Porosity and delam at joggle area-help needed

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Porosity and delam at joggle area-help needed

http://www.talkcomposites.com/Topic22964.aspx

By ejump80 - 3/18/2017 7:12:52 PM

Hi all,

I'm working with the part ( refer pic) that has joggle area.

After cure, this part easily create a porosity and delam at this area. I believe it is because of the bridging between the first and second ply carbon woven. As in pic, we put peel ply to bleed the excess resin betwen the first and two plies.

Also in final bag, we cut off the N10 bagging at the radiius to minimize the bridging.But still the result is still inconsistent.

Need help.

Thanks

By ejump80 - 3/22/2017 12:34:05 PM

Below details of the product;

1) Sandwich panel-fabricate using carbon fiber reinforced prepreg,5HS fabric/280g/m2/180 deg curing with nomex core.

2) cure with 2 step cure cycle, dwell at 105 deg C for 30 minutes, then continue heat up at 180 deg C, stsrt 2nd dwell when reach 175deg c for 160 minutes then start cool down until 60 deg C

.Full vacuum start cure and reduce until -0.2bars when pressure reach 1.4bar.

Cure pressure 3 bars

3)Tool made from nickel

Currently, we have problem at the joggle area because the 1st and 2nd layer plies lack of contact on the mould surface which create bridging and delamination.