What is the least expensive way to prototype a part made in Liquid Silicone Rubber?

Question: With all the new options today, could you please tell me what is the best and least expensive way to prototype a part (about 3″ x 2″ x 2″) made in Liquid Medical Silicone Rubber?

Answer: For low volume prototyping of medical silicone parts your best option is typically to create a single cavity aluminum (faster and cheaper than steel) compression or transfer molding tool.  While others may swear by jumping straight into an injection molding tool, it could take a machinist and technician longer to set up and process a liquid silicone injection molding tool than it would to make 25 parts in a compression mold.

If cost is your most critical concern, and your target first run of medical silicone volume is extremely low, you may also wish to look into getting an acrylic mold made (instead of aluminum).  The costs of fabricating an acrylic mold is significantly less than a metal mold.  But be forewarned, if you purchase an acrylic tool, you will likely be stuck running an RTV (Room Temperature Vulcanization) material (so your cycle times will be long), you won’t be able to put any real pressure on it (so your dimensions could vary significantly), and your mold is going to wear out FAST.  You might only get 10 parts out of an acrylic tool, vs. 10,000 out of an aluminum tool, and 100,000 out of a steel tool.

While many can be seduced by the $500 – $1,000 price tag on an acrylic mold, it might take 10 of them to make 100 parts, at this point, an aluminum tool would already have been paid for, and well into a small scale production run.  It is for this reason that Albright Technologies does not fabricate acrylic molds.

If you have any other questions, please email Kevin Franzino directly at kevin@albright1.com.




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About Kevin

Kevin received a Bachelor of Science Degree in Biomedical Engineering from the University of Connecticut in Storrs, CT. He has been with at Albright Technologies, Inc. for over two years where he does development work on silicone medical devices. He lives in Connecticut, with his wife (Megan) and their two dogs (Abby and Ripley).