Peel ply, method of surface preparation and bonding composite structures using the same
AssigneeCytec Technology Corp.
InventorsYiqiang Zhao, Dalip Kumar Kohli, Kunal Gaurang Shah
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Abstract
A resin-rich peel ply that does not leave behind residual fibers after peeling and can work well with different resin-based composite substrates. The resin-rich peel ply is composed of a woven fabric impregnated with a resin matrix different from the resin matrix of the composite substrate. The peel ply is designed such that, upon manual removal of the peel ply from the composite substrate's surface, a thin film of the peel ply resin remains on the composite substrate's surface to create a bondable surface capable of bonding with another composite substrate, but no fibrous material from the woven fabric remains on the same surface.
Claims16
A peel ply system for surface preparation of various composite substrates, said system comprising:
- (a) a composite substrate comprising reinforcing fibers impregnated with a cured, first resin matrix;
- and
- (b) a removable, resin-rich peel ply adhered to a surface of the composite substrate, said peel ply comprising a woven fabric impregnated with a cured, second resin matrix different from the first resin matrix,
- whereby, upon manual removal of the peel ply from the composite substrate's surface, a thin film of the second resin matrix remains on the composite substrate's surface to provide a bondable surface capable of co-bonding and secondary bonding with another composite substrate,
- wherein said second resin matrix is formed from a resin composition comprising:
- at least one epoxidized novolac resin having epoxy functionality of at least 2;
- di-functional epoxy resin selected from diglycidyl ethers of polyhydric phenols;
- tri-functional epoxy resin selected from triglycidyl ethers of aminophenols;
- a curing agent;
- and
- inorganic filler particles;
- wherein said peel ply has a resin content of at least 20% by weight based on the total weight of the peel ply, and
- wherein said woven fabric comprises a plurality of yarns woven in a weaving pattern, said yarns having warp tensile strength of ≧70 lbf/in, fill tensile strength of ≧40 lbf/in, warp linear mass density within the range of 50-250 deniers, and fill linear mass density within the range of 50-250 deniers.
Dependencies are inferred from the claim text.