Prototyping with Silicone

“So, I have this silicone product idea and I am not sure if it’s exactly the way I want it. What’s the best approach?”

You are not alone. Most customers are uncomfortable moving ahead with hard production tooling without prototype parts that verify their design will perform as intended and be accepted in the marketplace. Unlike plastics, which can often be economically and quickly prototyped using 3D printing methods, silicone materials present prototyping challenges. Challenging yes, impossible, no. We will present some options for the new entrepreneur as well as the established business.

3D SILICONE PRINTING

Some of the newer technology in research and development available from Wacker and Loctite is 3D printing in silicone. Neither allow you to use the actual silicone material you will use in production but you do get a prototype silicone elastomeric part with a very similar feel to the actual product. Very limited availability of the printers and the material. Still very new R&D technology. A general ballpark price is nearly impossible due to part geometry. You can expect to have prototype in hand within 2 weeks.

CASTING WITH RTV

Silicone casting in RTV (room temperature vulcanized) materials have been around a long time.   It is attractive due to its low cost, relatively quick method of producing a prototype silicone part. It allows you to transform your CAD model into an actual part. RTV silicone is used to make a mold from which RTV silicone prototypes are made. It is a very manual process that requires patience and experience.

Casting can be helpful for those who have trouble visualizing the part from a drawing or for marketing purposes; in photoshoots and presentations. The big negative is that RTV material does not have the same properties as production silicone materials and functional testing is not possible with cast prototypes. Think of it as more of a visual then functional product.

The budget for casting RTV silicone prototypes is typically in the range of $1,000-$2,500 and sourced within a week or two.

COMPRESSION MOLDING

Compression molding silicone is the most economical and fastest way to make silicone prototype parts that are suitable for end use functional testing. Typically, an aluminum single cavity compression mold is made in 2-4 weeks. This mold is then used to produce LSR (Liquid Silicone Rubber) molded parts that are equivalent in properties to high volume LSR injection molded parts. Compression molded parts are made in a more manual fashion than injection molding which often results in some flash making them slightly less attractive in appearance vs. the final injection molded parts. Compression molding is a great way to submit parts for required end use testing and to evaluate a variety of durometers and colors for functionality and appearance in the marketplace.

Compression molding is only capable of producing under 100 parts. It can be used in a multiple cavitation scenario for low volume production runs usually up to 1000 parts/year.

Compression molds are typically capable of producing 50-100 parts in an 8 hour shift. This is why it should not be considered for long term production. The labor involved drives part pricing up significantly.

The budget for prototyping a part in compression is in the range of $3,000-10,000 dependent on part geometry and the number of prototypes needed.

SOFT TOOLING INJECTION MOLDING

If you require hundreds to thousands of silicone prototype parts using LSR for actual end use testing or initial sales campaigns it is best to build a single cavity aluminum injection mold. This aluminum mold is also suitable for low volume production runs typically up to 10,000 parts per year.

The lead time for a single cavity aluminum injection mold is typically 4-6 weeks making it an attractive lower cost way to enter the marketplace with new products. The life of the mold can be extended using NiBore coating and it is possible to use these molds for 100,000 or more silicone parts in some cases.

Single cavity injection molds are typically capable of producing hundreds of your part per day. The typical cost for an aluminum injection single cavity mold is $5,000-$15,000 dependent on part geometry and whether a NiBore coating is applied to extend life.

For more information on prototyping your silicone product please reach out to the small business partnership experts at Extreme Molding. As a silicone mold prototype manufacturer, we can work with you to help produce your product efficiently and domestically right here in the United States. Contact us today!