GB2268705A

GB2268705A - Layup preparation for fibre reinforced composites

Info

Publication number: GB2268705A
Application number: GB9314757A
Authority: GB
Inventors: Andrew Mills; Graham John Burley; Andrew Paul Godbehere; Richard J Pedwell; Raymond Griffiths
Original assignee: British Aerospace PLC
Current assignee: BAE Systems PLC
Priority date: 1992-07-16
Filing date: 1993-07-16
Publication date: 1994-01-19
Anticipated expiration: 2013-07-16
Also published as: GB9314757D0; GB2268704A; GB2268705B; GB2268704B; GB9215148D0

Abstract

An apparatus for preparing a layup of plies of fibrous material for the manufacture of a fibre reinforced plastics composite comprises a moveable head (28), the head carrying a supply of fibrous material and means (15) to cut the fibrous material into individual shaped plies (32), and means to move the head (28) relative to a layup surface (12, 12a) onto which each cut ply (32) is to be laid whereby to drape the ply across the said layup surface (12, 12a) as cutting proceeds. The method involves using the apparatus in a series of passes of the head (28) to create a layup of the necessary thickness. <IMAGE>

Description

1 2268705 LAYUP PREPARATION FOR FIBRE REINFORCED COMPOSITES This invention

relates to layup preparation for fibre reinforced composites.

It is known to prepare a f ibre reinforced composite part by hand layup onto a curved mould tool. Hand layup may be assisted by automated ply profiling to profile individual plies at high speed. Layup of the plies still needs to be carried out by hand however, which is extremely time consuming and labour and skill intensive.

It is an object of the invention to provide apparatus and a method for laying up a fibre reinforced composites part which is faster and cheaper than at present possible.

According to one aspect of the invention there is provided apparatus for preparing a layup of plies of fibrous material for the manufacture of a fibre reinforced plastics composite, the apparatus comprising a moveable head, the head carrying a supply of fibrous material and means to cut the fibrous material into individual shaped plies, and means to move the head relative to a layup surface onto which each cut ply is to be laid whereby to drape the ply across the said layup surface as cutting proceeds.

2 Ply cutting and layup may accordingly be accomplished mechanically thus saving large amounts of time over presently known hand layup methods.

The head may include a supply of resin film material and means to combine the film material with the fibrous material prior to cutting taking place.

In this way the cost advantages of purchasing separate fibrous material and resin film material can be obtained without losing the advantage of automated cutting and layup of the plies. Alternatively pre-impregnated fibrous material, Uprepreg", already containing resin may be used from a single supply.

The or each said supply of material may comprise a rotatable roll carrying the material.

The means to combine the film material with the fibrous material may include a pair of opposed rollers at least one of which is heated, alternatively or in addition, the combination means may include the application of heated gas or air to the material to be combined, either by a pressurised stream or by passing the material through a heated oven.

The apparatus may include means to remove a backing layer from the resin film material, which means may conveniently comprise a further roller onto which the backing film is rolled during material cutting. More than one roller may be included for this purpose and the backing film removal roller may be located adjacent an opposed pair of rollers between which the material passes.

The cutting means may include a cutter and a support for the material being cut which conveys the material past the cutter.

Any suitable cutting means may be used, for example, conventional blade, ultrasonic knife or laser apparatus.

The conveying support is desirably positionable closely above a said layup surface onto which each cut ply is to be draped and may be angled suitably to facilitate accurate draping of each cut ply on the layup surface.

The relative movement means may include a mounting to a gantry, for example, an overhead gantry, providing at least transverse movement of the head with respect to the lay-up surface. Additionally the relative movement means may also provide vertical relative movement between the head and the layup surface respectively.

It may be advantageous for the apparatus to include means to draw the material past the cutting means under tension.

opposed rollers may be suitable for this purpose.

The apparatus may include retractable support means acting as a layup surface and adapted to receive a layup of the plies as individually deposited from the head. The retractable support 4 means may be carried by a peripheral frame defining an open central area covered by the support means when extended.

The retractable support means advantageously comprises a series of elongate members flexibly mounted adjacent one another and wound on a roller for drawing acrQss the open central area. The said flexible mounting may comprise a porous membrane connecting the members together.

The retractable support means may comprise a f irst f ixed axis roller, a slatted portion wound thereon and a second travelling roller, the first roller and a free end of the slatted portion being located at one end of the open central area with the travelling roller engaging the slatted portion between the first roller and free end whereby to draw the slatted portion across the open central area when travelling in a f irst direction and to allow withdrawal of the slatted portion across the open central area when travelling in a second direction It may be found helpful for the conveying support and/or the retractable support means to be adapted to apply suction to the material supported thereby during layup to assist in locating the material.

In addition, or alternatively the conveying support and/or the retractable support means may be adapted selectively to expel air under pressure to urge the material therefrom as it leaves the conveying support or support means respectively. It will be appreciated that identical pipework with appropriate valves could be used to carry out both these steps.

The apparatus may include clamping means to clamp and support edges of the material adjacent to the open central area for use, for example, during consolidation of the layup.

The apparatus may include means to consolidate the layup on the layup surface which may conveniently comprise a roller for rolling across the surface, or alternatively may comprise means to exert a pressure on the layup eg a vacuum bag, to consolidate same.

The apparatus may include a resiliently deformable sheet of material defining a said layup surface, the deformable sheet of material being supported by a series of spaced jacks adjustable for height in a programmed sequence.

According to a second aspect of the invention there is provided a method of forming a layup of plies of fibrous material for the manufacture of a fibre reinforced plastics composite including the steps of drawing a length of the material across a layup surface, cutting a piece of material from the length to form a cut ply and allowing same to drape onto the layup surface and repeating the above steps as necessary until a layup of the required thickness is formed.

The method may include the steps of extending support means beneath the length of material prior to layup in order to 6 support the material during layup and subsequently progressively withdrawing the support means to allow the layup progressively to drape further onto a tool surface therebeneath.

The method may further include the step of combining the length of fibrous material with a length of resin film material, immediately prior to cutting.

The invention will now be described by way of example with reference to the accompanying drawings of which:

Figure 1 shows in perspective apparatus according to one aspect of the invention, Figure 2 diagrammatically shows a layup sequence, Figure 3 shows in perspective a layup table comprised in the apparatus of figure 1, and Figure 4 is a side view of a modified version of the apparatus.

Referring to figure 1 and figure 4, apparatus 1 according to the invention comprises a moveable head 28 mounted on a gantry 46 for transverse sliding movement in the direction of the arrows above a stationary part of the apparatus in the form of a retractable support table 18 upon which plies of material are layed up from the moveable head 28. The moveable head 28 and gantry 46 may or may not be used In conjunction with the retractable support table 18. For applications other than the one illustrated layup from the removeable head 28 may take place directly onto a fixed mould tool 51 (see figure 4) 7 suitable f or insertion into an autoclave or may take place onto a layup table 26 such as the one shown in f igures 1 and 3.

The moveable head 28, shown only schematically, is mounted to a mounting arm 48 of the gantry which is itself suspended on rollers (not shown) for sliding movement along a rail 47. The moveable head includes feed rollers 4 and 5 comprising a supply of non-crimp fabric fibrous material 16 and resin film material 17 respectively. These rollers feed between pinch rollers 7 and 8 which are heated and which combine the fibrous material 16 and resin film material 17 together. The combined material 52 (f igure 4) then passes downwardly at an angle between a further pair of pinch rollers 9 and 10 at which stage a backing film 29 is removed onto a takeup roller 30. The material 52 then passes over a conveying support 41 comprising a pair of spaced rollers 42, 43 around which is stretched a porous endless support belt 44 for supporting the material 52 during cutting. The conveying support 41 also includes vacuum means 45 for applying a vacuum to the combined material 52 through the support belt 44 and blowing jets 55 to urge the cut material 31 from the conveying support 41 as ply draping and take up of surplus material proceeds. Cutting means for the head comprises the aforesaid conveying support 41 and also two ultrasonic cutting knives 15 moveable in the direction of the arrows (see figure 1) for cutting each ply of material. The cut material 31 including one or more cut plies 32 is draped during layup from the conveying support 41 of the head onto a layup surface 12 whilst the head moves 8 along the gantry 46. Surplus material 53 (see figure 4) is taken up by a second takeup roll 54 mounted on the head 28. In the embodiment shown in Figure 1 the second takeup roll 54 is mounted on the retractable support table 18.

Referring to figure 1, the retractable support table 18 has a frame 2 defining an open central area 3. The support table 18 has a first end 6 and a second end 11. The layup surface 12 can constitute an upper surface of a deformable sheed of material 13 supported by a series of spaced j acks 14 of the layup table 26 (see figure 3). Alternatively the layup surface may comprise part 12a of the retractable support table 18 as shown or the surface 12 of a shaped mould tool (figure 4).

Referring to figure 1, the retractable support table 18 includes a retractable support 49 comprising a first roller 22 having a fixed axis, a second travelling roller 23 and a slatted portion 24 wound on the first roller 22. The slatted portion 24 has one end fixed at the first end 6 of the table at a level to support the combined material 52 as it is draped over the open central area 3. The travelling roller 23 has its axis moveable in a jorizontal plane along a slide 25 so as to pass across the open central area 3. A consolidation roller 20 is also moveable along the slide 25 for rolling across the layup surface 12 during consolidation. A consolidation roller may alternatively be sited to roll across the surface 12a prior to retraction of the retractable support 9 49. Each slat of the slatted portion 24 is hollow and connectible to either a pressure source or a vacuum source.

The layup surf ace 12 forms the top surf ace of the layup 26 which is adjustable in height (see figures 1 and 3). The layup table 26 runs on rails 27 between work-stations of a flexible manufacturing centre (not shown).

The table further comprises clamping means 19 on either side of the table to grip edges of the combined material 52 as required, for example during consolidation.

Figure 2 shows one method of laying up whole or part of the wing skin using an apparatus and method according to the invention. A first lay 33 extends between positions 34 and 35 and second to fifth lays, 36 to 39 extend for different distances between positions 34 and 35 to create a layup 21 of thickness tapering along its length. The layup as shown can be laid up in the f lat on the deformable sheet of material 13 on the layup tabke 26. and thus can be fully automated using the apparatus of the invention. The layup table 26 is then lowered to clear the frame 2 of the support table and moved along the rails 27 to a workstation where the deformable sheet of material is slowly deformed by the jacks 14 into the desired shape, heat and pressure optionally being applied at this stage to ensure that the layup is consolidated and that no wrinkling of the material occurs. When formed in this way the part formed from the layup can be moved, either on the layup table or lifted from the layup table into an autoclave for final application of pressure and heat to cure if necessary.

In use the moveable head 28 is moved to the first end 6 of the table 18, the layup table 26 is raised to its upper position go that the layup surface 12 sits just underneath the retractable support 29 of the table 18. In figure 1 the retractable support 49 is extended across the open central area 3 by moving the travelling roller 23 underneath the open central area 3 to draw the slatted portion 24 thereacross thus unwinding the slatted portion 24 from the first roller 22.

The moveable head 28 is then traversed to the left towards the second end 11 of the support table 18, the rollers, 4, 5, 7, 8, 9, 10, 30, 42, 43 are set in motion to feed, and the cutting means to cut and drape the combined material 52 onto the layup surface 12 as the head 28 traverses across the table 18 from right to left.

A complete layup is formed on the retractable support table 18 and may be consolidated if required before the retractable support 49 is retracted to allow the complete layup to drape onto the layup table 26. After each ply is layed up the head 28 is traversed back to the f irst end 6 of the layup table whereupon the operation of cutting and draping is repeated with the next ply. Unused material 31 Is wound onto the roller 54 for subsequent use on smaller parts if necessary. After either each cut ply 32 or complete layup 21 has been draped onto the layup table 26, the consolidation roller 20 can be operated across the layup surface 12 to consolidate the layup.

The apparatus according to the invention can be as wide as is desired to allow extremely large components to be laid up in a single operation and in the flat. Great speed of layup may thus be achieved, also automation.

4 12

Claims

1.Apparatus for preparing a layup of plies of fibrous material for the manufacture of a fibre reinforced plastics composite, the apparatus comprising a moveable head, the head carrying a supply of fibrous material and means to cut the fibrous material Into individual shaped plies, and means to move the head relative to a layup surface onto which each cut ply is to be laid whereby to drape the ply across the said layup surface as cutting proceeds.

2. Apparatus as in claim 1 including a supply of resin film material and means to combine the film material with the fibrous material prior to cutting taking place.

3. Apparatus as in claim 1 or 2 in which a said supply comprises a rotatable roll carrying the material.

4. Apparatus as in claim 2, or 3 when dependent on 2, in which the means to combine the film material with the fibrous material includes a pair of opposed rollers at least one of which is heated.

5.Apparatus as in claim 2, claim 3 when dependent on claim 2, or claim 4, including means to remove a backing layer from the resin film material.

6. Apparatus as in any preceding claim including takeup means to take up surplus material forming a remainder, following cutting.

7. Apparatus as in any preceding claim in which the cutting means includes a cutter and a support for the material being cut which conveys the material past the cutter.

13

8.Apparatus as in claim 7 in which the conveying support draws to itself by suction the material being cut.

9.Apparatus as in claim 7 or 8 including means to urge the cut material from the conveying support during draping thereof.

10.Apparatus as in claim 6, 7, 8 or 9 in which the conveying support is positionable closely above a said layup surface onto which each cut ply is to be draped.

11.Apparatus as in any preceding claim in which the relative movement means includes a mounting to a gantry providing at least transverse movement of the head therealong.

12.Apparatus as in claim 11 in which the relative movement means also provides vertical relative movement between the head and layup surface.

13.Apparatus as in any preceding claim including means to draw the material past the cutting means under tension.

14.Apparatus as in any preceding claim including retractable support means acting as a layup surface and adapted to receive a layup of said plies as individually deposited from the head.

15.Apparatus as in claim 14 in which the retractable support means is carried by a peripheral frame defining an open central area covered by the support means when extended.

16.Apparatus as in claim 15 in which the retractable support means comprises a series of elongate members flexibly mounted adjacent one another and wound on a roller for drawing across the open central area.

17.Apparatus as in claim 16 in which the retractable support means comprises a first fixed axis roller, a slatted 14 portion wound thereon and a second travelling roller, the first roller and a free end of the slatted portion being located at one end of the open central area with the travelling roller engaging the slatted portion between the first roller and free end whereby to draw the slatted portion across the open central area when travelling in a first direction and to allow withdrawal of the slatted portion across the open central area when travelling in a second direction.

18.Apparatus as in claim 14, 15, 16 or 17 in which the retractable support means is adapted to apply a suction to the material supported thereby during layup.

19.Apparatus as in any of claims 14 to 18 in which the retractable support means is adapted selectively to expel air under pressure to urge the material therefrom during retraction.

20.Apparatus as in any of claims 15 to 19 including clamping means to clamp and support edges of the material adjacent to the open central area.

21.Apparatus as in any preceding claim including means to consolidate the layup on the layup surface.

22.Apparatus as in claim 21 in which the means to consolidate the layup comprises a roller for rolling across the surface.

23.Apparatus as in any preceding claim including a layup table having a resiliently deformable sheet of material defining a said layup surface, the deformable sheet of material being supported by a series of spaced jacks adjustable for height in a programmed sequence.

24.A method of forming a layup of plies of fibrous material for the manufacture of a fibre reinforced plastics composite including the steps of drawing a length of the material across a layup surface, cutting a piece of material from the length to form a cut ply and allowing same to drape onto the layup surface and repeating the above steps as necessary until a layup of the required thickness is formed.

25.A method as in claim 24 including the steps of extending support means beneath the length of material prior to layup in order to support the material during layup and subsequently progressively withdrawing the support means to allow the layup progressively to further drape onto a tool surface therebeneath.

26.A method as in claim 24 or 25 including the step of combining the length of fibrous material with a length of resin film material, immediately prior to cutting.

27.Apparatus for preparing a layup of plies of fibrous material for the manufacture of a fibre reinforced plastics composite substantially as described herein with reference to the accompanying drawings.

28.A method of forming a layup of plies of fibrous material for the manufacture of a fibre reinforced plastics composite substantially as herein described.