for medium to large parts. Lastly, cast parts have superior finish and fine detail when compared to 3D printed parts, which means they can accurately create the look and feel of consumer products without any additional finishing.
Common applications for rapid casting include:
Performance parts for transportation and aerospace
Whenever applicable, we use 3D printing to create the master patterns for silicone and urethane mold-making, so you can have tooling in weeks, not months. Because urethane casting is so good at rendering fine details, it can easily reproduce custom finishes, saving time and money. If you have a part that you need replicated, we can easily reverse engineer existing objects with 3D scanning as well.
Once created, each mold can be used to cast thousands of parts with the look, feel and durability of finished products. Because they are relatively quick and inexpensive to produce, silicone and urethane molds are also a cost-effective option for iterating prototypes for cast or molded parts.
Urethane and silicone molds can cast a range of materials, including elastomers and rigid plastics, as well as silicone, plaster and even concrete. Cast plastic parts can range from 20A – 90D on a durometer and come in high-heat, flame-retardant, food-safe and medical-grade options.
As a result, cast parts can stand up to a variety of specialty applications in demanding environments including the aerospace, medical and food industries. We can even work with other materials like concrete and plaster! Contact us if you don’t see the material you want to use below.
Hard Pro 70-3
Lowest cost, fast-curing rigid urethane. Popular choice for general uses. Not suited to high-stress applications.
ABS-like material. Extremely tough and rigid, not suited to applications that require flexibility.
Polypropylene-like material. Very flexible and tough. Not suited to high-stress applications which require rigidity.
Clear, acrylic-like resin with high UV stability. Expensive and slow to cure. May require multiple molds.
Food-grade and biocompatible urethane for medical applications. Relatively expensive compared to other materials.
High-heat resin with 345°F heat operating temperature. Extremely rigid, not suited to flexible applications.
UL 94 V-1 flame-retardant polyurethane with ABS-like mechanical properties. More expensive and slower to cure than TP-4050.
UL 94 V-0 and FAR 25.853 flame-retardant polyurethane. Better flame rating than Inno 4016 but not as stiff or durable.
Heavy aluminum-filled composite for tooling. Zero shrink, dissipates heat and extremely rigid. Not for mechanical parts.
Fast-curing, flexible urethane rubber material with a range of applications. Available in all A hardness ratings.
Fast-curing platinum silicone, able to cheaply make many parts a day. Cures too fast for larger parts.
Durable, slow-curing platinum silicone for tooling and large volumes. More expensive than urethane and Moldstar 20T.
Smooth Sil 960
Green, food-grade silicone approved for direct food contact. Relatively high rigidity and low shrinkage.
Clear, food-grade silicone approved for direct food contact. Less rigid than Smooth Sil. Low shrinkage.
If you’re ready to start a cast urethane or silicone project, get a free quote in 24 hours or less by filling out our quick quote form.
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Our engineers will review your project and get back to you with a cost estimate and project analysis. Want to learn more? Give us a call!