Casting Services:
Silicone & Urethane Casting
Our casting services offer the following:
- No Expensive Tooling Needed
- Precise, Consistent, Fast
- Low to Medium Volume Production Runs
- Instant and Engineer-Assisted Quotes
- Certifications: ISO 9001:2015, AS9100D, and ITAR
- Instant and Engineer-Assisted Quotes
- Certifications: ISO 9001:2015, AS9100D, and ITAR
-
Instant and
Engineer-Assisted
Quotes - 100+ Materials
-
40+ Surface
Finishes -
Certifications:
ISO 9001:2015,
AS9100D, and ITAR -
In-House Services: 3D Printing,
CNC Machining, Urethane Casting,
and Sheet Metal Fabrication
Our Process is Simple.
Upload a CAD file and request a quote.
Our team will start production.
Once complete, it passes through quality control.
Lastly, our team ships the part(s) to you.
What is Silicone and Urethane Casting?
Silicone and urethane casting commonly create replicas or reproductions of original objects or models. Silicone casting involves pouring liquid silicone rubber into a mold to create a highly detailed and flexible replica of the original object. This method produces toys, prosthetics, or medical devices.
On the other hand, urethane casting utilizes a liquid resin material that hardens during curing, resulting in a durable and rigid copy of the original object. This method can be applied to various applications, including the production of automotive and aerospace components, consumer products, and architectural models.
Both silicone and urethane casting require creating a mold of the original object before the casting material can be poured into it. Additionally, the quality of the final product depends on the quality of the mold and the casting material used.
In summary, silicone and urethane casting are two effective methods for creating replicas or reproductions of original objects or models. Each method has its unique benefits and applications. Furthermore, the quality of the final product is dependent on the quality of the mold and casting material used.
How does silicone & urethane casting work?
The first step is producing a master pattern. For this additive manufacturing process, techniques such as stereolithography, Stereolithography QuickCast®, or material jetting can create the desired final product. The master pattern, which serves as a template for the final product, is then refined by hand to ensure optimal surface detail before proceeding to the next step.
Next, the liquid silicone is poured around the master pattern, solidifying and capturing all its features. Once the mold hardens, a technician cuts it into distinct halves. Then, the technician removes the 3D-printed master pattern, leaving a perfectly shaped internal cavity behind. This meticulous process ensures the highest quality of the mold.
A technician will pour liquid urethane or silicone into the mold as the final step. The mold is then placed in a chamber, a critical component that ensures the quality of the final part. The chamber is typically pressurized for opaque parts, while for clear parts, the chamber pulls a vacuum to eliminate air bubbles and enhance clarity. Once the material has cured, the silicone halves are separated. Then, the next step is to remove the newly formed part. This careful process ensures the highest quality of the final part. This process is repeated to produce the desired quantity of parts in the short run.
Types of Molds
At Prototek, we offer various types of molds based on your project’s requirements.
A box mold for urethane casting is a simple yet effective tool used in the manufacturing process. It consists of a rigid frame, typically made of wood, which serves as the container for the liquid urethane material. The mold holds the urethane in place as it cures, allowing it to take the desired shape. This type of mold to create various products is common, from small components to more significant, complex parts. The versatility and ease of use make the box mold popular for urethane casting applications across multiple industries.
The first step in creating a cut-molded part involves attaching gates and vents to the master pattern. Then, the master pattern is suspended in a frame, and silicone is poured around it. The frame with the material is placed in a pressurized tank. Once the process is complete, the structure is removed from the material, and the cut lines are determined based on the location and geometry of the part.
We can 3D print molds for silicone parts in-house. These molds are easy to remove the components from and can be re-used indefinitely, provided that heat is not introduced. Additionally, using 3D-printed molds eliminates the need for a master pattern.
Gravity molds are used for creating more complex parts that have locked-in features. The mold creation process is similar to that of a cut mold. The master pattern is suspended in the frame, and silicone is poured around it. Once the silicone is set in a pressurized tank, the box can be removed, and cut lines are created around the pieces. However, this process is very time-consuming, and the time required depends on the part’s complexity.
The main difference between the gravity mold and the cut mold is that the former has no gates and vents. As a result, the end-use material can be poured directly into the mold.
Designing Parts for Casting
When designing parts for silicone and cast urethane production, it is crucial to consider the characteristics of these materials. Silicone is known for its flexibility, elasticity, and ability to withstand high temperatures, while cast urethane parts offer durability and resistance to abrasion.
When designing parts for silicone production, it’s essential to ensure that the design allows for easy demolding. It means avoiding undercuts or sharp corners that may cause tearing upon removal. Additionally, it’s crucial to incorporate fillets and draft angles to allow for good material flow.
Optimizing the design for the molding process for cast urethane is also essential. It includes ensuring an appropriate wall thickness, providing gates and runners for material flow, and utilizing a cavity that quickly removes the cast urethane part.
In both cases, it is essential to review the design with the manufacturer to ensure it suits the chosen material and production process.
| Feature | Recommended |
|---|---|
|
Bosses |
boss base: r = .25t |
|
Drafts |
3 – 5° reduces strain |
|
Embossing |
≥ 0.050 in between letters |
|
Joints |
include gap (0.025 – 0.080 in) |
|
General Tolerances |
± 0.010 or ± 0.003 per in (whichever is larger is typical) 0.15 % shrinkage due to thermal expansion |
|
Radii & Fillets |
0.25t or 0.125 in inside corners |
|
Ribs |
h = ≥ 3t |
|
Walls |
recommended thickness: 0.040 in feasible thickness: 0.020 in the larger the part the thicker the walls |
w (width) | d (depth) | r (radius) | in (inches) | ± (plus or minus) | > (greater than) | ≥ (greater than or equal to) | t (material thickness)
Cast Urethane
| Feature | Recommended |
|---|---|
|
Bosses |
boss base: r = .25t |
|
Drafts |
3 – 5° reduces strain |
|
Embossing |
≥ 1.27 mm between letters |
|
Joints |
include gap (0.64 – 2.03 mm) |
|
General Tolerances |
± 0.25 or ± 0.076 per mm (whichever is larger is typical) 0.15 % shrinkage due to thermal expansion |
|
Radii & Fillets |
0.25t or 3.18 mm inside corners |
|
Ribs |
h = ≥ 3t |
|
Walls |
recommended thickness: 1 mm |
w (width) | d (depth) | r (radius) | mm (millimeter) | ± (plus or minus) | > (greater than) | ≥ (greater than or equal to) | t (material thickness)
Production-Grade Casting Materials
Prototek Digital Manufacturing proudly offers a diverse range of production-grade cast urethane and silicone materials designed to meet your precise and unique needs. We have various materials available, so let us know if you have a specific material in mind or need help making a decision.
Silicone & Urethane Casting Finishes
Silicone and urethane casting finishes are coating materials that add a final layer of protection and aesthetic value to sculptures, model prototypes, and other resin-cast products. Silicone finishes come in two varieties: clear and pigmented. They are resistant to heat and chemicals, provide UV protection, and offer a glossy surface that highlights the product’s details. On the other hand, Urethane finishes are available in various finishes, such as matte, gloss, or satin, and can be mixed to create a custom aesthetic. Urethane coatings also offer protection from UV rays, chemicals, and scratches, and are more resilient than silicone finishes. Both silicone and urethane casting finishes require proper preparation, including removing mold-release agents and contaminants before application. In summary, choosing the right casting finish depends on the desired look and durability needed for the project.
Why choose Prototek for your next silicone or urethane casting project?
If you need silicone or urethane casting services for your project, you should consider working with Prototek. Prototek offers high-quality casting services with a fast turnaround time. Our experienced team is skilled in creating molds and castings of various sizes, complexities, and purposes. We use advanced equipment and techniques to ensure precise and accurate results. Additionally, Prototek uses top-of-the-line materials to ensure their castings are durable, long-lasting, and withstand various conditions and environments. Furthermore, our team is committed to providing excellent customer service and works closely with clients throughout the casting process to meet their needs and specifications. With Prototek, you can expect professional service and high-quality castings to complete your project needs.
