According to the present invention there is provided a flexible elongate composite comprising a core of flexible fibre material adhered to and encapsulated in a flexible polymeric matrix and at least one functional component incorporated in or applied to at least one of the core and the flexible polymeric matrix, wherein the functional component is selected from magnetically, electrically, thermally and strictively functional material.

By"strictively functional material"there is meant herein a material which changes its properties in response to the degree of strain applied to the material.

The functional component may be a passive component, for example for monitoring purposes, or may be an active component, for example for providing a signal in response to a detected event.

The core may comprise flexible fibre material selected from one or more of glass (including optical) fibres, carbon fibres, aramid fibres, polyethylene fibres,

silicon carbide fibres, boron carbide fibres, boron nitride fibres, and textile fibres.

The flexible fibres may be provided in one or more tows which may be of straight (i. e. unidirectional), twisted or braided form.

The flexible polymeric matrix may be adhered to the flexible fibre material of the core by means of an adhesive or by means of chemical bonding between material of the flexible polymeric matrix and the flexible fibre material.

The flexible polymeric matrix may be selected from an elastomer, thermoplastic plastics material and thermosetting plastics material.

Suitable elastomers may be selected from polyurethane and silicone rubber.

Suitable thermoplastic plastics materials may be selected from: polyethylene; polyamide materials such as nylon; methacrylate ; trimethylolpropane triacrylate; ethoxyethoxyethyl acrylate ; and polyvinyl chloride.

Flexibilised derivatives of thermoplastic plastics materials may also be provided.

Suitable thermosetting plastics material may be selected from vinyl esters, flexible derivatives of polyester resins, and flexibilised epoxy material.

The flexible polymeric matrix may be applied as a prepolymeric material which is subsequently polymerised,

such as by heating or by means of applied radiation, such as ultra-violet radiation.

Where the at least one functional component is a magnetically functional material, the functional component may be selected from magnetic material of hard or soft form. Hard magnetic materials remain magnetised whether in or out of a magnetic field, while soft magnetic materials lose their magnetism when removed from a magnetic field.

Where the at least one functional component is an electrically functional material, the functional component may be selected from electrically conducting material, dielectric material, electroluminescent material and electrochromic material. Dielectric materials are electrical insulators or semiconductors.

Electroluminescent materials generate light when in an electric field, while electrochromic materials change colour when in an electric field.

Where the at least one functional component is a thermally functional material, the functional component may be thermochromic material. Thermochromic materials change colour when heated.

Where the at least one functional component is a strictively functional material, the functional component may be selected from piezoelectric material, piezochromic material, magneto-strictive material and electro- strictive material. Piezoelectric materials generate electricity when stressed, while piezochromic materials change colour when stressed. Magneto-strictive materials change shape under the influence of a magnetic field,

while electro-strictive materials change shape under the influence of an electric field.

Material or materials of the functional component may be incorporated in the flexible polymeric matrix, or applied to the surface of the flexible polymeric matrix either directly, or in or on a flexible covering layer, adhered to the surface of the flexible polymeric matrix. Such layer may comprise a polymer material, such as polyurethane, polyethylene, polyvinyl chloride, polyamide or acrylate, material. An activator material for adhesion promotion may be applied to the surface of the flexible polymeric matrix prior to application of the layer.

The at least one functional component may be distributed uniformly or non-uniformly along the length of the composite and may be in the form of one or more bands or strips.

The at least one component may be arranged to provide coded data.

The functional monitoring purpose may include linear measurement, automatic line marking, surveying, pressure and stress sensing and dynamic profiling (where the rate at which the elongate composite is moved is determined).

The elongate composite may be in the form of a line or a tape, such as for use as a digital tape measure.

If required, at least one flexible final covering layer may be provided on the elongate composite, such as for protective or aesthetic purposes. Such at least one final covering layer may be coloured.

By means of the present invention, the at least one functional component is integrated in the flexible elongate composite, which is light in weight, durable and of high strength.

For a better understanding of the invention and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawing which is a perspective view of an embodiment of a flexible elongate composite according to the present invention.

Referring to the drawing, a flexible elongate composite in the form of a line 2, such as for use as a digital tape measure, an automatic line marker, or for surveying purposes, comprises a core 4 of flexible fibre material adhered to and encapsulated in a flexible polymeric matrix 6.

The core 4 suitably comprises flexible fibres of high strength selected from glass fibres, carbon fibres, aramid fibres, polyethylene fibres, silicon carbide fibres, boron carbide fibres, boron nitride fibres, and textile fibres.

The flexible fibres of the core 4 may be provided in one or more tows which may be of straight (i. e. unidirectional), twisted or braided form.

The flexible polymeric matrix 6 is arranged to adhere to the fibres of the core 4. Such adhesion may be by means of an adhesive material, but is most suitably by means of chemical bonding between material of the flexible polymeric matrix 6 and the flexible fibres of the core 4.

The flexible polymeric matrix comprises a suitably flexible elastomer, or a suitably flexible thermoplastic plastics material, or a suitably flexible thermosetting plastics material.

Suitable elastomers may comprise polyurethane or silicone rubber.

Suitable thermoplastic plastics materials may comprise: polyethylene; polyamide materials such as nylon; methacrylate ; trimethylolpropane triacrylate ; ethoxyethoxyethyl acrylate; or polyvinyl chloride.

Flexibilised derivatives of thermoplastic plastics materials may also be used.

Suitable thermosetting plastics material may comprise vinyl esters, flexible derivatives of polyester resins, or flexibilised epoxy material.

The flexible polymeric matrix 6 can be applied as a prepolymeric resin material which is subsequently polymerised, such as by heating or by subjecting it to radiation, such as ultra-violet radiation.

A flexible layer or coating 8, such as of a polymer material is adherently provided on the surface of the flexible polymeric matrix 6. Such layer 8 may suitably comprise a material such as polyurethane, polyethylene, polyvinyl chloride, polyamide or acrylate. An activator material for adhesion promotion may be first applied to the surface of the flexible polymeric matrix 6.

The flexible layer or coating 8 has applied thereto or incorporated therein at least one component 10 serving a

functional purpose. Such functional purpose may be active or passive and may be linear measurement, automatic line marking, surveying, pressure sensing or dynamic profiling. The line 2 can be in the form of a tape, such as for use as a digital tape measure.

The at least one functional component 10 may be distributed uniformly or non-uniformly along the layer or coating 8 and may be in the form of at least one band or strip, if required.

The at least one component 10 is selected from a magnetically functional material, an electrically functional material, a thermally functional material and a strictively functional material.

Where the at least one functional component is a magnetically functional material, the functional component may be selected from magnetic material of hard or soft form.

Hard magnetic materials include hard ferrites such as BaFe12Ol9 and SrFe12Ol9, rare earth magnetic materials such as NdFel4B, Sm2Co17 and SmCo5, and alnico. Hard magnetic materials can be used, for example, to encode information (e. g., as N-S pairs) onto carbon fibre or like line or tape material for use as a distance measuring device.

Such a distance measuring device may be, for example, a tape measure or a position sensing device employing quadrature sensing of the N-S pairs (for example to sense the length of line that has been paid out, as in smart fishing lines or nets or smart washing line).

Soft magnetic materials include soft ferrites (nickel- zinc or manganese-zinc ferrites), cobalt-based amorphous

alloys, iron, nickel, iron-silicon alloys, iron nickel alloys and iron cobalt alloys. Soft magnetic materials may be used, for example, as a transformer core material for flexible cloth-like transformers. The flexible elongate composite can be woven around the primary/secondary windings of an electrical transformer.

Where the at least one functional component is an electrically functional material, the functional component may be selected from electrically conducting material, dielectric material, electroluminescent material and electrochromic material.

Electrically conducting materials include metals (such as copper, silver, platinum and the like), semi-metals (such as graphite) and electrically conducting polymers. Such a flexible elongate composite is substantially stronger than copper wire and could be used, for example as a rope or tow line along which electrical power and/or signals can be passed or as a material with inherent lightning conducting properties.

Dielectric materials include PTFE (poly (tetrafluoroethylene)). It is possible to employ transmission line techniques to composites incorporating such materials to determine where the composite has been damaged (an electrical pulse is reflected from a point where a loss of dielectric material has occurred.

Electrochromic materials include light emitting polymers and liquid crystal materials. Electroluminescent materials include zinc sulphide. Electrically conducting paths along the flexible elongate composite can be used to stimulate an electrochromic or electroluminescent material to cause the composite to light up. Thus, the

composite can be used as a visual warning aid, as a visual enhancement for fences (especially electric fences), tow lines, ropes and the like which can be illuminated as and when required. Alternatively, the composite can be used for high strength displays such as sails, banners and the like.

Where the composite is used in the construction of a fence, especially an electric fence, the line is connected to a source of electric power to illuminate the fence at night and/or, in the case of an electric fence, additionally shows the fence is operational during hours of darkness.

An electroluminescent or electrochromic material is useful as the sleeving material for electrical wiring in order to provide a visual indication of when the wiring is live.

Where the at least one functional component is a thermally functional material, the functional component may be, for example, a thermochromic material.

Thermochromic materials include liquid crystal materials.

Composites incorporating thermochromic materials can be used, for example, to indicate the temperature of the composite.

There are many thermoelectric materials, examples including manganites ( (La, Sr, Ca) Mn03 and variations).

Flexible elongate composites incorporating such materials can be used, for example, to monitor change in electrical properties (e. g., resistance, impedance, etc.) with temperature such as for distributed (i. e., not at a

single point) temperature monitoring or detection of a threshold temperature.

Similarly, an thermochromic or thermoelectric material can be employed in the line attached to a weather balloon for providing a continuous indication of temperature.

Where the at least one functional component is a strictively functional material, the functional component may be selected from piezoelectric material, piezochromic material, magneto-strictive material and electro- strictive material.

Piezoelectric materials include lead zirconate titanate (PZT) (Pb (Zr, Ti) 03), lead titanate (PbTiO3) and poly (vinylidenefluoride) (PVDF). A flexible elongate composite can incorporate a piezoelectric material if the core serves as one electrode and the composite incorporates a further, outer layer, which could for example be sputtered onto the surface of the composite, to serve as the other electrode. Such a composite can be used to measure transverse stress/pressure experienced by the composite, which may be in the form of, for example, a fishing line, fence material or measuring line or tape.

The stress/pressure could be used for monitoring the condition of the composite and/or for detection purposes (such as when a net made of the composite is impacted by a large object).

Piezochromic materials include polydiacetylene polymers, polysilanes and polyalkysilanes. In the case of a flexible elongate composite incorporating such materials stress will cause a change in the colour of the piezochromic material and the composite can be used as a visual monitor of the condition of a line (for fishing,

measuring, fencing or the like) and/or the stress experienced by the line and/or as a visual detection device.

Thus, where a piezochromic material is used in the construction of a fence, the colour of the line indicates which parts of the fence are under most stress and therefore in danger of breaking and allowing the undesired passage of people and/or animals. Such a material is also be useful in conjunction with electrical wiring: an indication of a region of stress may well correspond to a break in the electrical conductor. A piezochromic material can usefully be incorporated into a sail so as to indicate the pressure distribution across the sail: this enables the helmsman to adjust the sail for improved performance.

Magneto-strictive materials include terfenol (Tro. 27Dyo. 73Fe2), SmFe2 and nickel. A change in magnetic induction of a composite incorporating such a material can be detected by magnetic field sensors (e. g., pick-up coils) close to the composite and thus the composite can again be used for condition monitoring and detection purposes.

Electro-strictive materials include lead magnesium niobate-lead titanate (PMN-PT) (Pb (Mg, Nb) 03-PbTiO3).

Composites incorporating electro-strictive materials can be used in the same way as composites incorporating piezoelectric materials.

Such at least one component 10 may be addressed visually or by external monitoring means (not shown) of well known form.

Instead of the at least one component 10 being provided on or in the layer or coating 8, it could be incorporated in, or applied directly to the surface of, the flexible polymeric matrix 6.

At least one flexible final covering layer 12 can optionally be provided, suitably comprising a polymer material. Such at least one layer 12 may be coloured and may serve to protect the line 2, such as against abrasion or against degradation resulting from exposure to water or ultra-violet radiation.

The resulting flexible elongate composite line 2 has high tensile strength and axial stiffness, high durability, low thermal expansion, light weight, and low bend radius.