Patent Description:
Embodiments of the present invention relate to composite twisted elongate elements, such as tapes or yarns, which may be used to produce a fabric or material incorporating similar or dissimilar materials in the warp and weft, such fabric being suitable for consolidating into single layer or multilayer shells or structures, e.g. under the action of heat and pressure without the need for additional resin or adhesive.

Self-reinforcing polypropylene (srPP) fabric is known. Such is marketed by the present Applicant under the brand names ARMORDON ® or TORODON ®. Similar materials are available from other companies, e.g. CURV ® from Propex and PURE ® from DIT.

<CIT> (DON & LOW) discloses a thermoplastic composite material or tape comprising a molecularly-oriented thermoplastic polymer base having at least one thermoplastic surface polymeric layer compatibly bonded to said polymer base by molecular interspersion between the contiguous surfaces of the adjoining base and surface layers, and said surface polymeric layer having a softening temperature lower than that of the polymer base.

<CIT> (DON & LOW) discloses a fabric or material comprising: at least first elongate elements and second elongate elements that are mutually interspersed; wherein the first elongate elements comprise a polymer base and at least one polymeric surface layer, wherein the at least one polymeric surface layer has a softening temperature lower than that of the polymer base; and wherein at least a surface of the second elongate elements comprises an ultra high molecular weight polyalkylene (UHMWPA), wherein the ultra high molecular weight polyalkylene is a material dissimilar to the polymeric surface layer, and the first elongate elements are fusible together with the second elongate elements at least at intersections.

By "molecular interspersion" is meant the intimate molecular compatibility of molecules of the surface layer and the adjacent polymer and vice versa, so that there is intermingling or fusion at their contiguous boundaries. It is believed that such molecular interspersion effectively forms an amorphous sheath which protects the polymer base against fracture during drawing, thus providing mutual mechanical reinforcement.

<CIT> discloses a yarn comprising a multifilamentary core, comprising many filaments of material of lower melting point, wrapped by at least one and preferably two multifilamentary strands, each also comprising filaments of material of higher melting point.

<CIT> discloses a string made of a core comprising a plurality of low melt twisted filamentous strands which is then provided with a high melt sheath on its outer side.

Mutual mechanical reinforcement involves the surface material being capable of high elongation when drawn in the solid state (or even being drawn at a temperature above its softening point, i.e. in the molten state). With a polymer layer of high modulus, and crystalline or oriented material sandwiched between amorphous high elongation surface layers, propagation of transverse fractures is inhibited allowing the total composite to be highly drawn.

A problem exists in the prior art. Single ribbon tapes of co-extruded polymer are used as warp and weft to weave fabrics. These fabrics are then layered up and hot pressed to make shaped articles. When those articles are subjected to shock loads then an article may fail due to delamination between consolidated fabric layers.

Coextruded yarns of thermoplastic polymers of at least A-B construction, where A has a melting temperature at least <NUM> below that of B can be formed into fabrics eg. woven fabrics, which can, in turn, be formed into three dimensional shaped articles under the influence of heat and pressure without the need for additional adhesives or films. However, these yarns can be limited in their ratio of A to (A+B) to between <NUM> to <NUM>% or less, more typically <NUM> to <NUM>% or less. This can limit the strength of bonding of the tape or yarn both internally to itself and also externally to other materials. A fabric can be made from said tapes or yarns, e.g. by weaving, which is capable of being formed into <NUM> or <NUM> dimensional items under the action of heat and pressure both by itself and in conjunction with dissimilar materials. The bond strength of such fabric can be limited.

It is an object of at least one embodiment of at least one aspect of the present invention to obviate or at least mitigate one or more problems or disadvantages in the prior art.

It is an object of at least one embodiment of at least one aspect of the present invention to provide a fabric or material that may be formed without the use of, for example, a resin matrix material, a film, or an adhesive. The fabric or material may, therefore, be self-adhering or self-supporting.

It is an object of at least one embodiment of at least one aspect of the present invention to provide a single layer fabric or material which has sufficient impact resistance for use in a formed article, e.g. a suitcase shell.

It is an object of at least one embodiment of at least one aspect of the present invention to provide a laminated fabric or material which has sufficient impact resistance for use in a formed article, e.g. a suitcase shell, and which has a reduced number of layers compared to the prior art.

According to a first aspect of the present invention there is provided a composite twisted elongate element comprising a plurality of elongate elements twisted together and which comprise at least one first elongate element and at least one second elongate element, wherein each of said plurality of elongate elements is substantially planar prior to twisting, the at least one first elongate element consists of a single homogeneous layer consisting of a first thermoplastic polymeric material A and the at least one second elongate element consists of a single homogeneous layer consisting of a second molecularly-oriented thermoplastic polymeric material B. The melting point or softening point of the first polymeric material is at least <NUM> less than the melting point or softening point of the second polymeric material, and the first and second polymeric materials are capable of being autogeneously bonded.

The Inventors believe that (composite and/or non-coextruded twisted) elongate elements according to the present invention may provide benefit/advantage over prior elongate elements comprising coextruded elongate elements, e.g. of the construction A-B or A-B-A, where B comprises a polymeric base or substrate and A comprises at least one polymeric surface layer or opposing polymeric surface layers.

Herein, 'composite elongate element' is meant to comprise or include a plurality of elongate elements, yarns, tapes, strands, plies, or fibres that are twisted together.

It has been found that twisting together of the plurality of elongate elements (e.g. along their length) may provide advantage over the prior art, e.g. weaving together of single yarns. An advantage may be beneficial increased distribution of the first polymeric material throughout a matrix of a material or fabric, e.g. a woven material.

In the present invention, the first polymeric material may comprise a first polyolefin.

The second polymeric material may comprise a second polyolefin.

The first polymeric material acts as a matrix binder or adhesive agent within the material or fabric. The second polymeric material acts as a strengthening or integrity providing agent within the material or fabric.

Each of the plurality of elongate elements and/or the composite elongate elements may have tensile strength, but may be too flexible to provide compressive strength. The/each of the plurality of elongate elements and/or composite elongate elements may be coilable or reelable. The composite elongate element(s) may be capable of being woven.

The composite twisted elongate elements may be twisted or 'laid' together.

In one preferred implementation, the second polymeric material may comprise polypropylene, e.g. polypropylene homopolymer.

In said preferred implementation, the first polymeric material may comprise polyethylene, e.g. polyethylene homopolymer.

The composite twisted elongate element may comprise one or more first elongate elements twisted together with one or more second elongate elements.

In a first embodiment the composite twisted elongate element may comprise a first elongate element twisted together with a second elongate element.

In a second embodiment the composite twisted elongate element may comprise one first elongate element twisted together with two second elongate elements.

In a third embodiment the composite twisted elongate element may comprise one first elongate element twisted together with three second elongate elements.

In a fourth embodiment the composite twisted elongate element may comprise one or more first elongate elements twisted together with one or more second elongate elements so as to form a composite twisted elongate element, and two or more of said composite twisted elongate elements are twisted together. In such arrangement there is provided a first twist between the first and second elongate elements. In such arrangement there is provided a second twist between the two or more composite twisted elongate elements.

In any of the above embodiments the first and second elongate elements may have a similar or substantially the same tex (mass in grams per <NUM>,<NUM> metres), e.g. <NUM> to <NUM> grams/<NUM>,<NUM> metres, or <NUM> to <NUM> grams/<NUM>,<NUM> metres). There may be provided <NUM> to <NUM>, e.g. <NUM> to <NUM>, e.g. <NUM> to <NUM> twists/turns per metre (tpm), and preferably around <NUM> tpm, along a length of the composite twisted elongate element and/or each of the plurality of elongate elements.

In one embodiment of the present invention the plurality of elongate elements may comprise two elongate elements. In another embodiment of the present invention the plurality of elongate elements may comprise three elongate elements. Alternatively, the plurality of elongate elements may comprise more than three elongate elements.

The plurality of elongate elements may be twisted together in a left-handed or S-twist or in a right-handed or Z-twist (according to ISO <NUM>).

In one implementation each of the plurality of (e.g. first and/or second) elongate elements may be a tape, orior to twisting.

Each of the plurality of elongate elements may be an extruded tape, for example, made by an extrusion process.

Advantageously the at least one second elongate element may comprise a self-reinforcing polymeric material such as self-reinforcing polypropylene (srPP).

The/each at least one second elongate element may be selected from polypropylene, polyesters, polyethyleneterephthalate, polyamides, Nylon (e.g. Nylon <NUM> or <NUM>), or a polyethylene, e.g. having a density in the range <NUM> to <NUM>, or linear low density polyethylene.

The second polymeric material may comprise a molecularly-oriented polyolefin polymer, such as a polypropylene polymer.

The first polymeric material may comprise ethylene-propylene co-polymer, polybutylene, polybutene-<NUM> or a co-polymer comprising two or more of butylene, ethylene and propylene, co-polyesters and co-polyamides.

The second polymeric material may comprise polypropylene and/or the first polymeric material may comprise an ethylene-propylene co-polymer, a polybutylene such as polybutene-<NUM> or a co-polymer comprising two or more of butylene, ethylene and propylene.

The second polymeric material may comprise polyester and/or the first polymeric material may comprise a co-polyester, or the second polymeric material may be a polyamide and the first polymeric material may comprise a co-polyamide.

According to a second aspect of the present invention there is provided a material or fabric, comprising at least one composite twisted elongate element according to the first aspect of the present invention.

The material or fabric may comprise a plurality of composite twisted elongate elements according to the first aspect of the present invention.

The material or fabric may advantageously comprise a single layer of material or fabric. The material or fabric, e.g. advantageously single layer of material or fabric, may be consolidated or consolidatable, e.g. by application of heat and/or pressure. The material or fabric of the present invention has been found to possibly provide advantages over the prior art, e.g. it has been found that since a single layer of the material or fabric may be heavier than a single layer of single yarn weave of the prior art, whereas in the prior art single layers have been laminated together to provide a suitable material for forming of a product, a single layer of fabric of the present invention suffices. This may avoid the need for lamination, so simplifying the manufacturing process and/or obviating and/or mitigating the problem of delamination.

The material or fabric may also comprise a plurality of further elongate elements, e.g. twisted elongate elements, which may be polymeric. The plurality of further elongate elements may beneficially be the same as the plurality of composite twisted elongate elements.

The plurality of composite twisted elongate elements and plurality of further elongate elements may be mutually interspersed.

At least some of the further elongate elements may comprise a material or materials similar or dissimilar to the first polymeric material.

Adjacent, e.g. side-by-side, overlaid, cross-laid or intersecting, elongate elements may be fusible together at least at intersections.

Fusing may comprise heating the fabric above the melting temperature of the first polymeric material A, e.g. at a temperature between MPA and MPB. Fusing may comprise cooling the fabric to allow the surface layer to solidify. Fusing the elements may comprise subjecting the fabric to pressure. Fusing may be achieved by single closure press with flat or contoured plates, continuous belt press, induction heated press or via vacuum bagging and autoclaving.

The material or fabric may comprise a woven material or fabric.

The material or fabric may comprise at least one mat of mutually intersecting composite twisted elongate elements fusible together at least at their intersections.

Preferably the thermoplastic material or fabric may comprise a consolidated mat or sheet, wherein the plurality of composite twisted elongate elements may have been consolidated together, e.g. by application of heat and/or pressure.

Preferably the fabric or material may be formed without the use of, for example, a resin matrix material, a film or an adhesive.

The further elongate elements may be selected from tapes, threads, fibres, filaments, strands, or the like.

The further elongate elements may comprise a single layer and/or homogenous layer.

The further elongate elements may comprise a material similar or dissimilar to the first polymeric material.

The elongate elements and the further elongate elements may be formed as tapes.

The composite twisted elongate elements and/or further elongate elements may be woven, knitted, stitched, or may be laid out to form a random fibrous web or may be randomly interspersed to form the material.

Beneficially, the composite twisted elongate elements and/or further elongate elements may be woven together to form a fabric.

The composite twisted elongate elements and further elongate elements may be woven together to form the fabric or material. The warp may be formed of composite twisted or further elongate elements and the weft may be formed of the other. The warp may be formed of composite twisted elongate elements and the weft may be formed of further elongate elements. Alternatively, the warp may be formed of further elongate elements and the weft may be formed of composite twisted elongate elements.

Alternatively, the composite twisted and further elongate elements may be woven together to form the fabric or material, and the warp and/or the weft may comprise a mixture of composite twisted and further elongate elements. The mixture of composite twisted and further elongate elements may be a random arrangement of composite twisted and further elongate elements. Alternatively, the mixture of composite twisted and further elongate elements may be a regular alternation of composite twisted and elongate elements.

Alternatively warp and weft may comprise, e.g. solely comprise, the composite twisted elongate elements.

The further elongate elements may comprise one or more of: polyesters, polyamides, aramids, thermoplastic polymers, molecularly-oriented thermoplastic polymers, ultra high molecular weight polyalkylenes (UHMWPA), such as ultra high molecular weight polyethylene (UHMWPE) or ultra high molecular weight polypropylene (UHMWPP), multifilament nucleated polypropylenes, and/or carbon fibres.

The further elongate elements may be formed of hybrid yarns.

The hybrid yarns may be formed of at least two different materials or fibres comprising polyesters, polyamides, aramids, thermoplastic polymers, molecularly-oriented thermoplastic polymers, ultra high molecular weight polyalkylenes (UHMWPA), such as ultra high molecular weight polyethylene (UHMWPE) or ultra high molecular weight polypropylene (UHMWPP), multifilament nucleated polypropylenes, and/or carbon fibres.

The further elongate elements may be formed of hybrid yarns selected from hybrid yarns comprising aramids and UHMWPE or hybrid yarns comprising polypropylene.

The further elongate elements may comprise or consist of ultra high molecular weight polyalkylenes selected from UHMWPE or UHMWPP.

According to a third aspect of the present invention there is provided a laminated material, such as a rigid and/or self-supporting laminated material, comprising a plurality of layers, wherein at least one of said layers comprises a material or fabric according to the second aspect of the present invention.

In one implementation the laminated material comprises two layers, e.g. only two layers, or three layers, e.g. only three layers.

Preferably each layer comprises a material or fabric according to the second aspect of the present invention.

According to a fourth aspect of the present invention there is provided an article, such as a formed and/or three-dimensional and/or rigid and/or self-supporting article, formed from a (single layer of) material or fabric of the second aspect of the present invention, or alternatively formed from a laminated material of the third aspect of the present invention.

The article may be formed by a moulding technique, e.g. press-moulding.

The article may be capable of withstanding relatively high impact, i.e. the article may have high impact resistance properties.

The article may comprise a luggage shell, e.g. a shell for a suitcase, or at least part of a container.

The article may comprise or be selected from: an armour product, e.g. body armour, an automotive (vehicle) component, a sportswear product.

The article may be adapted for antiballistic purposes and/or comprises bulletproof vests, body armour, panels suitable for the protection of vehicles, such as military and/or commercial vehicles, bin liners, blast basket or blast blankets to contain fragmentation debris from the detonation of explosive devices.

The article may find use as carpet backing which may be used in automotive or aerospace application, or which may comprise panels suitable for use on automotive vehicles.

The article may comprise a toe-cap(s) for protective footwear, connecting straps of handles of intermediate bulk containers or the containers themselves, tarpaulins, packaging, luggage, protective cases, pipes.

According to a fifth aspect of the present invention there is provided a method of forming a composite twisted elongate element, the method comprising:.

According to a sixth aspect of the present invention there is provided a method of forming a fabric or material, the method comprising:.

Said fabric or material may comprise a sheet or mat.

Said step of providing may also comprise providing a plurality of further elongate elements, which may be polymeric.

Said step of forming may comprise weaving.

In such case, the plurality of composite twisted elongate elements may comprise warp yarns. Alternatively or additionally, the plurality of composite twisted elongate elements may comprise weft yarns.

The method may further comprise the (subsequent) step of consolidating the fabric or material, e.g. single layer fabric or material, by application of heat and/or pressure.

According to a seventh aspect of the present invention there is provided a method of forming an article, such as a three-dimensional and/or rigid and/or self-supporting article, comprising the steps of:.

Embodiments of the present invention will now be described by way of example only, with reference to the accompanying drawings, which are:.

Referring to <FIG>, there are shown first to fourth embodiments of a composite twisted elongate element <NUM>; 5a to 5d, comprising a plurality of elongate elements <NUM> twisted together and which comprise at least one first elongate element <NUM> and at least one second elongate element <NUM>, wherein each first elongate element <NUM> consists of a first polymeric material A and each second elongate element <NUM> consists of a second polymeric material B.

The Inventors believe that composite twisted elongate elements according to the present invention provide benefit/advantage over prior art elongate elements comprising coextruded elongate elements, e.g. of the construction A-B or A-B-A, where B comprises a polymeric base or substrate, and A comprises at least one polymeric surface layer or opposing polymeric surface layers.

It has been found that twisting together of the plurality of elongate elements (e.g. along their length) provides advantage over the prior art, e.g. weaving together of single yarns. An advantage is believed to be beneficial increased distribution of the first polymeric material throughout a matrix of a material or fabric, e.g. a woven material.

In the present invention, the first polymeric material A comprises a first polyolefin. The second polymeric material B comprises a second polyolefin.

The first polymeric material A acts as a matrix binder or adhesive agent within the material or fabric. The second polymeric material B acts as a strengthening or integrity providing agent within the material or fabric.

Each of the plurality of elongate elements <NUM> and/or the composite elongate elements <NUM>; 5a to 5d have tensile strength, but are too flexible to provide compressive strength. The/each of the plurality of elongate elements <NUM> and/or composite elongate elements <NUM>; 5a to 5d are coilable or reelable. The composite elongate element(s) <NUM>; 5a to 5d are capable of being woven. The elongate elements <NUM>; <NUM>; 5a to 5d are twisted or 'laid' together.

The first polymeric/polyolefinic material and the second polymeric/polyolefinic material are dissimilar, i.e. dissimilar polymers/polyolefins. The melting point or softening point MPA of the first polymeric material is lower than the melting point or softening point MPB of the second polymeric material. The first and second polymeric materials are thermally compatible, and capable of being autogenously bonded. The melting point MPA of the first polymeric material is at least <NUM> less than the melting point MPB of the second polymeric material.

The first elongate element(s) <NUM> solely consist of the first polymeric material A, e.g. a first homopolymer. The second elongate element(s) <NUM> solely consist of the second polymeric material B, e.g. a second homopolymer. The first elongate element(s) <NUM> comprise a single homogeneous layer. The second elongate element(s) <NUM> comprise a single homogeneous layer.

In one preferred implementation, the second polymeric material comprises polypropylene, e.g. polypropylene homopolymer. In said preferred implementation, the first polymeric material comprises polyethylene, e.g. polyethylene homopolymer. As can be seen from <FIG>, the elongate element <NUM>; 5a to 5d comprises one or more first elongate elements <NUM> twisted together with one or more second elongate elements <NUM>.

In said preferred implementation, the second elongate element is: extruded, made from polypropylene, highly drawn, has molecularly aligned polymer chains, and/or has a melting point (MPB) of <NUM> or higher. Also, the first elongate element is: extruded and/or made from polyethylene. The first elongate element need not be highly drawn to achieve molecular alignment. This is because the first elongate element melts away, in use, to form a matrix material, and if there is not molecular alignment, material shrinkage can be avoided. The first elongate element is sacrificially melted in the elongate element or fabric or article made therefrom. The polyethylene has a melting point MPA of around <NUM>.

In a first embodiment (see <FIG>) the elongate element 5a comprises a first elongate element <NUM> twisted together with a second elongate element <NUM>. In said first embodiment, first elongate element <NUM> can be twisted together with a second elongate element <NUM>, e.g. of the same or similar tex (mass in grams of <NUM>,<NUM> metres). The twist level is typically between <NUM> and <NUM> turns per metre, preferably around <NUM> tpm. The resultant twisted element can be used to construct a fabric, e.g. a woven fabric. Said woven fabric made from said elements can then be formed into a three dimensionally formed article by the action of heat and pressure in a mould, said article then being cooled in the mould prior to release. Thus forming can be of a single layer of fabric or of multiple layers of fabric. The resultant article can then display superior lamination strength versus a similar fabric formed only from conventionally coextruded A-B or A-B-A tapes or yarns with a lower ratio of A to (A+B), e.g. <NUM>% versus <NUM>% for the present invention.

In a second embodiment (see <FIG>) the elongate element 5b comprises one first elongate element <NUM> twisted together with two second elongate elements <NUM>. In said second embodiment two tapes of type B are twisted with a single tape of type A of similar tex to yield a twisted tape equivalent to <NUM>% cap layer (ratio of A to (A+B)).

In a third embodiment the elongate element 5c comprises one first elongate element <NUM> twisted together with three second elongate elements <NUM>. In said third embodiment three tapes of type B are twisted with a ratio single tape of type A of very similar tex to yield a twisted tape equivalent to <NUM>% cap layer (ratio of A to (A+B)), which is around twice that which can be achieved with conventionally coextruded A-B or A-B-A tapes or yarns.

In a fourth embodiment the elongate element 5d comprises one or more first elongate elements <NUM> twisted together with one or more second elongate elements <NUM> so as to form a composite twisted elongate element 5a, and two or more of said composite twisted elongate elements are twisted together.

In such arrangement there is provided a first twist between the first and second elongate elements <NUM>, <NUM>. In such arrangement there is also provided a second twist between the two or more composite twisted elongate elements 5a. In said fourth embodiment one tape of type A is twisted with one tape of type B. Then, two of said twisted A-B tapes are further twisted together with each other to yield a composite tape of two B and two A type tapes.

The distribution of 'cap' layer A can thus be improved versus a typical side-by-side coextruded tape or yarn of A-B or A-B-A construction. Fabrics woven from said tapes, and articles processed from said fabrics may demonstrate superior internal bond strength or lamination strength due to the improved distribution of lower melt layer A.

In any of the above embodiments the first and second elongate elements <NUM>, <NUM> advantageously have a similar or substantially the same tex (mass in grams per <NUM>,<NUM> metres), e.g. <NUM> to <NUM> grams/<NUM>,<NUM> metres, or <NUM> to <NUM> grams/<NUM>,<NUM> metres). There is also advantageously provided <NUM> to <NUM>, e.g. <NUM> to <NUM>, e.g. <NUM> to <NUM>, twists/turns per metre (tpm), and preferably around <NUM> tpm, along a length of the composite twisted elongate element 5a - 5d and/or each of the plurality of elongate elements <NUM>, <NUM>.

It will be appreciated that, while in the first embodiment of the present invention, the plurality of elongate elements comprise two elongate elements, and in the second embodiment of the present invention the plurality of elongate elements comprise three elongate elements, in an alternative embodiment the plurality of elongate elements <NUM> can comprise more than three elongate elements <NUM>, <NUM>.

The plurality of elongate elements <NUM>, <NUM>; 5a to 5d can be twisted together in a left-handed or S-twist or in a right-handed or Z-twist (according to ISO <NUM>). According to the invention each of the plurality of elongate elements is planar, e.g. comprises a tape, prior to twisting. The/each elongate element <NUM>, <NUM> is an extruded yarn or tape, for example, made by an extrusion process.

Advantageously the at least one second elongate element <NUM> comprises a self-reinforcing polymeric material such as self-reinforcing polypropylene (srPP). Each elongate element <NUM>, <NUM> comprises a thermoplastic. Each second elongate element <NUM> comprises a molecularly-oriented thermoplastic polymeric material.

The/each at least one second elongate element <NUM> can be selected from polypropylene, polyesters, polyethyleneterephthalate, polyamides, Nylon (e.g. Nylon <NUM> or <NUM>), or a polyethylene, e.g. having a density in the range <NUM> to <NUM>, or linear low density polyethylene. The second polymeric material B comprises a molecularly-oriented polyolefin polymer, such as a polypropylene polymer. The first polymeric material A comprises a thermoplastic polymer. The first polymeric material A can comprise ethylene-propylene co-polymer, polybutylene, polybutene-<NUM> or a co-polymer comprising two or more of butylene, ethylene and propylene, co-polyesters and co-polyamides.

The second polymeric material B can be polypropylene and/or the first polymeric material A can comprise an ethylene-propylene co-polymer, a polybutylene such as polybutene-<NUM> or a co-polymer comprising two or more of butylene, ethylene and propylene.

The second polymeric material B can be polyester and/or the first polymeric material A can comprise a co-polyester, or the second polymeric material B can be a polyamide and the first polymeric material can comprise a co-polyamide.

The first polymeric material A is autogenously bondable with the second polymeric material B. The second polymeric material B has a softening point of <NUM> or more higher than the softening point of the first polymeric material A.

Referring now to <FIG>, there is shown a material or fabric <NUM>, such as a thermoplastic composite material according to an embodiment of the present invention, comprising at least one elongate element 5a to 5d of <FIG>.

The material or fabric <NUM> comprises a plurality of composite twisted elongate elements <NUM>; 5a to 5d.

The material or fabric <NUM> advantageously comprise a single layer of material or fabric <NUM>. The material or fabric <NUM>, e.g. advantageously single layer of material or fabric, can be consolidated or is consolidatable, e.g. by application of heat and/or pressure. The material or fabric <NUM> has been found to possibly provide advantages over the prior art, e.g. it has been found that since a single layer of the material or fabric <NUM> can be heavier than a single layer of single yarn weave of the prior art, whereas in the prior art single layers have been laminated together to provide a suitable material for forming of a product, a single layer of material or fabric <NUM> of the present invention suffices. This can avoid the need for lamination, so simplifying the manufacturing process and/or obviating and/or mitigating the problem of delamination.

The material or fabric <NUM> can also comprise a plurality of further elongate elements <NUM>, e.g. twisted elongate elements, which are polymeric. The plurality of further elongate elements <NUM> can beneficially be the same as the plurality of composite twisted elongate elements 5a to 5d.

The plurality of composite twisted elongate elements 5a to 5d and plurality of further elongate elements <NUM> can be mutually interspersed. At least some of the further elongate elements <NUM> can comprise a material or materials similar or dissimilar to the first polymeric material.

Adjacent, e.g. side-by-side, overlaid, cross-laid or intersecting, elongate elements 5a to 5d can be fused together at least at intersections. Fusing can comprise heating the fabric above the melting temperature of the first polymeric material A, e.g. to a temperature between MPA and MPB. Fusing can comprise cooling the fabric to allow the surface layer to solidify. Fusing the elements can comprise subjecting the fabric to pressure. Fusing can be achieved by single closure press with flat or contoured plates, continuous belt press, induction heated press or via vacuum bagging and autoclaving.

<FIG> shows the fabric <NUM> after consolidation via a combination of heat and/or pressure. As seen from <FIG>, the fabric <NUM> comprises a woven fabric. The fabric <NUM> comprises at least one mat of mutually intersecting elongate elements 5a to 5d, <NUM> fusible together at least at their intersections.

The further elongate elements <NUM> can comprise a single layer or homogenous layer. The further elongate elements <NUM> can comprise a material or materials similar or dissimilar to the first polymeric material A. The composite twisted elongate elements 5a to 5d and the further elongate elements <NUM> are formed as tapes. The elongate elements <NUM>, <NUM>; 5a to 5d comprise one or two surface layers or two opposing surface layers.

The material or fabric <NUM> typically comprises a woven material or fabric. The material or fabric <NUM> can comprise at least one mat of mutually intersecting elongate elements fusible together at least at their intersections. The thermoplastic material or fabric <NUM> comprises a consolidated mat or sheet, wherein the plurality of composite twisted elongate elements 5a to 5b have been consolidated together, e.g. by application of heat and/or pressure. The fabric or material can be formed without the use of, for example, a resin matrix material, a film or an adhesive. The elongate elements <NUM>, <NUM>; 5a to 5d and/or further elongate elements <NUM> can be selected from tapes, threads, fibres, filaments, strands, or the like. The further elongate elements can comprise a single layer and/or homogenous layer. The further elongate elements can comprise a material similar or dissimilar and/or thermally compatible and/or autogenously bondable with the first polymeric material.

The elongate elements <NUM>, <NUM>; 5a to 5d and the further elongate members <NUM> can be formed as tapes. The composite twisted elongate elements 5a to 5d and/or further elongate elements can be woven, knitted, stitched, or can be laid out to form a random fibrous web or may be randomly interspersed to form the material. Beneficially, the composite twisted elongate elements 5a to 5d and/or further elongate elements <NUM> can be woven together to form a fabric.

The composite twisted elongate elements 5a to 5d and further elongate elements <NUM> can be woven together to form the fabric or material <NUM>. The warp can be formed of composite or further elongate elements 5a to 5d and the weft may be formed of the other. The warp can be formed of composite elongate elements 5a to 5d and the weft may be formed of further elongate elements <NUM>. Alternatively, the warp can be formed of further elongate elements <NUM> and the weft may be formed of composite elongate elements 5a to 5d.

As mentioned above, the further elongate elements <NUM> can be the same as (i.e. can be identical to) the composite twisted elongate elements 5a to 5d.

Alternatively, the composite and further elongate elements can be woven together to form the fabric or material, and the warp and/or the weft may comprise a mixture of composite and further elongate elements. The mixture of composite and further elongate elements can be a random arrangement of composite and further elongate elements. Alternatively, the mixture of composite and further elongate elements can be a regular alternation of composite and elongate elements.

Alternatively warp and weft can comprise, e.g. solely comprise, the composite elongate elements 5a to 5d.

The further elongate elements <NUM> can comprise one or more of: polyesters, polyamides, aramids, thermoplastic polymers, molecularly-oriented thermoplastic polymers, ultra high molecular weight polyalkylenes (UHMWPA), such as ultra high molecular weight polyethylene (UHMWPE) or ultra high molecular weight polypropylene (UHMWPP), multifilament nucleated polypropylenes, and/or carbon fibres.

The further elongate elements can be formed of hybrid yarns. The hybrid yarns can be formed of at least two different materials or fibres comprising polyesters, polyamides, aramids, thermoplastic polymers, molecularly-oriented thermoplastic polymers, ultra high molecular weight polyalkylenes (UHMWPA), such as ultra high molecular weight polyethylene (UHMWPE) or ultra high molecular weight polypropylene (UHMWPP), multifilament nucleated polypropylenes, and/or carbon fibres.

The further elongate elements <NUM> can be formed of hybrid yarns selected from hybrid yarns comprising aramids and UHMWPE or hybrid yarns comprising polypropylene.

The further elongate elements <NUM> can comprise or consist of ultra high molecular weight polyalkylenes selected from UHMWPE or UHMWPP.

Referring now to <FIG>, there is shown two layers of fabric <NUM> prior to lamination and after thermal lamination, respectively. Lamination of the two layers of fabric <NUM> forms a laminated material <NUM>.

The laminated material <NUM> (which is rigid or nondrapable at normal room/ambient temperature) comprises a plurality of layers <NUM>, wherein at least one of said layers <NUM> comprise the fabric <NUM>. In one implementation the laminated material <NUM> comprises two layers <NUM>, e.g. only two layers, or alternatively three layers, e.g. only three layers (see <FIG>). Advantageously, each layer <NUM> comprises the fabric <NUM>.

Referring now to <FIG>, there are shown articles, i.e. three-dimensional (rigid or self-supporting) articles formed from fabric <NUM>, or alternatively formed from the laminated material <NUM>.

The articles 400a to 400d are typically formed by a moulding technique, e.g. press-moulding. The articles 400a to 400d are capable of withstanding relatively high impact, i.e. the articles 400a to 400d have relatively high impact resistance properties.

Referring to <FIG>, the article 400a comprises a luggage shell, e.g. a shell for a suitcase. Alternatively, the article can comprise or be selected from: a container, an armour product, e.g. body armour, automotive (vehicle) component, sportswear product. The article can be adapted for high impact and/or antiballistic purposes, and/or comprises bulletproof vests, body armour, panels suitable for the protection of military and commercial vehicles, bin liners, blast basket or blast blankets to contain fragmentation debris from the detonation of explosive devices. The article may find use as carpet backing which may be used in automotive or aerospace application or which comprises panels suitable for use on automotive vehicles.

Referring to <FIG> and <FIG>, the article 400b comprises a toe-cap(s) for protective footwear. Alternatively, the article can comprise connecting straps of handles of intermediate bulk containers or the containers themselves, tarpaulins, packaging, luggage, protective cases, pipes. <FIG> shows an article 400d comprising an automotive component (e.g. door trim) prior to finishing/trimming.

The present invention provides a method of forming a composite twisted elongate element <NUM>, the method comprising:.

The present invention provides a method of forming a fabric or material <NUM>, the method comprising:.

Said fabric <NUM> typically comprises a sheet or mat. Said step of providing can also comprise providing a plurality of further elongate elements <NUM>. Said step of forming comprises weaving. In such case, the plurality of composite twisted elongate elements 5a to 5d can comprise warp/weft yarns. Alternatively or additionally, the plurality of composite twisted elongate elements can comprise weft/warp yarns. The method further comprises the (subsequent) step of consolidating the fabric <NUM> by application of heat and/or pressure.

The present invention provides a method of forming an article <NUM>, such as a three-dimensional article, comprising the steps of:.

It will be appreciated that the embodiments of the present invention hereinbefore described are given by way of example only, and are not meant to be limiting to the scope of the invention in any way. It will, for example, be appreciated that the typically heavier fabrics produced by compound weaving of twisted tapes as warp and/or weft avoid the need for multi-layering of fabric. The resultant thermoformed articles are, therefore, less likely to be subject to failure by delamination. The material can be failure averted and utility of the thermoformed parts enhanced.

The present invention seeks to provide a solution to one or more issues in the prior art by permitting the ratio of cap layer to be increased beyond that which can presently be realised by coextrusion. The ratio of cap layer may, for example, be effectively tuned to any particular value between <NUM> and <NUM>% or, indeed, higher. By twisting together at least one second polyolefin tape or yarn with at least one first polyolefin tape or yarn of a different polyolefinic nature, and with a melting point at least <NUM> below that of the second tape or yarn, a means is provided for tuning the cap layer ratio anywhere between <NUM> and <NUM>% or even higher. Any ratio can be achieved by controlling the number of each type of tape or yarn incorporated into the twisting operation and by controlling the relative weight or tex of the at least one B tape with the at least one A tape or yarn.

Claim 1:
A composite twisted elongate element (5a-5d), comprising a plurality of elongate elements (<NUM>) twisted together and which comprise at least one first elongate element (<NUM>) and at least one second elongate element (<NUM>), wherein each of said plurality of elongate elements is substantially planar prior to twisting, the at least one first elongate element (<NUM>) consists of a single homogeneous layer consisting of a first thermoplastic polymeric material (A), and the at least one second elongate element (<NUM>) consists of a single homogeneous layer consisting of a second molecularly-oriented thermoplastic polymeric material (B), and wherein the melting point or softening point (MPA) of the first polymeric material is at least <NUM> less than the melting point or softening point (MPB) of the second polymeric material, and the first and second polymeric materials are capable of being autogeneously bonded.