Updated: Dec 4, 2018
Test # 2 we wanted to work out what impact the direct 'jet' heat blasting at the panel has on the heat transfer. Being that there is no flame or forceful heat on the final AS1530.4 test we need to be comfortable that with additional time required for compliance that our system will pass.
So this test is with less heat (around 900deg still which is more than required for the Class 1 building compliance) which is at a point where the harsh flame is not forcing into the panel.
The attached video is the entire test (boring and no-edited for time or comment). Its added just for reference. This test goes for around 24 minutes.
The results were a little unexpected.
Initially the heat at the rear of the panel was only 25deg - 30deg. After around 10mins it started very slowly creeping up in heat to approx 165deg where it plateaued for the final 16 minutes. At the 26 minute mark it was still consistently at 165deg so we stopped the test.
Once we cut the panel to examine later, we found that a similar boring into the panel happened as there was still direct flame and force (just less than test 1). This is why the heat began to rise. But the force / heat seemed to be countered by the product at a certain point. ACS-A seem to think that this is because an air gap was created which helps reduce heat transfer.
Our feelings are that the heat would rise again if we left on for 1 hour as over time the vermiculite would continue to get broken down. As we dont have direct flame we feel this is not worth pursuing.
What we learnt from this is that direct flame of significant temp and force will break down almost anything. For the AS1530.4 we dont have to worry about this, and test # 2 shows we are well better performing than we expected.
So for the final AS1530.4 compliance test (where we will receive our certification) we plan to build our normal wall and have it tested where it will certainly reach the 60mins at 800deg required for a pass. We will then leave this to see how far it goes until it fails - up to 3 hours which is an insane rating. If it fails prior to 120min, then we know we simply need to tweak the design to either make the vermiculite thicker (preferred as easy to do) or add another 10mm layer with a small air gap which will definitely perform to this high requirement.
Either way we will change the density we order our custom vermiculite where we predict this will slow down any breaking down of the material under forced heat.
Generally this was a very successful test.