WO2019057929A1

WO2019057929A1 - Method of moulding a fibre-reinforced thermosetting resin to form a moulded article

Info

Publication number: WO2019057929A1
Application number: PCT/EP2018/075679
Authority: WO
Inventors: Hendrik DE KEYSER
Original assignee: Vyncolit N.V.
Priority date: 2017-09-22
Filing date: 2018-09-21
Publication date: 2019-03-28
Also published as: GB2567141A; GB201715381D0; GB2567141A8; GB2567141B

Abstract

Method of moulding a fibre-reinforced thermosetting resin to form a moulded article, the method comprising the steps of (a) reactively compounding a thermosetting resin in a compounding apparatus to form a plurality of pieces of a compounded thermosetting resin; (b) directly inputting these pieces into an extrusion apparatus; (c) adding reinforcement fibres to the compounded thermosetting resin to form a fibre-containing compounded thermosetting resin, the reinforcement fibres being added to the resin in the compounding apparatus before step (b) so that the pieces comprise fibre-containing compounded thermosetting resin and/or in the extrusion apparatus after step (b); (d) in the extrusion apparatus, forming a body of the fibre-containing compounded thermosetting resin and extruding a continuous elongate extruded length of the resin; (e) cutting a section of the continuous elongate extruded length to form a preform of the resin; (f) directly transporting the preform to a moulding machine comprising a ram and a mould tool; and (g) injecting the resin into the mould tool to form a moulded article.

Description

METHOD OF MOULDING A FIBRE-REINFORCED THERMOSETTING RESIN

TO FORM A MOULDED ARTICLE

Background to the Invention

The present invention relates to a method of moulding a fibre-reinforced thermosetting resin to form a moulded article. The present invention has particular application to the manufacture of moulded components of an automotive engine system, in particular an internal combustion engine, such as a cylinder block or a cylinder head of an internal combustion engine

Description of the Prior Art

A wide range of injection moulding apparatus and methods are known in the art, for manufacturing variety of different products using a variety of different moulding materials. Recently, there has developed a technical need to manufacture large mouldings of fibre- reinforced thermoset resin, for example glass-fibre reinforced phenolic resins in the manufacture of automotive engine parts, specifically internal combustion engine (ICE) cylinder blocks. For example, US-A-2015/0159582 discloses ICE cylinder blocks composed of fibre-reinforced resin matrix composite material (FRC) and DE-A- 102015 202336 discloses ICE cylinder head covers composed of fibre-reinforced resin matrix composite material (FRC).

Injection moulding technology is widely employed for moulding smaller parts. However, when injection moulding large thermoset parts, in which injection must be carried out on a large volume of curable thermosetting resin, the problems of premature resin curing in the injection machine and/or poor moulding quality are typically encountered.

The present invention aims at least partially to solve one or more of these technical problems associated with known methods of moulding a fibre-reinforced thermosetting resin to form a moulded article, in particular a large article such as an automotive engine part.

Summary of the Invention

The present invention provides a method of moulding a fibre-reinforced thermosetting resin to form a moulded article, the method comprising the steps of: a. reactively compounding a thermosetting resin in a compounding apparatus to form a plurality of pieces of a compounded thermosetting resin;

b. directly inputting the plurality of pieces of the compounded thermosetting resin from the compounding apparatus into an extrusion apparatus;

c. adding reinforcement fibres to the compounded thermosetting resin to form a fibre- containing compounded thermosetting resin, the reinforcement fibres being added to the compounded thermosetting resin (i) in the compounding apparatus before step b so that the pieces comprise fibre-containing compounded thermosetting resin and/or (ii) in the extrusion apparatus after step b;

d. in the extrusion apparatus, forming a body of the fibre-containing compounded thermosetting resin and extruding a continuous elongate extruded length of the fibre- containing compounded thermosetting resin;

e. cutting a section of the continuous elongate extruded length to form a solid preform of the fibre-containing compounded thermosetting resin, wherein the preform has a weight of at least 2.5 kg;

f. directly transporting the solid preform to a moulding machine comprising a ram and a mould tool having an inlet for material to be moulded in a mould cavity of the mould tool; and

g. injecting the fibre-containing compounded thermosetting resin into the mould tool by transfer moulding to form a moulded article in the mould cavity by moving the ram to urge the solid preform into the mould cavity through the inlet.

The process is a continuous process from step (a) reactive compounding through to step (g) injection moulding.

In preferred embodiments of the present invention, the preform has a weight of from 2.5 to 10 kg-

Typically, the preform has a cut length of from 5 to 1000 mm. Typically, the extruded length has a cross sectional area of from 70 to 8000 mm².

In preferred embodiments of the present invention, the thermosetting resin comprises a phenolic resin. In preferred embodiments of the present invention, the reinforcement fibres comprise glass fibres. The reinforcement fibres may be added as cut fibres or as elongate fibre rovings. Preferably, the fibre-containing compounded thermosetting resin comprises from 20 to 80 wt% reinforcement fibres and from 80 to 20 wt% thermosetting resin, each based on the total weight of the fibre-containing compounded thermosetting resin, and further comprises a curing and catalyst system for the thermosetting resin and optional filler material.

In preferred embodiments of the present invention, step (a) comprises the sub-steps of: (i) inputting components to form the thermosetting resin into an elongate screw mixer of the compounding apparatus and re actively compounding the resin therein; (ii) extracting from the elongate screw mixer air and/or volatiles and/or gaseous reactant products produced from the compounding of the resin; (iii) introducing a plurality of individual reinforcement fibres into the elongate screw mixer; and (iv) extruding pieces of the fibre-containing compounded thermosetting resin from the elongate screw mixer.

Typically, the pieces have a weight of from 100 to 10,000 grams and/or a maximum dimension of 5 to 1000 mm. Typically, the pieces comprise dough portions, pellets, or granulates or any mixture of two or more thereof.

In preferred embodiments of the present invention, in step (b) the pieces are inputted into the extrusion apparatus at a rate of from 200 to 1000 kg/hour, and in step (c) the continuous elongate extruded length of the fibre-containing compounded thermosetting resin is extruded at a rate of from 200 to 1000 kg/hour.

Preferably, in step (d) the extrusion apparatus comprises an elongate screw mixer, optionally a single screw extruder.

Preferably, in step (a) the compounding apparatus comprises an elongate double screw mixer.

In preferred embodiments of the present invention, in step (d) the continuous elongate extruded length of the fibre-containing compounded thermosetting resin is extruded onto a conveyor and the cutting step (e) is carried out so that the cut preforms are conveyed from the extrusion apparatus by the conveyor. In preferred embodiments of the present invention, the cutting step (e) is carried out at a die outlet of the extrusion apparatus.

Typically, the conveyor is an endless belt conveyor.

In preferred embodiments of the present invention, the continuous elongate extruded length exits a die of the extrusion apparatus at an extrusion temperature and further comprising the step of heating the preforms on the conveyor, optionally by infrared radiation, to maintain the temperature of each preform, prior to step (g), (i) substantially uniform throughout its thickness, optionally within +/-5°C, preferably +/- 2°C throughout its thickness and/or (ii) at the extrusion temperature, which is the temperature of the fibre-containing compounded thermosetting resin during extrusion, optionally within 5°C, preferably 2°C, of the extrusion temperature.

In preferred embodiments of the present invention, in step (f) the preforms are individually and successively transported to the injection moulding machine by a robotic arm. Preferably, in step (f) the cut preforms are engaged by a mechanical grab device of the robotic arm. Preferably, the mechanical grab device of the robotic arm is thermally insulated so that the preform is not substantially cooled during step (f), optionally is not cooled by more than 2°C, preferably 1 °C, during step (f).

In preferred embodiments of the present invention, step (f) is carried out over a period of less than 10 seconds, optionally less than 5 seconds.

Typically, in step (g) each preform forms a single respective moulded article or multiple moulded articles.

In preferred embodiments of the present invention, the moulded article is a component of an automotive engine system, optionally of an internal combustion engine, further optionally a cylinder block or a cylinder head of an internal combustion engine.

The preferred embodiments of the present invention can overcome the problems of injection moulding of large parts formed of thermosetting resins, particularly fibre-reinforced thermosetting resins in which the resin comprises an extrudable and injectable solid material comprising a uniform mixture of fibres distributed through the resin material. The reactive compounding and moulding steps are integrated into a single continuous production line in which the thermosetting resin is reactively compounded, by reactively compounding the resin monomers, cross linkers, and any required curing agents, together with optional catalysts and fillers, and other optional components may be added. After the thermosetting resin system has been reactively compounded, the fibres are added, either to the compounding apparatus and/or to an extrusion apparatus, and mixed with the compounded resin to form an extrudable and injectable solid material comprising a uniform mixture of fibres distributed through the resin material. That material is then extruded, cut into preforms and then the preforms are directly transported to a moulding machine where they are individually injection moulded, for example by transfer moulding.

This sequence of steps can provide consistent reactive compounding of the resin components at high production rates. There is a high yield process because the reactively compounded resin is extruded, cut and then transfer injection moulded while at a low viscosity, without being cooled or final curing which would otherwise cause a significant increase in viscosity and the material would be essentially solidified. Consequently, these is no need, as in known processes, to deliberately cool (e.g. to room temperature) and solidify the resin, and then re- melt and re-plastify the resin, prior to injection moulding.

In known processes, the compounded resin is extruded as a sheet and then granulated. This can produce a high proportion of compounded resin in the form of dust, which requires recycling and constitutes a health hazard, and some dust material may be lost as waste. For example, up to 20 wt% of the output of the sheet extruder in the known process may be lost as dust. In contrast, the present invention produces pieces which are immediately extruded, and so no dust is produced and all the output of the compounded resin can be employed to produce the extruded preforms for transfer injection moulding.

In known processes in which the compounded resin is deliberately cooled to room temperature and solidified, prior to later re-melting and re-plastifying of the resin for the purpose of injection moulding, it is difficult accurately to control the stopping of initial curing of the resin. Consequently, any given resin batch does not necessarily have the same degree of cure and viscosity when re-melted as any previous or subsequent batch. Therefore, it is conventional to blend plural batches to achieve in a resin blend a desired initial degree of cure and viscosity prior to later re-melting and re-plastifying of the resin blend for the purpose of injection moulding and final curing. Since the present invention, in a continuous process including reactive compounding through to injection moulding, directly extrudes the compounded resin, to form preforms which are then injection moulded, without any solidifying of the resin by cooling to room temperature, the resin properties can be dynamically and continuously controlled, without requiring a blending process, prior to injection moulding.

These reactive compounding and extrusion steps in the process of the invention can also provide large weight preforms, greater than 2.5 kg in weight, which can be employed as individual single shots for injection moulding, by transfer moulding in which the solid preform is urged by a ram into a moulding cavity. The moulding quality of large moulded parts can be improved, achieving consistent part quality at a high production rate. The provision of a single integrated continuous production line in which the base resin components are compounded, fibres are added, then the resultant extruded preforms are directly transfer injection moulded in a continuous process provides a high output apparatus at low capital and running cost as compared to the use of separate compounding and moulding facilities, which may incur additional transport and storage costs.

Brief Description of the Drawings

Figure 1 is a schematic side of a compounding, extrusion and moulding apparatus for use in a method of moulding a fibre-reinforced thermosetting resin to form a moulded article according to an embodiment of the present invention.

Detailed Description of the Preferred Embodiments

Referring to Figure 1 , there is shown a compounding, extrusion and moulding apparatus for use in a method of moulding a fibre-reinforced thermosetting resin to form a moulded article according to an embodiment of the present invention. A compounding apparatus 2 is provided in which a fibre-reinforced thermosetting resin is formed by mixing together the monomer, cross-linker, and curing agent and optional catalyst components of the resin and reactive! y compounding these components to cause the resin monomers and any cross linkers to begin the react together by curing to form a cross-linked thermoset polymer. The reactive compounding may also react with the resin other reactive components such as reactive thermoplastic toughening agents. The reactive compounding is exothermic and generates volatile products, such as steam. The compounding apparatus 2 comprises an elongate screw mixer 4 having at least one helical screw 6 driven by a motor 8. An input hopper 10 is provided at an inlet end 12 of the elongate screw mixer 4. A gas extractor 14 is provided at a central part 16 of the mixer 4.

Typically, the elongate screw mixer 4 is a double screw mixer with two helical screws 6 in a parallel horizontal configuration which are caused to rotate in opposite rotational directions. The elongate screw mixer 4 mixes the components, causing exothermic reactive compounding, and transports the components along the mixer 4. Volatiles are released and the pressure within the mixer increases. At the gas extractor 14 volatiles are removed. After the gas extractor 14, the compounded mixture can be cooled in the elongate screw mixer 4, or at least the temperature of the compounded mixture can be maintained.

A fibre input 18 is provided downstream of the gas extractor 14 and upstream of an outlet end 52 of the mixer 4.

The compounding apparatus 2 mixes together a first component comprising the compounded thermosetting resin and a second component comprising reinforcement fibres to form a plurality of pieces of a fibre-containing compounded thermosetting resin.

The thermosetting resin preferably comprises a phenolic resin, although other thermosetting resins, such as epoxy resins, may be employed in alternative embodiments of the present invention. The thermosetting resin further comprises a curing and catalyst system for the thermosetting resin, suitable curing and catalyst agents for phenolic resins being well known to those skilled in the art, and optional filler material, such as inorganic particles, for example silica particles and other well-known fillers, and optionally other components such as toughening agents, for example reactive toughening agents. The reinforcement fibres comprise glass fibres, although other fibrous reinforcement materials, such as carbon fibres, may be employed in alternative embodiments of the present invention.

Typically, the fibre-containing compounded thermosetting resin comprises from 20 to 80 wt% reinforcement fibres and from 80 to 20 wt% thermosetting resin, each based on the total weight of the fibre-containing compounded thermosetting resin.

In one preferred embodiment, the fibre-containing compounded thermosetting resin is a phenolic resin comprising (i) a curable phenolic resin system including additives such as one or more curing agents and cross-linking agents, and optionally one or more reactive elastomers and other chemical additives known for use in curable phenolic resins; (ii) one or more particulate fillers, for example composed of inorganic materials; and (iii ) reinforcing fibres. The curable resin system typically comprises from 20 to 55 wt% of the fibre-containing compounded thermosetting resin. The one or more particulate fillers typically comprise from 45 to 70 wt% of the fibre-containing compounded thermosetting resin. The reinforcing fibres typically comprise from 20 to 60 wt% of the fibre-containing compounded thermosetting resin. The reinforcing fibres typically comprise glass fibres.

The fibres may be added in the form of short cut fibres or elongate fibre rovings. The elongate rovings are chopped up in the mixer to form shorter fibre lengths. Initially, when the reinforcing fibres comprise short cut fibres, particularly when the fibres are glass fibres, the short cut fibres have a typical length of from 1 to 5 mm, more typically about 3 mm. After injection, the fibres have been broken as a result of fluid flow and high pressure, and typically have a length of less than 60 microns (Lim), for example from 150 to 300 microns (μηι). Other suitable fibre- reinforced thermosetting resin systems will be readily apparent to those skilled in the art.

The components (monomers, cross-linkers, catalysts, curing agents, tougheners, fillers, etc.) to form the compounded thermosetting resin are introduced into the input hopper 10 of the elongate screw mixer 4. The elongate screw mixer 4 mixes and reactively compounds the resin, and the resin is conveyed along the compounding apparatus 2. At the gas extractor 14, air and/or volatile and/or gaseous reactant products produced from the compounding of the resin are extracted. For example, a source of vacuum is applied by the gas extractor 14 to extract the gaseous components from the elongate screw mixer. At the fibre input 18 downstream of the input hopper 10 and the gas extractor 14, a plurality of individual reinforcement fibres are introduced into the elongate screw mixer. The fibres are mixed with the compounded resin to disperse the fibres substantially uniformly throughout the compounded resin. At the outlet end 16 of the mixer 4, an extrusion die 20 is provided through which pieces 22 of the fibre- containing compounded thermosetting resin are extruded from the elongate screw mixer 4. Typically, the pieces 22 have a weight of from 100 to 10,000 grams. Typically, the pieces 22 have a maximum dimension of from 5 to 1000 mm. The pieces comprise dough portions, pellets, or granulates or any mixture of two or more thereof. The pieces may have an irregular shape and may vary in size and shape.

The plurality of pieces 22 from the compounding apparatus 4 are directly input into an input end 24 of extrusion apparatus 26. The extrusion apparatus 26 comprises an elongate screw mixer 28 and an extrusion die 30 at an output end 32 thereof. Typically, the pieces 22 are inputted into the extrusion apparatus 26 at a rate of from 200 to 1000 kg/hour. The extrusion apparatus 26 is typically a single screw extruder which builds up pressure in the material and compresses the material so that a coherent body of consistent and uniform composition and properties is extruded at the output end 32.

In the extrusion apparatus 26, the pieces 22 are formed into a body of the fibre-containing compounded thermosetting resin and a continuous elongate extruded length 34 of the fibre- containing compounded thermosetting resin is extruded. The continuous elongate extruded length 34 typically has a cross-sectional area of from 70 to 8000 mm². The continuous elongate extruded length 34 of the fibre-containing compounded thermosetting resin is typically extruded at a rate of from 200 to 1000 kg/hour. The continuous elongate extruded length 34 of the fibre-containing compounded thermosetting resin is extruded onto a conveyor 36 which is typically an endless belt conveyor.

In the illustrated embodiment, the fibres are added to the mixer 4 of the compounding apparatus 2.

In an alternative embodiment, fibres are not added to the compounding apparatus 2 but instead fibres are added to the input end 24 of the extrusion apparatus 26. The fibres may again be added as short cut fibres or as elongate fibre rovings. The compounding apparatus 2 therefore outputs compounded resin pieces, and then the compounded resin pieces are mixed with fibres in the extrusion apparatus 26 so that the fibre-containing compounded thermosetting resin is extruded.

In a further alternative embodiment, fibres may be added to both the compounding apparatus 2 and the extrusion apparatus 26 as described above.

A section of the continuous elongate extruded length 34 is cut to form a preform 38 of the fibre- containing compounded thermosetting resin. Typically, the cutting is carried out at a die outlet 56 of the extrusion apparatus 26. The single continuous elongate extruded length 34 is successively cut to form a series of preforms 36. The cutting step is carried out so that the cut preforms 36 are conveyed from the extrusion apparatus 26 by the conveyor 56. The preform 38 has a weight of at least 2.5 kg and typically has a weight of from 2.5 to 10 kg. The preform 38 typically has a cut length of from 5 to 1000 mm.

The preforms 38 are directly transported, individually and successively, from the conveyor 36 to a moulding machine 40 which is adapted for transfer moulding of the preform to form one or more moulded articles using an applied moulding pressure, and optionally applied heat.

The moulding machine 40 comprises a ram 42 and a mould tool 44 having an inlet 46 for material to be moulded in a mould cavity of the mould tool 44. The preforms 38 are individually and successively transported to the moulding machine 40 by a robotic arm 54. The robotic arm 54 picks up a preform 38 form the conveyor 36 and places the preform 38 in the inlet 46 of the moulding machine 40. The cut preforms 38 are engaged by a mechanical grab device 50 of the robotic arm 54.

The continuous elongate extruded length 34 exits the die 30 of the extrusion apparatus 26 at an extrusion temperature, which is typically from 80 to 130 °C, optionally from 90 to 120 °C. In the preferred embodiment, the preforms 38 are heated the on the conveyor 36, optionally by infrared radiation using an infrared heater 60, to maintain the temperature of each preform 38 prior to moulding by the moulding machine 40. Preferably, the heating provides that the temperature of each preform 38 prior to moulding is substantially uniform throughout its thickness, preferably within +/-5°C, more preferably +/- 2°C, throughout its thickness. Alternatively or additionally the heating may provide that the temperature of each preform 38 prior to moulding is at the extrusion temperature, which is the temperature of the fibre- containing compounded thermosetting resin during extrusion, preferably within 5°C, more preferably 2°C, of the extrusion temperature.

The mechanical grab device 50 is thermally insulated so that the preform 38 is not substantially cooled during the transporting from the conveyor 36 to the moulding machine 40. Preferably, the preform 38 is not cooled by more than 2°C, preferably ! °C, during the transporting step. Preferably, the transporting step is carried out over a period of less than 10 seconds, more preferably less than 5 seconds.

At the moulding machine 40 the fibre-containing compounded thermosetting resin of the preform 38 is injected into the mould tool 44 to form, by transfer injection moulding, a moulded article in the mould cavity by moving the ram 42 to urge the preform 38 into the mould cavity through the inlet 46. The moulding exerts a high moulding pressure and high friction on the fibre-containing compounded thermosetting resin of the preform 38, which causes the resin to be heated and to fully cure. In this moulding step, each preform 38 may form a single respective moulded article or multiple moulded articles. After transfer injection moulding, the thermosetting resin is fully cured and optionally cross-linked.

In preferred embodiments of the present invention, the moulded article is a component of an automotive engine system, for example an internal combustion engine, such as a cylinder block or a cylinder head of an internal combustion engine.

Claims

1. A method of moulding a fibre-reinforced thermosetting resin to form a moulded article, the method comprising the steps of:

a. reactively compounding a thermosetting resin in a compounding apparatus to form a plurality of pieces of a compounded thermosetting resin;

2. A method according to claim 1 wherein the preform has a weight of from 2.5 to 10 kg.

3. A method according to claim 1 or claim 2 wherein the preform has a cut length of from 5 to 1000 mm.

4. A method according to any one of claims 1 to 3 wherein the extruded length has a cross sectional area of from 70 to 8000 mm².

5. A method according to any one of claims 1 to 4 wherein the thermosetting resin comprises a phenolic resin.

6. A method according to any one of claims 1 to 5 wherein the reinforcement fibres are added as cut fibres.

7. A method according to any one of claims 1 to 5 wherein the reinforcement fibres are added as elongate fibre rovings.

8. A method according to any one of claims 1 to 7 wherein the reinforcement fibres comprise glass fibres.

9. A method according to any one of claims 1 to 8 wherein the fibre-containing compounded thermosetting resin comprises from 20 to 80 wt% reinforcement fibres and from 80 to 20 wt% thermosetting resin, each based on the total weight of the fibre-containing compounded thermosetting resin, and further comprises a curing and catalyst system for the thermosetting resin.

10. A method according to any one of claims 1 to 9 wherein step (a) comprises the sub- steps of: (i) inputting components to form the thermosetting resin into an elongate screw mixer of the compounding apparatus and reactively compounding the resin therein; (ii) extracting from the elongate screw mixer air and/or volatile and/or gaseous reactant products produced from the compounding of the resin; (iii) introducing a plurality of individual reinforcement fibres into the elongate screw mixer; and (iv) extruding pieces of the fibre-containing compounded thermosetting resin from the elongate screw mixer.

1 1 . A method according to any one of claims 1 to 10 wherein the pieces have a weight of from 100 to 10,000 grams and/or a maximum dimension of 5 to 1000 mm.

12. A method according to any one of claims 1 to 1 1 wherein in step (b) the pieces are inputted into the extrusion apparatus at a rate of from 200 to 1000 kg/hour, and in step (d) the continuous elongate extruded length of the fibre-containing compounded thermosetting resin is extruded at a rate of from 200 to 1000 kg/hour.

13. A method according to any one of claims 1 to 1 2 wherein the pieces comprise dough portions, pellets, or granulates or any mixture of two or more thereof.

14. A method according to any one of claims 1 to 13 wherein in step (d) the extrusion apparatus comprises an elongate screw mixer, or a single screw extruder.

15. A method according to any one of claims 1 to 14 wherein in step (a) the compounding apparatus comprises an elongate double screw mixer.

16. A method according to any one of claims 1 to 1 5 wherein in step (d) the continuous elongate extruded length of the fibre-containing compounded thermosetting resin is extruded onto a conveyor and the cutting step (e) is carried out so that the cut preforms are conveyed from the extrusion apparatus by the conveyor.

17 A method according to claim 16 wherein the cutting step (e) is carried out at a die outlet of the extrusion apparatus.

18. A method according to claim 16 or claim 17 wherein the conveyor is an endless belt conveyor.

19. A method according to any one of claims 1 to 18 wherein the continuous elongate extruded length exits a die of the extrusion apparatus at an extrusion temperature and further comprising the step of heating the preforms on the conveyor to maintain the temperature of each preform, prior to step (g), (i) substantially uniform throughout its thickness, or within +/- 5°C, or +/- 2°C throughout its thickness and/or (ii) at the extrusion temperature, which is the temperature of the fibre-containing compounded thermosetting resin during extrusion, or within 5°C, or 2°C, of the extrusion temperature.

20. A method according to any one of claims 1 to 19 wherein the step of heating the preforms on the conveyor heats the preforms by infrared radiation.

21. A method according to any one of claims 1 to 20 wherein in step (f) the preforms are individually and successively transported to the injection moulding machine by a robotic arm.

22. A method according to claim 21 wherein in step (f) the cut preforms are engaged by a mechanical grab device of the robotic arm.

23. A method according to claim 22 wherein the mechanical grab device of the robotic arm is thermally insulated so that the preform is not substantially cooled during step (f), or is not cooled by more than 2°C, or 1 °C, during step (f).

24. A method according to any one of claims 1 to 23 wherein step (f) is carried out over a period of less than 10 seconds, or less than 5 seconds.

25. A method according to any one of claims 1 to 24 wherein in step (g) each preform forms a single respective moulded article.

26. A method according to any one of claims 1 to 24 wherein in step (g) each preform forms multiple moulded articles.

27. A method according to any one of claims 1 to 26 wherein the moulded article is a component of an automotive engine system.

28. A method according to claim 27 wherein the moulded article is a component of an internal combustion engine.

29. A method according to claim 28 wherein the component is a cylinder block or a cylinder head of an internal combustion engine.