WO2025242693A1

WO2025242693A1 - A tape, a reinforced thermoplastic pipe comprising the tape, and a method of manufacturing and uses of the tape

Info

Publication number: WO2025242693A1
Application number: PCT/EP2025/063897
Authority: WO
Inventors: Recep YALDIZ; Faisal Abdulaziz AL-MANA; Ali Mohammed S ALGHAMDI; Yousof Mustafa GHAZZAWI
Original assignee: SABIC Global Technologies BV
Current assignee: SABIC Global Technologies BV
Priority date: 2024-05-24
Filing date: 2025-05-20
Publication date: 2025-11-27
Anticipated expiration: 2026-11-24

Abstract

A tape (1) comprising an array of a plurality of longitudinally oriented fibres (3), wherein said array of fibres (3) has two longitudinal sides (5, 7), wherein one longitudinal side (5) of the array (3) is at least partially covered by a thermoplastic material (9). A reinforced transportation pipe (RTP) (11) configured for transporting fluids, said RTP (11) comprising from a centre to a periphery a thermoplastic inner liner, a reinforcing layer comprising at least one layer of helically wound tape (1) according to claim 1, and a thermoplastic outer jacket, wherein said tape (1) has a longitudinal side facing towards the periphery of the RTP (11) and a longitudinal side facing towards the centre of the RTP (11), wherein on the other longitudinal side (7) of the array (3) channels (13) are present which channels (13) are each defined by two adjacent longitudinally oriented fibres, the thermoplastic material (9) of said tape (1) and one of the thermoplastic inner liner, the thermoplastic outer jacket and thermoplastic material (9) of another layer of helically wound tape (1) in said reinforcing layer, which channels (13) allow for the transport of one or more gases along a helical direction of the RTP (11). A method (101) of manufacturing said tape (1), a use of said tape (1) for a reinforced thermoplastic pipe (RTP) configured for transporting of fluids, and a use of said tape for transporting one or more gases that accumulate in channels (13) present on the other longitudinal side (7) of the array of fibers (3) along a helical direction of an RTP.

Description

TITLE A tape, a reinforced thermoplastic pipe comprising the tape, and a method of manufacturing and uses of the tape

TECHNICAL FIELD

The present disclosure relates to a tape, a reinforced thermoplastic pipe (RTP) comprising the tape, a method of manufacturing the tape and to uses of the tape.

BACKGROUND

Introduced more than a half century ago, fibre-reinforced polymer compositions are composite materials with a wide range of applications in industry, for example in the automotive industry. The term "composite" can apply to any combination of individual materials, for example to a thermoplastic polymer (the matrix) in which fibres (reinforcing filler) have been dispersed. The reinforced plastics industry has used glass fibres and fibrous textiles in different forms for reinforcing polymer matrices to produce a diversity of products.

An example of the variety of products are fibre-reinforced thermoplastic unidirectional UD tapes. Fibre-reinforced thermoplastic UD tapes are endless tapes that are reinforced with continuous fibres, wherein the fibres, e.g., glass, basalt, or carbon fibres, are unidirectionally aligned and embedded (covered/dispersed) in a thermoplastic material of the tape. The UD tapes are often used in spoolable reinforced thermoplastic pipes (RTPs), that are for example used for transporting fluids, like hydrocarbon fluids. The RTPs are sought in oil and gas transport to replace carbon steel pipes, which have the tendency to corrode. An RTP usually comprises an inner liner, through which the hydrocarbon fluid flows, an outer jacket, and, positioned between the inner liner and the outer jacket, a reinforcement layer. The reinforcement layer comprises the UD tape.

The thermoplastic materials that are used in the different layers of the RTP may not be completely impermeable to the components in the fluid, for example a hydrocarbon fluid like oil, that flows through the RTP. For example, oil contains aliphatic and aromatic hydrocarbons, but also CH₄, H₂S, CO₂ and H₂O. These gases can migrate through the inner liner and/or the reinforcement layer and accumulate at the interfaces between the layers of the RTP, thus for example at the interface between the inner liner and the reinforcement layer. The accumulation of these gases may cause delamination and/or ballooning/swelling issues.

Another issue that may occur due to the accumulation of the gases is material degradation due to high concentration of corrosive gases at the interfaces. The reinforcing fibres are susceptible to attack by water and acidic gases like H₂S and CO₂. These destroy the strength of the fibres and thus, weaken the RTP’s integrity.

EP 1473132 A2 relates to materials and methods for producing preform materials for impact-resistant composite materials suitable for liquid moulding. An interlayer comprises a spunbonded, spun laced, or mesh fabric is introduced between noncrimped layers of unidirectional reinforcing fibres o produce a preform for use in liquidmoulding processes to produce composite materials.

EP O 504 708 A 1 relates to a fibre reinforced plastics hollow object consisting of a resin-impregnated winding of high-strength fibres using a curing resin.

In light of these prior approaches there remains a need to reduce the accumulation of gases at the interfaces between the different layers of the RTP.

OBJECTIVE

It is therefore an object of the present invention to provide for a tape and a reinforced transportation pipe (RTP) comprising said tape and configured for transporting fluids.

SUMMARY

The foregoing object is achieved according to a first aspect of the invention that relates to a tape comprising an array of a plurality of longitudinally oriented fibres, wherein said array of fibres has two longitudinal sides, wherein one longitudinal side of the array is at least partially covered by a thermoplastic material.

The channels present between the longitudinally oriented fibres in the tape allow moisture and corrosive gases that diffuse through polymeric material of one or more layers of an RTP, e.g., the thermoplastic inner liner, the reinforcing layer, and the thermoplastic outer jacket, to be removed at such a rate before accumulation of the moisture and corrosive gases, such as acidic gases like H₂S and CO₂, at interfaces between the layers of the RTP can cause damage to said RTP. Hence, issues like delamination and ballooning/swelling and degradation of the fibres in the tape that could negatively affect the mechanical strength of said fibres can be strongly decreased or even prevented.

In a second aspect, the invention relates to a reinforced transportation pipe (RTP) configured for transporting fluids, said RTP comprising from a centre to a periphery a thermoplastic inner liner, a reinforcing layer comprising at least one layer of helically wound tape according to claim 1 , and a thermoplastic outer jacket, wherein said tape has a longitudinal side facing towards the periphery of the RTP and a longitudinal side facing towards the centre of the RTP, wherein on the other longitudinal side of the array channels are present which channels are each defined by two adjacent longitudinally oriented fibres, the thermoplastic material of said tape and one of the thermoplastic inner liner, the thermoplastic outer jacket and thermoplastic material of another layer of helically wound tape in said reinforcing layer, which channels allow for the transport of one or more gases along a helical direction of the RTP.

In a third aspect, the invention relates to a method of manufacturing a tape according to the first aspect, comprising the steps of:

1) providing the thermoplastic material;

2) melt compounding the thermoplastic material provided in step 1) in an extruder, preferably at 230 to 360 °C, to obtain a thermoplastic material melt;

3) providing the array comprising the plurality of longitudinally oriented fibres; 4) contacting the one longitudinal side of the array of fibres provided in step 3) with the thermoplastic material melt obtained in step 2), such that the one longitudinal side of the array of fibres is covered by the thermoplastic material melt and subsequently solidifying to obtain the tape.

In a fourth aspect, the invention relates to a use of a tape according to the first aspect or manufactured according to the method according to the third aspect for a reinforced thermoplastic pipe (RTP) configured for transporting of fluids.

In a fifth aspect, the invention relates to a use of a tape according to the first aspect of manufactured according to the method according to the third aspect for transporting one or more gases that accumulate in channels present on the other longitudinal side of the array of fibres along a helical direction of a reinforced thermoplastic pipe (RTP).

Corresponding embodiments disclosed below for the first aspect are also applicable to the RTP comprising the tape (second aspect), the method of manufacturing the tape (third aspect), and the uses of the tape (fourth and fifth aspects) according to the present disclosure, unless stated otherwise.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present disclosure is elucidated below with a detailed description.

Thermoplastic material

In the present description, with “thermoplastic material” is meant a thermoplastic polymer material that forms the matrix of the fibre-reinforced thermoplastic composite. The thermoplastic polymer material may comprise of at least one non-polar polymer and/or at least one polar-polymer.

Non-polar polymers

In the present description, with “non-polar polymer” is meant a type of polymer that lacks significant polar functional groups or has a symmetrical molecular structure that results in an even distribution of charge. In non-polar polymers, the electronegativity of the atoms involved is relatively balanced, leading to a lack of a net dipole moment within the polymer molecule.

Non-polar polymers typically exhibit properties such as low surface energy, resistance to polar solvents, and lower reactivity with other polar substances. They are often used in applications where these characteristics are advantageous, such as in packaging materials, insulating coatings, and non-stick surfaces.

The thermoplastic material comprises at least one non-polar polymer, such as polyolefins, polytetrafluoroethylene, or polyphenylene sulphide.

In the present description, with “polyolefin” is meant a polymer of olefin monomers, having the general formula (CH₂CHR)_n where R is an alkyl group. Examples are polyethylene, polypropylene, and polymethylpentene.

In the present description, with “PE” is meant polyethylene which is according to the structure below:

PE is usually a mixture of similar polymers of ethylene, with various values of n. It is a thermoplastic, non-polar polymer and can be low-density or high-density and many variations thereof. PE is relatively cheap and therefore commonly employed in packaging materials, containers, and various plastic products.

In the present description, with “PP” is meant polypropylene which is according to the structure below:

PP is a thermoplastic, non-polar polymer and is very similar to PE, but a much stronger polymer. Like PE, it is a relatively cheap polymer making it a popular choice in manufacturing. In the present description, with “PMP” is meant polymethylpentene which is according to the structure below:

PMP is a thermoplastic, non-polar polymer that has high heat resistance and low density. It has similar properties of PE and PP, although it is more brittle and more gas permeable.

In the present description, with “PTFE” is meant polytetrafluoroethylene according to the structure below:

Polytetrafluoroethylene is a fluorocarbon solid, as it is a high-molecular-weight polymer consisting wholly of carbon and fluorine.

In the present description, with “PPS” is meant polyphenylene sulphide according to the structure below:

This is a thermoplastic polymer consisting of aromatic rings linked by sulphides.

In the present description, with “PPO” is meant polyphenylene oxide according to the structure below:

Polyphenylene oxide (PPO), also known as polyphenylene ether, also has the polar ether linkage. This polymer has high hydrolytic and chemical stability and creep resistance at high temperatures. Neat PPO is thermally unstable at melting and extrusion temperatures. It is modified with polystyrene (PS), a non-polar polymer. The modified PPO is used for extrusion purposes. The modified PPO, which is a blend of PPO and PS, is a miscible system.

In an embodiment, the at least one non-polar polymer is selected from the group consisting of a polyolefin - such as polyethylene (PE), polypropylene (PP) and polymethylpentene (PMP) - polytetrafluoroethylene (PTFE), polyphenylene sulphide (PPS), polyphenylene oxide (PPO), and a combination of two or more thereof, preferably a polyolefin, such as polyethylene (PE) and polypropylene (PP).

Polar polymers

In the present description, with “polar polymer” is meant a type of polymer that contains polar functional groups or asymmetric structures, leading to an uneven distribution of charge within the polymer molecule. Polar functional groups typically involve electronegative atoms, such as oxygen, nitrogen, or fluorine, which create regions of partial negative and positive charges within the molecule.

In a polar polymer, the distribution of electrons is not uniform, resulting in a net dipole moment. This dipole moment gives the polymer certain properties, including enhanced interactions with other polar substances, higher surface energy, and specific electrical characteristics.

Polar polymers often exhibit different physical and chemical properties compared to non-polar polymers. They may have higher melting points, be more prone to interaction with polar solvents, and display different surface behaviours.

The thermoplastic material comprises at least one polar polymer, such as polyester, polyamide, aliphatic polyketone, aromatic polyketone, polyurethane, polyether sulfone, polyetherimide, polyvinyl chloride, polyvinylidene fluoride, polyvinyl acetate, polyacrylonitrile, polycarbonate. In the present description, with “polyester” is meant a polymer that contains an ester functional group in every repeat unit of their main chain and is according to the structure below:

Examples of polyesters are polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and liquid-crystal polyester.

In the present description, with “PET” is meant polyethylene terephthalate according to the structure below:

PET is a thermoplastic, polar polymer that consists of repeating (CI₀H₈O₄) units. It was formerly produced from ethylene glycol (monoethylene glycol, MEG) and dimethyl terephthalate (DMT) but mostly produced now by the reaction of MEG with terephthalic acid (purified terephthalic acid, PTA).

In the present description, with “PBT” is meant polybutylene terephthalate according to the structure below:

PBT is a thermoplastic, polar polymer that is closely related to PET. Compared to PET, PBT has slightly lower strength and rigidity, slightly better impact resistance, and a slightly lower glass transition temperature.

In the present description, with “PEN” is meant polyethylene naphthalate according to the structure below: PEN is a thermoplastic, polar polymer derived from naphthalene-2,6-dicarboxylic acid and ethylene glycol (MEG). It is related to PET, but with superior barrier properties.

In the present description, with “LCP” is meant liquid-crystal polyester which is a polymer having the property of forming a liquid crystal melt, usually containing aromatic rings as mesogens.

In the description, with “mesogen” is meant a compound that displays liquid crystal properties and can best be described as disordered solids or ordered liquids because they arise from a unique state of matter that exhibits both solid- and liquid-like properties called the liquid crystalline state.

In the present description, with “polyamides” is meant a polymer comprising amide bonds. There are several types of polyamides, such as aliphatic polyamides, aromatic polyamides or polyphthalamides. Examples are polyamide 11 and polyamide 12.

In the description, with “PA11 ” is meant polyamide 11 , also known as nylon 11 , according to the structure below:

PA11 is a type of synthetic polyamide known for its high strength, flexibility, and chemical resistance.

In the description, with “PA12” is meant polyamide 12, also known as nylon 12, according to the structure below:

PA12 is a versatile thermoplastic polymer valued for its flexibility, impact resistance, and chemical stability.

In the present description, with “aliphatic polyketone” is meant a polyketone comprising aliphatic comonomer(s) (POK), such as carbon monoxide, ethylene, and propylene monomers, according to the structure below:

In the present description, with “POK” is meant a polyketone polymer that is built from aliphatic comonomers. POKs are a family of thermoplastic polymers comprising polar ketone groups in the polymer backbone. They are prepared by polymerizing carbon monoxide with an olefin as comonomer (e.g., ethylene). POK come in different types depending on 1) the number of comonomers and; 2) the types of comonomer(s). When one olefin comonomer is used the term copolymer is often used and when two olefin comonomers are used the term terpolymer is often used.

The two most common types of aliphatic POK are copolymers built from the monomers carbon monoxide and ethylene (R being hydrogen), and terpolymers built from the monomers carbon monoxide, ethylene, and a second olefin comonomer which can be propylene, butylene (e.g., 1-butene), hexylene, octene, or dodecene (in the comonomers, R is methyl, butyl, hexyl, octyl, or dodecyl).

POKs have polar ketone groups in the polymer backbone and the presence of these ketone groups provides strong attraction between polymer chains, which increases the material’s melting point to about 260 °C for the copolymer (having carbon monoxide and ethylene monomers) and about 220 °C for the terpolymer (having carbon monoxide, ethylene, and propylene monomers).

In the present description, with “aromatic polyetherketone” is meant a polyetherketone comprising comonomer(s) having aromatic groups (PEK). PEKs are polymers whose backbone contain alternating ketone (R-CO-R) and ether (R-O-R) functionalities. The most common are PAEKs.

In the present description, with “PAEK” is meant polyaryletherketone. This is a family of PEK whose molecular backbone contains alternately ketone (Aryl-CO-Aryl) and ether groups (Aryl-O-Aryl), wherein Aryl is a 1 ,4-substituted aryl group. These polymers are semi-crystalline thermoplastics with high-temperature stability and high mechanical strength. In the present description, with “PEEK” is meant polyetheretherketone according to the structure below:

PEEK is a PEK, more specifically of the PAEK family. PEEK is a semicrystalline thermoplastic with excellent mechanical and chemical resistance properties that are retained to high temperatures. The processing conditions used to mould PEEK can influence the crystallinity and hence the mechanical properties.

In the present description, with “PEKK” is meant polyetherketoneketone according to the structure below:

PEKK is also a PEK, more specifically of the PAEK family. PEKK is a semicrystalline thermoplastic with excellent mechanical and chemical resistance properties that are retained to high temperatures.

In the present description, with “PU” is meant polyurethane, also often abbreviated as PUR. It is a class of polymers composed of organic units joined by carbamate (urethane) links. It can be produced from a wide range of starting materials leading to a variety of polyurethanes with different chemical structures and thus, different properties. An example of a PU is the structure below:

PU is typically produced by reacting an isocyanate with a polyol (resulting in the polyurethane structure above). Since a polyurethane contains two types of monomers, which polymerize one after the other, they are classed as alternating copolymers. Both the isocyanates and polyols used to make a polyurethane contain two or more functional groups per molecule.

In the present description, with “PES” is meant polyethersulfone according to the structure below. This is a thermoplastic polymer comprising ether bonds, aromatic rings, and sulfone bonds in the backbone:

In the present description, with “PEI” is meant polyetherimide. This is a high- temperature thermoplastic polymer just like PEEK. Compared to PEEK, it has a lower impact strength. PEI contains phthalimide and bisphenol A subunits. It has the following structure:

In the present description, with “PVC” is meant polyvinylchloride according to the structure below:

PVC is produced by polymerization of the vinyl chloride monomer (VCM). The presence of the chloride groups gives the polymer very different properties from the structurally related PE.

In the present description, with “PVDF” is meant polyvinylidene fluoride, being a fluorinated type of polyolefin. It has the following structure:

PVDF is a thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. In the description, with PVA is meant polyvinyl acetate according to the structure below:

PVA is an aliphatic rubbery synthetic polymer. It is a type of thermoplastic polymer. PVA is prepared by the polymerization of vinyl acetate monomer (free-radical vinyl polymerization of the monomer vinyl acetate).

In the present description, with “PAN” is meant polyacrylonitrile according to the structure below:

PAN is a synthetic, semicrystalline organic polymer resin. Almost all PAN are copolymers with acrylonitrile as the main monomer.

In the present description, with “PC” is meant polycarbonate according to the structure below:

PC is a group of thermoplastic polymers containing carbonate groups in their chemical structures. The main PC material is produced by the reaction of bisphenol A (BPA) and phosgene (COCI₂). An alternative route to produce PC entails transesterification from BPA and diphenyl carbonate.

The thermoplastic material may have: a melt mass-flow rate (MFR) of at least 30 g/10min, preferably at least 60 g/10min, more preferably at least 100 g/10min, most preferably between 30 and 150 g/10min measured at 240 °C with a load of 2.16 kg according to ASTM D1238-23; and/or a viscosity of at most 100 Pa s, preferably at most 70 Pa s, measured about 20 °C above the melting temperature of the composition according to ISO 6721.

The MFR of a polyamide or polyester can be adjusted by controlling the moisture present in the melt by selecting the drying time of the polar polymer. The MFR of a PP can be adjusted by controlling its molecular weight by 'cracking' of the PP.

In order to blend the non-polar and the polar polymers, each of said non-polar and polar polymers preferably has a viscosity of from about 50 to about 100 Pa s, measured at 240 °C according to ISO 6721.

In an embodiment, said thermoplastic material comprises at least one non-polar polymer, at least one polar polymer, or a polymer blend of at least one non-polar polymer and at least one polar polymer, preferably said thermoplastic material comprises polyethylene (PE) or polypropylene (PP).

(Reinforcing) fibres

The fibres in the array, which may be reinforcing fibres, are covered by the thermoplastic material, preferably such that they are unidirectionally aligned in the thermoplastic material in order to obtain the fibre-reinforced thermoplastic tape according to the first aspect of the invention. The fibres may be selected from the group consisting of glass fibres, carbon fibres, basalt fibres, ceramic fibres, aramid fibres, hemp fibres, flax fibres, sisal fibres, and one or more combinations thereof, preferably glass fibres, carbon fibres, and/or basalt fibres. This broad range of types of fibres that are suitable for reinforcing the thermoplastic material provides extra flexibility to the manufacturing process and makes it less dependent on one or a few types of fibres. In the present description, with “unidirectionally aligned reinforcing fibres” is meant that substantially all fibres, preferably all fibres, are aligned in a single direction. In the present description, with “single direction” is meant the longitudinal direction of the tape, i.e., the machine direction in which the tape is manufactured.

In the present description, with “parallel aligned continuous multifilament strands” is meant that the reinforcing fibres are continuous strands of fibres that are positioned in parallel to each other in the longitudinal direction of the tape. The fibres in the fibre- reinforced thermoplastic tape are generally supplied as a plurality of continuous, very long filaments, and can be in the form of strands, rovings, or yarns.

A filament is an individual fibre of reinforcing material. A strand is a plurality of bundled filaments. Yarns are collections of strands, for example strands twisted together. A roving refers to a collection of strands wound into a package.

In the present description, with “continuous” in connection with fibres, filaments, strands, yarns, or rovings is meant that the fibres, strands, filaments, yarns, or rovings generally have a significant length. However, it should not be understood to mean that the length of the fibres, strands, filaments, yarns, or rovings is perpetual or infinite. Continuous fibres, such as continuous filaments, strands, yarns, or rovings have a length of more than 100 mm, preferably more than 1000 mm, depending on the length of the of the tape. Most preferably, the fibres have the same length as the tape.

In the present description, with “reinforcing fibres” is meant fibres that are added to the thermoplastic material with the purpose of improving the thermoplastic material’s strength. In other words, fibres that reinforce the thermoplastic material.

In the present description, with “glass fibres” is meant a material that consists of numerous extremely fine fibres of glass. Thin strands of silica-based or other formulation glass are extruded into many fibres with small diameters suitable for textile processing. The most common type of glass fibre is E-glass, which is alumino-borosilicate glass. E-glass has less than 1 wt.% alkali oxides and is mainly used for glass-reinforced plastics. Other types of glass used are A-glass (alkali-lime glass with little or no boron oxide), E-CR-glass (Electrical/Chemical Resistance; alumino-lime silicate with less than 1 wt.% alkali oxides, with high acid resistance), C-glass (alkali-lime glass with high boron oxide content, used for glass staple fibres and insulation), D-glass (borosilicate glass, named for its low dielectric constant), R-glass (alumino silicate glass without MgO and CaO with high mechanical requirements as reinforcement), and S-glass (alumino silicate glass without CaO but with high MgO content with high tensile strength).

In the present description, with “carbon fibres” is meant carbon fibres (alternatively OF or graphite fibre) having a diameter of about 5 to 10 micrometres that are composed mostly of carbon atoms, arranged in a graphitic structure. Specifically, the graphene planes are oriented parallel to the carbon fibre’s axis. Carbon fibres have several advantages: high stiffness, high tensile strength, high strength to weight ratio, high chemical resistance, high-temperature tolerance, and low thermal expansion.

However, they are relatively expensive compared to similar fibres, such as glass fibres and basalt fibres.

In the present description, with “basalt fibres” is meant fibres that are produced from basalt rocks by melting them and converting the melt into fibres. Basalt fibres, or more specifically basalt continuous fibres, can be used for the production of reinforcing materials and composite products. Basalt fibres are made from a single material, crushed basalt, from a carefully chosen quarry source. Basalt of high acidity (over 46% silica content) and low iron content is considered desirable for fibre production. Unlike with other composites, essentially no materials are added during its production: the basalt is simply washed and then melted. Basalt fibres are fire resistant and do not burn, which makes them very suitable as a reinforcing material in a tape that requires good flame retardancy. Furthermore, when basalt fibres are used to strengthen polymers, its composites have good strength, high working temperature range, good chemical resistance, excellent heat and sound insulation properties and low water absorption. In addition, basalt fibres are easy to process, environmentally friendly, and relatively cheap.

In the present description, with “ceramic fibres” is meant fibres that are smalldimension filaments or threads composed of ceramic material, usually alumina and silica, used in lightweight units for electrical, thermal, and sound insulation. Mainly, ceramic fibres are of two types: ceramic oxide fibres and ceramic non-oxide fibres.

Ceramic oxide fibres mostly consist of alumina (AI₂O₃) and alumina-silica (AI₂O₃-SiO₂) mixtures and are generally used for high-temperature applications due to their high melting points. Ceramic oxide fibres are used both as insulation and as reinforcement material. The mostly known examples for oxide ceramic fibres are composed of oxides such as silica (SiO₂), mullite (3AI₂O₃ 2SiO₂), alumina (AI₂O₃), and zirconia (ZrO₂) having different characteristic properties.

Production of non-oxide fibres is difficult due to their high melting points and resistance to densification. Oxidation resistance tends to be their main deficiency. Examples are silicon carbide-based fibres. Silicon carbide (SiC) fibres have an excellent combination of high strength, modulus, and thermal stability, including good oxidation resistance and mechanical properties (compressive-tensile strength) at high temperatures. Silicon carbide-based fibres are generally applied as continuous fibre in ceramic matrix. This type of ceramic matrix composites (CMCs) is used in hot section of engines for power, etc.

In the present description, with “aramid fibres” is meant aromatic polyamide fibres, which are a class of heat-resistant and strong synthetic fibres. The chain molecules in the fibres are highly oriented along the fibre axis. As a result, a higher proportion of the chemical bond contributes more to fibre strength than in many other synthetic fibres. Aramids have a very high melting point (>500 °C). Aromatic in the name refers to the presence of aromatic rings of six carbon atoms. In aramids these rings are connected via amide linkages each comprising a CO group attached to an NH group. Aramids are divided into two main types according to where the linkages attach to the rings: para-aramids and meta-aramids. Numbering the carbon atoms sequentially around a ring, para-aramids have the linkages attached at positions 1 and 4, while meta-aramids have them at positions 1 and 3. That is, the attachment points are diametrically opposite each other in para-aramids, and two atoms apart in metaaramids.

In the present description, with “hemp fibres” is meant vegetable fibres that are generally based on arrangements of cellulose, often with lignin, derived from the hemp plant under the species Cannabis.

In the present description, with “flax fibres” is meant vegetable fibres that are extracted from the bast or skin of the stem of the flax plant (Linum usitatissimum L).

In the present description, with “sisal fibres” is meant vegetable fibres that are derived from the plant under the species Agave Sisalana.

Whichever fibre is chosen, the fibres should have a suitable size applied to them. The size is selected to protect the fibre during handling, but also to provide good adhesion to the thermoplastic polymer, thereby increasing the strength of the tape. The size on the fibre has to be selected according to the thermoplastic material.

In the present description, with “distribution of fibres throughout the tape” is meant the distribution of the fibres over the width of the fibre-reinforced thermoplastic tape transverse to the longitudinal direction (i.e., machine direction) of the fibres. A relatively uneven distribution may result in the tape having undesirable and/or unpredictable structural characteristics. A relatively even distribution means that the continuous unidirectionally aligned fibres are evenly distributed in the tape and provides a tape having desirable and/or predictable structural characteristics. Preferably, the distribution of the fibres is relatively even.

In the present description, with “close to surface” is meant that the average distance between the top or bottom surface of the fibre-reinforced thermoplastic tape and the fibres embedded in or covered by the fibre-reinforced thermoplastic tape is between 5 and 20 % of the thickness of the fibre-reinforced thermoplastic tape.

The fibres may have a diameter of between 4 and 20 pm, preferably between 8 and 13 pm and/or a length of at least 100 mm, preferably at least 1000 mm. The fibres of this specific diameter and/or length provide sufficient strength to the tape over the whole length (in the longitudinal direction) of the U tape. Furthermore, it also allows the preparation of a fibre-reinforced thermoplastic tape having a relatively low thickness.

Preferably, said longitudinally oriented fibres are unidirectionally aligned reinforcing fibres that extend in the longitudinal direction of the tape. Hence, the tape according to the first aspect of the present disclosure is thus a fibre-reinforced thermoplastic unidirectional (UD) tape. Such an orientation of the fibres not only has the function of transporting diffusing gases, but it also improves the strength of the tape over the whole length (in the longitudinal direction) of the tape while maintaining the flexibility of the tape. In the present description, with “longitudinal direction” is meant the machine direction in which the tape is produced.

Additives

The thermoplastic material of the tape may comprise one or more additives. The one or more additives is preferably selected from the group consisting of compatibilizers, adhesion-enhancing copromotors, stabilizers, impregnation agents, lubricants, antioxidants, and flame retardants.

In the present description, with “additives” is meant an additive for the thermoplastic polymers used that may be present in the thermoplastic material. Additives are often used to improve the properties of the thermoplastic polymers. Examples include compatibilizers and stabilizers.

In the present description, with “compatibilizers” is meant an additive that aids in the compatibility between different thermoplastic polymers. Compatibilizer are polymers that have functional groups similar to both non-polar and polar polymers. Without them, immiscible polymers in the molten state when shearing is stopped would segregate into two layers like oil and water.

Block copolymers comprise of two or more homopolymer subunits linked by covalent bonds. They are made up of blocks of different polymerized monomers. Examples are diblock copolymers, which have two distinct blocks (e.g., ~A-A-A-A-A-B-B-B-B-B~), and triblock copolymers, which have three distinct blocks (e.g., ~A-A-A-A-B-B-B-B-C- C-C-C-).

Graft copolymers are segmented copolymers with a linear backbone of one chain segment and randomly distributed branches of another chain segment, which is structurally different from the former chain segment forming the linear backbone.

A terpolymer is a copolymer that contains three types of repeat units. Hence, a terpolymer is formed from the polymerization of three different monomers. The resulting polymer chain contains repeating units of all three monomers. An example is a random terpolymer of ethylene, acrylic ester, and glycidyl methacrylate.

In the present description, with “adhesion-enhancing copromotors” is meant a substance, being a copromotor, that enhances the adhesion of the thermoplastic material and the fibres covered by the thermoplastic material.

In the present description, with “stabilizers” is meant an additive that aids in the prevention of heat, oxidation, and chemical degradation of the fibre-reinforced thermoplastic composite. Examples include phenolic alkylene dicarboxylates that provide stabilization against degradation with a reduced tendency to yellow discoloration and improved melt, processing performance over an extended period of time, aluminium phosphate or aluminium silicate treated with polyethylene glycol that improves the colour stability of the material, and zinc oxide or lead stabilizer that also improves the colour stability and furthermore improves the thermal stability of POK and its processing temperature window. In the present description, with “impregnation agent” or “impregnating agent” is meant a material that is compatible with the thermoplastic polymer to be reinforced and may even be soluble in said polymer. The skilled person can select suitable combinations based on general knowledge, and may also find such combinations in the art.

Suitable examples of impregnating agents include low molar mass compounds, for example low molar mass or oligomeric polyurethanes, polyesters such as unsaturated polyesters, polycaprolactones, polyethyleneterephthalate, poly(alpha-olefins), such as highly branched polyethylenes and polypropylenes, polyamides, such as nylons, and other hydrocarbon resins.

Preferably, the impregnating agent is non-volatile, and/or substantially solvent-free. In the context of the present invention, non-volatile means that the impregnating agent has a boiling point or range higher than the temperatures (about 230-240 °C) at which the polymer’s melt impregnation is conducted over the reinforcing fibres. In the context of present invention, “substantially solvent-free” means that the impregnating agent contains less than 10 wt.% of solvent, preferably less than 5 wt.% of solvent based on the impregnating agent. In a preferred embodiment, the impregnating agent does not contain any organic solvent.

In the present description, with “lubricants” is meant a material that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. Examples are stearamides and stearates, such as EBS, calcium stearate or magnesium stearate.

In the present description, with “antioxidants” is meant a compound that inhibits oxidation, a chemical reaction that can produce free radicals. The antioxidant additive may comprise one, two or more phenolic groups. These phenolic antioxidant additives may be sterically hindered phenolic additives. Examples are tris(2,4-di-tert- butylphenyl)phosphite, commercially available as Irgafos 168, and octadecyl-3-[3,5- di-tert-butyl-4-hydroxyphenyl]propionate, available from BASF as Irganox 1076. In the present description, with “flame retardants” is meant a material that is activated by the presence of an ignition source and is intended to prevent or slow the further development of ignition by a variety of different physical and chemical methods. They may be added as a copolymer during the polymerisation process, or later added to the polymer at a moulding or extrusion process or applied as a topical finish. Examples are minerals such as aluminium hydroxide (ATH), magnesium hydroxide (MDH), huntite and hydromagnesite, organohalogen compounds such as organochlorines, organobromines, and polymeric brominated compounds, organophosphorus compounds such as organophosphates, phosphonates, and phosphinates, and organic compounds such as carboxylic acid and dicarboxylic acid.

Reference to the tape applies to the tape according to the first aspect and the tape of the RTP according to the second aspect, unless otherwise stated.

The tape according to the first aspect of the present disclosure comprises a plurality of longitudinally oriented fibres that is partially covered by the thermoplastic material. In other words, the tape comprises a parallel array of fibres covered by the thermoplastic material.

The tape may have channels present on both longitudinal sides of the array of fibres that allow the transport of one or more gases along a longitudinal direction of the tape or along a longitudinal direction of the RTP, respectively. Thus, in this particular embodiment, both longitudinal sides of the array of fibres are partially covered by the thermoplastic material. In some applications, gases/moisture may diffuse from both the outside and inside of the RTP through the thermoplastic material. By having channels present at both sides of the tape, the gases/moisture diffusing from the centre towards the periphery of the RTP (thus diffusing through the thermoplastic inner liner) and diffusing from the periphery towards the centre of the RTP (thus diffusing through the thermoplastic outer jacket) can be removed before they can damage the RTP. In an embodiment, the one longitudinal side of the array of fibres that is at least partially covered by the thermoplastic material, is completely covered by the thermoplastic material.

The skilled person will understand that the feature wherein on the other longitudinal side of the array channels are present which channels are each defined by two adjacent longitudinally oriented fibres also includes a tape having sections, like 1 -2 cm wide sections along the longitudinal direction of the tape, that are partially impregnated. Lower amounts of resin could be applied from the die on the tape at those sections, which may result into partially impregnated bands of tape. To be clear, these partially impregnated band-like sections may be present on both longitudinal sides of the array of fibres of the tape.

In the present description, with “unidirectional (UD) tape” is meant a tape that comprises endless fibre-reinforced tapes of different widths with unidirectionally aligned reinforcing fibres. In UD tapes, fibres, such as glass fibres or carbon fibres, are covered so ideally by the thermoplastic material that completely new possibilities arise in the production of components. Despite their low thickness, UD tapes have a high level of stability and are also particularly light. In addition, UD tapes can be processed efficiently and, depending on the combination and additives present, are flame retardant. Furthermore, the UD tape is collected and stored on rolls and hence it can be cut to length and width according to the application. Another important property of thermoplastic UD tape is the possibility of recycling.

The tape may have a width of at least 2 cm, preferably between 5 and 20 cm, more preferably between 8 and 15 cm and/or has a thickness of between 100 and 800 pm, preferably between 150 and 500 pm, more preferably between 250 and 350 pm. A tape of these dimensions provides optimal balance between flexibility and applicability and strength. This makes them particularly suitable for the production of complex component shapes.

In an embodiment, the longitudinal sides of the array of fibres each have a thickness and wherein a ratio between said thicknesses of the longitudinal sides of the array of fibres is between 20:1 and 1 :20, preferably between 10:1 and 1 :10, more preferably between 3: 1 and 1 :3, such as between 2:1 and 1 :2.

Conversion of the thermoplastic material to a thermoset material

For some applications, it is desirable to convert the thermoplastic material of the tape to a thermoset material. This can for example be done via heat-induced cross-linking. The cross-linking of the thermoplastic material is performed after production (shaping or moulding) of the article comprising the tape, such as the UD tape.

In an embodiment, the thermoplastic material of the tape comprises at least one crosslinked non-polar polymer and/or at least one cross-linked polar polymer. This is beneficial, as the tape is more resistant to creep, and this allows for the use above the lowest melting point of the polymers in the tape for short periods of time.

Method of manufacturing the tape

By reducing the feed of thermoplastic material at some regions bands of partially impregnated tape sections can be generated. By tweaking the impregnation process metrics, e.g., hardware and settings, the impregnation quality at different parts of the tape can be influenced. By doing so, the desired output, i.e., tape having a partially or completely covered surface, can be obtained.

Contacting of the one longitudinal side of the array of fibres with the thermoplastic material melt is preferably done by impregnating. The impregnating the array of fibres contacted with the thermoplastic material melt is done by extruding a thin layer, also known as a film layer, of the thermoplastic material melt over the array of fibres and passing the array of fibres contacted with the thermoplastic material melt through hot rollers.

In the present disclosure, the thickness at the die opening is about 0.8 mm and the film layer get thinner when falling onto fibres. The melt/resin flow is controlled knowing that the resin can flow and be pushed through thickness and in plane (width direction) when going along the impregnation rollers. The thickness of the film layer gets to about 0.15 mm thickness. The film layer is thus in the order of 0.1 to 0.3 mm depending on the tape thickness.

In the present disclosure, with “solidification” is meant that the tape goes through rollers for cooling and calendaring.

Depending on the thickness of the layer, the contacted (impregnated) side of the array of fibres is partially or almost completely, preferably completely, covered by the thermoplastic material melt. For the array of fibres to be partially covered by the thermoplastic material melt and thus, to have the channels present between the fibres, the impregnation rollers process settings, like temperature and pressure, can be tuned accordingly.

It is also possible to obtain tapes having sections, like 1 -2 cm wide sections along the length of the tape, that are partially impregnated. Lower amounts of resin could be applied from the die on the tape at those sections, which may result into partially impregnated bands of tape. This may be on one or both longitudinal sides of the tape.

In step 4) of the method according to the third aspect of the present disclosure, the other longitudinal side of the array of fibres may be contacted with the thermoplastic material melt obtained in step 2) in a similar manner as the one longitudinal side.

The tape can be made in a continuous process and can be collected as a roll.

Use

In an embodiment of the fourth aspect of the present disclosure, the tape according to the first aspect or manufactured according to the third aspect is used for an RTP configured for transporting hydrocarbon fluids. In the present description, with “fluids” is meant liquids, such as water, and gasses, such as butane.

Applications

In the present description, with “reinforced thermoplastic pipe (RTP)” is meant a multilayer pipe of thermoplastic material that is reinforced. Other names used are Flexible Composite Pipes, Thermoplastic Composite Pipes, Flexible Flowline, Flexible Line Pipe, Spoolable Reinforced Plastic Line Pipe, Flexible Reinforced Pipe, Reinforced Line Pipe or Spoolable Composites. For offshore use other names include Offshore Flexibles or Flexible Umbilical Risers. According to the present disclosure, an RTP includes from the centre of the RTP to the periphery of the RTP at least the following layers: a thermoplastic inner liner, a reinforcement layer comprising one or more windings of tape, and a thermoplastic outer jacket. The outer jacket provides protection of the tape windings from external mechanical damage.

The RTP may further comprise at least one vent positioned at an end fitting of the RTP arranged for releasing one or more gases that accumulate in and are transported through the channels along the helical direction of the RTP. Another option is to strip a section of the outer jacket, e.g., 1 cm wide, close to the end fitting for releasing the one or more gases. This allows faster removal of the gases and reduces the issues of delamination and/or ballooning/swelling even further. The risk of material degradation, of for example the fibres in the tape, is also further reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is described hereinafter with reference to the accompanying drawings in which embodiments of the present disclosure are shown and in which like reference numbers indicate the same or similar elements. The present disclosure is in no manner whatsoever limited to the embodiments disclosed therein.

Figure 1 shows a tape according to the present disclosure;

Figure 2A shows a close-up view of part of one longitudinal side of the array of fibres of the tape of Fig. 1 ;

Figure 2B shows a close-up view of part of another longitudinal side of the array of fibres of the tape of Fig. 1 ;

Figure 3 shows a cross-sectional view of the tape of Fig. 1 ;

Figure 4 shows a schematic representation of an end part of an RTP;

Figure 5 shows a schematic representation of part of an RTP comprising a tape helically wound around the thermoplastic inner liner of the RTP; Figure 6 shows schematically a method of manufacturing the tape according to the present disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a tape 1 of glass fibres covered by a polypropylene material 9. The tape 1 comprises an array 3 comprising a plurality of glass fibres that are oriented in the longitudinal direction of the tape 1 (indicated by the arrow). The glass fibres are partially covered by the polypropylene material 9.

The partial covering of the glass fibres in the polypropylene 9 is shown in Fig 2A. The close-up view of part of the surface of the one longitudinal side 7 of the array of fibres 3 of the tape 1 of Fig. 1 shows that the surface is relatively rough. The rough surface is due to the array of fibres 3 being partially covered by the polymeric material (polypropylene) 9. Hence, the fibres are partially impregnated with the polypropylene 9. The partial covering results in channels 13 being present between the longitudinally oriented fibres. These channels 13 allow the transport of gases along the longitudinal direction of the tape 1 (indicated by the arrow).

Fig. 2B shows a close-up view of the other longitudinal side 7 of the array of fibres 3 of the tape 1 of Fig. 1 . The other longitudinal side 7 shows a smooth surface indicating that this side 7 of the array of fibres 3 is completely, or nearly completely, impregnated by the polypropylene 9.

Fig.3 shows a cross-sectional view along the line A-A shown in Fig. 1 of the tape 1 . It clearly shows that the one longitudinal side 5 of the array of fibres 3 is (almost) completely covered by the thermoplastic material 9 and that the other longitudinal side 7 of the array of fibres 3 comprises multiple channels 13.

In Fig. 4, an end part 17 of an RTP 1 1 is shown. The end part 17 comprises multiple vents 15 that are arranged for releasing one or more gases that accumulate in and are transported through the channels 13 along the helical direction of the RTP 1 1 . Fig. 5 shows part of an RTP 11 , wherein the tape 1 is wound around the thermoplastic inner liner of the RTP 11 in the helical direction, as indicated with the arrow.

A schematic representation of the method 101 of manufacturing a tape 1 according to the present disclosure is shown in Fig. 6. The method 101 comprises the steps of 1) providing 103 the thermoplastic material 9; 2) melt compounding 105 the thermoplastic material 9 provided in step 1) in an extruder to obtain a thermoplastic material melt; 3) providing 107 the array comprising the plurality of longitudinally oriented fibres 3; 4) contacting 109 the one longitudinal side 5 of the array of fibres 3 provided in step 3) with the thermoplastic material melt obtained in step 2) such that the one longitudinal side 5 of the array of fibres 3 is covered by the thermoplastic material melt and subsequently solidifying to obtain the tape 1.

Modifications and additions to the embodiments disclosed above are obvious to those skilled in the art and covered by the scope of the appended claims. Embodiments of the first aspect of the present disclosure are also applicable to the second or further aspects of the present disclosure.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope thereof. The scope of the present disclosure is defined by the appended claims. One or more of the objects of the present disclosure are achieved by the appended claims.

Claims

1 . A tape (1) comprising an array of a plurality of longitudinally oriented fibres (3), wherein said array of fibres (3) has two longitudinal sides (5, 7), wherein one longitudinal side (5) of the array (3) is at least partially covered by a thermoplastic material (9) and the other longitudinal side (7) defines channels (13), with each channel (13) defined by two adjacent longitudinally oriented fibres, wherein the channels (13) are sized to allow for the transport of one or more gases along a helical direction of an RTP (11) made from the tape (1) with the tape (1) covered by a liner or jacket.

2. A reinforced transportation pipe (RTP) (11) configured for transporting fluids, said RTP (11) comprising from a centre to a periphery a thermoplastic inner liner, a reinforcing layer comprising at least one layer of helically wound tape (1) according to claim 1 , and a thermoplastic outer jacket, wherein said tape (1) has a longitudinal side facing towards the periphery of the RTP (11) and a longitudinal side facing towards the centre of the RTP (11), wherein on the other longitudinal side (7) of the array (3) channels (13) are present which channels (13) are each defined by two adjacent longitudinally oriented fibres, the thermoplastic material (9) of said tape (1) and one of the thermoplastic inner liner, the thermoplastic outer jacket and thermoplastic material (9) of another layer of helically wound tape (1) in said reinforcing layer, which channels (13) allow for the transport of one or more gases along a helical direction of the RTP (11).

3. Tape (1) according to claim 1 or RTP (11) according to claim 2, wherein on both longitudinal sides (5, 7) of the array (3) channels (13) are present that allow the transport of one or more gases along a longitudinal direction of the tape (1) or along a longitudinal direction of the RTP (11), respectively.

4. Tape (1) according to claim 1 or RTP (11) according to claim 2, wherein the one longitudinal side (5) of the array (3) that is at least partially covered by the thermoplastic material (9), is completely covered by the thermoplastic material (9).

5. Tape (1) according to claim 1 or RTP (11) according to any of the claims 2 to

4, wherein said longitudinally oriented fibres are unidirectionally aligned reinforcing fibres that extend in the longitudinal direction of the tape (1).

6. Tape (1) according to claim 1 or RTP (11) according to any of the claims 2 to

5, wherein said fibres are selected from the group consisting of glass fibres, carbon fibres, basalt fibres, ceramic fibres, aramid fibres, hemp fibres, flax fibres, sisal fibres, and one or more combinations thereof, preferably glass fibres, carbon fibres, and/or basalt fibres.

7. Tape (1) according to claim 1 or RTP (11) according to any of the claims 2 to

6, wherein said tape (1) has a width of at least 2 cm, preferably between 5 and 20 cm, more preferably between 8 and 15 cm.

8. Tape (1) according to claim 1 or RTP (11) according to any of the claims 2 to 6, wherein said tape (1) has a thickness of between 100 and 800 pm, preferably between 150 and 500 pm, more preferably between 250 and 350 pm.

9. Tape (1) according to claim 1 or RTP (11) according to any of the claims 2 to

8, wherein said thermoplastic material (9) comprises at least one non-polar polymer, at least one polar polymer, or a polymer blend of at least one non-polar polymer and at least one polar polymer, preferably said thermoplastic material (9) comprises polyethylene (PE) or polypropylene (PP).

10. Tape (1) according to claim 1 or RTP (11) according to any of the claims 2 to

9, wherein the longitudinal sides (5, 7) of the array of fibres (3) each have a thickness and wherein a ratio between said thicknesses of the longitudinal sides (5, 7) of the array of fibres (3) is between 20: 1 and 1 :20, preferably between 10:1 and 1 :10, more preferably between 3:1 and 1 :3, such as between 2:1 and 1 :2.

11. RTP (11) according to claim 2, further comprising at least one vent (15) positioned at an end fitting (17) of the RTP (11) arranged for releasing one or more gases that accumulate in and are transported through the channels (13) along the helical direction of the RTP (11).

12. A method (101) of manufacturing a tape (1) comprising an array of a plurality of longitudinally oriented fibres (3), wherein said array of fibres (3) has two longitudinal sides (5, 7), wherein one longitudinal side (5) of the array (3) is at least partially covered by a thermoplastic material (9), the method com comprising the steps of:

1) providing (103) the thermoplastic material (9);

2) melt compounding (105) the thermoplastic material (9) provided in step 1) in an extruder, preferably at 230 to 360 °C, to obtain a thermoplastic material melt;

3) providing (107) the array comprising the plurality of longitudinally oriented fibres (3);

4) contacting (109) the one longitudinal side (5) of the array of fibres (3) provided in step 3) with the thermoplastic material melt obtained in step 2), preferably by impregnating, such that the one longitudinal side (5) of the array of fibres (3) is covered by the thermoplastic material melt and subsequently solidifying to obtain the tape (1).

13. A use of a tape (1) according to claim 1 or manufactured according to the method (101) according to claim 12 for a reinforced thermoplastic pipe (RTP) (11) configured for transporting of fluids, preferably hydrocarbon fluids.

14. A use of a tape (1) according to claim 1 or manufactured according to the method (101) according to claim 12 for transporting one or more gases that accumulate in channels (13) present on the other longitudinal side (7) of the array of fibres (3) along a helical direction of a reinforced thermoplastic pipe (RTP) (11).