GB2090183A - Method of manufacture of a perforated composite structure - Google Patents

Method of manufacture of a perforated composite structure Download PDF

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Publication number
GB2090183A
GB2090183A GB8041395A GB8041395A GB2090183A GB 2090183 A GB2090183 A GB 2090183A GB 8041395 A GB8041395 A GB 8041395A GB 8041395 A GB8041395 A GB 8041395A GB 2090183 A GB2090183 A GB 2090183A
Authority
GB
United Kingdom
Prior art keywords
former
mould
manufacturing
perforate
pattern
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB8041395A
Other versions
GB2090183B (en
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rolls Royce PLC
Original Assignee
Rolls Royce PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rolls Royce PLC filed Critical Rolls Royce PLC
Priority to GB8041395A priority Critical patent/GB2090183B/en
Publication of GB2090183A publication Critical patent/GB2090183A/en
Application granted granted Critical
Publication of GB2090183B publication Critical patent/GB2090183B/en
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
    • B29C70/28—Shaping operations therefor
    • B29C70/54—Component parts, details or accessories; Auxiliary operations, e.g. feeding or storage of prepregs or SMC after impregnation or during ageing
    • B29C70/545—Perforating, cutting or machining during or after moulding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C33/00—Moulds or cores; Details thereof or accessories therefor
    • B29C33/0033—Moulds or cores; Details thereof or accessories therefor constructed for making articles provided with holes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C33/00—Moulds or cores; Details thereof or accessories therefor
    • B29C33/44—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles
    • B29C33/52—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles soluble or fusible
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
    • B29C70/28—Shaping operations therefor
    • B29C70/30—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core
    • B29C70/34—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core and shaping or impregnating by compression, i.e. combined with compressing after the lay-up operation
    • B29C70/345—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core and shaping or impregnating by compression, i.e. combined with compressing after the lay-up operation using matched moulds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D28/00—Producing nets or the like, e.g. meshes, lattices
    • B29D28/005—Reticulated structure comprising reinforcements of substantial or continuous length
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2793/00—Shaping techniques involving a cutting or machining operation
    • B29C2793/0045—Perforating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0001—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular acoustical properties
    • B29K2995/0002—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular acoustical properties insulating

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Composite Materials (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)

Abstract

A method of manufacturing a perforate composite structure includes the steps of making a pattern, from which a mould 13 Fig. 2 is taken, casting a former 15 Fig. 3 within the mould, laying up at least one layer of fibre reinforced resin material 16, Fig. 4 upon the former, consolidating the sheet material, curing the resin, and melting the former from the completed composite structure. <IMAGE>

Description

SPECIFICATION Method of manufacture of a perforated composite structure This invention relates to a method of manufacturing a perforate composite structure, and more particularly to such a structure consisting of a fibre reinforced resin sheet or sheets.
In recent years it has become well known to use fibre reinforced resin structures for the manufacture of gas turbine parts. Such structures usually consist of either glass or carbon fibres secured together within a thermosetting resin matrix in the form of sheets, the fibres being in the form of continuous or discontinuous fibres, or woven cloths or felts. The separate sheets are usually laid up together to form the structure such as for example engine cowling portions or access doors, acoustic liners etc. for use within engine cowlings, or alternatively compressor blades and stators. In certain instances such as for example acoustic liners etc. it is necessary that the structure is perforated for sound absorption or cooling purposes. Such perforation has in the past however proved difficult to achieve particularly in thick section or curved structures.The most common way of providing the perforations is to either drill or punch the necessary holes within the structure, however this is both time consuming and expensive, and it also has a further disadvantage in that it severs a proportion of the fibres within the structure thus affecting its strength. A further method which has also been attempted to overcome this problem is to lay up the layers of fibre reinforced resin sheets in its uncured form upon a former consisting of a bed of nails, such that the nails project through the structure. The fibres are subsequently consolidated upon the former and the resin cured.
However it has proved difficult if sometimes impossible to successfully remove the completed structure from the former because of the inflexibility of the combination of the former and structure.
The object of the present invention is to provide a method of manufacturing a perforate composite structure which substantially overcomes the aforementioned problems.
According to the present invention a method of manufacturina a perforate composite structure includes the steps of making a pattern from which pattern is taken a mould having a shape the same as that of the finished perforations, casting within the mould a former, subsequently removing the former from the mould and laying up at least one layer of fibre reinforced resin sheet upon the former and consolidating the sheet and curing the resin therein and subsequently melting the former from the completed composite structure.
Preferably the pattern comprises a "bed of nails" construction in which the nail shape is the same as that of the completed perforations.
Furthermore the mould is made from an elastomeric material which is cast upon the pattern and subsequently removed therefrom.
Preferably the elastomeric material from which the mould is cast consists of silicon rubber.
Furthermore the former made within the mould is cast from a low melting point metal.
Preferably the low melting point metal consists of an alloy of lead and tin.
Preferably after the at least one fibre reinforced resin sheet is laid up on the former it is substantially consolidated and cured within an autoclave.
For better understanding thereof an embodiment of the present invention will be more particularly described by way of example only and with reference to the accompanying drawings in which:~ Figure 1 shows a pictorial view of the "bed of nails" type pattern, Figure 2 shows a cross-sectional view of the pattern including the cast elastomeric mould, Figure 3 shows a cross-sectional view of the casting of the liquid metal former within the elastomeric mould, Figure 4 shows a cross-sectional view of the laid up fibre reinforced resin sheets upon the metal former, and Figure 5 shows a pictorial view of the completed perforated composite structure.
Referring to the drawings the "bed of nails" type pattern shown generally at 10 may be manufactured by any suitable means. In its simplest form it may simply consist of a wooden backing member through which is driven pins or nails. Alternatively for greater accuracy and durability it may be machined from the solid or cast. It will be appreciated that the upstanding pins or nails may be made of any desired shape cross-section or spacing. In this way its porosity or sound absorption characteristics of the completed structure may be varied to suit particular requirements. Furthermore the pins or nails may be tapered towards their projecting ends to produce re-entrant holes if so desired.
To cast the mould the pattern 10 is located within a suitable container 12 which is then filled with silicon rubber or some other similar elastomeric type material. After this material has set or become cured the completed mould 13 may be peeled from the pattern 10. Obviously the pattern 10 may be used any number of times to produce the mould.
The mould 13 is then placed within a further container 14 and the former 15 is then cast in some suitable low melting point metal such as for example solder or some other similar tin or lead based alloy such that after the metal has solidified the mould may simply be peeled from the cast former. The former may if required be reinforced with a steel n-,esh which may be cast into it, or alternatively be bonded to it after casting. It will be appreciated that if such a former is manufactured in relatively large areas or fabricated from several sections of former it would be necessary either to make it extremely thick; or alternatively to provide reinforcement to make it handleable. Furthermore it has also been found that the casting is best done under vacuum to ensure that the liquid metal enters all the holes within the mould and hence completely fills it.Obviously the silicon mould may be used many times to produce furtherformers before it will become necessary to replace it.
After removal of the former 1 5 from the mould 14 it may be coated with a suitable release agent and a layer or layers of fibre reinforced resin material 16 may be placed upon the upstanding "bed of nails" and be pressed down upon them to produce the necessary perforations. It has been found beneficial to press the layers or sheets individually onto the projecting "bed of nails" by use of a stiff bristle or nylon brush or rolling with a resilient roller.
After the laying up is completed it is necessary to further consolidate the structure and cure the resin within it. This can be conveniently accomplished by placing a release layer and bleed cloth over the ends of the bed of nails and pressing down with the brush or roller such that the pins protrude. Subsequently a compression pad made from silicon rubber is placed over the ends of the pins projecting from the laid up composite structure. The assembly is then placed in an enclosed vacuum bag and then autoclaved to further consolidate the structure and cure the resin within it. Alternatively the structure may be further consolidated by compression moulding.
The fully consolidated and cured structure is subsequently removed from the autoclave and subjected to a further and higher temperature heating operation to melt out the metal former, this operation may also be utilised to finally cure the resin. Any particles of metal remaining within the structure may be subsequently dissolved away from a dilute solution of nitric acid.
It will be appreciated that by use of the method described perforated composite structures of any size, shape or thickness may be conveniently manufactured to serve a variety of purposes. The applicants present main intended use for such perforate structure is in the manufacture of carbon fibre reinforced acoustic panels and liner for use in gas turbine engine fan ducts. However it is not contemplated that the invention be restricted to such components.

Claims (8)

1. A method of manufacturing a perforate composite structure includes the steps of making a pattern, from which pattern a mould is taken, the mould having a shape the same as that of the finished perforations, casting within the mould a former, subsequently removing the former from the mould and laying up at least one layer of fibre reinforced resin sheet upon the former and consolidating the sheet and upon the former and consolidating the sheet and curing the resin therein and subsequently melting the former from the completed composite structure.
2. A method of manufacturing a perforate structure as claimed in claim 1 in which the pattern comprises a "bed of nails" construction in which the nail shape is the same as that of the completed perforations.
3. A method of manufacturing a perforate structure as claimed in claim 1 in which the mould is made from an elastomeric material which is cast upon the pattern and subsequently removed therefrom.
4. A method of manufacturing a perforate structure as claimed in claim 1 in which the former made within the mould is cast from a low melting point metal.
5. A method of manufacturing a perforate structure as claimed in claim 4 in which the low melting point metal consists of an alloy of lead and tin.
6. A method of manufacturing a perforate structure as claimed in claim 1 in which after the at least one fibre reinforced resin sheet is laid up on the former it is substantially consolidated and cured within an autoclave.
7. A perforate composite structure made by the method as claimed in any preceding claim.
8. A method of manufacturing a perforate structure as claimed in claims 1 to 6 substantially as hereinbefore described by wav of example only and with reference to the accompanying drawings.
GB8041395A 1980-12-29 1980-12-29 Method of manufacture of a perforated composite structure Expired GB2090183B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8041395A GB2090183B (en) 1980-12-29 1980-12-29 Method of manufacture of a perforated composite structure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8041395A GB2090183B (en) 1980-12-29 1980-12-29 Method of manufacture of a perforated composite structure

Publications (2)

Publication Number Publication Date
GB2090183A true GB2090183A (en) 1982-07-07
GB2090183B GB2090183B (en) 1984-04-26

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB8041395A Expired GB2090183B (en) 1980-12-29 1980-12-29 Method of manufacture of a perforated composite structure

Country Status (1)

Country Link
GB (1) GB2090183B (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5141690A (en) * 1989-02-24 1992-08-25 The British Petroleum Company P.L.C. Method for manufacturing composite material
WO1993022128A1 (en) * 1992-05-01 1993-11-11 Martin Marietta Corporation High temperature resistant perforated polymer composite material and method for making same
US5354394A (en) * 1992-11-10 1994-10-11 Seeton Technologies Apparatus and method for forming honeycomb core
EP0688647A3 (en) * 1994-06-22 1996-03-27 Mitsubishi Heavy Ind Ltd A method of manufacturing a multi-holed surface plate made of a composite material and a raw forming element of the composite material therefor
WO2004089607A1 (en) * 2003-04-01 2004-10-21 The Boeing Company Method and system having a flowable pressure pad for consolidating an uncured laminate sheet in a cure process
DE102010001634A1 (en) * 2010-02-05 2011-08-11 Brose Fahrzeugteile GmbH & Co. Kommanditgesellschaft, Coburg, 96450 Method for producing a component from an organic sheet

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5141690A (en) * 1989-02-24 1992-08-25 The British Petroleum Company P.L.C. Method for manufacturing composite material
WO1993022128A1 (en) * 1992-05-01 1993-11-11 Martin Marietta Corporation High temperature resistant perforated polymer composite material and method for making same
US5354394A (en) * 1992-11-10 1994-10-11 Seeton Technologies Apparatus and method for forming honeycomb core
EP0688647A3 (en) * 1994-06-22 1996-03-27 Mitsubishi Heavy Ind Ltd A method of manufacturing a multi-holed surface plate made of a composite material and a raw forming element of the composite material therefor
US5637272A (en) * 1994-06-22 1997-06-10 Mitsubishi Jukogyo Kabushiki Kaisha Method of manufacturing a multi-holed surface plate made of a composite material and a raw forming element of the composite material therefor
WO2004089607A1 (en) * 2003-04-01 2004-10-21 The Boeing Company Method and system having a flowable pressure pad for consolidating an uncured laminate sheet in a cure process
DE102010001634A1 (en) * 2010-02-05 2011-08-11 Brose Fahrzeugteile GmbH & Co. Kommanditgesellschaft, Coburg, 96450 Method for producing a component from an organic sheet

Also Published As

Publication number Publication date
GB2090183B (en) 1984-04-26

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PCNP Patent ceased through non-payment of renewal fee