EP4665785A1

EP4665785A1 - A method of producing a carbon fibre reinforced composite

Info

Publication number: EP4665785A1
Application number: EP24705233.5A
Authority: EP
Inventors: John GRASMEDER; Harry HOLT; Weili Qiu; Adam Chaplin
Original assignee: Victrex Manufacturing Ltd
Current assignee: Victrex Manufacturing Ltd
Priority date: 2023-02-17
Filing date: 2024-02-05
Publication date: 2025-12-24
Also published as: WO2024170871A1; GB202302250D0

Abstract

The invention relates to a method of producing a carbon fibre reinforced composite comprising: a) providing a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, b) providing a second PAEK polymer, c) melting the second PAEK polymer to form a polymer melt, d) mixing the polymer melt and the particulate material to form a mixture, and e) shaping the mixture to form the carbon fibre reinforced composite, wherein the D90 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 150 µm to about 2 mm.

Description

A Method of Producing a Carbon Fibre Reinforced Composite

The present invention relates to a method of producing a carbon fibre reinforced composite, a carbon fibre reinforced composite, a method of producing a carbon fibre reinforced article and a carbon fibre reinforced article.

Background to the invention

Over the last few decades, the so called advanced reinforced thermoplastic materials, based on composite materials having fibres embedded in a thermoplastic polymer, have been increasingly used in several industries, such as aerospace, automotive, general manufacturing, chemical, oil and gas, medical, sport and leisure. One of the main drivers for the use of composites is weight reduction. Their high strength and stiffness at low weight allows composites to partly or fully replace metals for many applications. Such composite materials can provide good performance and controlled properties through high fibre volume fractions and well-defined fibre alignment within the composite.

Advanced reinforced thermoplastic materials may be used in the form of tapes, in which reinforcing fibres are embedded in a thermoplastic matrix polymer. The manufacture of tapes is described in, for instance, US Patent 4,626,306 where an aqueous dispersion impregnation method is set out. Such tapes may be used to manufacture composite articles by using processes in which the tapes are formed and consolidated together, typically subjected to heat to make the thermoplastic polymer malleable, and pressure to shape the component, followed by a cooling step to return the thermoplastic polymer to a solidified state.

The process of making the tapes results in waste material which is not suitable for use tapes. This may be due to the manufacturing process, such as trimming the tape, cutting the material to size, when the manufacturing process is started up or shut down, and due to quality control checks. The waste material is often sent to landfill. The process of making tapes which are in the form of a unidirectional carbon fibre reinforced polymer result may be around 80% to 90% efficient resulting in a large amount of waste material.

There is a need to reduce the waste produced in manufacturing unidirectional carbon fibre reinforced polymer tapes. There is a need to reduce the amount of reinforced polymer waste that is sent to landfill. There is a need to recycle reinforced polymer material. There is a need to produce reinforced polymer products that are more environmentally friendly. Further there is a need to improve the properties of reinforced polymer products.

It is, therefore, an object of the present invention to seek to alleviate the above identified problems.

Summary of the invention

In a first aspect, there is provided a method of producing a carbon fibre reinforced composite comprising: a) providing a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, b) providing a second PAEK polymer, c) melting the second PAEK polymer to form a polymer melt, d) mixing the polymer melt and the particulate material to form a mixture, and e) shaping the mixture to form the carbon fibre reinforced composite, wherein the D90 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 150 pm to about 2 mm.

In a second aspect, there is provided a carbon fibre reinforced composite produced according to the first aspect.

In a third aspect, there is provided a carbon fibre reinforced composite comprising: about 10 wt% to about 80 wt% of a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, and about 20 wt% to about 90 wt% of a second polyaryletherketone (PAEK) polymer.

In a fourth aspect, there is provided a method of producing a carbon fibre reinforced article comprising; i. providing a carbon fibre reinforced composite produced according to the first aspect or a carbon fibre reinforced composite according to the second aspect, ii. melting the carbon fibre reinforced composite to form a carbon reinforced fibre melt, and iii. shaping the carbon fibre reinforced melt to form the carbon fibre reinforced article.

In a fifth aspect, there is provided a carbon fibre reinforced article produced according to the fourth aspect.

In a sixth aspect, there is provided a carbon fibre reinforced article comprising: about 10 wt% to about 80 wt% of a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, and about 20 wt% to about 90 wt% of a second polyaryletherketone (PAEK) polymer.

In a seventh aspect, there is provided a method of producing a carbon fibre reinforced composite comprising: a) providing a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, b) providing a second PAEK polymer, c) melting the second PAEK polymer to form a polymer melt, d) mixing the polymer melt and the particulate material to form a mixture, and e) shaping the mixture to form the carbon fibre reinforced composite, wherein the first PAEK polymer is a polyetheretherketone (PEEK) polymer or a polyetheretherketone/polyetherdiphenyletherketone/ (PEEK/PEDEK) copolymer.

In an eighth aspect, there is provided a method of producing a carbon fibre reinforced composite comprising: a) providing a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, b) providing a second PAEK polymer, c) melting the second PAEK polymer to form a polymer melt, d) mixing the polymer melt and the particulate material to form a mixture, and e) shaping the mixture to form the carbon fibre reinforced composite, wherein the melt viscosity of the second PAEK polymer is higher than the melt viscosity of the first PAEK polymer. Detailed Description

The method allows waste produced in manufacturing reinforced thermoplastic tapes to be diverted from landfill and recycled. This reduces the amount of reinforced thermoplastic waste that is sent to landfill. This enables the production of thermoplastic products that are more environmentally friendly as the amount of waste is reduced and further the need for new raw materials, such as thermoplastic polymer and carbon fibres is reduced. This has the dual impact of reducing landfill and reducing the amount of raw materials needed and allows thermoplastic products to be produced in an environmentally friendly manner.

Surprisingly, as shown in the examples, the properties of the carbon fibre reinforced composite have a further advantage of providing an improved composite compared to using virgin carbon fibres. Physical properties of the composite such tensile strength and notched impact strength may be improved using the unidirectional carbon fibre reinforced polymer particulate material instead of virgin carbon fibres. While not being bound by theory, it may be that providing the carbon fibres as part of the unidirectional carbon fibre reinforced polymer particulate material results in longer carbon fibres in the composite due to the carbon fibres being pre-impregnated with the first PAEK polymer. The first PAEK polymer may reduce the impact of the mixing step on the carbon fibres, resulting in longer carbon fibres in the end product. The length of the carbon fibres in step a) are typically the size of the particulate material, such as the width or the length of the particulate material. It is a further advantage of the invention that providing a unidirectional carbon fibre reinforced polymer particulate material is easier to handle and convey than virgin carbon fibres. This is because the carbon fibres are already bonded to the first PAEK polymer and therefore they are easier to transport and dose using conventional feeding equipment.

Unidirectional carbon fibre reinforced polymers such as tapes are known in the art. Unidirectional carbon fibre reinforced polymers such as tapes comprise a polymer and carbon fibres, wherein the carbon fibres are arranged in the same direction, preferably wherein multiple carbon fibres are arranged substantially parallel to each other.

Preferably, step a) comprises providing a unidirectional carbon fibre reinforced polymer tape and comminuting the tape to form the unidirectional carbon fibre reinforced polymer particulate material, preferably wherein step a) comprises providing a unidirectional carbon fibre reinforced polymer tape and comminuting the tape to form the unidirectional carbon fibre reinforced polymer particulate material. When a unidirectional carbon fibre reinforced polymer tape is made, waste is generated, such as when the tape is cut to size, trimmed, when the manufacturing process is started up or shut down, and due to quality control checks. This waste material comprises both polymer and carbon fibres and it is advantageous to recycle these.

Preferably, comminuting the tape comprises chopping or slitting the tape. These are useful methods of forming the particulate material.

Preferably, comminuting the tape comprises: i. slitting the tape, preferably substantially parallel to the length of the tape; and/or ii. chopping the tape, preferably substantially perpendicular to the length of the tape.

It is advantageous to slit the tape and then chop it to produce a substantially uniform particulate material. This helps the mixing step achieve a more uniform result. It is particularly advantageous to slit the tape substantially parallel to the length of the tape as this is substantially parallel to the carbon fibres which is an efficient process. An advantage of chopping the tape substantially perpendicular to the length of the tape is that the carbon fibres in the particulate material will be of a substantially similar length which makes them easier to dose using conventional feeding equipment. In some cases, only chopping will be required as the width of the tape may be of an appropriate size.

These are useful methods of forming the particulate material with substantially uniform particle size and carbon fibres with substantially similar lengths.

Preferably, the particulate material has a length in the range of about 3 mm to about 20 mm, preferably in the range of about 10 mm to about 15 mm. Preferably, the particulate material has a width in the range of about 2 mm to about 15 mm, preferably in the range of about 3 mm to about 10 mm. Preferably, the particulate material has a height in the range of about 0.10 mm to about 2.0 mm preferably in the range of about 0.13 mm to about 1.0 mm.

Such sizes are particularly suitable for the particulate material for mixing with the second PAEK polymer. In particular, such sizes allow the particulate material to be efficiently mixed with the second PAEK polymer.

Preferably, the height of the particulate material relates to the thickness of the tape.

Preferably, the length of the particulate material relates to the longest dimension. Preferably, the length of the particulate material relates to the direction substantially parallel to the carbon fibres.

Preferably, the particulate material is in the form of flakes. This aids the mixing step as the first PAEK polymer can melt more easily than a thicker particulate material. Preferably, the height of a flake is less than half of the length and/or width of the flake, preferably less than a third of the length and/or width of the flake.

Preferably, the tape has a width in the range of about 5 mm to about 200 mm, preferably in the range of about 6 mm to about 50 mm. Such widths are suitable for forming the particulate material from.

Preferably, the D90 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 170 pm to about 1 mm, preferably about 200 pm to about 500 pm.

Preferably, the D50 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 50 pm to about 500 pm, preferably about 100 pm to about 300 pm. Preferably, the D10 fibre length of the carbon fibre is in the range of about 20 m to about 200 pm, preferably about 40 pm to about 100 pm.

The Examples support that such fibre lengths and fibre distributions result is a carbon fibre reinforced polymer with improved properties.

Preferably, the carbon fibre reinforced composite comprises about 3 wt% to about 50 wt% of carbon fibre, preferably about 5 wt% to about 45 wt%, preferably about 20 wt% to about 40 wt%. Such amounts provide suitable reinforcement.

Preferably, the carbon fibre reinforced composite is used in 3D printing, preferably the carbon fibre reinforced composite comprises about 3 wt% to about 5 wt% of carbon fibre. Such amounts are suitable for this application.

Preferably, the carbon fibre reinforced composite is used in injection molding or extrusion, preferably the carbon fibre reinforced composite comprises about 20 wt% to about 40 wt% of carbon fibre. Such amounts are suitable for this application.

Preferably, the melt viscosity of the second PAEK polymer is greater than the melt viscosity of the first PAEK polymer. It is advantageous to be able to modify the melt viscosity of the carbon fibre reinforced composite by choosing an appropriate second PAEK polymer. Surprisingly, choosing a second PAEK polymer with a greater melt viscosity than the first PAEK polymer results in a mixture which is easy to process. Further, the examples show that using a second PAEK polymer with a greater melt viscosity increases the tensile elongation and the notched impact of the resulting composite.

Preferably, the melt viscosity of the first PAEK polymer is in the range of about 0.05 - 0.20 kNs/m². Preferably, the melt viscosity of the second PAEK polymer is in the range of about 0.05 - 0.85 kNs/m² and preferably 0.21 - 0.85 kNs/m².

Preferably, the melt viscosity is measured using capillary rheometry operating at 400°C and at a shear rate of 1000s'¹ using a circular cross-section tungsten carbide die, 0.5mm (capillary diameter) x 3.175mm (capillary length). The melt viscosity measurement is taken 5 minutes after the polymer has fully melted, which is taken to be 5 minutes after the polymer is loaded into the barrel of the rheometer.

Preferably, the first and/or second PAEK polymer has a repeat unit of formula

-O-Ph-O-Ph-CO-Ph- I wherein Ph represents a phenylene moiety. In this embodiment, all phenylenes are 1 ,3- and I or 1 ,4-substituted to the adjacent ether and /or carbonyl groups.

In another embodiment the polymeric material has a repeat unit of formula

-O-Ph-CO-Ph- II wherein Ph represents a phenylene moiety. In this embodiment, all phenylenes are 1 ,3- and I or 1 ,4-substituted to the adjacent ether and /or carbonyl groups.

Preferably, the first and/or second PAEK polymer has a repeat unit of formula

-O-Ph-CO-Ph-O-Ph-CO-Ph-CO-Ph- 111 wherein Ph represents a phenylene moiety. In this embodiment, all phenylenes are 1 ,3- and I or 1 ,4-substituted to the adjacent ether and /or carbonyl groups.

Preferably, the first and/or second PAEK polymer has a repeat unit of formula

-O-Ph-O-Ph-CO-Ph- I and a repeat unit of formula

-O-Ph-Ph-O-Ph-CO-Ph- IV wherein Ph represents a phenylene moiety and wherein the repeat units I and IV are in the relative molar properties l:ll of from 55:45 to 95:5. In this embodiment, all phenylenes are 1 ,3- and I or 1 ,4-substituted to the adjacent ether and /or carbonyl groups.

Preferably, the first and/or second PAEK polymer does not have a repeat unit of formula

-O-Ph-CO-Ph-CO-Ph- V wherein Ph represents a phenylene moiety. In this embodiment, all phenylenes are 1 ,3- and I or 1 ,4-substituted to the adjacent ether and /or carbonyl groups.

Preferably, the first and/or second PAEK polymer is not a polyetherketoneketone (PEKK) polymer.

PEKK polymers of repeat unit V are preferably not used due to their slow crystallisation rates and low degrees of crystallinity, compared to those of a PEEK polymer.

Preferably, the first PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the first PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer.

Preferably, the second PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the second PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer.

Preferably, the first PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK polymer.Such polymers are suitable for use in the present invention.

Preferably, the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK polymer.

Preferably, the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer.

Preferably, the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer.

Preferably, the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK polymer.

It is an advantage of the invention that different recycling streams can be used. It is an advantage that the first and second PAEK polymers can be the same. It is an advantage that the first and second PAEK polymers can be different.

Preferably, the second PAEK polymer is a recycled polymer. It is particularly desirable to use a recycled polymer as this is environmentally friendly. It reduces the amount of unidirectional carbon reinforced polymer and the amount of PAEK polymer being sent to landfill and allows these materials to be recycled. Recycled polymer is not virgin polymer. Recycled polymer is polymer that has been recovered or diverted from solid waste and has been utilized in place of raw or virgin polymer. Typically, it is derived from one or more of the following sources: post-consumer recycled material, manufacturing waste, industrial scrap, and other waste material. Preferably, recycled polymer is in the form of powder or granule. Preferably a polymer article is comminuted to form a recycled polymer. The recycled polymer can then be used in the present invention. Preferably, wherein step e) comprises pelletising the mixture, preferably wherein the carbon fibre reinforced composite is substantially cylindrical, preferably wherein the carbon fibre reinforced composite has a diameter in the range of about 1 mm to about 5 mm, and a length in the range of about 1 mm to about 7 mm, preferably wherein the carbon fibre reinforced composite has a diameter in the range of about 2 mm to about 4 mm, and a length in the range of about 2 mm to about 5 mm. Such composites are suitable for further processing into carbon fibre reinforced polymer articles.

Preferably, step c) is carried out in an extruder, preferably in a twin screw co-rotating intermeshing compounding extruder. Preferably, step d) is carried out in an extruder, preferably in a twin screw co-rotating intermeshing compounding extruder. Preferably, step c) and step d) are carried out in an extruder, preferably in a twin screw co-rotating intermeshing compounding extruder. This is an efficient way to carry out these steps.

Preferably, steps c) and d) are carried out in a twin screw co-rotating intermeshing compounding extruder. It is advantageous to start to melt the second PAEK polymer, before adding the particulate material. This improves the mixing and distribution of the carbon fibre in the resulting composite. The second PAEK polymer is preferably provided and metered into the solids conveying zone (zone 1) of the extruder and the particulate material is provided and metered at about 0% to about 80% of the distance along the extruder, preferably about 10% to about 80% of the distance along the extruder, preferably about 40% to about 70% of the distance along the extruder.

Preferably, the composite comprises about 10 wt% to about 80 wt% of the unidirectional carbon fibre reinforced polymer particulate material, and about 20 wt% to about 90 wt% of the second polyaryletherketone (PAEK) polymer. This allows a useful amount of carbon fibre to be present in the composite.

In a further aspect, there is a carbon fibre reinforced composite produced as described herein. Surprisingly, as shown in the examples, the composite has improved properties, compared to a composite made with carbon fibres that were not part of a unidirectional carbon fibre reinforced polymer particulate material.

In a further aspect, there is provided a carbon fibre reinforced composite comprising: about 10 wt% to about 80 wt% of a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, and about 20 wt% to about 90 wt% of a second polyaryletherketone (PAEK) polymer.

It will be appreciated that the unidirectional carbon fibre reinforced polymer particulate material is a component of the composite. Preferably, the article comprises further features of the aspects described herein.

Surprisingly, as shown in the examples, the composite has improved properties, compared to a composite made with carbon fibres that were not part of a unidirectional carbon fibre reinforced polymer particulate material.

In a further aspect, there is a method of producing a carbon fibre reinforced article comprising; i. providing a carbon fibre reinforced composite produced as described herein or a carbon fibre reinforced composite as described herein, ii. melting the carbon fibre reinforced composite to form a carbon fibre reinforced melt, and iii. shaping the carbon fibre reinforced melt to form the carbon fibre reinforced article.

It is an advantage of the invention that the composite can be further processed into carbon fibre reinforced articles with improved properties.

Preferably, wherein step iii. comprises injection moulding, extrusion or 3D-printing, preferably injection moulding or extrusion.

Preferably, wherein step iii. comprises making filaments, preferably wherein the filaments are subsequently fused to form a fused filament.

In a further aspect, there is a carbon fibre reinforced article produced as described herein.

Preferably, the article is an injection moulded article or an extruded article.

In a further aspect, there is a carbon fibre reinforced article comprising: about 10 wt% to about 80 wt% of a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, and about 20 wt% to about 90 wt% of a second polyaryletherketone (PAEK) polymer. It will be appreciated that the unidirectional carbon fibre reinforced polymer particulate material is a component of the article. Preferably, the article comprises further features of the aspects described herein.

Examples

Experiments were carried out to compare the properties of a carbon fibre reinforced composite made from a carbon fibre reinforced particulate material (a tape) and carbon fibres. A twin screw extruder () was used to melt mix a second PAEK polymer with carbon fibres provided by recycled tape compared with carbon fibres. The composition of the examples and the results are shown in Table 1. Examples 1-3, 5-7, 9 and 13-15 relate to using recycled tape as the source of carbon fibres. The recycled tape is a 58% by weight carbon fibre reinforced UD tape made with Hexcel AS4A fibres and VICTREX PEEK 150 polymer. Examples 4, 8 and 10-12 relate to using carbon fibres which were SGL Sigrafil carbon fibre C30 006 APS. The carbon fibre loading rate refers to the amount of carbon fibre present in the resulting composite. The carbon fibres and the recycled tape were provided in particulate form and had a length of about 5 - 7 mm.

The second PAEK polymer was introduced at zone 1 of the twin extruder. Recycled tape or carbon fibres were added at various zones along the twin extruder. Zone 1 was furthest from the die and zone 10 is just before the die.

Tensile properties were measured according to ISO 527 using Type 1A specimens; flexural properties were measured according to ISO 178 using the preferred specimen dimensions and unnotched impact properties were measured according to ISO 180/U and notched impact properties according to ISO 180/A. Further, the fibre length distribution of the carbon fibres in the product were measured as set out below.

The flexural properties are hereinafter referred to as “flex modulus” and “flex strength”.

As shown in Table 1 , using recycled tape compared to using carbon fibres results in an increased tensile strength, unnotched impact and notched impact for the composite. This surprisingly shows advantages of using a carbon fibre reinforced particulate material instead of carbon fibres. Surprisingly, the fibre length distribution data shows that using a carbon fibre reinforced particulate material instead of carbon fibres results in a longer fibre length. This is shown by comparing examples 3 and 4 with 20% carbon fibre loading and examples 7 and 8 with 30% carbon fibre loading. Further, using recycled tape compared to using carbon fibres results in an increased tensile strength and notched impact for the composite for second PAEK polymers with different melt viscosities. This surprisingly shows advantages of using a carbon fibre reinforced particulate material instead of carbon fibres. This is shown by comparing examples 13 and 10 ,14 and 11 , and 15 and 12.

Further, increasing the amount of carbon fibre present increases the tensile strength, flex modulus, flex strength and notched impact of the composite. Further the fibre length distribution data shows that having more carbon fibre present appears to result in shorted carbon fibres. This is shown be comparing examples 7 and 3, and 9 and 7. Further, increasing the melt viscosity of the second PAEK polymer surprisingly increases the tensile elongation and notched impact of the composite. This is shown by comparing examples 7 and 13, 14 and 7, and 15 and 14.

In examples 1-15, the base polymer type in the tape is a PEEK polymer.

Table 2 illustrates how the quantities of UD tape and added polymer are calculated to achieve the target carbon fibre content in the final compound.

Table 2

Tables 3 and 4 show examples 16-18. In examples 16-18, the base polymer type in the tape is a PEEK/PEDEK copolymer, with the PEDEK content being 25 mol% and the polymer being made according to the process described in European patent no. EP3013888B1.

Examples 16 and 18 also relate to using recycled tape as the source of carbon fibres. The recycled tape is a 65% by weight carbon fibre reinforced UD tape made with Hexcel AS4A fibres and VICTREX AE 250 polymer. Example 17 relates to using carbon fibres which were SGL carbon fibre C C6-4.0/240-T190 (also known as C30 006 APS).

As shown in Table 3, increasing the carbon fibre content of the tape further increases the tensile strength, flex modulus, flex strength and unnotched impact of the composite. This is shown by comparing examples 16 and 8. Further, example 16 shows that a PEEK/PEDEK copolymer can be used as the base polymer type in the tape.

As shown in Table 4, increasing the carbon fibre content of the tape further increases the tensile strength, flex modulus, flex strength, notched and unnotched impact of the composite. This is shown by comparing examples 18 and 17. Further, examples 17 and 18 show that a PEEK/PEDEK copolymer can be used as the base polymer type in both the tape and the compound. Table 3

Table 4

Method for measuring the fibre length distribution

Sample preparation using acid digestion

Acid digestions were performed on the samples. The samples were dried in 120°C drying oven for at least 3 hours. Once dry, they were stored in a desiccator to cool to room temperature.

1.0g of granules were weighed into a clean dry 100ml B24 conical flask. In a fume cupboard, 25mls of concentrated sulfuric acid was added to each of the flasks. Splash adapters were fitted and the flasks were left in the fume cupboard on a hotplate set at 100°C, for 7 days. Following the digestion period, the flasks were agitated to ensure all the polymer was dissolved.

A sufficient number of previously cleaned sintered crucibles were dried at 120 °C and left to cool to room temperature in a desiccator. The weight of each crucible was recorded once at room temperature.

The crucible was placed on top of a Buchner flask. The hot solution/fibre was transferred into the sintered glass crucible. The vacuum was applied. The flask was washed out into the crucible with ~ 15mls cone, sulfuric acid, then repeated with a further 15mls of acid ensuring the transfer was complete.

The same sintered crucible containing the fibre was then transferred onto a second Buchner flask and washed using 1 L of deionised water and vacuum filtration. The sinter/fibre was dried in an oven at 120°C for 3 hours minimum and then cooled in a desiccator to room temperature. The fibres were collected from the sinter and placed into a plastic bag.

Sympatec QICPIC - analysis

Each fibre sample was added to a separate glass phial with polysorbate surfactant and water. The phials are shaken to disperse the fibres. The Sympatec QICPIC analyser was turned on and PAQXOS 4.0 Control and Evaluation Software was opened.

A beaker was filled with approximately 500ml of water and a proportion of the fibres were added. Using a Medorex water pump machine and connecting tubes, a Sympatec Lixell QICPIC (450Hz) was used to pump the well-diluted fibre/water solution through a closed system. Images were taken using a 0.5mm Cell and M5 Lens. Once complete, the pump system and beakers were cleaned with clean deionised water. The next sample was then added.

The QICPIC test method consists of a 90 second test at 85Hz. It looks to identify shapes with a diameter DI Fl (Diameter of fibre) greater than 4pm, with an aspect ratio less than 0.5, and a diameter LEFI (Length of fibre) greater than 10pm.

The PAQXOS 4.0 Software is able to read, measure, and record the particle fibre length and the number of fibres within the solution via the camera. A cumulative frequency graph is plotted using this data, and D10, D50, and D90 values are recorded. D10, D50, and D90 are percentile values. They indicate the number of particles with a size below 10%, 50%, or 90% of all particles which are found.

Within this specification embodiments have been described in a way which enables a clear and concise specification to be written, but it is intended and will be appreciated that embodiments may be variously combined or separated without parting from the invention. For example, it will be appreciated that all preferred features described herein are applicable to all aspects of the invention described herein and vice versa. For example, all preferred features of the composite apply to all aspects of the invention.

Within this specification, the term "about" means plus or minus 20%, more preferably plus or minus 10%, even more preferably plus or minus 5%, most preferably plus or minus 2%.

Within this specification, the term "substantially" means a deviation of plus or minus 20%, more preferably plus or minus 10%, even more preferably plus or minus 5%, most preferably plus or minus 2%.

Within this specification, reference to “substantially” includes reference to “completely” and/or “exactly”. That is, where the word substantially is included, it will be appreciated that this also includes reference to the particular sentence without the word substantially.

It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications are covered by the appended claims. The present invention may be described in accordance with the following clauses:

1) A method of producing a carbon fibre reinforced composite comprising: a) providing a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, b) providing a second PAEK polymer, c) melting the second PAEK polymer to form a polymer melt, d) mixing the polymer melt and the particulate material to form a mixture, and e) shaping the mixture to form the carbon fibre reinforced composite, preferably, wherein the D90 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 150 pm to about 2 mm.

2) A method according to clause 1 , wherein step a) comprises providing a unidirectional carbon fibre reinforced polymer tape and comminuting the tape to form the unidirectional carbon fibre reinforced polymer particulate material.

3) A method according to clause 2, wherein comminuting the tape comprises: i. slitting the tape, preferably substantially parallel to the length of the tape; and/or ii. chopping the tape, preferably substantially perpendicular to the length of the tape.

4) A method according to any preceding clause, wherein the particulate material has a length in the range of about 3 mm to about 20 mm, preferably in the range of about 10 mm to about 15 mm; and/or wherein the particulate material has a width in the range of about 2 mm to about 15 mm, preferably in the range of about 3 mm to about 10 mm; and/or wherein the particulate material has a height in the range of about 0.1 mm to about 2 mm preferably in the range of about 0.13 mm to about 1 .0 mm.

5) A method according to any preceding clause, wherein the particulate material is in the form of flakes. ) A method according to any of clauses 2 to 5, wherein the tape has a width in the range of about 5 mm to about 200 mm, preferably in the range of about 6 mm to about 50 mm. ) A method according to any preceding clause, wherein the D90 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 170 pm to about 1 mm, preferably about 200 pm to about 500 pm. ) A method according to any preceding clause, wherein the wherein the D50 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 50 pm to about 500 pm, preferably about 100 pm to about 300 pm. ) A method according to any preceding clause, wherein the D10 fibre length of the carbon fibre is in the range of about 20 pm to about 200 pm, preferably about 40 pm to about 100 pm. 0) A method according to any preceding clause, wherein the carbon fibre reinforced composite comprises about 3 wt% to about 50 wt% of carbon fibre, preferably about 5 wt% to about 45 wt%, preferably about 20 wt% to about 40 wt%. 1)A method according to any preceding clause, wherein the melt viscosity of the second PAEK polymer is higher than the melt viscosity of the first PAEK polymer. 2) A method according to any preceding clause, wherein the melt viscosity of the first PAEK polymer is in the range of about 0.05 - 0.20 kNs/m²; and/or wherein the melt viscosity of the second PAEK polymer is in the range of about 0.05 - 0.85 kNs/m² and preferably 0.21 - 0.85 kNs/m². 3) A method according to any preceding clause, wherein the first PAEK polymer is not a PEKK polymer; and/or wherein the second PAEK polymer is not a PEKK polymer. 4) A method according to any preceding clause, wherein the first PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the first PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer. ) A method according to any preceding clause, wherein the second PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the second PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer. ) A method according to any preceding clause, wherein the second PAEK polymer is a recycled polymer. ) A method according to any preceding clause, wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK polymer; or wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK polymer. ) A method according to any preceding clause, wherein step e) comprises pelletising the mixture, preferably wherein the carbon fibre reinforced composite is substantially cylindrical, preferably wherein the carbon fibre reinforced composite has a diameter in the range of about 1 mm to about 5 mm, and a length in the range of about 1 mm to about 7 mm, preferably wherein the carbon fibre reinforced composite has a diameter in the range of about 2 mm to about 4 mm, and a length in the range of about 2 mm to about 5 mm. ) A method according to any preceding clause, wherein step c) and/or step d) is carried out in an extruder, preferably in a twin screw co-rotating intermeshing compounding extruder. ) A method according to clause 19, wherein step d) is carried out in a twin screw corotating intermeshing compounding extruder and the particulate material is provided at about 0% to about 80% of the distance along the extruder, preferably about 10% to about 80% of the distance along the extruder, preferably about 40% to about 70% of the distance along the extruder.

21) A method according to any preceding clause, wherein the composite comprises about 10 wt% to about 80 wt% of the unidirectional carbon fibre reinforced polymer particulate material, and about 20 wt% to about 90 wt% of the second polyaryletherketone (PAEK) polymer.

22)A carbon fibre reinforced composite produced according to any preceding clause.

23)A carbon fibre reinforced composite comprising: about 10 wt% to about 80 wt% of a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, and about 20 wt% to about 90 wt% of a second polyaryletherketone (PAEK) polymer.

24)A carbon fibre reinforced composite according to clause 23, wherein the D90 fibre length of the carbon fibre in the carbon fibre reinforced article is in the range of about 170 pm to about 1 mm, preferably about 200 pm to about 500 pm; and/or wherein the wherein the D50 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 50 pm to about 500 pm, preferably about 100 pm to about 300 pm; and/or wherein the D10 fibre length of the carbon fibre is in the range of about 20 pm to about 200 pm, preferably about 40 pm to about 100 pm.

25)A carbon fibre reinforced composite according to clause 23 or clause 24, wherein the carbon fibre reinforced article comprises about 3 wt% to about 50 wt% of carbon fibre, preferably about 5 wt% to about 45 wt%, preferably about 20 wt% to about 40 wt%.

26)A carbon fibre reinforced composite according to any of clauses 23 to 25, wherein the melt viscosity of the second PAEK polymer is greater than the melt viscosity of the first PAEK polymer, and/or wherein the melt viscosity of the first PAEK polymer is in the range of about 0.05 - 0.20 kNs/m²; and/or wherein the melt viscosity of the second PAEK polymer is in the range of about 0.05 - 0.85 kNs/m² and preferably 0.21 - 0.85 kNs/m².

27) A carbon fibre reinforced composite according to any of clauses 23 to 26, wherein the first PAEK polymer is not a PEKK polymer; and/or wherein the second PAEK polymer is not a PEKK polymer.

28) A carbon fibre reinforced composite according to any of clauses 23 to 27, wherein the first PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the first PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer.

29) A carbon fibre reinforced composite according to any of clauses 23 to 28, wherein the second PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the second PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer.

30) A carbon fibre reinforced composite according to any of clauses 23 to 29, wherein the second PAEK polymer is a recycled polymer.

31) A carbon fibre reinforced composite according to any of clauses 23 to 30, wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK polymer; or wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK polymer. 32)A method of producing a carbon fibre reinforced article comprising; i. providing a carbon fibre reinforced composite produced according to any of clauses 1 to 21 or a carbon fibre reinforced composite according to any of clauses 22 to 31 , ii. melting the carbon fibre reinforced composite to form a carbon reinforced fibre melt, and iii. shaping the carbon fibre reinforced melt to form the carbon fibre reinforced article.

33)A method according to clause 32, wherein step iii. comprises injection molding, extrusion or 3D-printing, preferably injection molding or extrusion.

34)A method according to clause 32 or clause 33, wherein step iii. comprises making filaments, preferably wherein the filaments are subsequently fused to form a fused filament.

35)A carbon fibre reinforced article produced according to any of clauses 32 to 34.

36)A carbon fibre reinforced article comprising: about 10 wt% to about 80 wt% of a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, and about 20 wt% to about 90 wt% of a second polyaryletherketone (PAEK) polymer.

37)A carbon fibre reinforced article according to clause 36, wherein the D90 fibre length of the carbon fibre in the carbon fibre reinforced article is in the range of about 170 pm to about 1 mm, preferably about 200 pm to about 500 pm; and/or wherein the wherein the D50 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 50 pm to about 500 pm, preferably about 100 pm to about 300 pm; and/or wherein the D10 fibre length of the carbon fibre is in the range of about 20 pm to about 200 pm, preferably about 40 pm to about 100 pm. 38)A carbon fibre reinforced article according to clause 36 or clause 37, wherein the carbon fibre reinforced article comprises about 3 wt% to about 50 wt% of carbon fibre, preferably about 5 wt% to about 45 wt%, preferably about 20 wt% to about 40 wt%.

39)A carbon fibre reinforced article according to any of clauses 36 to 38, wherein the melt viscosity of the second PAEK polymer is greater than the melt viscosity of the first PAEK polymer; and/or wherein the melt viscosity of the first PAEK polymer is in the range of about 0.05 - 0.20 kNs/m²; and/or wherein the melt viscosity of the second PAEK polymer is in the range of about 0.05 - 0.85 kNs/m² and preferably 0.21 - 0.85 kNs/m².

40)A carbon fibre reinforced article according to any of clauses 36 to 39, wherein the first PAEK polymer is not a PEKK polymer; and/or wherein the second PAEK polymer is not a PEKK polymer.

41) A carbon fibre reinforced article according to any of clauses 36 to 40, wherein the first PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the first PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer.

42) A carbon fibre reinforced article according to any of clauses 36 to 41 , wherein the second PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the second PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer.

43)A carbon fibre reinforced article according to any of clauses 36 to 42, wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK polymer; or wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK polymer. )A carbon fibre reinforced article according to any of clauses 36 to 43, wherein the second PAEK polymer is a recycled polymer. A carbon fibre reinforced article according to any of clauses 36 to 44, wherein the article is an injection molded article or an extruded article.

Claims

1) A method of producing a carbon fibre reinforced composite comprising: a) providing a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, b) providing a second PAEK polymer, c) melting the second PAEK polymer to form a polymer melt, d) mixing the polymer melt and the particulate material to form a mixture, and e) shaping the mixture to form the carbon fibre reinforced composite, wherein the D90 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 150 pm to about 2 mm.

2) A method according to claim 1 , wherein step a) comprises providing a unidirectional carbon fibre reinforced polymer tape and comminuting the tape to form the unidirectional carbon fibre reinforced polymer particulate material, preferably wherein comminuting the tape comprises: i. slitting the tape, preferably substantially parallel to the length of the tape; and/or ii. chopping the tape, preferably substantially perpendicular to the length of the tape.

3) A method according to any preceding claim, wherein the particulate material has a length in the range of about 3 mm to about 20 mm, preferably in the range of about 10 mm to about 15 mm; and/or wherein the particulate material has a width in the range of about 2 mm to about 15 mm, preferably in the range of about 3 mm to about 10 mm; and/or wherein the particulate material has a height in the range of about 0.1 mm to about 2 mm preferably in the range of about 0.13 mm to about 1 .0 mm. 4) A method according to any preceding claim, wherein the D90 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 170 pm to about 1 mm, preferably about 200 pm to about 500 pm; and/or wherein the wherein the D50 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 50 pm to about 500 pm, preferably about 100 pm to about 300 pm; and/or wherein the D10 fibre length of the carbon fibre is in the range of about 20 pm to about 200 pm, preferably about 40 pm to about 100 pm.

5) A method according to any preceding claim, wherein the carbon fibre reinforced composite comprises about 3 wt% to about 50 wt% of carbon fibre, preferably about 5 wt% to about 45 wt%, preferably about 20 wt% to about 40 wt%.

6) A method according to any preceding claim, wherein the melt viscosity of the second PAEK polymer is higher than the melt viscosity of the first PAEK polymer; and/or wherein the melt viscosity of the first PAEK polymer is in the range of about 0.05 - 0.20 kNs/m²; and/or wherein the melt viscosity of the second PAEK polymer is in the range of about 0.05 - 0.85 kNs/m² and preferably 0.21 - 0.85 kNs/m².

7) A method according to any preceding claim, wherein the first PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the first PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer and/or wherein the second PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the second PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer; and/or wherein the second PAEK polymer is a recycled polymer. 8) A method according to any preceding claim, wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK polymer; or wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK polymer.

9) A method according to any preceding claim, wherein step e) comprises pelletising the mixture, preferably wherein the carbon fibre reinforced composite is substantially cylindrical, preferably wherein the carbon fibre reinforced composite has a diameter in the range of about 1 mm to about 5 mm, and a length in the range of about 1 mm to about 7 mm, preferably wherein the carbon fibre reinforced composite has a diameter in the range of about 2 mm to about 4 mm, and a length in the range of about 2 mm to about 5 mm.

10) A method according to any preceding claim, wherein step c) and/or step d) is carried out in an extruder, preferably in a twin screw co-rotating intermeshing compounding extruder, preferably, wherein step d) is carried out in a twin screw co-rotating intermeshing compounding extruder and the particulate material is provided at about 0% to about 80% of the distance along the extruder, preferably about 10% to about 80% of the distance along the extruder, preferably about 40% to about 70% of the distance along the extruder.

11)A method according to any preceding claim, wherein the composite comprises about 10 wt% to about 80 wt% of the unidirectional carbon fibre reinforced polymer particulate material, and about 20 wt% to about 90 wt% of the second polyaryletherketone (PAEK) polymer.

12) A carbon fibre reinforced composite produced according to any preceding claim.

13) A carbon fibre reinforced composite comprising: about 10 wt% to about 80 wt% of a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, and about 20 wt% to about 90 wt% of a second polyaryletherketone (PAEK) polymer.

14) A carbon fibre reinforced composite according to claim 13, wherein the D90 fibre length of the carbon fibre in the carbon fibre reinforced article is in the range of about 170 pm to about 1 mm, preferably about 200 pm to about 500 pm; and/or wherein the wherein the D50 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 50 pm to about 500 pm, preferably about 100 pm to about 300 pm; and/or wherein the D10 fibre length of the carbon fibre is in the range of about 20 pm to about 200 pm, preferably about 40 pm to about 100 pm.

15) A carbon fibre reinforced composite according to claim 13 or claim 14, wherein the carbon fibre reinforced article comprises about 3 wt% to about 50 wt% of carbon fibre, preferably about 5 wt% to about 45 wt%, preferably about 20 wt% to about 40 wt%.

16) A carbon fibre reinforced composite according to any of claims 13 to 15, wherein the melt viscosity of the second PAEK polymer is greater than the melt viscosity of the first PAEK polymer; and/or wherein the melt viscosity of the first PAEK polymer is in the range of about 0.05 - 0.20 kNs/m²; and/or wherein the melt viscosity of the second PAEK polymer is in the range of about 0.05 - 0.85 kNs/m² and preferably 0.21 - 0.85 kNs/m².

17) A carbon fibre reinforced composite according to any of claims 13 to 16, wherein the first PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the first PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer; and/or wherein the second PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the second PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer; and/or wherein the second PAEK polymer is a recycled polymer.

18) A carbon fibre reinforced composite according to any of claims 13 to 17, wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK polymer; or wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK polymer.

19) A method of producing a carbon fibre reinforced article comprising; i. providing a carbon fibre reinforced composite produced according to any of claims 1 to 11 or a carbon fibre reinforced composite according to any of claims 12 to 18, ii. melting the carbon fibre reinforced composite to form a carbon reinforced fibre melt, and iii. shaping the carbon fibre reinforced melt to form the carbon fibre reinforced article.

20) A method according to claim 19, wherein step iii. comprises injection molding, extrusion or 3D-printing, preferably injection molding or extrusion. 21) A method according to claim 19 or claim 20, wherein step iii. comprises making filaments, preferably wherein the filaments are subsequently fused to form a fused filament.

22) A carbon fibre reinforced article produced according to any of claims 19 to 21 .

23)A carbon fibre reinforced article comprising: about 10 wt% to about 80 wt% of a unidirectional carbon fibre reinforced polymer particulate material, wherein the particulate material comprises a first polyaryletherketone (PAEK) polymer, and about 20 wt% to about 90 wt% of a second polyaryletherketone (PAEK) polymer.

24) A carbon fibre reinforced article according to claim 23, wherein the D90 fibre length of the carbon fibre in the carbon fibre reinforced article is in the range of about 170 pm to about 1 mm, preferably about 200 pm to about 500 pm; and/or wherein the wherein the D50 fibre length of the carbon fibre in the carbon fibre reinforced composite is in the range of about 50 pm to about 500 pm, preferably about 100 pm to about 300 pm; and/or wherein the D10 fibre length of the carbon fibre is in the range of about 20 pm to about 200 pm, preferably about 40 pm to about 100 pm.

25)A carbon fibre reinforced article according to claim 23 or claim 24, wherein the carbon fibre reinforced article comprises about 3 wt% to about 50 wt% of carbon fibre, preferably about 5 wt% to about 45 wt%, preferably about 20 wt% to about 40 wt%.

26)A carbon fibre reinforced article according to any of claims 23 to 25, wherein the first PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the first PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer; and/or wherein the second PAEK polymer comprises a polyetheretherketone (PEEK) polymer, a polyetherdiphenyletherketone (PEDEK) polymer, a polyetherketone (PEK) polymer, a polyetherketoneetherketoneketone (PEKEKK) polymer or a copolymer of two or more thereof, preferably the second PAEK polymer comprises a PEEK polymer or a PEEK/PEDEK copolymer; and/or wherein the second PAEK polymer is a recycled polymer. )A carbon fibre reinforced article according to any of claims 23 to 26, wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK polymer; or wherein the first PAEK polymer comprises a PEEK polymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK/PEDEK copolymer; or wherein the first PAEK polymer comprises a PEEK/PEDEK copolymer and the second PAEK polymer comprises a PEEK polymer. )A carbon fibre reinforced article according to any of claims 22 to 27, wherein the article is an injection molded article or an extruded article.