COMPOSITION

Abstract

A composition for application to a substrate is provided. The composition comprises a base component and an activator component. The base component comprises hydroxyl functional prepolymers and the activator comprises isocyanate prepolymers. The composition further comprises an amount of carbon fibre. The hydroxyl functional prepolymers are formulated to polymerise with the isocyanate prepolymers to form a polymer containing carbon fibre.

Claims

1. A method of applying a composition to a pipe, the method comprising the steps of: mixing a base component and an activator component to form a mixed composition, wherein the base component comprises hydroxyl functional prepolymers and the activator comprises isocyanate prepolymers, wherein the mixed composition further comprises an amount of carbon fiber, and wherein the hydroxyl functional prepolymers are formulated to polymerize with the isocyanate prepolymers to form a polymer containing carbon fiber; applying the mixed composition to the inside of a pipe with an apparatus, wherein the apparatus comprises; a first flow path for carrying the base component; a second flow path for carrying the activator component; a mixer coupled to the first flow path and the second flow path, wherein the mixer is configured to mix the base component and activator component to form the mixed composition; and an applicator head coupled to the mixer, where the applicator head is configured for rotation about an axis and comprises an applicator hole, wherein the applicator is configured for applying the mixed composition to the inside of the pipe.

2. The method of claim 1, wherein: the applicator hole comprises a plurality of the applicator holes spaced along an axial length of the applicator head, wherein the plurality of applicator holes are arranged in a spiral extending around a surface of the applicator head.

3. The method of claim 1, wherein: the applicator hole comprises a plurality of applicator holes arranged in a first spiral and a second spiral extending around a surface of the applicator head, wherein the first spiral is a right-handed spiral and the second spiral is a left-handed spiral.

4. The method of claim 1, wherein: the applicator head comprises a cylindrical portion, and wherein the applicator hole comprises a plurality of applicator holes extending through a surface of the cylindrical portion.

5. The method of claim 1, wherein: the applicator head comprises a first end coupled to the mixer, the applicator head comprises a second end distal the first end, and wherein the second end is closed.

6. The method of claim 1, wherein: at least one of the first flow path and the second flow path comprises a hose coupled to the mixer and configured to carry at least one of the base component and the activator component to the mixer, wherein the hose has a diameter of 25 mm or greater; and wherein the applicator hole has a diameter of 3 mm or greater.

7. The method of claim 1, wherein: at least one of the first flow path and the second flow path comprises a hose coupled to the mixer and configured to carry at least one of the base component and the activator component to the mixer, and wherein the hose is lined with polytetrafluoroethylene.

8. The method of claim 1, wherein: the applicator head is configured for atomizing the mixed composition by a centrifugal force generated by rotation of the applicator head about the axis.

9. The method of claim 8 wherein: the mixed composition is applied to the inside of the pipe by virtue of the centrifugal force.

10. The method of claim 1 further comprising: a motor coupled to the applicator head, wherein the motor is configured to drive rotation of the applicator head.

11. The method of claim 1, wherein: the base component comprises amine functional prepolymers.

12. The method of claim 1, further comprising: heating the base component in a first reservoir, wherein the first reservoir is coupled to the first flow path.

13. The method of claim 12, wherein: heating the base component in the first reservoir comprises heating the base component to a temperature of from 60 to 70 degrees Celsius.

14. An apparatus configured for application of a mixed composition to the inside of a pipe, the apparatus comprising: a first flow path for carrying a first component of the mixed composition, a second flow path for carrying a second component of the mixed composition, a mixer coupled to the first flow path and the second flow path, wherein the mixer is configured to mix the first component and the second component together to form the mixed composition, and an applicator head coupled to the mixer, the applicator head configured for rotation about an axis, the applicator head comprising an applicator hole, the applicator head and applicator hole configured for applying the mixed composition to the inside of the pipe.

15. The apparatus of claim 14, further comprising: a first reservoir coupled to the first flow path, wherein the first reservoir comprises a heating jacket.

16. The apparatus of claim 14, wherein: the applicator hole comprises a plurality of the applicator holes spaced along the axial length of the applicator head, wherein the plurality of applicator holes are arranged in a spiral extending around a surface of the applicator head.

17. The apparatus of claim 14, wherein: the applicator holes comprises a plurality of applicator holes arranged in a first spiral and a second spiral, wherein the first spiral is a right-handed spiral and the second spiral is a left-handed spiral.

18. The apparatus of claim 14, wherein: the applicator head comprises a cylindrical portion, and wherein the applicator hole comprises a plurality of the applicator holes extending through a surface of the cylindrical portion.

19. The apparatus of claim 14, wherein: the applicator head comprises a first end coupled to the mixer, the applicator head comprises a second end distal the first end, and wherein the second end is closed.

20. The apparatus of claim 14, wherein: at least one of the first flow path and the second flow path comprises a hose coupled to the mixer, and wherein the hose is lined with polytetrafluoroethylene.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0082] Embodiments will now be described with reference to the accompanying drawings, in which:

[0083] FIG. 1 is a schematic illustration of a pipe to which a composition according to the present disclosure has been applied as a lining;

[0084] FIG. 2 shows an apparatus for applying a composition to a substrate;

[0085] FIG. 3 shows a schematic illustration of the apparatus of FIG. 2;

[0086] FIG. 4 shows a cross-sectional schematic illustration of a supply line of the apparatus of FIG. 2; and

[0087] FIG. 5 shows a schematic illustration of the applicator head of the apparatus of FIG. 2.

DETAILED DESCRIPTION

[0088] With reference to FIG. 1, compositions 2 disclosed herein can be applied to a pipe 4, for example a water pipe, such that the composition 2 is applied to line the interior of the pipe 4. The composition comprises two components: a base and an activator which, when mixed to form a mixed composition, cure to form a hard, impervious coating on the pipe. This coating enhances the structural integrity of the pipe and so enables the pipe to remain in service for a longer period of time.

[0089] The examples herein are provided to facilitate an understanding of the disclosure. The examples are not intended to limit the scope of the claims.

EXAMPLE 1

[0090] A composition for lining a pipe was made using a base component and an activator component having the following constituents:

TABLE-US-00001 Percentage by weight of Constituent the respective component Base Component Liquid polymer resin including a hydroxyl In some embodiments, the liquid polymer functional prepolymer resin including a hydroxyl functional In some embodiments the liquid polymer prepolymer makes up to 80% by weight of the resin includes the product sold as Isopol 160- base component, for example up to 70%, for 3500 and/or the product sold as Isopol 230- example up to 60%, for example up to 50%, 3000 by Iso-elektra GmbH, and/or the product for example up to 40% of the base sold as Desmophen ® 1150 and/or the product component. In some embodiments, the liquid sold as Desmophen ® 1145 by Covestro. polymer resin including a hydroxyl functional prepolymer makes up between 80% and 30% of the base component by weight, for example between 75% and 50%, for example between 70% and 60%. Filler liquid In some embodiments, the filler liquid makes For example, the filler liquid may be castor up to 5% of the base component. For oil. example, between 3% and 4% of the base component. It will be understood that any volume of filler liquid may be used to make the base component up to the desired volume. Mineral pigment In some embodiments, the silica based For example silica, e.g. kaolin. For example mineral pigment makes up to 40%, for micronised silica e.g. kaolin. In example between 10% and 30%, for example some embodiments, the product sold as between 10% and 20%. In some embodiments Sillitin Z 86 puriss by Hoffmann Mineral is the base component includes between 15% used. and 20% silica mineral pigment. Mineral pigment In some embodiments, the barium sulphate For example, barium sulphate. For example based mineral pigment makes up to 40%, for micronised barium sulphate. In some example between 10% and 30%, for example embodiments the product sold as Portaryte ® between 15% and 25%. In some embodiments the base component includes between 20% B15 sold by Sibelco Specialty Minerals and 25% barium sulphate based mineral Europe is used. pigment. Colour pigment In some embodiments, the base component For example a colour pigment dispersion in comprises 10% or less colour pigment by solvent, e.g. titanium dioxide pigment, or weight, for example, up to 5% colour pigment other desired colour pigment. by weight. For example up to 3% colour pigment may be used, for example less than 1% colour pigment may be used. In some embodiments, any amount of pigment sufficient to achieve the desired colour is used. Moisture scavenger liquid or solid In some embodiments, the base component For example a zeolite based moisture comprises up to 10% of zeolite based scavenger pigment. For example, the product moisture scavenger by weight, for example sold as Sylosiv ® A3 by W. R. Grace & Co. between 2 and 8%, for example between 3 and 7%, for example between 4 and 6%. In some embodiments, the base component comprises 5% zeolite based moisture scavenger. Thickener In some embodiments, the base component In some embodiments a silicate based comprises up to 1.5% silicate based thickener thickener powder is used, for example the by weight, for example between 1% and product sold as Cab-o-sil ® TS-720 by Cabot 1.5%. In some embodiments, the base Corporation. component comprises between 1.1% and 1.4% silicate based thickener, for example between 1.2% and 1.3% silicate based thickener. Liquid polymer resin including an amine In some embodiments, the base component functional prepolymer comprises up to 1% liquid polymer resin including an amine functional prepolymer, for example between 1% and 1.5%. In some In some embodiments the product sold embodiments, the base component comprises as Ethacure ® 100 by Albemarle Corporation between 0.2% and 0.8% liquid polymer resin is used. including an amine functional prepolymer, for example between 0.2% and 0.6%, for example between 0.3% and 0.5%. Cure accelerator In some embodiments, the base component In some embodiments, an amine based cure comprises up to 2.5% of amine based cure accelerator is used e.g. a tertiary amine, for accelerator, for example up to 2%, for example for example an amine based liquid example up to 1% of amine based cure cure accelerator. In some embodiments the accelerator. In some embodiments less than product sold as Dabco ® 33-LV sold by Air 0.5% of amine based cure accelerator is used. Products and Chemicals, Inc. In some embodiments a tin based cure accelerator is used, for example a tin based cure accelerator liquid, e.g. dibutyltin dilaurate. In some embodiments a bismuth based cure accelerator is used. Carbon Fibre In some embodiments, the base component In some embodiments milled carbon fibre includes between 5% and 40% of carbon powder is used, for example the product sold fibres by weight, for example between 5% as Sigrafil C M150-3.0 by SGL Group. and 30%. In some embodiments, the base component includes between 5% and 25% of carbon fibres by weight, for example between 10% and 25%, for example between 15% and 20%. Catalyst In some embodiments, the base component In some embodiments a catalyst is used to includes 1% or less of catalyst by weight, for catalyse the reaction between the hydroxyl example 0.5% or less. In some embodiments 0.2% or less of catalyst is used, for example functional prepolymers and the isocyanate 0.1%. In some embodiments, no catalyst is groups of the activator component. Any used. suitable catalyst may be used, for example a metal catalyst, for example a tin or bismuth based catalyst may be used. For example, the product sold as TIB KAT ® 716 by TIB Chemicals may be used. Activator Component Liquid isocyanate polymer blend Up to 100% For example, the product sold as Desmodur ® VL sold by Covestro is used. For example, the product sold as Suprasec ® 2496 sold by Huntsman Corporation is used.

[0091] The base component includes a liquid polymer resin including a hydroxyl functional prepolymer. In other words, the liquid polymer resin includes prepolymers having —OH functional groups. In some embodiments, the liquid polymer resin includes polyols. In some embodiments, the liquid polymer resin has a castor oil base.

[0092] In some embodiments, the base component includes a blend of two or more different liquid polymer resins including hydroxyl functional prepolymers. In some embodiments, the different liquid polymer resins are present in equal proportions by weight of the base component. In other embodiments, the different liquid polymer resins are present in different proportions by weight of the base component. Different liquid polymer resins result in different properties of the resulting polymer, depending on the nature of the prepolymers contained in the liquid polymer resins. For example, the degree of flexibility or hardness of the resulting polymer can be affected by the liquid polymer resin used. By including a blend of two or more different liquid polymer resins, the properties of the resulting polymer can be tailored as desired, depending to the requirements of the resulting polymer.

[0093] In some embodiments, the base component includes a liquid polymer resin including amine functional prepolymers. In other words, the liquid polymer resin includes prepolymers having amine functional groups. As will be understood by those skilled in the art, amine functional groups react with isocyanates to form a polyurea. Accordingly, by including amine functional prepolymers as well as hydroxyl functional prepolymers in the base component, a copolymer including both polyurea and polyurethane is formed when the base and activator components are mixed.

[0094] Polyurea and polyurethane have different properties, for example polyurethane tends to be more thermoplastic and less heat resistant than polyurea. By adjusting the amount and type of liquid polymer resin including amine functional prepolymers as compared with the amount and type of liquid polymer resin including hydroxyl functional prepolymers, the ratio of polyurethane to polyurea in the resulting polymer can be adjusted. Hence the properties of the resulting polymer are consequently adjusted.

[0095] In addition, the reaction between amines and isocyanates is faster than that between hydroxyl groups and isocyanates. Accordingly, by adjusting the amount and type of liquid polymer resin including amine functional prepolymers as compared with the amount and type of liquid polymer resin including hydroxyl functional prepolymers, the time taken to cure can be tailored.

[0096] In some embodiments the proportion of hydroxyl functional groups to amine functional groups present in the liquid polymer resin(s) of the base component is 2% hydroxyl to 98% amine. In some embodiments, the liquid polymer resin(s) of the base component contains exclusively hydroxyl function groups, in other words there is no amine present. All combinations of amine/hydroxyl functional groups between these two extremes are possible.

[0097] In some embodiments, the base component is formulated such that 5-100% polyurethane to 0-95% polyurea is formed. In some embodiments, the base component is formulated such that 30-100% polyurethane to 0-70% polyurea is formed. In some embodiments, the base component is formulated such that 50%-100% polyurethane to 0-50% polyurea is formed. In some embodiments the resulting polymer comprises >95% polyurethane to <5% polyurea.

[0098] Since the reaction between amines and isocyanates is faster than that between hydroxyl groups and isocyanates, the liquid polymer including amines will polymerise faster than the liquid polymer including hydroxyl groups. This results in faster thickening of the mixed composition as polyurea is formed. The liquid polymer resin including amine functional prepolymers therefore also acts as a thickener. The thickness of the mixed composition is important in controlling the flow of the mixed composition. In some embodiments, when the mixed composition is applied to line a pipe, it is undesirable for the composition to flow down the sides of the pipe under gravity and collect at the lowermost edge of the pipe. By modifying the thickness of the mixed component, undesirable flow of the mixed composition can be minimised.

[0099] In some embodiments, the base includes an amount of filler liquid to make the base component up to a desired volume. The filler liquid is formulated such that it does not react with the activator component of the composition. In some embodiments, the filler liquid is castor oil. In some embodiments, the base component includes an amount of mineral pigment. For example, one or more mineral pigments may be present. Such mineral pigments impart different physical and chemical properties to the resulting cured composition, accordingly, mineral pigments can be selected to provide desired properties to the resulting cured composition. For example, properties such as strength, density, rigidity, hardness, water resistance and elasticity of the resulting cured composition can be modified by including suitable mineral fillers. Any mineral pigment which is inert, chemical resistant, and acid and alkaline resistant may be used. In some embodiments, a combination of silica, e.g. Kaolin, and barium sulphate filler is used. This results in increased strength, increased density, increased rigidity, increased hardness, increased water resistance and reduced elasticity of the resulting cured composition. This improves the effectiveness of the resulting cured composition as a pipe liner.

[0100] If desired, a colour pigment can be added to the primer formulation to give the primer a desired colour. Any colour pigment may be used as desired. Alternatively, no colour pigment need be added.

[0101] In some embodiments the base component also includes a moisture scavenger component or drying additive. Any suitable moisture scavenger liquid or solid may be used. As will be understood by those skilled in the art, isocyanates react with water in preference to hydroxyl and amine groups. Therefore, it is important that excess moisture is removed from the base component before it is mixed with the activator component to ensure that the isocyanate in the activator react with the liquid polymer resin (i.e. the hydroxyl functional groups) in the base to form the desired polymer, rather than any water contained therein.

[0102] Water can, for example, be present in the filler pigments included in the base component, for example the colour pigment. Accordingly, including a drying additive in the base component acts to reduce or remove this water.

[0103] The base component may also contain a thickener, for example a mineral thickener and/or a liquid thickener, which acts to keep the various fillers, additives and constituents dispersed throughout the formulation, for example by altering the rheology of the mixture. In some embodiments, a mineral based, for example a silicate based, thickener is used. The thickness of the base component is important in controlling the flow of the mixed composition i.e. the mixture of the base component and activator component. In some embodiments, when the mixed composition is applied to line a pipe, it is undesirable for the composition to flow down the sides of the pipe under gravity and collect at the lowermost edge of the pipe. By modifying the thickness of the base component, undesirable flow of the mixed composition can be minimised.

[0104] In order to adjust and/or tailor the time taken for the mixed composition to cure, a cure accelerator may be included in the base component. The cure time will therefore depend, at least in part, on the amount of cure accelerator present. Any cure accelerator which acts to catalyse the reaction between the hydroxyl functional groups of the liquid polymer resin and the isocyanate in the activator may be used, for example an amine based cure accelerator. In some embodiments a tertiary amine based cure accelerator is used. As will be understood by those skilled in the art, tertiary amines act as a catalyst for the reaction between hydroxyl functional groups and isocyanates. Therefore, including a tertiary amine in the base component has the advantage of accelerating the reaction between hydroxyl functional prepolymers and the isocyanate groups. In some embodiments a tin based cure accelerator is used. In some embodiments a bismuth based cure accelerator is used. In some embodiments, the cure accelerator reacts with the curing agent (i.e. the isocyanate prepolymer) to speed up the curing reaction.

[0105] In some embodiments, the base component includes an amount of carbon fibres. Inclusion of the carbon fibres in the base component results in the cured mixed composition containing carbon fibres. In some embodiments, the carbon fibre is 500μ.Math.η or less in length, for example 200μ.Math.η or less, for example between 50μ.Math.η and 200μ.Math.η in length, for example between 80 and 150μ.Math.η in length. In some embodiments the carbon fibres are between 5 and 25μ.Math.η in width, for example between 5 and 15μ.Math.η, for example between 5 and 10μ.Math.η. In some embodiments, the carbon fibres have a width of 7μ.Math.η.

[0106] In some embodiments, the base component includes an amount of catalyst formulated to catalyse the reaction between the hydroxyl functional prepolymers and the isocyanate groups in the activator. Addition of such a catalyst accelerates the cure reaction and so reduces the cure time. Therefore, by adjusting the amount of catalyst used, the cure time of the composition can be adjusted. Any suitable catalyst may be used, for example a tin or bismuth based catalyst. In some embodiments the product sold as TIB KAT® 716 by TIB Chemicals may be used since this is considered to be harmless and so suitable for use in a potable water supply. In some embodiments, the catalyst is formulated to speed up the cure reaction, but is not directly involved with it.

[0107] The composition includes a second component, an activator. The activator includes a liquid isocyanate polymer blend.

[0108] When the base component and activator component are mixed together, they cure to form a hard polymer layer. The base component and the activator component of the composition are formulated to be mixed in the ration of 4:1 by volume of base component to activator component. When the base component and activator component are mixed, the hydroxyl groups of the base component react with the isocyante of the activator to produce a polyurethane according to reaction mechanism (1) below (where and R′ are alkyl or aryl groups).

R—OH+R′—N═C═O(isocyanate).fwdarw.R′N(H)C(O)OR(urethane linkage)  (1)

[0109] It is believed that, in the composition disclosed herein, each hydroxyl functional prepolymer reacts with a single isocyanate molecule.

[0110] In the case where the base component also comprises liquid polymer resin having amine functional groups, the amine groups of the base component react with the isocyanate of the activator to produce polyurea according to the reaction mechanism (2) below (where R and R′ are alkyl or aryl groups).

R—NH.sub.2+R′—N═C═O.fwdarw.RN(H)C(O)N(H)R′(urea linkage)  (2)

[0111] It is believed that, in the composition disclosed herein, each amine functional prepolymer reacts with a single isocyanate molecule.

[0112] Where there is water present in the base component, the isocyanate of the activator will react with this water in preference to the hydroxyl and amine functional groups of the base component according to the reaction mechanism (3) below (where R and R′ are alkyl or aryl groups).

H.sub.2O+R—N═C═O(isocyanate).fwdarw.R—NH.sub.2+CO.sub.2

R—NH.sub.2+R′—N═C═O.fwdarw.RN(H)C(O)N(H)R′(urea linkage)  (3)

[0113] Consequently the desired polymers will not be formed. In addition, the reaction between isocyanates and water produces CO.sub.2 as a bi-product which results in undesirable bubbling in the resulting polymer. Therefore, the removal or reduction of the amount of water present in the base component by the addition of a drying agent is advantageous to encourage the mixed composition to follow reaction mechanism (1) and (2) above. When the mixed composition is applied to the surface of a pipe, the mixed composition is at this stage exposed to water in the atmosphere. Accordingly the addition is a drying agent is also advantageous in drying the mixed composition as it is applied to the pipe, thereby reducing the amount of CO.sub.2 produced and therefore reducing the amount of bubbling in the resulting polymer.

EXAMPLE 2

[0114] A composition for lining a pipe was made using a base component and activator having the following constituents:

TABLE-US-00002 Percentage by weight of Constituent the respective component Base Component Liquid polymer resin including a hydroxyl 20.039 functional prepolymer Isopol 160-3500 and/or Desmophen ® 1150 Liquid polymer resin including a hydroxyl 13.625 functional prepolymer Isopol 230-3000 and/or Desmophen ® 1145 Filler liquid 3.286 Castor oil Mineral pigment 16.015 Sillitin Z 86 puriss Mineral pigment 20.703 Portaryte ® B15 Colour pigment 0.951 Titanium dioxide Moisture scavenger liquid or solid 5.000 Sylosiv ® A3 Thickener 1.219 Cab-o-sil ® TS-720 Liquid polymer resin including an amine 0.482 functional prepolymer Ethacure ® 100 Cure accelerator 0.402 Dabco ® 33-LV Carbon Fibre 18.278 Sigrafil C M150-3.0 Activator Component Isocyanate polymer blend 100.00 Desmodur ® VL and/or Suprasec ® 2496

[0115] To make the base component of Example 2, the Isopol 160-3500 and castor oil are introduced into a clean vessel and mixed using a high speed disperser. Sillitin Z 86 puriss, Portaryte® B15, Titanium dioxide, Sylosiv® A3 and Cab-o-sil® TS-720 are slowly added to the mixture and mixed at a relatively high speed until a dispersion of 4-5 hegman is achieved. Speeds of between 500 and 5000 rpm are used for this stage.

[0116] At a slow mixing speed, for example about 500 rpm, the Isopol 230-300 and the Ethacure® 100 are added to the mixture. The cure time is adjusted using the Dabco® 33-LV.

[0117] Under slow speed stirring, for example 500-600 rpm, the Sigrafil C M150-3.0 is added and stirred into the mixture until fully mixed in. The mixture is then passed through a 3 mm mesh to remove any contaminants.

EXAMPLE 3

[0118] A composition for lining a pipe was made using a base component and activator having the following constituents:

TABLE-US-00003 Percentage by weight of Constituent the respective component Base Component Liquid polymer resin including a hydroxyl 19.98 functional prepolymer Isopol 160-3500 and/or Desmophen ® 1150 Liquid polymer resin including a hydroxyl 13.58 functional prepolymer Isopol 230-3000 and/or Desmophen ® 1145 Filler liquid 3.37 Castor oil Mineral pigment 16.08 Stillitin Z 86 puriss Mineral pigment 14.68 Portaryte ® B15 Colour pigment 6.93 Titanium dioxide Moisture scavenger liquid or solid 4.99 Sylosiv ® A3 Thickener 1.19 Cab-o-sil ® TS-720 Liquid polymer resin including an amine 0.48 functional prepolymer Ethacure ® 100 Cure accelerator 0.40 Dabco ® 33-LV Carbon Fibre 18.22 Sigrafil C M150-3.0 Catalyst 0.10 TIB KAT ® 716 Activator Component Isocyanate polymer blend 100.000 Desmodur ® VL and/or Suprasec ® 2496

[0119] To make the base component of Example 3, the following method can be used. The Isopol 160-3500, Isopol 230-3000 and Castor Oil are introduced into a clean vessel under a suitable sized high speed disperser (HSD). It has been found that addition of all the liquid resins comprising hydroxyl functional prepolymers at the beginning of the process facilitates the manufacturing process. It has also been found that the resins mix together easily and so high speed dispersion is not required at this stage.

[0120] The mixer is turned on and the Sillitin Z 86 puriss, Portaryte® B 15, Titanium dioxide and Sylosiv® A3 are slowly added. The mixer is then run at high speed until a dispersion of 4-5 hegman is achieved. Sigrafil C M150-3.0 is slowly added, ensuring that dust is kept to a minimum, for example by pouring into the moving vortex under the mixer. Dabco® 33-LV and Ethacure® 100 are then added. It is believed that the Sigrafil C M150-3.0 may absorb some of the Ethacure® 100. Accordingly the Ethacure® 100 is added after the Sigrafil C M 150-3.0 is fully dispersed. It is believed this promotes the reactivity of the base composition.

[0121] The Cab-o-sil® TS-720 is then added to the mixture, ensuring that dust is kept to a minimum, for example by pouring into the moving vortex under the mixer. Due to the large viscosity increase when the Cab-o-sil® TS-720 is added, this is added towards the end of the process when the majority of the components have been introduced.

[0122] The mixture is mixed for approximately 30 minutes. To facilitate handling, the temperature is kept below 90° C.

[0123] TIB KAT® 716 is added to adjust the cure time (or gel time). This is added at the end for a final adjustment of the composition. The mixture is then passed through a 3 mm mesh to remove any contaminants.

[0124] The base component of examples 1 to 3 has been found to be dilatant, otherwise termed shear thickening. Accordingly, the viscosity of the base component increases with the applied shear stress. Conversely, the viscosity of the base component is less when lower shear forces are applied.

[0125] Compositions disclosed herein, for example those in examples 1 to 3 above, can be used to line a pipe by applying the mixed composition to the interior of the pipe before the mixed composition has cured. The mixed composition can be applied to a pipe which is in service, or to a new pipe prior to the pipe being positioned in place for use.

[0126] Referring to FIG. 2, an apparatus 6 which can be used to apply a composition to a water pipe 4 is shown. The apparatus 6 is housed in a vehicle 8 such that the apparatus 6 can be transported to the location of the pipe 4 such that the composition can be applied to a pipe 4 in situ.

[0127] A schematic illustration of the apparatus 6 is shown in FIG. 3. The apparatus 6 includes a flow path 10 for a first component of a composition, for example the base component of examples 1 to 3 above. This flow path shall be referred to as the base flow path 10. The base flow path 10 is configured to carry the base component from a base tank 12 to a mixer 14. The apparatus 6 also includes a flow path 16 for a second component of a composition, for example the activator component of examples 1 to 3 above. This flow path shall be referred to as the activator flow path 16. The activator flow path 16 is configured to carry the activator component from an activator tank 18 to the mixer 14.

[0128] The mixer 14 includes a baffle (not shown) configured to mix the activator and base components together to form a mixed composition. The mixer 14 is in fluid communication with a feed tube 20 which is configured to introduce the mixed composition into an applicator head 22, from which the mixed composition is applied to the interior of a pipe 4 to line the pipe 4.

[0129] Referring to FIG. 3, the base flow path 10 comprises a base tank 12. The base tank 12 is in the form of a cylindrical tank having a cylindrical side wall coupled to a base. Alternatively, the base tank 12 is cuboid in shape and includes four side walls coupled to a base. Other suitably shaped tanks may be used. The base tank 12 is provided with a heating jacket 24 extending around the base and the side wall(s). The heating jacket 24 includes two skins and an insulating space therebetween and is configured to apply heat to the base tank 12. The base tank 12 includes an outlet 26 from which the base component can leave the tank 12. The outlet 26 can be opened and closed by employing a tap (not shown). The outlet is 7.62 cm (3″) in diameter. In some embodiments, the outlet is between 6 cm and 10 cm in diameter. The outlet 26 of the base tank 12 is in fluid communication with a pump 28 configured to pump the base component along the base flow path 10. A filter 30 is provided between the outlet 26 of the base tank 12 and the pump 28. The filter 30 is configured to remove contaminants from the base component as it flows through the filter 30. The filter 30 has a mesh diameter of about 3 mm.

[0130] The pump 28 is in fluid communication with a heater 32 which is configured to heat the base component. The heater 32 is in fluid communication with a flow meter 34 which is configured to measure the flow of base component through the flow path 10.

[0131] The flow meter 34 comprises positive displacement flow meter, for example a gear flow meter. In some embodiments, the flow meter 34 is a helical gear flow meter. In a helical gear flow meter, an arrangement of helical or spiral shaped gears is provided to measure flow through the flow meter. For example, an S series helical screw geared flow meter as manufactured by VSE.flow® can be used. Such flow meters operate based on the screw pump principle.

[0132] The heater 32 is also in fluid communication with the base tank 12 via a short cycle path 60. The base component can be passed around this short cycle path 60, for example, when increased heating of the base component is required. The flow meter 34 is coupled to the mixer 14 via a base line hose 36, through which the base component can flow. The base line hose 36 has a diameter of 25 mm or more.

[0133] The base flow path 10 is at least partially lined with polytetrafluoroethylene (PTFE). For example, all or part of the base line hose 36 is lined with PTFE.

[0134] In some embodiments, the base flow path 10 is at least partially lined with nylon. For example, all or part of the base line hose 36 is lined with nylon.

[0135] The base line hose 36 terminates at a non-return valve 38 such that fluid cannot enter the base line hose 36 at this point. The non-return valve has a diameter of 19.05 mm. The terminal end of the base line hose 36, for example the non-return valve 38, is also coupled to a return base line hose 64 which is in fluid communication with the base tank 12. The base component can be returned to the base tank 12 via the return base line hose 64, for example when additional heating is required. As can be seen from FIG. 3, the activator flow path 16 has a similar construction. The activator flow path 16 comprises an activator tank 18. The activator tank 18 is in the form of a cylindrical tank having a cylindrical side wall coupled to a base. Alternatively, the activator tank 18 is cuboid in shape and includes four side walls coupled to a base. Other suitably shaped tanks may be used. The activator tank 18 has an outlet 40. The outlet 40 can be opened and closed by employing a tap (not shown). The outlet 40 which is in fluid communication with a pump 42 configured to pump the activator component along the activator flow path 16. A filter 44 is provided between the outlet 40 of the activator tank 18 and the pump 42. The filter 44 is configured to remove contaminants from the activator component as it flows through the filter 44. The pump 42 is in fluid communication with a heater 46 which is configured to heat the activator component. The heater 46 is in fluid communication with a flow meter 48 which is configured to measure the flow of the activator component through the flow path 16. The heater 46 is also in fluid communication with the activator tank 18 via a short cycle path 62. The activator component can be passed around this short cycle path 62, for example, when increased heating of the activator component is required.

[0136] The flow meter 48 is coupled to the mixer 14 via an activator line hose 50, through which the activator component can flow. The activator line hose 50 has a diameter of 6.35 mm (0.25″). In some embodiments, the activator line hose 50 can have a diameter of between 5 mm and 25 mm for example between 5 and 15 cm. The activator line hose 50 terminates at a non-return valve 52 such that fluid cannot enter the activator line hose 52 at this point. The terminal end of the activator line hose 50, for example the non-return valve 52, is also coupled to a return activator line hose 66 which is in fluid communication with the activator tank 16. The activator component can be returned to the activator tank 18 via the return activator line hose 66, for example when additional heating is required. With reference to FIG. 4, the base line hose 36, the return base line hose 60, the activator line hose 50, and the return activator line hose 66 are carried together in a supply line 54. The supply line 54 includes an insulating case 56 configured to carry at least a portion of the base line hose 36, the return base line hose 60, the activator line hose 50, and the return activator line hose 66. The supply line 54 is filled with oil 68 which can be heated to heat the activator and base components which are being carried down the respective hoses. The supply line 54 can be of any desired length, for example between 100 and 300 m, for example between 150 m and 250 m. In some embodiments, the supply line 54 is 200 m in length. The base line hose 36 and the activator line hose 50 are in fluid communication with the mixer 14 such that base component and activator component can be introduced to the mixer 14. The mixer 14 includes a baffle configured to mix the activator and base components together to form a mixed composition. The mixer 14 is in fluid communication with a feed tube 20 which is configured to introduce the mixed composition into an applicator head 22.

[0137] As shown in FIG. 5, the applicator head 22 is shaped to form a hollow truncated cone 68, the narrow end of the truncated cone 68 being coupled to the feed tube 20 such that mixed composition can be introduced onto the interior surface of the truncated cone 68. The hollow truncated cone 68 is approximately 10 cm to 30 cm in length, for example between 15 cm and 20 cm in length, for example between 15.24 cm and 20.32 cm (6″ to 8″). In some embodiments the wide end of the truncated cone 68 is open such that the mixed composition can exit the applicator head 22 through the open end of the truncated cone 68. In other embodiments, the wide end of the truncated cone 68 is closed. In some embodiments, the applicator head comprises a cylindrical portion instead of a truncated cone. The applicator head 22 includes a plurality of applicator holes 70 arranged to extend through the surface of the cone 68 such that the interior and exterior of the cone 68 are in fluid communication. The applicator holes 70 are arranged evenly around the surface of the truncated cone 68. In some embodiments, the applicator holes 70 are arranged to form a spiral of holes 70 around the surface of the truncated cone 68. For example, in some embodiments the applicator holes are arranged to form two spirals, for example one being left-handed and one being right-handed. In other embodiments, other suitable arrangements of the applicator holes 70 are used, for example, the holes 70 may be arranged to form concentric rings around the truncated cone 68 or may be arranged in lines extending from the narrow end of the truncated cone 68 to the wide end or may be arranged to form a cross shape. The applicator holes 70 have a diameter of approximately 3 mm. In some embodiments a larger diameter is used.

[0138] The applicator head 22 is mounted on the feed tube 20 such that it is free to rotate about an axis A, as shown in FIG. 5. The axis A is the axis of symmetry of the truncated cone 68 and extends from the narrow end of the truncated cone 68 to the wide end. The applicator head 22 is coupled to a motor (not shown) which is configured to drive rotation of the applicator head 22. In use, for example to apply the composition of examples 1 to 3 above, the applicator head 22 of the apparatus is positioned inside a pipe 4 to be lined. A base component is introduced into the base tank 12. The outlet 26 of the tank 12 is initially closed. Once the base component has been introduced to the base tank 12, the tank is sealed and pressured with nitrogen or dry air. Pressurising the tank facilitates flow of the base component through the base flow path 10. In the tank 12, the base component is heated to between 60 and 70° C. Heating the base component to this temperature also facilitates flow of the base component. The heating jacket 24 acts to facilitate heating of the base component. When the base component has reached the desired temperature, the outlet 26 is opened and the base component flows through the outlet 26. The outlet 26 of the base tank 12 is relatively large at 7.62 cm (3″) in diameter. This larger diameter reduces the shear forces acting on the base component which, due to the shear thickening nature of the base component, encourages the base component to maintain a relatively low viscosity and hence facilitates flow of the base component out of the base tank.

[0139] The base component passes along the base flow path 10 to the pump 28. In doing so, the base component passes through the filter 30. The filter 30 has a mesh diameter of 3 mm. A mesh diameter of 3 mm or more is advantageous in permitting carbon fibres present in the base component to pass through the filter 30, with a low risk of the carbon fibres clumping together and blocking the filter 30. If the filter mesh is too small in diameter, carbon fibres present in the base component are prone to clumping and blocking the filter.

[0140] The pump 28 pumps the base component along the flow path 10 to the heater 32. Heating the base component facilitates the flow of the base component. Should additional heating be required, the base component is directed back to the base tank 12 along the short cycle path 60. Alternatively, the base component is directed from the heater 32 to the flow meter 34, where the flow of the base component can be measured. It has been found that the use of a helical gear flow meter is advantageous since the carbon fibre present in the base component tends not to clog the helical gears.

[0141] From the flow meter, the base component enters the base line hose 36. It has been found that by lining at least part of the base flow path 10, for example at least part of the base line hose 36, with PTFE, carbon fibres present in the base component are less likely to become embedded in the hose wall. When carbon fibres become embedded in the hose wall, they tend to clump together, clogging the base line. Therefore, the use of PTFE to line the base line hose 36 reduces the likelihood of the base line 36 becoming blocked. Further, since the use of PTFE reduces the likelihood of carbon fibres becoming embedded in the base line wall, the pressure applied to the base component flowing through the base line hose 36 can be increased. This can be achieved by reducing the diameter of the base line hose 36. Increasing the pressure applied to the base component can be advantageous in ensuring the correct mix ratio of base to activator components.

[0142] Turning to the activator flow path, in use, activator component is introduced to the activator tank 18. The outlet 40 of the tank 18 is initially closed. Once the activator component has been introduced into the activator tank 18, the tank is sealed and pressurised with nitrogen or dry air. Pressurising the tank 18 facilitates flow of the activator component through the activator flow path 16. Since the activator component comprises isocyanate which reacts with water, it is advantageous to pressurise the activator tank with dry air to prevent reaction of the isocyanate with water.

[0143] The activator in the tank 18 is heated and, when it has reached the desired temperature, the outlet 40 is opened and the activator component flows through the outlet 40.

[0144] The activator component passes along the activator flow path 16 to the pump 42. In doing so, the activator component passes through the filter 44 to remove contaminants from the activator. The pump 42 pumps the activator component along the flow path 16 to the heater 46. Heating the activator component facilitates the flow of the activator component. Should additional heating be required, the activator component is directed back to the activator tank 18 along the short cycle path 62. Alternatively, the activator component is directed from the heater 46 to the flow meter 48, where the flow of the activator component can be measured. From the flow meter, the activator component enters the activator line hose 50.

[0145] The base component and the activator component flow along the respective line hose 36, 50 through the supply line 54. The insulating case 56 of the supply line 54 acts to reduce loss of heat from the base and activator components and therefore to facilitate flow of these components. In addition, the base line hose 36 and the activator line hose 50 are immersed in hot oil 56 within the supply line 54. This hot oil 56 acts to further heat the base component and the activator component as they flow along the supply line 54, thereby further facilitating flow of the components. At the end of the base line hose 36 the base component flows through a non-return valve 38.

[0146] Should further heating of the base component be required, the base component is directed along the return base line hose 64 to the base tank 12. Alternatively, the base component is directed to the mixer 14.

[0147] Similarly, at the end of the activator line hose 50 the activator component flows through a non-return valve 52. Should further heating of the activator component be required, the activator component is directed along the return activator line hose 64 to the activator tank 18. Alternatively, the activator component is directed to the mixer 14. The pump 28 of the base flow path 10 and the pump 42 of the activator flow path 16 are arranged to pump base component and activator component respectively to the mixer 14 such that the base component and activator component are mixed at a ratio of 4:1 by volume of base component to activator component. The mixer 14 includes flow path having a series of baffles such that, as the base and activator components pass along the mixer flow path, the baffles disrupt the flow to cause mixing of the base component and activator component.

[0148] The mixed composition then flows to the feed tube 20 from which is it introduced to the interior surface of the truncated cone 68 of the applicator head 22. The applicator head 22 is rotated about the axis A generating a centrifugal force. As the mixed composition flows along the internal surface of the truncated cone 68 it reaches the applicator holes 70. The centrifugal force generated by the rotating applicator head 22 causes the mixed composition to flow through the applicator hole 70 and atomise as it leaves the applicator hole 70. The applicator holes 70 are 3 mm in diameter or larger. A diameter of 3 mm or more is advantageous in permitting carbon fibres present in the mixed composition to pass through the applicator holes 70, with a low risk of the carbon fibres clumping together and blocking the holes 70. If the applicator holes 70 are too small in diameter, carbon fibres present in the base component are prone to clumping and blocking the holes 70.

[0149] The applicator head 22 is positioned inside a pipe 4 to be lined with the mixed composition. In this way, the mixed composition is applied to the interior of a pipe 4. Due to the long length of the supply line 54, the supply line 54 can be passed along a length of pipe 4 such that a long length of the pipe 4 can be coated with the composition. The applicator head 22 can be retracted along the pipe, in direction B shown on FIG. 3, such that a length of pipe 4 can be lined in a single application. If desirable, multiple applications or passes may be made to a length of pipe, alternatively, the pipe may be lined in a single pass. The cure time of the mixed composition is such that it does not cure until it has left the applicator head 22. A sufficiently long cure time is used to ensure that the mixed composition does not begin to harden until after the time taken for the mixed composition to flow along the length of the truncated cone 68 of the applicator head 22. Since the cure time can be tailored, a longer truncated cone length can be used, which enables the composition to be applied to a pipe in larger band widths and therefore more evenly.

[0150] Although the present disclosure has been described above with reference to one or more embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the present disclosure as defined in the appended claims. For example, whilst the examples above are illustrative of an apparatus used to apply a composition disclosed herein, it will be appreciated that any suitable composition can be applied with the apparatus disclosed herein.