Leaks during or after resin infusion
Leaks during or after resin infusion
(OP)
Hey all,
I have been running into a problem for the last few months and I am in need of some advice from the forum.
I am working in a production environment where we are using resin infusion. We are leak checking our parts for at least half an hour (with the actual requirement being 0"hg in 5min). The operators will do their leak check and measure no leaks during their leak check however during infusion they are somehow getting air into their parts. Sometimes we have discovered that there was a leak in the bag and other times we can't find a leak at all. Sometimes instead of leaking during the infusion the part will randomly begin to show streaks of air while it is sitting in the clean room waiting for cure.
All of this happens after we have leak checked the parts. We are getting at least 27"Hg at all times. What is confusing me the most is that this does not happen all the time and it never happens at the same spot while infusing. These parts have been infused, sat in the clean room for 6 hours with no leaks or air, and when we come in the next morning there will be air right through the part.
I have been thinking about the possibility of micro fractures in the composite tooling or possibly something to do with the resin/hardener mixture as it is heating up.
Any help or tips on this situation would be much appreciated!!
Thanks.
I have been running into a problem for the last few months and I am in need of some advice from the forum.
I am working in a production environment where we are using resin infusion. We are leak checking our parts for at least half an hour (with the actual requirement being 0"hg in 5min). The operators will do their leak check and measure no leaks during their leak check however during infusion they are somehow getting air into their parts. Sometimes we have discovered that there was a leak in the bag and other times we can't find a leak at all. Sometimes instead of leaking during the infusion the part will randomly begin to show streaks of air while it is sitting in the clean room waiting for cure.
All of this happens after we have leak checked the parts. We are getting at least 27"Hg at all times. What is confusing me the most is that this does not happen all the time and it never happens at the same spot while infusing. These parts have been infused, sat in the clean room for 6 hours with no leaks or air, and when we come in the next morning there will be air right through the part.
I have been thinking about the possibility of micro fractures in the composite tooling or possibly something to do with the resin/hardener mixture as it is heating up.
Any help or tips on this situation would be much appreciated!!
Thanks.





RE: Leaks during or after resin infusion
It sounds like you are using a two part room temperature cure resin. If you get any significant exotherm it is quite likely that the rise in temperature could increase the vapor pressure of the resin to above ambient pressure and the resin "boils". If you continue to apply vaccum to outlet port after infusion is complete you can be boiling the resin. Same applies if you have resin leakage into the breather.
RE: Leaks during or after resin infusion
Thanks for you reply.
We are using the following on top of the part: a layer of peel ply, the infusion pad (edge injection), a layer of infusion mesh, and then the vacuum bag. We can't actually see the part itself but you can see the air in the resin that sits on the top of the part.
If anyone responding to this needs any more information I can provide most (not all) of the details.
Thanks.
RE: Leaks during or after resin infusion
RE: Leaks during or after resin infusion
RE: Leaks during or after resin infusion