GB2490152A

GB2490152A - Automated Prepreg Processing, removal of an external film

Info

Publication number: GB2490152A
Application number: GB1106673.5A
Authority: GB
Inventors: Thomas Corden; Alasdair Ryder
Original assignee: Umeco Structural Materials Derby Ltd
Current assignee: Cytec Industrial Materials Derby Ltd
Priority date: 2011-04-20
Filing date: 2011-04-20
Publication date: 2012-10-24
Also published as: GB201106673D0

Abstract

Method and apparatus for processing a prepreg 10 by the removal of an external film 12 from the prepreg, the apparatus comprising a film removal means in the form of a head 16 having tack reducing means (18, fig 9) operable to reduce the resinous tack properties of an area of a prepreg to be processed and further comprising film removing means 20 operable to attract an external film from the said area thereagainst, and drive means 22 operable to drive relative movement between the prepreg and the film removal head to peel the film from the prepreg. Preferably, the tack reducing means comprises a chilling means, which may be in the form of a compressed gas directed at the prepreg through a nozzle provided in the head to freeze an area of the prepreg. The film removing means preferably comprises a suction cup (32, figure 9) comprising collapsible sides and the nozzle for the chilling means may extend through the suction cup. A pivotable film retaining means 44 may be provided to hold the film against the suction head. A method of removing an external film frm a prepreg comprising applying a chilling substance and applying suction to lift the film from the prepreg is also provided.

Description

Automated Prepreg Processing The present invention relates to automated prepreg processing, particularly but not exclusively to the automated processing of prepregs using robotic apparatus.

Prepregs are typically used in the manufacture of composite components. Prepregs generally comprise fibrous reinforcement impregnated at least partially with a matrix resin. Prepregs are often in the form of sheets or rolls of a single ply or a plurality of plies laminated together. Prepregs are well known to those skilled in the art. The fibrous reinforcement and the matrix resin for prepregs for which the present invention finds utility can be of any suitable type, and are typically selected by those skilled in the art according to the desired properties and characteristics of both the prepreg and the product formed using the prepreg.

The matrix resin in prepregs is generally tacky at temperatures from 5°C upwards. This inherent tackiness can render the prepregs tricky to handle at typical ambient temperatures and so conventionally a backing film is provided, usually on each tacky surface or side of a prepreg. Such backing films are typically of polythene or similar plastic material, but can be of paper and the like. The inherent tackiness of the prepreg is usually sufficient to hold the backing film in place whilst the backing film prevents the tacky resin from generally being contacted when the prepreg is being handled.

When a prepreg is to be placed in a mould or on a tool to form a composite component, it is generally preferable that the or each backing film is removed.

According to the present invention there is provided apparatus for processing a prepreg by the removal of an external film from the prepreg, the apparatus comprising a film removal head having tack reducing means operable to reduce the resinous tack properties of an area of a prepreg to be processed and further comprising film removal means operable to aft ract an external film from the said area thereagainst, and drive means operable to drive relative movement between the prepreg and the head to peel the film fromtheprepreg.

The term "resinous tack properties" is used in this specification to refer to the adhesive tack, typically provided by the matrix resin in a prepreg, but which could include the tackiness presented by any adhesive or other resinous material that acts to retain an external film, in particular a backing film, on a prepreg.

The tack reducing means may comprise chill means operable to chill, desirably to a frozen or partially frozen condition, the said area of prepreg to reduce the inherent tackiness of resinous material in the area and thereby reduce the adherence of the external film to the prepreg at that area.

The chill means may comprise or be connectable to a chilling substance source, which may comprise a store of cryogen material such as compressed gas, including liquefied nitrogen, carbon dioxide or the like. The tack reducing means may comprise a delivery arrangement for the selective delivery of chilling substance to the said area of prepreg. The delivery arrangement may comprise a delivery nozzle or needle locatable against or in the proximity of the area of a prepreg to be chilled and operable to deliver a chilling substance to the area whereby to chill the prepreg at that area. The proximity of the delivery nozzle to the area of prepreg may be adjustable.

The film removal head may comprise a robotic head, which may be located on a robotic arm.

The film removal means may comprise a suction arrangement operable to draw the external film in a direction from the prepreg. The suction arrangement may comprise a suction source and a suction head, the suction head being locatable in use against or adjacent a film to be removed and preferably at or in the proximity of the said area of the prepreg.

The suction arrangement may comprise means to enable selective provision of suction from the suction source to the suction head, which means may be activated upon or shortly after the operation of the chill means, and at least within the time the resinous tack properties of the area remain sufficiently reduced to enable removal of the external film from the area.

The suction head may comprise a suction cup which may comprise an outer cup section defining therein a suction chamber. The outer cup section may comprise collapsible sides, which may be collapsible in a concertina-type fashion, and may be formed of resilient, maybe elastomeric material. The suction cup may be attached at one end thereof to a housing and defines may be at another end a suction mouth against which film is drawn and may releasably seal in operation.

The delivery nozzle of the chill means may be located, at least partially, within the suction chamber. The delivery nozzle may be arranged to deliver a chilling substance at or in the proximity of the suction mouth of the suction cup. This helps to ensure that the chilling substance is directed onto the area to be chilled and reduces the risk of the substance chilling the suction cup to an undesirable degree.

The tack reducing means may be automatically actuated when the film removal head and a prepreg to be processed are brought into close proximity and may be actuated upon or shortly following entry of the tack reducing means and/or a prepreg to be processed into a processing position.

The film removal means may be automatically actuated when the film removal head and prepreg to be processed are brought into close proximity, and may be actuated upon or shortly following actuation of the tack reducing means.

The apparatus may comprise drive means to drive movement of the robotic head both to and from an area of a prepreg to be processed. The drive means may drive a peeling motion that acts to peel film from a prepreg.

Alternatively or in addition the apparatus may comprise drive means to drive movement of the prepreg to be processed, in particular the area of a prepreg to be processed, to and from the film removal head. The drive means may drive a peeling motion that acts to peel film from a prepreg.

The drive means may comprise one or more motors, such as electric motors.

The apparatus may comprise retaining means to retain attracted film against the film removal means. The retaining means may comprise a retaining member which may be located on the film removal head and which may be moveable between a first, non-retaining position and a second, film retaining position. When in the first position, the retaining member may be away from the suction mouth and when in the second position may extend, at least in part, across the suction mouth to retain film held against the suction mouth. The member may be pivotally moveable between the said first and second positions and may be so moveable automatically upon attracted film locating against the film removal head.

The apparatus may comprise prepreg delivery means to deliver a prepreg to be processed to the or a further film removal means. The prepreg delivery means may comprise selectively operable prepreg retention means operable to selectively retain a prepreg to be processed thereagainst. The prepreg retention means may comprise a suction arrangement operable to draw and hold a prepreg against the delivery means. The suction arrangement may comprise one or more suction cups selectively connectable to a suction source and operable to apply suction to a prepreg to hold the prepreg thereagainst. The prepreg delivery means may comprise a robotic arm that drives movement of the prepreg retention means from a first position to a second position to deliver prepreg held against the delivery means to the film removal means.

The apparatus may comprise a processing station at which a prepreg can be processed. The station may comprise a surface on which a prepreg is presented to be processed. The station may comprise indexing means to ensure appropriate positioning of prepreg at the station. The indexing means may comprise one or more formations, such as projections, extending from the surface, against or with which the prepreg locates. The apparatus may comprise automated prepreg placement means to place prepreg in location at the processing station. The placement means may comprise one or more robotic arms.

According to a second aspect of the present invention there is provided a method of removing an external film from a prepreg, the method comprising applying a chilling substance to a prepreg to reduce the resinous tack properties of resinous material in an area of the prepreg and applying suction to lift the film from the prepreg.

The method may involve the use of apparatus as hereinbefore described.

The method may comprise cryogenic cooling or chilling by applying compressed gas, such as liquid nitrogen, to an area of the prepreg, which may be conveniently located at or near an edge or corner of the prepreg. It will be appreciated that any suitable cryogen can be used instead of or as well as liquid nitrogen, such as liquid C02, liquid helium or other compressed gases. The chilling substance may be automatically applied, may be through a film removal head, and may be when the film removal head is located against or is within a predetermined proximity to the prepreg.

The chilling substance may be applied using tack reducing means as described above.

Film may be removed using film removal means as described above.

Suction may be applied using a suction arrangement which may be as described above.

The method may comprise a first step of removing one external film from a prepreg.

Drive means may be used, such as one or more motors, to drive relative movement between the film removal head and the prepreg. The film removal head may be driven between a first position in which the head locates against or is in close proximity to the prepreg to apply suction to the prepreg and a second position in which the head is distanced from the prepreg, movement from the first position to the second position preferably comprising a peeling motion to enable lifted film to be peeled from the prepreg. The suction may be released when the head is in the second position or another position remote from the prepreg, releasing the removed film, typically allowing it to drop desirably into a collection receptacle.

The method may further comprise removal of a second external film, typically provided on a second surface of a prepreg, which may involve presenting the prepreg to the or a further tack reducing means and removing the second film, preferably by exposing an area of the second surface of the prepreg to a chilling substance and applying suction to that area to remove the second external film from the prepreg.

The prepreg may be lifted using lifting means, which may comprise prepreg delivery means as described above, which may comprise a suction arrangement that enables selective retention and release of the prepreg therefrom. The suction arrangement may be operable to locate against a surface of the prepreg exposed upon removal of one external film.

Drive means may be used, such as one or more motors, to drive movement of the lifting means between a first position in which the prepreg locates against or is in close proximity to a film removal head and a second position in which the prepreg is remote from the film removal head, movement from the first to the second position preferably comprising a peeling motion, such as to enable the second film to be peeled from the prepreg.

The film removal head, which may comprise a robotic head, may be as described above and may apply a chilling substance to an area of the second surface when the prepreg is in the first position to reduce the resinous tack properties of the resinous material in the area and apply suction to that area to attract the second film thereto away from the prepreg. The film removal head may be static during film removal, with the lifting means moving relative thereto.

The film retained on the film removal head may be held thereon by retention means. The retention means may be applied automatically when the film is located on the removal head, to help secure retention. The retention means used may comprise retaining means as described above.

Particular embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which: Fig 1 is a diagrammatic perspective view of a typical prepreg in relation to which the present invention finds utility; Fig 2 is a diagrammatic representation of a prepreg located at a processing station, ready to be processed in accordance with the present invention; Figs 3, 4 and 5 are schematic representations of successive stages of the removal of a first backing film from a prepreg in accordance with the present invention; Figs 6, 7 and 8 are schematic illustrations of successive stages of the removal of a second backing film from a prepreg in accordance with the present invention; Fig 9 is a diagrammatic cross-section (enlarged) of a film removal head of apparatus according to the present invention; Fig 10 is a diagrammatic cross-sectional view (enlarged) of a prepreg delivery head in accordance with the present invention; and Fig 11 is a diagrammatic illustration of alternative indexing means according to the present invention.

The present invention provides a method and apparatus for processing a prepreg 10 by the removal of an external film 12 from the prepreg 10, the apparatus comprising a film removal means in the form of a head 16 having tack reducing means 18 operable to reduce the resinous tack properties of an area of a prepreg to be processed and further comprising film removing means 20 operable to attract an external film 12 from the said area thereagainst, and drive means 22 operable to drive relative movement between the prepreg 10 and the film removal head 16 to peel the film 12 from the prepreg 10. a

The method and apparatus of the present invention find particular application in the automated removal of external films, in particular backing films that are conventionally provided on the outside of resinous prepregs to improve the handling characteristics of such materials. The present invention finds particular application in the removal of such external films from generally flat or sheet-like prepregs, but the invention could be adapted for use with other forms of prepreg.

The backing films are typically held in position by the inherent tackiness of the matrix resin within the prepreg and at the temperatures that such prepregs would typically be handled and processed (often ambient room temperatures (10°C to 40°C)) the backing films can be held quite tightly by the inherent tack.

Conventional backing films are typically polythene or other plastics materials, although alternatives such as paper and the like can be used. It is generally the case that such backing films are removed prior to the prepreg being laid on a tool or mould to form a composite component or product and conventionally the films are removed manually, often involving the use of a knife or blade to provide initial separation and then the manual pulling of the film from the prepreg. Such a process is labour intensive and does not allow for the automation of the handling and processing of prepregs from their storage condition, ie with the backing film or films in place, to a moulding condition, ie with the backing film or films removed.

The present invention provides for the automated processing of prepregs as described herein.

The apparatus of the present invention comprises a film removal head 16 that comprises tack reducing means 18 and film removal means 20. With particular reference to Fig 9, the film removal head 16 comprises a housing or base 24 which is attached in an airtight manner to a robotic arm 26. The film removal means 20 comprises a suction head 28 which includes the base 24 and a suction cup 30 attached to the opposite side of the base 24 to which the robotic arm 26 is attached. Again, the attachment of the suction cup 30 to the base 24 is substantially airtight. The cup 30 is able to compress in a direction towards and away from the base 24 and in this embodiment comprises an outer cup 32 of resilient, elastomeric material that is formed with a concertinaed configuration to define therewithin a suction chamber 34. The suction cup 30 defines a suction mouth 36 against which backing film is drawn and retained, as will be explained. The suction chamber 34 is connected by passages 38 that extend through the base 24 to be in communication with a suction source (not shown) which in this embodiment is remote from the head 16 but in communication therewith via an air passage that runs through the robotic arm 26. It will however be appreciated that the suction source could be more directly associated with the suction head 28 and/or could be in communication via one or more separate conduits or pipelines that can be internal and/or external of the robotic arm 26. Such pipelines may be flexible.

It will further be appreciated that although two passages 38 are illustrated in this embodiment, any number of suitable passages can be provided.

The tack reducing means 18 comprises means to deliver a chilling substance to the area of the prepreg 10 against which the film removal head 16 is located for use and comprises a delivery nozzle or needle 40 which extends through the base 24 into the chamber 34 to define an outlet 42 located at or in close proximity to the suction mouth 36. The delivery nozzle/needle 40 is in communication with a source (not shown) of chilling substance, such as compressed gas, which when delivered through the outlet 42 chills the area of prepreg 10 against or in close proximity to the mouth 36 of the suction head 28. The chilling substance can comprise any suitably cold or chilling substance including cryogens such as liquid nitrogen, liquid C02, liquid helium.

In the particular embodiment shown, the delivery needle 40 extends into the inside of the robotic arm 28 to be connected to the chilling substance source, such as by a connecting conduit 43, which provides for not only a neat arrangement, but also helps protect the internalised tack reducing means 18 from accidental damage. It will however be appreciated that the conduit(s) through which the chilling substance is/are delivered to the needle 40 can extend internally and/or externally of the robotic arm 26.

The robotic arm 26 comprises the drive 22 for the selective movement of the film removal head 16, as will be explained. The drive 22 may comprise one or more motors, such as electric motors (not shown). The robotic arm 26 can of itself be of generally conventional design.

The film removal head 16 further comprises retaining means 44 operable to retain film that has been attracted from the prepreg to the mouth 36 of the suction cup 30. The retaining means 44 comprises an arm 46 pivotally connected about a pivot 48 to the outside of the base 24. The arm 46 comprises a first section 50 which extends between the pivot 48 and a second section 52 which extends generally perpendicular to the section 50 to give the arm 46 a generally 12 shaped profile. The arm 46 is generally rigid, although some degree of flexibility may be provided.

The arm 46 is moveable between a first, non-retaining position (generally as shown in Fig 9) and a second, film retaining position (as can be seen in Figs 4 and 5). When in the first position the arm 46, in particular the section 52 thereof, is away from location over the mouth 36, but when in the second position the section 52 extends over at least part of the mouth 36 to clamp any backing film 12 held against the mouth 36 by the suction head 28 (as will be explained).

The apparatus further comprises a processing station 54, as shown in Figs 2 to 6, at which the prepreg 10 to be processed is located. The station 54 provides a surface 56 on which prepreg 10 is presented. Indexing means 58, shown in this embodiment as three upstanding pegs or projections, extend from the surface 56 to provide for accurate location to ensure correct positioning at the station 34 which in turn ensures correct processing of the prepreg 10. It will be appreciated that other suitable types or forms of indexing means can be used.

The apparatus described above can be used to remove an external backing film or ply from a prepreg 10, as will now be described.

Prepreg 10 to be processed is located at the processing station 54 using the indexing means 58 to ensure that the prepreg is accurately positioned.

Automated prepreg placement means (not shown) may be employed, which may comprise one or more robotic arms, configured to place prepreg in the correct indexed position at the station 54. The automated prepreg placement means may be part of an upstream prepreg processing apparatus that provides for the automated cutting and sizing of prepreg material, such as from rolls or larger sheets, to form the desired size and shape of prepreg 10 for use at the station 54.

The automated prepreg placement means may comprise a suction arrangement provided in a suction head on a robotic arm that acts against the surface of the prepreg 10 to hold it thereagainst to enable the prepreg to be moved to the indexed position and left following release of the suction.

The prepreg 10 is positioned at the station 54 with the external backing film 12 to be removed exposed for access by the film removal head 16. Fig 2 shows a prepreg in position at the processing station 54, with the film 12 uppermost.

Once the prepreg is correctly positioned, a film removal head 16 is positioned by the driven robotic arm 26 so that the mouth 36 of the suction head 28 locates against or is in close proximity to an area of the prepreg 10, as shown in Fig 3. The area is generally predetermined and is preferably an area on or adjacent an edge or corner of the prepreg 10. Such predetermination of the location of the area and thus positioning of the head 28 facilitates the removal of the backing film 12 through the peeling action, as will be described.

When the removal head 16 is in such position, the retaining means 44 is in the first position, with the section 52 remote from the mouth 36, so as not to interfere with the application of suction to the area of the prepreg 10.

Once the film removal head 16 is in position, the chill means is activated and chilling substance, liquid nitrogen and/or CO2, is delivered from the chilling substance source (not shown) through the delivery needle 40 (as shown diagrammatically by the sequence of arrows A in Fig 9) to project a spray or burst of chilling substance from the outlet 42 directly onto the area of the prepreg 10.

The location of the outlet 42 at or in close proximity to the opening of the mouth 36 helps to ensure the chilling substance has direct chilling effect on the prepreg area and that the exposure of the outer cup 32 to chilling is controlled and kept to within a level that does not adversely affect the function or the material of the suction cup 30. The positioning of the outlet 42 relative to the mouth 36 can be varied and engineered according to the chilling substances used, the material and the design of the outer cup 32 and the degree of chilling required for the particular prepreg being processed.

The actuation of the delivery of chilling substance desirably occurs automatically when the film removal head 16 is positioned over the prepreg 10. Alternatively, it may be manually activated by an operative.

Once the required, usually predetermined amount of chilling substance has been dispensed to provide the requisite degree of chilling of the area of the prepreg, communication with the chilling source is blocked. The extent to which the prepreg is chilled is determined with reference to the chilling substance, the time of exposure and the tack characteristics of the resin in the prepreg retaining the backing film in position. It is important that the tack characteristics are reduced to a sufficient degree so that when the available suction is applied through the suction head 28, as will now be described, the backing film 12 can be satisfactorily lifted or drawn from the prepreg 10 to locate against the mouth 36.

The actuation of the suction can be timed to start up on the cessation of the delivery of chilling substance, or shortly thereafter, providing of course any delay following cessation does not result in an undesirable return of tackiness of the prepreg, which could hinder or prevent satisfactory removal of the backing film 12. It is also possible for the suction to be applied before cessation of the delivery of the chilling substance.

Suction is applied by the withdrawal of air from within the chamber 34 by the suction source, which can be in the form of a pump or similar such arrangement (not shown). Air is drawn from the chamber 34, through the passage 38, through the conduit of the robotic arm 26 (or other conduit(s)) connecting the passage(s) 38 in the base to the suction source. The degree of suction is predetermined to be sufficient to attract and draw the film 12 at the area of the chilled prepreg 10 away from the prepreg to locate against the mouth 36. It will be appreciated that the suction required to pull the film 12 away from the prepreg will be determined, at least in part, by the residual tack holding the film 12 in place, which in turn will be determined in part by the inherent tackiness of the resin holding the film on the prepreg and the temperature to which it has been chilled. These parameters and characteristics, and potentially also others, can be used to determine with some precision the degree of chilling and suction force needed to achieve satisfactory film removal from any given prepreg. Once the film 12 has located over the mouth 36, the head 16 can be moved away from the area, preferably in a motion that acts to peel the film from the prepreg 10. The peeling motion is found to facilitate removal and setting the area at which the prepreg is chilled and thus from where the peeling motion takes place at the edge or corner of the prepreg 10 helps with the peeling removal of the film 12.

When the film 12 locates against the mouth 36, the retaining means 44 is automatically actuated to move from the first position to the second position, to hold the film 12 between the section 52 of the arm 44 and the mouth 36, thus helping to retain the film in position during removal.

It is envisaged that the suction would generally be maintained whilst the film 12 is completely removed from the prepreg, but it is possible that once the retaining means 44 is in the second position, the suction could be released or reduced.

Once the film 12 has been completely removed (see Fig 5), the film removal head 16 can be moved to a position at which the retaining means 44 is returned to the first position, any remaining suction released and the removed film 12 allowed to drop from the head 16, preferably into a collection receptacle (not shown).

The apparatus and process described above provide for the automated removal of an exterior backing film or ply 12 from a prepreg 10.

Often, prepregs have a backing film on either side and the apparatus and methodology of the present invention further provides for the removal of a second backing film 14 from a prepreg 10, as will now be described.

The apparatus comprises prepreg delivery means 60 in the form of a prepreg retention head 62 on a robotic arm 64. The prepreg retention head 62 comprises a suction arrangement 66 which will now be described with particular reference to Fig 10. Prepreg retention head 62 comprises a base or housing 68, which is attached at one side to the robotic arm 64. The suction arrangement 66 comprises a suction cup 70 which may be of generally similar configuration and construction as the aforedescribed suction cup 30. The suction cup 70 comprises an outer, resilient concertinaed cup 72 which defines a suction chamber 74 and which opens with a suction mouth 76 for location against the prepreg 10, as will be described. Air passages 78 extend through the base 68 to provide communication between the chamber 74 and the suction source (not shown), such as a pump or similar such device.

In the embodiment shown, the conduit defined by the robotic arm 64 connects the passages 78 and chamber 74 to the remote suction source, but it will be appreciated that a separate line or lines such as a pressure line may define the conduit(s) connecting the passages 78/suction chamber 74 to the suction source.

It will further be appreciated that although two passages 78 are illustrated in this particular embodiment, any suitable number of passages, and in its simplest form just one passage, may be provided.

The apparatus further comprises a film removal head 116 cited away from the processing station 54. With particular reference to Figs 7 and 8, the film removal head 116 is of the same general design and construction as the film removal head 16 described above and in this embodiment is generally static in operation. Features of the film removal head 116 that are the same or substantially the same as corresponding features in the film removal head 16 and that can be seen in Figs 7 and 8 are referenced in the same reference numerals, prefixed with the number 1'. The film removal head 116 comprises tack reducing means and film removal means 120 that function in substantially the same manner, as will be described. The film removal head 116 is however mounted upon a fixed post 80.

The removal of a second backing film or of a film located on the underside of a prepreg 10 using the apparatus and methodology of the present invention can be described as follows. Typically, these next stages follow the successful removal of the first backing film 12, as described above.

Once the film 12 has been removed, the exposed upper surface of the prepreg 10 provides a surface against which the prepreg retention head 62 is moved to locate. The precise positioning of the prepreg 10 within the indexing means 58 ensures accurate automated positioning of the prepreg retention head 62 of the prepreg delivery means 60.

The prepreg retention head 62 is located such that the suction mouth 76 rests against or is in close juxtaposition to the desired area of the surface and then suction is applied to draw and retain the prepreg 10 over the suction mouth 76.

The suction may be automatically applied when the delivery head 62 is in position on or over the prepreg 10, or it may be manually activated.

The suction is sufficient to enable the prepreg 10 to be lifted from the processing station 54 to be manoeuvred and presented to the film removal head 116 (see Fig 7). It is also sufficient to ensure the prepreg 10 is retained in position thereon during the removal of the second film 14, as will be described. The film removal head 116 functions in similar manner to the film removal head 16 described above.

The prepreg delivery means 60 offers the prepreg 10 to the mouth 136 of the film removal head 116 such that the mouth 136 locates against a predetermined area of the prepreg 10, typically at or near an edge or corner of the prepreg. The orientation of the prepreg 10 is such that the backing film 14 locates against the mouth 136.

When the prepreg 10 is in the correct position, the tack reducing means of the film removal head 116, which is the same as the tack reducing means of the film removal head 16, is actuated to chill the area of prepreg 10 generally as described above. Actuation is desirably automated, occurring upon location of the prepreg against the mouth 136. The timely application of suction occurs to attract the film 14 away from the prepreg 10 to the mouth 136. Again, the timing of the application of the chilling substance and the suction is generally as described above.

Retaining means 144 of the film removal head 116 is again actuated in similar manner as described above in relation to the removal head 16, to help hold the film 14 against the mouth 136. The prepreg delivery means 60 then moves with a generally peeling motion to draw the prepreg 10 away from the film removal head 116 (see Fig 8) to peel the film 14 from the prepreg 10.

Once removed, the film 14 can be released from the film removal head 116 by release of retaining means 144 and the suction to allow the film 14 to drop, preferably into a collection receptacle.

The prepreg 10 is then ready for further processing, such as by placement on a tool or mould, and the prepreg delivery means 16 may be operable to present the prepreg 10 for further processing, or possibly placement at a storage location for future processing.

The above apparatus and methodologies provide efficient, automated removal of exterior films or plies from prepregs. The indexing of the position of the prepreg 10 at the processing station ensures the accurate location and thus functioning of the apparatus. ( I

It will be appreciated that once a removed film has been disposed of the apparatus can be reset for the removal of film from further indexed prepregs to provide for the automated processing of a plurality of prepregs.

It will be further appreciated that the apparatus of the present invention can be used to remove both a single backing film or ply from one side of a prepreg, to remove one or more films or plies from opposite sides of a prepreg, or indeed it could be used to remove a number of films or plies from one side of a prepreg through successive processing stages.

The use of suction forces in the apparatus and methodologies of the present invention help prevent undesirable damage to the prepregs during processing, which other more mechanical means of gripping and holding the prepreg may introduce.

It wUl be further appreciated that film removal head 116 may be the same removal head 16 located in the desired position and held static or generally static during the removal of the film 14 in the manner described above. Alternatively, the head 116 can move relative to the prepreg delivery means 60, to locate against the prepreg 10 which may be held static by the means 60, with the head 116 manoeuvred to remove the film 14. In a still further arrangement, both the means 60 and the head 116 can be moved in concert to provide the requisite relative movement to remove the film 14. The prepreg delivery means 60 may be used as the automated prepreg placement means to provide for the placement of prepreg at the station 54 at the outset of processing.

Fig 11 illustrates an alternative indexing means 158 in use to accurately locate the prepreg 10 at the processing station 54. The indexing means 158 comprises two upstanding projections or pegs which in this embodiment are positioned to extend from the surface 56 at the station 54, through the prepreg 10. Apertures (not shown) are preferably preformed in the prepreg 10 so that when the prepreg 10 is located at the station 54, over the pegs 158, the prepreg 10 is in the correct location and alignment. It will be appreciated that the number and positioning of the projections or pegs 58 can be of any suitable combination and the example of two pegs located generally centrally is just one example. In a very simple form, the indexing means 158 could comprise a single peg that is located preferably in the centre of the prepreg 10. However, for accuracy of location, both from a positional and orientational perspective, it is envisaged that a plurality of projections or pegs will be provided. Indeed, asymmetric arrangements of such pegs can help improve correct location of a prepreg 10 at the station 54. Such indexing means has particular advantage where the external shapes and dimensions of the prepregs 10 that can be located at the station can vary. The indexing means 58 described above find general application where the external size and shape of the prepreg being located at the station 54 are the same.

However, in practice prepregs of varying size and shape can be used in the apparatus of the present invention and therefore indexing means such as that illustrated at 158 which do not index against the external dimensions of the prepreg for location find utility for such applications.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

Claims 1. Apparatus for processing a prepreg by the removal of an external film from the prepreg, the apparatus comprising a film removal head having tack reducing means operable to reduce the resinous tack properties of an area of a prepreg to be processed and further comprising film removal means operable to attract an external film from the said area thereagainst, and drive means operable to drive relative movement between the prepreg and the head to peel the film from the prepreg.
2. Apparatus as claimed in claim 1, in which the tack reducing means comprises chill means operable to chill the said area of prepreg to reduce the inherent tackiness of resinous material in the area and thereby reduce the adherence of the external film to the prepreg at that area.
3. Apparatus as claimed in claim 2, in which the chill means chills the said area of prepreg to a frozen or partially frozen condition.
4. Apparatus as claimed in claim 2 or claim 3, in which the chill means comprises a chilling substance source.
5. Apparatus as claimed in claim 2 or claim 3, in which the chill means is connectable to a chilling substance source.: 25
6. Apparatus as claimed in claim 4 or claim 5, in which the chilling * substance source comprises a store of cryogenic material. *e.e*

S S
7. Apparatus as claimed in claim 6, in which the store is of compressed SSe gas.

:.:::.
8. Apparatus as claimed in claim 7, in which the compressed gas includes liquefied nitrogen, carbon dioxide.
9. Apparatus as claimed in any of claims 4 to 8, in which the tack reducing means comprises a delivery arrangement for the selective delivery of a chilling substance to the said area of prepreg.
10. Apparatus as claimed in claim 9, in which the delivery arrangement comprises a delivery nozzle or needle locatable against or in the proximity of the area of a prepreg to be chilled and operable to deliver a chilling substance to the area whereby to chill the prepreg at that area.
11. Apparatus as claimed in claim 10, in which the proximity of the delivery nozzle to the area of prepreg is adjustable.
12. Apparatus as claimed in any preceding claim, in which the film removal head comprises a robotic head.
13. Apparatus as claimed in claim 12, in which the robotic head is located on a robotic arm.
14. Apparatus as claimed in any preceding claim, in which the film removal means comprises a suction arrangement operable to draw the external film in a direction from the prepreg.
15. Apparatus as claimed in claim 14, in which the suction arrangement . :25 comprises a suction source and a suction head, the suction head being locatable in use against or adjacent a film to be removed at or in the proximity * of the said areaof the prepreg. ** .* ****
16. Apparatus as claimed in claim 14 or claim 15, in which the suction arrangement comprises means to enable selective provision of suction from the suction source to the suction head, at least within the time the resinous **s * * tack properties of the area remain sufficiently reduced to enable removal of the external film from the area.
17. Apparatus as claimed in claim 16, in which the means is actuated upon or shortly after the operation of the chill means.
18. Apparatus as claimed in any of claims 15 to 17, in which the suction head comprises a suction cup.
19. Apparatus as claimed in claim 18, in which the suction cup comprises an outer cup section defining therein a suction chamber.
20. Apparatus as claimed in claim 19, in which the outer cup section comprises collapsible sides.
21. Apparatus as claimed in claim 20, in which the collapsible sides are collapsible in a concertina type fashion.
22. Apparatus as claimed in claim 20 or claim 21, in which the collapsible sides are formed of resilient material.
23. Apparatus as claimed in any of claims 20 to 22, in which the collapsible sides are formed of elastomeric material.. :25
24. Apparatus as claimed in any of claims 18 to 23, in which the suction * cup is attached at one end thereof to a housing and defines a suction mouth S.....

* against which film is drawn in operation. * S...
25. Apparatus as claimed in claim 24, in which the suction cup defines the suction mouth at another end. * .. * . S * S..S
26. Apparatus as claimed in claim 24 or claim 25, in which the suction mouth releasably seals against film drawn thereto in operation.
27. Apparatus as claimed in any of claims 19 to 26, in which the delivery nozzle of the chill means is located, at least partially, within the suction chamber.
28. Apparatus as claimed in any of claims 19 to 27, in which the delivery nozzle is arranged to deliver a chilling substance at or in the proximity of the suction mouth of the suction cup.
29. Apparatus as claimed in any preceding claim, in which the tack reducing means is automatically actuated when the film removal head and a prepreg to be processed are brought into close proximity.
30. Apparatus as claimed in any preceding claim, in which the tack reducing means is actuated upon or shortly following entry of the tack reducing means and/or a prepreg to be processed into a processing position.
31. Apparatus as claimed in any preceding claim, in which the film removal means is automatically actuated when the film removal head and prepreg to be processed are brought into close proximity.
32. Apparatus as claimed in any preceding claim, in which the film removal :25 means is actuated upon or shortly following actuation of the tack reducing * means.S* .** .* * * *:**
33. Apparatus as claimed in any of claims 12 to 32, in which the apparatus S..comprises drive means to drive movement of the robotic head both to and from an area of a prepreg to be processed. * St * S *..*

S *0SS* * S
34. Apparatus as claimed in claim 33, in which the drive means drives a peeling motion that acts to peel film from a prepreg.
35. Apparatus as claimed in any preceding claim, in which the apparatus comprises drive means to drive movement of the prepreg to be processed to and from the film removal head.
36. Apparatus as claimed in claim 35, in which the drive means drives movement of the area of a prepreg to be processed to and from the film removal head.
37. Apparatus as claimed in claim 36, in which the drive means drives a peeling motion that acts to peel film from a prepreg.
38. Apparatus as claimed in any of claims 33 to 37, in which the drive means comprises one or more motors.
39. Apparatus as claimed in any preceding claim, in which the apparatus comprises retaining means to retain attracted film against the film removal means.
40. Apparatus as claimed in claim 39, in which the retaining means comprises a retaining member located on the film removal head.
41. Apparatus as claimed in claim 39 or claim 40, in which the retaining * member is moveable between a first, non-retaining position and a second, film *0e.. . . * * retaining position. I... *s*t
42. Apparatus as claimed in claim 41, in which when in the first position, the retaining member is away from the suction mouth. * ** * , * S...SS..... S *
43. Apparatus as claimed in claim 41 or claim 42, in which the retaining member when in the second position extends, at least in part, across the suction mouth to retain film held against the suction mouth.
44. Apparatus as claimed in any of claims 41 to 43, in which the member is pivotally moveable between the said first and second positions.
45. Apparatus as claimed in any of claims 41 to 44, in which the member is moveable automatically upon attracted film locating against the film removal head.
46. Apparatus as claimed in any preceding claim, in which the apparatus comprises prepreg delivery means to deliver a prepreg to be processed to the or a further film removal means.
47. Apparatus as claimed in claim 46, in which the prepreg delivery means comprises selectively operable prepreg retention means operable to selectively retain a prepreg to be processed thereagainst.
48. Apparatus as claimed in claim 47, in which the prepreg retention means comprises a suction arrangement operable to draw and hold a prepreg against the delivery means.
49. Apparatus as claimed in claim 48, in which the suction arrangement *25 comprises one or more suction cups selectively connectable to a suction source and operable to apply suction to a prepreg to hold the prepreg * thereagainst. *..*
50. Apparatus as claimed in any of claims 46 to 49, in which the prepreg delivery means comprises a robotic arm that drives movement of the prepreg retention means from a first position to a second position to deliver prepreg held against the delivery means to the film removal means.
51. Apparatus as claimed in any preceding claim, in which the apparatus comprises a processing station at which a prepreg can be processed.
52. Apparatus as claimed in claim 51, in which the station comprises a surface on which a prepreg is presented to be processed.
53. Apparatus as claimed in claim 51 or claim 52, in which the station comprises indexing means to ensure appropriate positioning of prepreg at the station.
54. Apparatus as claimed in claim 53, in which the indexing means comprises one or more formations extending from the surface, against or with which the prepreg locates.
55. Apparatus as claimed in any of claims 51 to 54, in which the apparatus comprises automated prepreg placement means to place prepreg in location at the processing station.
56. Apparatus as claimed in claim 55, in which the placement means may comprise one or more robotic arms.
57. A method of removing an external film from a prepreg, the method comprising applying a chilling substance to a prepreg to reduce the resinous 4.. :25 tack properties of resinous material in an area of the prepreg and applying * suction to lift the film from the prepreg.* S....S
58. A method as claimed in claim 57, in which an area of a prepreg is cryogenically cooled or chilled.
59. A method as claimed in claim 58, in which compressed gas is applied to the prepreg.
60. A method as claimed in claim 59, in which compressed gas is applied at or near an edge or corner of the prepreg.
61. A method as claimed in claim 59 or claim 60, in which compressed gas is applied automatically.
62. A method as claimed in any of claims 59 to 61, in which compressed gas is applied through a film removal head.
63. A method as claimed in claim 62, in which compressed gas is applied when the film removal head is located against or is within a predetermined proximity to the prepreg.
64. A method as claimed in any of claims 57 to 63, in which a chilling substance is applied using tack reducing means as defined in any of claims 1 to 56.
65. A method as claimed in any of claims 57 to 64, in which film may be removed using a film removal head as defined in any of claims 1 to 56.
66. A method as claimed in any of claims 57 to 65, in which suction is applied using a suction arrangement as defined in any of claims 14 to 56.
67. A method as claimed in any of claims 57 to 66, in which the method comprises a first step of removing one external film from a prepreg.* ** *** * * *:*
68. A method as claimed in any of claims 65 to 67, in which drive means is used to drive relative movement between the film removal head and the : prepreg. ***P

*** 0. * 0
69. A method as claimed in claim 68, in which the film removal head is driven between a first position in which the head locates against or is in close proximity to the prepreg to apply suction to the prepreg and a second position in which the head is distanced from the prepreg, movement from the first position to the second position comprising a peeling motion to enable lifted film to be peeled from the prepreg.
70. A method as claimed in claim 69, in which the suction is released when the head is in the second position or another position remote from the prepreg, releasing the removed film, typically allowing it to drop desirably into a collection receptacle.
71. A method as claimed in any of claims 57 to 70, in which the method further comprises removal of a second external film, which involves presenting the prepreg to the or a further tack reducing means and removing the second film.
72. A method as claimed in claim 71, in which the second external film is removed from a second surface of a prepreg.
73. A method as claimed in claim 71 or claim 72, in which the second external film is removed by exposing an area of the second surface of the prepreg to a chilling substance and applying suction to that area to remove the second external film from the prepreg. *. .

*
74. A method as claimed in any of claims 57 to 73, in which the prepreg is lifted using lifting means which comprise a suction arrangement that enables selective retention and release of the prepreg therefrom.
75. A method as claimed in claim 74, in which the lifting means comprises prepreg delivery means as defined in any of claims 46 to 56.S
76. A method as claimed in claim 74 or claim 75, in which the suction arrangement is operable to locate against a surface of the prepreg exposed upon removal of one external film.
77. A method as claimed in any of claims 74 to 76, in which drive means is used to drive movement of the lifting means between a first position in which the prepreg locates against or is in close proximity to a film removal head and a second position in which the prepreg is remote from the film removal head.
78. A method as claimed in claim 77, in which movement from the first to the second position comprises a peeling motion to enable the second film to be peeled from the prepreg.
79. A method as claimed in claim 77 or claim 78, in which the film removal head may comprise a robotic head.
80. A method as claimed in claim 77, 78 or 79, in which the film removal head applies a chilling substance to an area of the second surface when the prepreg is in the first position to reduce the resinous tack properties of the resinous material in the area and apply suction to that area to attract the second film thereto away from the prepreg.
81. A method as claimed in claim 80, in which the film removal head is static during film removal with the lifting means moving relative thereto.
82. A method as claimed in any of claims 77 to 81, in which the film retained on the film removal head is held thereon by retention means. *44
83. A method as claimed in claim 82, in which the retention means is applied automatically when the film is located on the removal head, to help secure retention. fl I *1 I
84. A method as claimed in claim 82 or claim 83, in which the retention means used comprises retaining means as defined in any of claims 39 to 56.
85. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.
86. A method substantially as hereinbefore described with reference to the accompanying drawings.
87. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims. * p P * as p*5555* *
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