Bonding of composite materials
AssigneeCytec Industries Inc.
InventorsLeonard MacAdams, Dalip Kohli
Life of this patent
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Abstract
A method for surface preparation of composite substrates prior to adhesive bonding. A curable surface treatment layer is applied onto a curable, resin-based composite substrate, followed by co-curing. After co-curing, the composite substrate is fully cured but the surface treatment layer remains partially cured. The surface treatment layer may be a resin film or a removal peel ply composed of resin-impregnated fabric. After surface preparation, the composite substrate is provided with a chemically-active, bondable surface that can be adhesively bonded to another composite substrate to form a covalently-bonded structure.
Claims21
A method for surface preparation prior to adhesive bonding comprising:
- (a) providing a composite substrate comprising reinforcing fibers impregnated with a first curable matrix resin;
- (b) applying a surface treatment layer onto a surface of the composite substrate, said surface treatment layer comprising a woven fabric infused with a second curable matrix resin different from the first matrix resin, wherein the second matrix resin is formulated to cure at a slower rate than the first matrix resin;
- (c) co-curing the composite substrate and the surface treatment layer until the composite substrate is fully cured but the surface treatment layer remains partially cured;
- and
- (d) removing the surface treatment layer from the composite substrate's surface, leaving a thin film of partially cured matrix resin on the composite substrate's surface, said thin film providing a roughened, bondable surface with chemically-active functional groups.
A bonding method comprising:
- (a) providing a first composite substrate comprising reinforcing fibers impregnated with a first curable matrix resin;
- (b) applying a removable, resin-rich peel ply onto a surface of the first composite substrate, said peel ply comprising a woven fabric infused or impregnated with a second curable matrix resin, which is formulated to cure at a slower rate than the first curable matrix resin;
- (c) co-curing the first composite substrate and the peel ply until the first composite substrate is fully cured but the second matrix resin in the peel ply remains partially cured;
- (d) removing the peel ply from the first composite substrate's surface, leaving a thin film of partially cured second matrix resin on the first composite substrate's surface, said thin film providing a roughened, bondable surface with chemically-active functional groups;
- (e) joining the cured, first composite substrate to a second composite substrate with a curable adhesive film in between the composite substrates,
- wherein the curable adhesive film comprises chemically-active functional groups capable of reacting with the chemically-active functional groups on the bondable surface of the first composite substrate;
- and
- (f) curing the adhesive film to form a covalently bonded structure.
Dependencies are inferred from the claim text.