Effect of gravity in autoclave cure

[asiegler]

Hi All,
Will resin tend to flow toward the lowest point of the mold during an autoclave cure at 50 psi? or is the effect of gravity negligible.

Thanks in advance

 

[Compositepro]

Yes, gravity has an effect. In most cases the effect is negligible.
Resin viscosity, fiber permeability, and fiber compaction supporting the vacuum bag, resist the effects of gravity on resin flow. Low resin viscosity and high resin content will magnify the effect of gravity.

 

[materialsliz]

I second the resin viscosity. There is a prepreg we use (customer specified) whose resin system runs like water during cure. We completely enclose the part on the mold with release film and seal it inside with tape. If it leaks we get porous parts.