Talk Composites - The Forum for Advanced Composites

Degassing Addition Cure Silicone Rubber

http://www.talkcomposites.com/Topic14146.aspx

By Ray Rogers - 12/11/2014 5:33:59 PM

I have today mixed and poured my first mould. Whilst degassing small (100 gram) mixes the rubber certainly bubbled up but I did not notice any significant 'collapse' as shown on your tutorial video, even after approximately 5 minutes.

The degassing chamber negative pressure was in excess of 0.8 bar. I left the pump running and chamber outlet valve open during this period.

Any reason I did not notice a collapse and is that negative pressure ok?

Regards

Ray
By Warren (Staff) - 5/7/2015 10:20:00 AM

Hi,

For small pots of silicone there may not be much air to come out so it may not be as dramatic.  Also the top surface area in a typical pot would be proportionately bigger for a small quantity.