Abstract: A curable sheet-like composite material comprising curable resin and at least one layer of structural fibers and comprising an outer backing layer of substantially resin-free material which is gas permeable but is substantially non-permeable with respect to the curable resin at room temperature.

Abstract: A resin composition for producing a composite part, comprising a first resin component comprising a glycidyl ether epoxy resin, a second resin component comprising a naphthalene based epoxy resin, and an amino-phenyl fluorene curative; wherein the epoxy resin components a) and b) contain up to 33 wt % of the second resin component.

Abstract: Semi-preg material is disclosed adapted for use in composite material comprising a) a first resin layer, b) covered on both side by layers of fibrous reinforcements whereby c) one of the two fabric layers is coated with a second resin layer and d) wherein said second resin layer has a tack level of not more than 100 N. Such semi-preg material has improved handling properties and contributes to the superior mechanical properties of the composite material formed therewith.

Abstract: A method of controlling a process for the manufacture of a multicomponent sheet material having a desired pre-determined parameter comprising applying an acoustic or an electromagnetic signal to interact with the sheet material whereby the interaction modifies the applied signal, detecting the modified signal, comparing the modified signal or data derived from it with data relating to the pre-determined parameter and modifying at least one step of the process whereby the data relating to the modified signal is modified towards the data relating to the pre-determined parameter.

Abstract: A composite material, the composite material comprising at least one prepreg, said prepreg comprising at least one polymeric resin and at least one fibrous reinforcement; and conducting particles dispersed in the polymeric resin.

Abstract: A composite structure (10) comprising one or more electrically conductive pathways (12) and one or more isolators for isolating the pathways (12) from the bulk of the structure (10).

Abstract: A non-fibrous, apertured membrane comprises at least one thermoplastic polymeric material and has a discrete porous structure. The membrane is soluble in the thermoset matrix polymer of a composite material.

Abstract: A method of controlling a process for the manufacture of a multicomponent sheet material having a desired pre-determined parameter comprising applying electromagnetic energy to interact with the sheet material whereby the interaction modifies the applied energy, detecting the modified energy, comparing the modified energy or data derived from it with data relating to the pre-determined parameter and modifying at least one step of the process whereby the data relating to the modified energy is modified towards the data relating to the predetermined parameter.

Abstract: A tape for use in automated tape laying machines that includes a multi-layer substrate composed of a plastic layer that includes at least one plastic film having an outer film surface and an inner film surface. The plastic film is adhered to a fibrous layer so that the inner surface of the fibrous layer is bonded to the inner film surface. An uncured composite material layer composed of a fibrous reinforcement and an uncured resin matrix is releasably adhered to either the plastic layer surface or the outer fiber layer surface to provide a tape suitable for use in an automatic tape layer.

Abstract: The adhesion between an underlying composite material and its surface finish is increased by including an adhesion promoting layer at the interface where the uncured composite material and the surface finish meet during the lay up of the uncured composite assembly. The adhesion promoting layer includes a cure accelerating agent for the composite material matrix resin.

Abstract: A structural panel comprising an internal core material having first and second opposing faces, first and second face sheets bonded to the first and second opposing faces respectively, wherein the panel comprises an open-structured sheet, interposed between a first face of the core material and its respective face sheet and the panel comprises less than 200 gsm adhesive.

Abstract: A curable resin comprising a compound having the structure wherein each carbon 2, together with either its carbon 1 or carbon 3, are members of a fused cycloaliphatic ring, and when carbon 1 is a member of the ring so is N, and wherein each of the aliphatic or aromatic ring-member carbons may either be members of further fused cycloaliphatic rings or be bonded to a group selected from H or linear or branched C1 to C5 alkyl.

Abstract: A prepreg comprising a structural layer of packed unidirectional conductive fibres comprising thermosetting resin in the interstices, and a first outer layer of resin comprising thermosetting resin, and being essentially free of unidirectional conductive fibres, which when cured under elevated temperature, produces a cured composite material comprising a cured structural layer of packed unidirectional conductive fibres and a first outer layer of cured resin comprising unidirectional conductive fibres dispersed within.

Abstract: A cured or partly cured fiber reinforced sheet material comprising reinforcement fibres and a reinforcement resin material, wherein the reinforcement resin material comprises an epoxy resin having an epoxy equivalent weight in the range of from 50 to 250, preferably from 100 to 200, and an amine hardener, the sheet material comprising a surface structure for spacing the sheet material from adjacent moulding materials.

Abstract: Epoxy formulations comprising a polyfunctional epoxy resin, a phenoxy resin, a fire retardant, a toughener and a curative are provided as is their use in prepregs which are useful in the production of aircraft components particularly interior and external panels and sleeves for helicopter rotor blades.

Abstract: A resin material is provided which comprises at least one thermoset resin, carbon conductive additive material, and at least one thermoplastic polymer resin. The thermoplastic polymer resin dissolves in the thermoset polymer resin and phase separates upon cure. There is also provided a method of making the resin material, and additionally a composite material that comprising said resin material in combination with a fibrous reinforcement. The resin material and composite material may each be used in an uncured or cured form, and may find particular use as a prepreg material.

Abstract: The invention relates to a prepreg comprising a structural layer of conductive fibers comprising thermosetting resin in the interstices, and a first outer layer of resin comprising thermosetting resin, and comprising a population of conductive free filaments located at the interface between the structural layer and the outer resin layer which, when cured under elevated temperature, produces a cured composite material comprising a cured structural layer of packed conductive fibers and a first outer layer of cured resin, the outer layer of cured resin, comprising a proportion of the population of conductive free filaments dispersed therein, and to a process for manufacturing prepregs wherein the electrically conductive fibers pass a fiber disrupting means to cause a proportion of the fibers on an external face of the sheet to become free filaments.

Abstract: A process for the manufacture of a cured composite material, the process comprising the steps of blending together a liquid curable resin and a curing agent having a melting point greater than 100° C. to form a liquid blend of curable resin and curing agent, at least partially impregnating a structural fiber arrangement with the blended curable resin and curing agent to form a curable composite material, followed by curing the composite material by exposure to elevated temperature and at a pressure of no greater than 3 bar absolute to form a cured composite material.

Abstract: A prepreg comprising resin and at least one fiber layer and further comprising an electrically insulating layer and an electrically conducting layer is provided, and particularly wherein the conductive layer is at or near the top surface, beneath that is the insulating layer and beneath that is a fiber/resin interleaf structure.

Abstract: The invention provides a prepreg comprising matrix and fibers, having deposited thereon a plurality of regions raised at least 5 micrometers relative to the surface of the matrix, a method of preparing such a prepreg, a method of curing a laminate of a plurality of such preprags and the cured laminate produced by such a method.