Processing of composites with partial plies
Methods of forming a composite structure from a preform with a vent are presented. A preform comprises a plurality of sets of full length plies, a plurality of sets of partial plies alternating with the plurality of sets of full length plies, and a vent extending through the plurality of sets of partial plies.
1 . A method of forming a composite structure, the method comprising:
forming a preform having a number of vents and a plurality of plies, the plurality of plies including a plurality of sets of full length plies and a plurality of sets of partial plies, the number of vents extending through the plurality of sets of partial plies;
positioning a plug into a vent of the number of vents in the preform prior to performing debulk; and
performing debulk on the preform such that at least one of air, volatiles, or resin are drawn from the plurality of sets of partial plies through the number of vents and out of the preform.
2 . The method of claim 1 , wherein forming the preform having the number of vents comprises:
forming the plurality of plies including the plurality of sets of full length plies and the plurality of sets of partial plies, the plurality of sets of partial plies comprising a number of vent holes; and
laying up the plurality of plies on a tool to form the preform, including stacking the number of vent holes vertically to form the number of vents in the preform.
3 . The method of claim 2 , wherein laying up the plurality of plies comprises alternating sets of partial plies and sets of full length plies.
4 . The method of claim 1 , wherein forming the preform having the number of vents comprises:
forming the plurality of plies including the plurality of sets of full length plies and the plurality of sets of partial plies;
laying up the plurality of plies on a tool to form the preform; and
cutting the number of vents into the preform through the plurality of sets of partial plies and at least one full length ply of the plurality of sets of full length plies using a cutting tool.
5 . The method of claim 1 , wherein forming the preform having the number of vents comprises:
forming the plurality of plies including the plurality of sets of full length plies and the plurality of sets of partial plies;
laying up the plurality of plies on a tool to form the preform; and
pressing a plurality of pins through the plurality of sets of partial plies to form the number of vents.
6 . The method of claim 1 , wherein the number of vents extend through an entirety of the preform.
7 . The method of claim 1 , wherein the number of vents extend partially through the preform.
8 . The method of claim 1 further comprising:
positioning a release film over the preform prior to performing the debulk, the release film comprising a number of perforations positioned over the number of vents.
9 . The method of claim 1 further comprising:
curing the preform to form a laminate; and
cutting the number of vents out of the laminate.
10 . The method of claim 1 , wherein positioning a plug into a vent of the number of vents comprises placing the plug having a length substantially the same as a depth of the vent into the vent.
11 . The method of claim 1 , wherein the number of vents extending through the plurality of sets of partial plies comprises a number of holes extending in a through thickness direction of the preform, wherein at least one vent of the number of vents extends through each set of the plurality of sets of partial plies.
12 . The method of claim 1 , wherein the at least one of air, volatiles, or resin travel along a plurality of air paths formed by each set of partial plies of the plurality of sets of partial plies and through a vent of the number of vents to exit the preform during the debulk.
13 . The method of claim 12 , wherein the vent acts as a shared conduit through the preform for all sets of partial plies of the plurality of sets of partial plies.
14 . The method of claim 1 , wherein full length plies of the plurality of sets of full length plies extend out to edges of the preform, and wherein partial plies of the plurality of sets of partial plies do not extend to the edges.
15 . The method of claim 1 , wherein partial plies of the plurality of sets of partial plies are sealed by respective full length plies of the plurality of sets of full length plies positioned above and below the partial plies.
16 . The method of claim 1 , wherein the plug comprises a material configured to maintain its geometry during debulk and cure of the preform.
17 . The method of claim 1 further comprising:
preventing creation of a resin starved area in the preform using the plug while performing the debulk.
18 . The method of claim 1 further comprising:
preventing excess resin from leaving the preform using the plug while performing the debulk.
19 . The method of claim 1 further comprising:
positioning a release film, a breather, and a vacuum bag over the preform prior to performing the debulk.
20 . The method of claim 1 further comprising:
pressing a plurality of pins through the plurality of sets of partial plies to locally displace fibers of the plurality of sets of partial plies to form the number of vents.
21 . The method of claim 1 , wherein performing the debulk comprises performing a double vacuum debulk.