Without muddying up the conversation too much I was wondering if anyone here has experience with the Hexcel 8552 resin system. If so, what were your first impressions and what applications have you used it for?
I’m currently using an 8552/AS4 prepreg and fighting a lot of porosity issues.
What method are you using to cure it? Oven, Autoclave, press?
Several of my employer’s customers use it, but only for autoclave. I am currently helping solve some porosity issues right now with it, but I can’t really talk specifics on it. What I can say is it would make a horrible out of autoclave system, unless you use a press and manage to keep the resin from bleeding excessively. It needs high pressure to reliably produce low-void parts.
If you are doing out of autoclave and can still change resin systems, I would recommend Hexcel’s F263 prepreg or Cytec’s 5276-1 prepreg. I am not at liberty to say why this is the case, but they both are far more forgiving than 8552 both in and out of an autoclave.
We are using it with an autoclave cure.
There’s no doubt it loves pressure. I’m currently using around 45 psi for a co-cure, but I’m afraid that going any higher might cause some localized core crushing. My biggest issue is porosity in the solid laminate areas in between core. The air from the core seems to be rushing in and we can’t seem to pull it out. I’ve heard of others fighting the resin system to a point where they had to go to co-bond to get acceptable parts.