DEVICE FOR MANUFACTURING A COMPOSITE PART

Abstract

There is provided a device for producing fibre-reinforced composite components from dry fibre components by means of an injection process for injecting curable matrix material, comprising a. a tool for arranging a dry fibre component; b. an envelope which is impermeable to gas and curable matrix material arranged on at least one side of the tool to form a space into which curable matrix material may be introduced to contact a dry fibre component arranged on the tool, the envelope sealing off the tool from the environment; c. an inlet for introducing curable matrix material into the space formed by the envelope; d. an outlet for removing gas from the space formed by the envelope so that curable matrix material may be drawn into the space to penetrate the dry fibre component arranged on the tool; and e. a patch formed from a membrane which is permeable to gas but impermeable to curable matrix material, the patch being associated with the outlet so that gas, but not curable matrix material, can be removed from the space formed by the envelope via the outlet; wherein the association between the outlet and the patch is stable at temperatures of at least 150° C. There is further provided a method for producing fibre-reinforced composite components by use of a device according to the invention.

Claims

1. A device for producing fibre-reinforced composite components from dry fibre components by means of an injection process for injecting curable matrix material, comprising a. a tool for arranging a dry fibre component; b. an envelope which is impermeable to gas and curable matrix material arranged on at least one side of the tool to form a space into which curable matrix material may be introduced to contact a dry fibre component arranged on the tool, the envelope sealing off the tool from the environment; c. an inlet for introducing curable matrix material into the space formed by the envelope; d. an outlet for removing gas from the space formed by the envelope so that curable matrix material may be drawn into the space to penetrate the dry fibre component arranged on the tool; and e. a patch formed from a membrane which is permeable to gas but impermeable to curable matrix material, the patch being associated with the outlet so that gas, but not curable matrix material, can be removed from the space formed by the envelope via the outlet; wherein the association between the outlet and the patch is stable at temperatures of at least 150° C.

2. A device according to claim 1 comprising more than one outlet, each outlet being associated with a patch formed from a membrane which is permeable to gas but impermeable to curable matrix material, so that gas, but not curable matrix material, can be removed from the space formed by the envelope via the outlets; wherein the association between each outlet and patch is stable at temperatures of at least 150° C.

3. (canceled)

4. A device according to claim 2, wherein the total area of the membrane forming the patch is less than 50% of the total area of the envelope.

5. A device according to claim 4, wherein the patch is in the form of a sealed tube located within the space formed by the envelope, and the interior of the sealed tube is connected to a vacuum line passing through the patch and the envelope, so that when vacuum is applied to the vacuum line, gas but not curable matrix material present in the space is pulled from the space into the interior of the sealed tube and out of the device via the vacuum line.

6. A device according to claim 5, wherein the sealed tube is formed substantially solely from the patch.

7. (canceled)

8. (canceled)

9. A device according to claim 4, wherein the patch is sealed to the envelope to form a second space within the space formed by the envelope, and the interior of the second space is connected to a vacuum line passing through the envelope, so that when vacuum is applied to the vacuum line, gas but not curable matrix material present in the space is pulled from the space into the second space and out of the device via the vacuum line.

10. A device according to claim 9, wherein the patch is sealed to the envelope by means of one or more adhesive bands.

11. A device according to claim 4, wherein the tool comprises a perforated section attached to a vacuum source, and the patch is sealed to the tool to entirely cover the perforated section to form a second space within the space formed by the envelope, so that when vacuum is applied to the perforated section, gas but not curable matrix material present in the space is pulled from the space into the second space and out of the device via the perforated section.

12. A device according to claim 11, wherein the patch is sealed to the tool by means of one or more adhesive bands.

13. A method for producing fibre-reinforced composite components by use of a device according to claim 1, comprising a. arranging a dry fibre component on the tool of the device; b. arranging the envelope of the device to isolate the tool and the dry fibre component from the environment and to form a space into which curable matrix material may be introduced to contact the dry fibre component; c. attaching the inlet of the device to a source of curable matrix material; and d. applying vacuum to the outlet of the device, so that gas is removed from the space formed by the envelope and curable matrix material is drawn into the space and penetrates the dry fibre component, but so that curable matrix material is not removed from the space.

14. A method according to claim 13, further including the step of curing the curable matrix material, wherein the curing temperature is at least 150° C.

15. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0077] The invention will now be clarified by way of example only and with reference to the following Figures and Examples in which:

[0078] FIG. 1 is a schematic drawing of a device according to a first embodiment of the present invention including a preform;

[0079] FIG. 2 is a schematic drawing of a wrap for use in a device according to a first embodiment of the present invention and its process of preparation;

[0080] FIG. 3 is a schematic drawing of a device according to a second embodiment of the present invention including a preform; and

[0081] FIG. 4 is a schematic drawing of a device according to a third embodiment of the present invention including a preform.

[0082] FIG. 1 shows a device 1 according to a first preferred embodiment of the present invention. The device 1 includes a tool 3 for supporting a dry fibre component 5 for infusion with a curable matrix material.

[0083] The dry fibre component 5 is in the form of a preform, and the device includes additional shaping components 7 to further shape and/or maintain the original shape of the preform during matrix material infusion.

[0084] The outer surface of the device 1 is formed from a vacuum foil or bag 9 which is impermeable to gas and curable matrix material. The vacuum foil 9 is sealed to the tool 3 to form a space 11 surrounding the dry fibre component 5 and to isolate the dry fibre component 5 from the surrounding environment. The seal 13 between the tool 3 and the vacuum foil 9 is sufficient to prevent the passage of gas or curable matrix material through the join and is stable at all temperatures to which the device will be subjected in normal use.

[0085] The device 1 further comprises an inlet 15 which passes through the vacuum foil 9 and is connected to a source of curable matrix material (not shown).

[0086] The device 1 further includes layers of flow mesh 17 positioned between the dry fibre component 5 and the tool 3, the additional shaping components 7 and the vacuum foil 13. A layer of microperforated foil (not shown) may optionally be present between the dry fibre component 5 and the layer of flow mesh 17 adjacent to the tool 3. Layers of peel ply 21 are also present on the upper and lower surfaces of the dry fibre component 5.

[0087] The device 1 further comprises a wrap 25 positioned above the dry fibre component 3 and forming an outlet 27 in the device 1. The wrap 25 is formed as a sealed tube of a gas permeable but curable matrix material impermeable membrane 29. The wrap 25 encloses a breather material 31 and may also enclose a layer of flow mesh 17.

[0088] As illustrated in FIG. 2, the wrap 25 of the device 1 may be formed either from a single piece of gas permeable but curable matrix material impermeable membrane 29 or from a section of gas permeable but curable matrix material impermeable membrane 29 and a section of gas and curable matrix material impermeable material 33. These materials are initially formed into a hollow tube 35 by seals 37, and breather material 31 and a vacuum port 39 are inserted into the hollow tube 35. The ends of the hollow tube 35 are then further sealed 37 to form a fully sealed wrap 25. The seals 37 are all stable at temperatures of at least 180° C., and may be formed, for example, by thermoforming at suitable temperatures.

[0089] In use, the vacuum port 39 of the wrap 25 present in the device 1 is connected to a vacuum line (not shown) which is passed through the vacuum foil 9 and the wrap 25 and sealed thereto. Vacuum applied to the vacuum port 39 from the vacuum line causes gas to be pulled from the wrap 25 and therefore for gas to be pulled from the space 11 into the wrap 25 (and subsequently out of the wrap 25). The removal of gas from the space 11 causes curable matrix material to be pulled into the space 11 and to impregnate the dry fibre component 5. The curable matrix material is held within the space 11 by the vacuum foil 9 and does not penetrate the wrap 25, so that there is no loss of curable matrix material via the vacuum line.

[0090] Once the dry fibre component 5 is sufficiently impregnated with curable matrix material the inlet 15 and the outlet 27 may be closed to prevent further flow of curable matrix material, and the impregnated fibre component 5 may be cured without removal from the device 1 at temperatures of 180° C. or greater.

[0091] FIG. 3 shows a device 41 according to a second preferred embodiment of the present invention.

[0092] The device 41 shown in FIG. 3 comprises many of the same components as the device 1 shown in FIG. 1 (which are numbered in the same manner). However, in the device 41 shown in FIG. 3 there is no wrap 25, and the outlet 27 is formed by a portion of gas permeable but curable matrix material impermeable membrane 29 attached to the vacuum foil 9 to form a second space 43 between the first space 11 and the vacuum foil 9. The gas permeable but curable matrix material impermeable membrane 29 may be sealed to the vacuum foil 9 in an suitable manner to ensure that the seal is stable at temperatures of 180° C. or higher, for example by one or more high temperature adhesive bands coated with PTFE 57.

[0093] The second space 43 contains breather material 31 and optionally a flow mesh 17 together with a vacuum port (not shown).

[0094] In use, the second space 43 of the device 41 is attached to a vacuum source (not shown) and operates in the same manner as the wrap 25 of the device 1 shown in FIG. 1. Thus, the vacuum port of the second space 43 is attached to a vacuum line (not shown) which is passed through the vacuum foil 9 and sealed thereto. Vacuum applied to the vacuum port from the vacuum line causes gas to be pulled from the second space 43, and therefore for gas to be pulled from the first space 11 into the second space 43 (and subsequently out of the second space 43). The removal of gas from the first space 11 causes curable matrix material to be pulled into the first space 11 and to impregnate the dry fibre component 5. The curable matrix material is held within the space 11 by the vacuum foil 9 and does not penetrate the second space 43, so that there is no loss of curable matrix material via the vacuum line.

[0095] Once the dry fibre component 5 is sufficiently impregnated with curable matrix material the inlet 15 and the outlet 27 may be closed to prevent further flow of curable matrix material, and the impregnated fibre component 5 may be cured without removal from the device 1 at temperatures of 180° C. or greater.

[0096] FIG. 4 shows a device 51 according to a third preferred embodiment of the present invention.

[0097] The device 51 shown in FIG. 4 comprises many of the same components as the device 1 shown in FIG. 1 (which are numbered in the same manner). However, in the device 51 shown in FIG. 4 there is no wrap 25, and there are two outlets 27, each formed by a perforated section 55 of the tool 3, and which are each covered by a gas permeable but curable matrix material impermeable membrane 29 to form second spaces 53 between the first space 11 and the perforated section 55 of the tool 3. The gas permeable but curable matrix material impermeable membranes 29 may each be sealed to the perforated section 55 of the tool 3 in an suitable manner to ensure that the seals are stable at temperatures of 180° C. or higher, for example by one or more high temperature adhesive bands coated with PTFE 57.

[0098] In this embodiment, the inlet 15 is positioned above the tool 3 and the dry fibre component 5.

[0099] In use, the second spaces 53 of the device 51 are each attached to a vacuum source (not shown) and operate in the same manner as the wrap 25 of the device 1 shown in FIG. 1. Thus, the perforated sections 55 of the tool 3 are each attached to a vacuum line (not shown), and vacuum applied to the vacuum ports from the vacuum line causes gas to be pulled from each of the second spaces 53, and therefore for gas to be pulled from the first space 11 into the second spaces 53 (and subsequently out of the second spaces 53). The removal of gas from the first space 11 causes curable matrix material to be pulled into the first space 11 and to impregnate the dry fibre component 5. The curable matrix material is held within the space 11 by the vacuum foil 9 and does not penetrate the second spaces 53, so that there is no loss of curable matrix material via the vacuum line.

[0100] Once the dry fibre component 5 is sufficiently impregnated with curable matrix material the inlet 15 and the outlets 27 may be closed to prevent further flow of curable matrix material, and the impregnated fibre component 5 may be cured without removal from the device 1 at temperatures of 180° C. or greater.

EXAMPLES

[0101] HiTape® material (as supplied by Hexcel Reinforcements, Les Avenieres) was deposited in multiple layers to form dry fibre components for infusion testing in devices according to the present invention. HiTape® is a dry tape which comprises unidirectional carbon fibre tows having thermoplastic veils on either side of the tows to facilitate heat bonding of the tape during lay-up.

[0102] The dry fibre components were shaped and laid up in devices corresponding to the devices shown in FIGS. 1, 3 and 4. In each device the patch of gas permeable but curable matrix material impermeable membrane was formed from a C2003 A-Laminate VAP membrane available from Trans-Textil GmbH. In the first device the gas permeable but curable matrix material impermeable membrane was formed into a wrap by thermoforming at a temperature of 200° C. In the second device the gas permeable but curable matrix material impermeable membrane was attached to the vacuum foil by single sided adhesive bands coated with PTFE. In the third device the gas permeable but curable matrix material impermeable membrane was attached to the perforated section of the tool by single sided adhesive bands coated with PTFE.

[0103] The assemblies were then infused with HexFlow® RTM 6 (available from Hexcel Composites SAS) and cured at a temperature of 180° C. according to the recommended cure schedule of RTM 6. In each case, the parts were fully infused, with a final fibre volume content of approximately 60%, and no leaks were found in the gas permeable but curable matrix material impermeable membrane or between the component(s) it was attached to.