# US 10,766,211 B2 · Method of forming pressure pad or other flexible element for use during cure of composite materials

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- Number: US 10,766,211 B2
- Document ID: US10766211B2
- Status: Granted
- Kind: B2
- Application number: 15/264,136
- Filed: 2016-09-13
- Published: 2017-08-10
- Granted: 2020-09-08
- Earliest claimed: 2015-09-14
- Assignees: Textron Innovations Inc.; National Research Council of Canada
- Applicants: Bell Helicopter Textron Inc.; National Research Council of Canada
- Inventors: Marc Lauzon; Patrick Dupré; Marc-André Octeau; Pascal Forget; Steven Roy
- Web page: https://patentgrep.com/patent/US10766211B2

## CPC

- B29C 70/443: {and impregnating by vacuum or injection}
- B29C 33/3842: {Manufacturing moulds, e.g. shaping the mould surface by machining}
- B29C 70/10: characterised by the structure of fibrous reinforcements {, e.g. hollow fibres}
- B29C 70/549: {Details of caul plates, e.g. materials or shape}
- B29C 70/547: {using channels or porous distribution layers incorporated in or associated with the product}
- B29K 2083/00: Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material
- B29K 2083/005: {LSR, i.e. liquid silicone rubbers, or derivatives thereof}
- B29K 2105/04: cellular or porous
- B29K 2267/00: Use of polyesters {or derivatives thereof} as reinforcement
- B29K 2313/00: Use of textile products or fabrics as reinforcement (B29K2105/06 takes precedence)
- B29L 2031/3055: {Cars}
- B29L 2031/3076: {Aircrafts (blades, propellers B29L2031/08)}
- B29L 2031/3082: {Fuselages}
- B29L 2031/3085: {Wings}
- B29L 2031/3088: {Helicopters}
- 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 (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- 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
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

A method of manufacturing a flexible element configured for pressing against composite material received on a mold surface of a mold during cure, including placing a porous material over the mold surface, forming a sealed enclosure containing the mold surface and the porous material, infusing a curable liquid material such as silicone in liquid form into the enclosure under vacuum and through the porous material, curing the liquid material to form the flexible element, and opening the enclosure and disengaging the flexible element from the mold. In a particular embodiment, the flexible element is a pressure pad.

## Claims

### Claim 1

A method of manufacturing a pressure pad configured for pressing against composite material received on a mold surface of a mold during cure, the method comprising:
placing a porous material over the mold surface;
forming a sealed enclosure containing the entire mold and the porous material, wherein a portion of the enclosure is movable relative to the mold surface when the sealed enclosure is under vacuum;
connecting an open liquid material supply bag to an inlet of the sealed enclosure and with the sealed enclosure under vacuum, infusing a curable liquid material from the liquid material supply bag into the enclosure and through the porous material;
after infusing the curable liquid material, closing the liquid material supply bag;
curing the liquid material under vacuum to form the pressure pad; and
opening the enclosure and disengaging the pressure pad from the mold;
wherein the sealed enclosure comprises a free bag that is not connected to the mold.

### Claim 2 (depends on 1)

The method according to claim 1, further comprising trimming excess material from the pressure pad after disengaging the pressure pad from the mold.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the porous material is placed with at least a portion thereof spaced apart from the mold so as to define a cavity between the mold and the portion of the porous material, and wherein placing the porous material includes removably connecting the porous material to the mold so that the portion remains spaced apart from the mold under vacuum.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the porous material is a first porous material, the method further comprising, before infusing the curable liquid material, placing at least one second porous material over the first porous material to overlap predetermined areas of the mold.

### Claim 5 (depends on 4)

The method according to claim 4, wherein the first porous material is shaped under vacuum against the mold surface before placing the at least one second porous material over the first porous material.

### Claim 6 (depends on 1)

The method according to claim 1, further comprising, before forming the enclosure, placing a protective material on the porous material over selected features of the mold, the protective material being more tear resistant than the porous material.

### Claim 7 (depends on 6)

The method according to claim 6, wherein the protective material is a polytetrafluoroethylene tape.

### Claim 8 (depends on 1)

The method according to claim 1, wherein the liquid material is cured at ambient temperature.

### Claim 9 (depends on 1)

The method according to claim 1, wherein the curable liquid material includes silicone.

### Claim 10 (depends on 1)

The method according to claim 1, wherein the porous material includes a polyester breather fabric.

### Claim 11 (depends on 1)

The method according to claim 1, further comprising adjusting a level of the vacuum during the infusion.

### Claim 12

A method of manufacturing a flexible element configured for pressing against composite material received on a mold surface of a mold during cure, the method comprising:
placing a porous material over the mold surface;
placing the entire mold and the porous material in a sealed enclosure under vacuum, wherein a portion of the enclosure is movable relative to the mold surface when the sealed enclosure is under vacuum;
connecting an open liquid material supply bag to an inlet of the sealed enclosure and infusing silicone in liquid form from the liquid material supply bag into the enclosure and through the porous material;
after infusing the silicone, closing the liquid material supply bag;
curing the silicone in the sealed enclosure under vacuum to form the flexible element with the porous material being embedded therein; and
disengaging the flexible element from the sealed enclosure and from the mold;
wherein the sealed enclosure comprises a free bag that is not connected to the mold.

### Claim 13 (depends on 12)

The method according to claim 12, wherein the flexible element is shaped for use as bagging material during the cure of the composite material.

### Claim 14 (depends on 12)

The method according to claim 12, wherein the flexible element is shaped for use as a pressure pad received inside a sealed enclosure also containing the composite material during the cure of the composite material.

### Claim 15 (depends on 12)

The method according to claim 12, wherein the porous material is placed with at least a portion thereof spaced apart from the mold so as to define a cavity between the mold and the portion of the porous material, and wherein placing the porous material includes removably connecting the porous material to the mold so that the portion remains spaced apart from the mold under vacuum.

### Claim 16 (depends on 12)

The method according to claim 12, wherein the porous material is a first porous material, the method further comprising, before infusing the curable liquid material, placing at least one second porous material over the first porous material to overlap predetermined areas of the mold.

### Claim 17 (depends on 16)

The method according to claim 16, wherein the first porous material is shaped under vacuum against the mold surface before placing the at least one second porous material over the first porous material.

### Claim 18 (depends on 12)

The method according to claim 12, further comprising, before forming the enclosure, placing a protective material on the porous material over selected features of the mold, the protective material being more tear resistant than the porous material.

### Claim 19 (depends on 12)

The method according to claim 12, wherein the liquid material is cured at ambient temperature.

### Claim 20 (depends on 12)

The method according to claim 12, wherein the porous material includes a polyester breather fabric.