1 Bar will easily hold the HDPE down the problem will be getting 1 Bar at the HDPE/MDF boundary. Standard vacuum cleaners produce much less and there are always sealing issues. Commercial 1 Bar pumps are just to expensive to be a viable option.
We will probably see in the order of 0.1 to 0.2 Bar but this is still nearly 100g per sq cm so maybe enough.
It will all be in the testing!
Ian
