Im wondering if anyone could offer some advice here…
Im looking to make a few tubes for a project that use both round and oval tubes. I’ve made multiple samples of the oval and each one seems to have issues with creasing and rippling. Ive been using shrink tape ( various types) aswell as bagging , and ive gone through the process of changing the pitch on the tape, debulks,and cure temperatures but i seem to keep having the same issues on the oval. I understand why im getting some pinholes on the flatter sections as the tape is pinching around the tighter radius on the edges and less pressure on the top and bottom but the creasing is more like material bunching. Im guessing this is due to to the material being roll wrapped with an element of air and non tensioned wraps then its trying to become smaller around the circumference during the cure and the excess needs somewhere to go as it retracts? but is there any way to fix this issue whilst keeping the male mandrel/shrink tape procedure? or is female tooling and oven/clave curing the only answer?
the layup consists of 10 layers of 0 and 90 UD and 2x2 twill. I normally debulk the first layer and then additional debulks every 3-4 layers…
Any suggestions or advice would be much appreciated! who would of thought a tube could be so tricky…!
