Hello friends,

i am currently working on a project where we are manufacturing CFRP Parts with vacuum assisted RTM process. We are using infusion resin with infusion hardener (HP Textiles (HP-HE3000RI-30) / HP Textiles (HP-HTE300RI-9)) and Semiperm Monofilm R&G Release Agent. We are experiencing weird white spots inside of the part after curing of the resin and arent able to fix them. The wierd thing is, that we have these white spots very concentrated at a few positions of the part. The rest of the resin inside the resin pot is clear!  What could be the problem? This is how the process looks like:

1) Inserting preform into the tool
2) Closing of the tool
3) Vacuuming of the tool
4) Injecting of the resin with 0,7 bar injection pressure
5) Wait 2 days until resin is cured
6) Open the tool

I have added a picture inside of my post. I hope you can help.

Thank you very much for your potential help,

All the best, Nik

during infusion, the outgassing happens where the pressure is the lowest, which is at the flow front. At bridging areas, this gas can accumulate, and stay there during the solidification. This gas consists of trapped air and physically soluted gasses, wich contains h2o. After the impregnation this moisture diffuses back into the resin, but can't get very far.