Large composite core structures formed by vacuum assisted resin transfer molding
First Claim
1. A method of forming a composite structure comprising:
- providing a plurality of cores each having a peripheral surface, the cores including spaces therebetween and arranged in at least one row to form a layer having an upper surface and a lower surface;
covering at least the upper surface of the layer with a fiber material;
providing a resin distribution network of channels arranged to distribute uncured resin throughout the fiber material and the spaces between the cores;
providing a feeder channel in fluid communication with the resin distribution network, the feeder channel having a larger cross-sectional area than individual ones of the channels of the resin distribution network;
sealing the cores and the fiber material with the resin distribution network and the feeder channel in a forming structure, at least a first portion of the forming structure comprising a mold surface and at least a further portion of the forming structure comprising a flexible portion collapsible under vacuum against an adjacent portion of the cores and the fiber material;
connecting a source of uncured resin through the flexible portion to the feeder channel;
connecting the interior of the forming structure to a vacuum outlet;
forcing the uncured resin under vacuum through the feeder channel and the resin distribution network to fill the forming structure to impregnate the fiber material and the spaces between the cores with the resin; and
curing the resin to form a composite structure.
4 Assignments
0 Petitions
Accused Products
Abstract
Large composite structures are produced using a vacuum assisted resin transfer molding process. The structures incorporate cores, which may be hollow cells or foam blocks. A plurality of cores, each of which may be wrapped with a fiber material, is arranged in a layer on a mold with a fiber material arranged to form face skins. The assembly is sealed under a vacuum bag to a mold surface. One or more main feeder conduits are provided in communication with a resin distribution network of smaller channels which facilitates flow of uncured resin into and through the fiber material. The resin distribution network may comprise a network of grooves formed in the surfaces or the cores and/or rounded corners of the cores. The network of smaller channels may also be provided between the vacuum bag and the fiber material, either integrally in the vacuum bag or via a separate distribution medium. Resin, introduced under vacuum, travels relatively quickly through the main feeder channel(s) and the network of smaller channels. After penetrating the fiber material to reach the surface of the cores, the resin again travels relatively quickly along the cores via the grooves in the cores or the spaces provided by the rounded corners to penetrate the fiber material between the cores, if present, and between the cores and the mold.
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Citations
26 Claims
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1. A method of forming a composite structure comprising:
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providing a plurality of cores each having a peripheral surface, the cores including spaces therebetween and arranged in at least one row to form a layer having an upper surface and a lower surface; covering at least the upper surface of the layer with a fiber material; providing a resin distribution network of channels arranged to distribute uncured resin throughout the fiber material and the spaces between the cores; providing a feeder channel in fluid communication with the resin distribution network, the feeder channel having a larger cross-sectional area than individual ones of the channels of the resin distribution network; sealing the cores and the fiber material with the resin distribution network and the feeder channel in a forming structure, at least a first portion of the forming structure comprising a mold surface and at least a further portion of the forming structure comprising a flexible portion collapsible under vacuum against an adjacent portion of the cores and the fiber material; connecting a source of uncured resin through the flexible portion to the feeder channel; connecting the interior of the forming structure to a vacuum outlet; forcing the uncured resin under vacuum through the feeder channel and the resin distribution network to fill the forming structure to impregnate the fiber material and the spaces between the cores with the resin; and curing the resin to form a composite structure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification