Composite laminate having improved impact strength and the use thereof
AssigneeE. I. Du Pont de Nemours and Company
InventorsYong Wang, Haihua Shen, Yongchao Ma
Life of this patent
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Abstract
A composite laminate having improved impact strength, which comprises: a multilayer carbon fiber fabric, wherein said carbon fiber fabric may be a bidirectional weave or a unidirectional weave; a multilayer nonwoven mat, wherein said nonwoven mat is made of para-aramid; and cured epoxy resin, wherein said cured epoxy resin is made of the epoxy resin system designed for impregnation that immersed in the carbon fiber fabric layer and at least one layer of the nonwoven mat is sandwiched between two layers of carbon fiber fabric layer and both outer surface layers of the composite laminate are carbon fiber fabric layer.
Claims12
A composite laminate having improved impact strength, which comprises:
- (a) a multilayer carbon fiber fabric, wherein said carbon fiber fabric may be a bidirectional weave or a unidirectional weave;
- (b) a multilayer nonwoven mat, wherein said nonwoven mat is made of para-aramid;
- and
- (c) cured epoxy resin;
- wherein said cured epoxy resin is made of an epoxy resin system designed for impregnation is impregnated in the carbon fiber fabric layer and at least one layer of the nonwoven mat is sandwiched between two layers of carbon fiber fabric layer.
A method of preparing a composite laminate having improved impact strength comprises:
- (i) providing a multilayer carbon fiber fabric and multilayer nonwoven mat wherein said carbon fiber fabric may be a bidirectional weave or a unidirectional weave and said nonwoven mat is made of para-aramid;
- (ii) impregnating said carbon fiber fabric layer with an epoxy resin system designed for impregnation;
- (iii) locating at least one layer of impregnated carbon fiber fabric layer as a first outer surface layer;
- (iv) locating at least one layer of nonwoven mat and at least one layer of the impregnated carbon fiber fabric layer as a second outer surface layer in an alternating manner until the total thickness of the composite laminate becomes 0.5-30 mm to form a preform;
- (v) placing the preform obtained in step (iv) into a mold and closing the mold;
- (vi) optionally, applying a vacuum to said mold containing the preform to exclude air bubbles retained between the layers;
- (vii) autoclaving the preform obtained in step (iv) and step (vi) for 0.5-12 hours (autoclave rated for 0.2-5.0 MPa at 50-200° C.) until said epoxy resin system designed for impregnation is cured;
- and
- (viii) removing the preform from the mold when the temperature is dropped to room temperature in order to obtain the composite laminate.
Dependencies are inferred from the claim text.