Fabricate custom silicone rubber prototypes efficiently with ARRK and learn more about the properties of these materials for your manufacturing processes.

Main topics

Are you looking for a solution to fabricate custom silicone rubber prototypes? With the advent of new technologies, making silicone rubber prototypes has become easier. Today, there is no need for companies to invest thousands of dollars in a process or machine that will use only a few times a year. Instead, all you need is ARRK as a partner in your production process. Let’s talk more about silicone rubber here.


Silicone molding processes use two different types of materials. One material is called silicone elastomer (SE), and the other is silicone rubber (SR). SE is a flexible polymer, while SR is a thermoplastic elastomer. Both materials have similar characteristics and the same curing agents. In addition to these similarities, each material has unique qualities that make it suitable for specific applications.

There are three basic types of silicone elastomers:

  • A-staged silicone elastomers are produced in larger sizes than B-stage elastomers, but they require longer times to cure and therefore must be handled carefully.
  • B-stage silicone elastomers are ideal for prototyping because they are inexpensive and quick to produce. However, their flexibility makes them challenging to work with once cured.
  • C-staged silicone elastomers are expensive and time-consuming to produce, but they offer superior mechanical properties compared to the other two types.


Silicone rubber is a thermoset resin that cures at room temperature. When mixed, the components undergo a chemical reaction that produces crosslinks between the molecules. These crosslinked molecules cause the silicone to harden and become rigid. Once cured, silicone rubber cannot return to its original state without being heated above its softening point.

There are many ways to create silicone rubber molds, including casting, compression molding, injection molding, and transfer molding.


Casting uses a liquid silicone mixture poured into a reusable steel pattern. Compression molding involves heating a pre-cured silicone mix until it becomes malleable. Then the silicone mix is placed around a metal pattern and compressed into place. Finally, transfer molding uses a female mold containing cavities that match the desired product.

The uncured silicone mix is then injected into the mold cavity and allowed to cool. Once cooled, the silicone is removed from the mold and any excess material trimmed away. Finally, the silicone mold is opened, and the finished product is released.

Fabricating prototypes out of silicone rubber offers several advantages over traditional fabrication methods because the material is:

  • Extremely strong and durable: its tensile strength is comparable to steel, and its shear strength is stronger than aluminum;
  • Lightweight and highly resistant to damage;
  • Safe for handling because it does not melt or burn easily;
  • Biocompatible and non-toxic;
  • Relatively cheap and easy to obtain.
  • It can provide excellent surface finish quality;
  • And it is highly versatile and can be fabricated in complex shapes and forms.


The primary advantage of silicone rubber molds is that they allow for rapid prototyping. By eliminating the step of building a physical model, designers can move forward much faster.

The mold is designed to hold the shape of the final product and removed once the part is done. It is a quick process because there is no need to wait for the silicone rubber to cure. Another benefit of silicone rubber molds is their versatility. There are several considerations to make when selecting a prototyping method.

ARRK’s entire team offers expertise in their available production methods, such as urethane casting, custom 3d printing, and tooling and injection molding. ARKK’s End-to-End service includes managing cost, speed, ease of use, and availability of materials. Contact us at (866) 912-2449 or fill out our form to Get a quote.