When trying to swell a silicone extrusion utilizing heptane on a percentage basis, what can one expect for a radial expansion and a longitudinal change? Does swelling the silicone compromise its strength and weaken it? Is the degree to which an extrusion will swell when exposed to heptane a function of time or exposure? To dissipate the heptane out of the silicone, what is the best way to process this—exposure to ambient room temperature, in an oven, etc.? @ Ask The Experts

Silicone Fabrication Q&A

When trying to swell a silicone extrusion utilizing heptane on a percentage basis, what can one expect for a radial expansion and a longitudinal change? Does swelling the silicone compromise its strength and weaken it? Is the degree to which an extrusion will swell when exposed to heptane a function of time or exposure? To dissipate the heptane out of the silicone, what is the best way to process this—exposure to ambient room temperature, in an oven, etc.?

Answered September 20th, 2010 by Expert: Brian Higgins

Swelling is dependent on the type of silicone, the size of the part, and how long it is exposed to heptane. Ultimately, there is no specific formula to calculate this. Over time and with extended exposure, heptane will degrade the silicone rubber. Each unique application requires its own trial and error procedure and process development—in other words, heptane exposure.

Brian Higgins

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