Method of making an airdam

A method of making an airdam to be placed along the edge of a composite work piece during a curing process is disclosed. The method comprises forming a strip of peel ply, forming a strip of tacky putty, and automatically affixing the strip of tacky putty to the strip of peel ply without human assistance to form a laminate comprising at least one layer of peel ply and at least one layer of tacky putty.

BACKGROUND

In the manufacture of a composite work piece, the composite work piece undergoes a curing process to allow gasses and volatiles to escape. A common curing process involves drawing a vacuum around the composite work piece to draw out the gasses and volatiles. A vacuum bag that encompasses the composite work piece is used to form a vacuum chamber. When the vacuum is drawn, the bag contours to the work piece surfaces.

BRIEF DESCRIPTION

In one aspect, the present application discloses a method of making an airdam including a laminate to be placed along the edge of a composite work piece during a curing process. The method includes forming a strip from a supply of peel ply, forming a strip from a supply of tacky putty and automatically affixing the strip of tacky putty to the strip of peel ply without human assistance to form the laminate including at least one layer of peel ply and at least one layer of tacky putty.

DETAILED DESCRIPTION

Referring now to the drawings and toFIG. 1in particular, there is shown a composite work piece10during a curing process. The composite work piece10includes layers of composite materials such as carbon fiber, impregnated with a resin such as an epoxy. During manufacturing, the composite work piece10must undergo a curing process which involves a vacuum bagging process. The vacuum bagging process imparts pressure on the composite work piece10to provide good consolidation and interlaminar bonds and draws a vacuum to draw out volatiles and trapped air, resulting in a low void content. A vacuum bag12encompasses the composite work piece10to form the vacuum chamber. Airdams16surround the composite work piece10at the edge portion17to aid in holding the perimeter shape of the composite work piece10.

FIGS. 2, 3 and 5shows the edge portion17of a composite work piece10after a curing process.FIG. 2shows the edge portion17of a composite work piece10without an airdam. A vacuum bag12encompasses the composite work piece10. As a vacuum force is drawn, the vacuum bag12is drawn against the composite work piece10and the force of the vacuum applied by the vacuum bag12may deform the original composite work piece shape14(shown in dashed lines) from a rectangular edge cross section to a sloped or partially rounded cross section when cured. Such deformation of the edge portion makes it difficult to assemble two such composite work pieces10in abutting relationship, which is common when the composite work pieces10are panels, such as composite panels or skins for an aircraft. To eliminate the sloping or rounding of the edge portion, an airdam16is placed against the composite work piece10as shown inFIG. 3. The force of the vacuum applied by the vacuum bag12acts on the airdam16and may deform the original airdam shape18instead of the composite work piece10. The use of the airdam16solves the problem of the sloping edge portion.

However, the airdam16introduces its own problems into the process because the edge portion17of the composite work piece10will tend to conform to the shape of the airdam16as shown inFIG. 4or be deformed by the force of the vacuum bag as shown inFIG. 5. If the airdam16is not straight and/or square, neither will be the portion of the composite work piece10adjacent the airdam16. For example, when the airdam16has a portion of a working edge20abutting the composite work piece10which is not straight or square as shown inFIG. 5, a gap22may be formed between the original composite work piece shape14and the airdam16. As a vacuum is drawn, the vacuum bag12is drawn against the composite work piece10and the force of the vacuum applied by the vacuum bag12may deform the original composite work piece shape14as well as the original airdam shape18. Furthermore, when the length of the airdam16is not straight as shown inFIG. 4, a gap24may be formed between the composite work piece10and the airdam16causing similar deformation to the composite work piece10as shown inFIG. 5and described above. In the context of composite panels that are arranged in abutting relationship, a non-straight edge portion17makes it impossible to assemble adjacent panels. Thus, the edge portions17will require finishing for straightening after the curing process, which is very time-consuming and costly.

FIG. 6illustrates an airdam25according to an embodiment. The airdam25has straight edges and is linear, which, when abutted against a composite work piece10will form the desired shape for the edge portion of the composite work piece10. The airdam25includes a laminate of tacky putty26and peel ply28. The laminate includes one layer of a strip of peel ply28and one layer of a strip of tacky putty26. The strip of peel ply28is wrapped around a strip of tacky putty26forming overlapping ends30. When an edge of the strips of peel ply28and tacky putty26align when the strips are affixed together, a working edge32is formed that is used to abut an edge of a composite work piece10. The tacky putty26is a soft malleable material which may have enough tack to affix to the peel ply28and the peel ply28is an open woven breathable material.

In another embodiment of an airdam27as shown inFIG. 7, the airdam27includes a laminate of a tacky putty26and peel ply28where the laminate includes one layer of a strip of peel ply and two layers of a strip of tacky putty26. The strip of peel ply28is wrapped around the two strips of tacky putty26forming overlapping ends30. When an edge of the strips of peel ply28and tacky putty26align when the strips are affixed together, a working edge34is formed that is used to abut an edge of the composite work piece10.

Referring now toFIGS. 6 and 7, it will be understood that an airdam25,27includes at least one layer of strip of peel ply28and at least one layer of strip of tacky putty26wherein the number of strips of tacky putty26is chosen to match the thickness of the of the composite work piece edge that the airdam working edge32,34will abut.

When a working edge32,34of an airdam25,27is placed against a composite work piece10during a vacuum bag curing process as described above, the peel ply28along the working edge32,34abutting with the composite work piece edge allows gases and volatiles to be drawn out due to the breathable quality of the material and the tacky putty absorbs the force of the vacuum bag acting along the composite work piece edge due to the malleable quality of the material.

Referring again toFIGS. 4 and 5, any force applied to the airdam16may deform the airdam16due to the malleable quality of the tacky putty resulting in an airdam16that is not straight and/or square. Previous airdams16were made by hand. The degree of straightness of the airdam16varied with the degree of skill of the person making the airdam16, with no person being perfect. When an airdam16is made by hand, the straightness along the working edge and the straightness along the length is only as good as the skill of the person making the airdam16which results in a non-repeatable curing process and in a deformed composite work piece10as shown inFIGS. 4 and 5and described above.

By automating the process of manufacturing, an airdam25,27shown inFIGS. 6 and 7may be made without human assistance. This allows for a repeatable method of making an airdam25,27that is straight along the length and that has a straight or square working edge32,34.

FIG. 8shows a schematic view of a machine100for making an airdam without human assistance. The machine100includes a payout and lamination station200and a meter, cut to length and material handling station400.

The machine100forms a strip of peel ply232from a supply of peel ply on the peel ply supply payout210and forms a strip of tacky putty228,230from a supply of tacky putty on the tacky putty supply roll payout202,204. The strips are automatically affixed together to form the laminate as described above. The payout and lamination station200supplies material for the airdam and forms an airdam web216. The meter, cut to length and material handling station400meters the materials and airdam web216, cuts the airdam web216to a desired length and transfers the cut airdam to storage.

Turning now toFIG. 9, there is shown a schematic view of the payout and lamination station200. The payout and lamination station200includes two tacky putty supply roll payouts202,204, lamination rollers206, tacky putty backing rewinds208,214, a peel ply supply roll payout210, horizontal axis forming rollers212, forming blocks218,224, and vertical axis forming rollers220. The horizontal axis forming rollers212has a recessed portion236in the lower roller. The vertical axis forming rollers220have one roller with a recessed portion238. Each forming block218,224includes two rectangular blocks spaced apart to form a substantially rectangular channel. It will be understood that the payouts, rewinds and rollers may include features well known in the art of web handling such as tension controls, pressure controls, servo controls and drive mechanisms.

The payout and lamination station200forms an airdam web216by supplying and forming material in a way indicated by the arrows226. Two strips of tacky putty228,230are unrolled from the two tacky putty supply roll payouts202,204and pass through lamination rollers206. The lamination rollers206affix the two strips of tacky putty228,230together without deforming the strips of tacky putty228,230. Backing material240on the lower strip of tacky putty230present to prevent the strip of tacky putty230from adhering to itself when in roll form is separated from the strip of tacky putty strip230and rewound onto the tacky putty backing rewind208. A strip of peel ply232is unrolled from the peel ply supply roll payout210and is introduced under the two strips of tacky putty228,230at the horizontal axis forming rollers212.

The horizontal axis forming rollers212has a recessed portion236in the lower roller with a depth and width that substantially correspond to the width and thickness of the two strips of tacky putty228,230after the lamination roller206. The horizontal axis forming rollers212affix the two strips of tacky putty228,230to the strip of peel ply232without deforming the strips of tacky putty228,230. The strip of peel ply232conforms to horizontal and vertical sides of the recessed portion236to at least partially affix the strip of peel ply232to the lower horizontal and vertical sides of the strips of tacky putty228,230respectively. The excess material of the strip of peel ply232not affixed to the two strips of tacky putty228,230is oriented in both the horizontal and vertical direction.

After the horizontal axis forming rollers212, backing material242on the upper strip of tacky putty228present to prevent the strip of tacky putty228from adhering to itself when in roll form is separated from the strip of tacky putty228and rewound onto the tacky putty backing rewind214.

The lamination including the two strips of tacky putty228,230and the strip of peel ply232passes through the channel of the forming block218that has a width and depth that substantially corresponds to the width and thickness of the two strips of tacky putty228,230after the lamination roller206. The horizontal and vertical sides of the channel affix the strip of peel ply232to the lower horizontal and vertical sides of the two strips of tacky putty228,230respectively without deforming the two trips of tacky putty228,230. The excess material of strip of peel ply232not affixed to the two strips of tacky putty228,230is oriented in substantially the vertical direction.

The lamination passes through vertical axis forming rollers220with a recessed portion238having a width and a depth corresponding to the width and thickness of the two strips of tacky putty228,230after the lamination rollers206. The strip of peel ply232conforms to horizontal and vertical sides of the recessed portion238to at least partially affix the strip of peel ply232to the upper horizontal and vertical sides of the strips of tacky putty228,230respectively. The excess material of strip of peel ply232not affixed to the two strips of tacky putty is oriented in a vertical direction between the non-recessed portion of the vertical axis forming rollers220forming overlapping ends234completing the airdam web216. The aligned edges of the strip of peel ply232and the edges of the strips of tacky putty228,230when the strip of peel ply232and the strips of tacky putty228,230are affixed to form a laminate, form at least one straight working edge that is to be used to abut an edge of a composite work piece during a curing process as described above.

The second forming block224is substantially similar to the first forming block218as described above. The forming block224also acts to stabilize and support the airdam web216for subsequent operations described herein after.

The top view of the payout and lamination station200shown inFIG. 10has portions of the station removed for clarity. Viewed from above, it can be seen that the horizontal forming rollers212begin the process of affixing the strip of peel ply232to the sides of the two strips of tacky putty228,230and the vertical forming rollers220complete the process of affixing the strip of peel ply232to the sides of the two strips of tacky putty228,230. It can also be seen that at no point throughout the payout and lamination station200are the two strips of tacky putty228,230permanently deformed.

FIG. 11shows a schematic view of a meter, cut to length and material handling station400. The meter, cut to length and material handling station400includes movable gripper402,404, a gripper guide rail406, an actuating cutting device412, a pivoting transfer trough408and an indexing storage trough410.

The movable gripper402,404is movable from a first position indicated by the movable gripper402to a second position indicated by the movable gripper404along the gripper guide rail406. The actuating cutting device412may actuate in the vertical direction indicated by arrows414and may perform cutting methods including but not limited to shear cutting, die cutting or kiss cutting. The pivoting transfer trough408may pivot in a direction indicated by arrow418. An indexing storage trough410may index in a direction perpendicular to both the arrow414and the direction of movement of the movable gripper402,404.

When in the first position, the movable gripper402grips the airdam web216by the overlapping ends234of the peel ply as it is stabilized and supported by the forming block224. As the movable gripper402,404moves to the second position, the airdam web is also moved as indicated by arrow416. The movement of the airdam web216caused by the movable gripper402,404forms more airdam web216as shown inFIGS. 8 and 9and described above.

When in the second position, a portion of the airdam web216including the laminate of peel play and tacky putty is supported by the movable gripper404and the forming block224so as to prevent permanent deformation of the tacky putty. While being supported, the actuating cutting device412actuates in the vertical direction and cuts the airdam web216forming an airdam. The movable gripper404releases the overlapping ends234and the airdam is received by the pivoting transfer trough408. The pivoting transfer trough408pivots downwards, dropping the airdam into an indexing storage trough410. The movable gripper402,404returns to the first position and the process is repeated. When an indexing storage trough410becomes full of airdams, it is indexed to introduce an empty indexing storage trough410for receiving subsequent airdams.

In one embodiment, the meter, cut to length and material handling station400may be configured to cut the airdam web216to form an airdam with a length less than two meters so as to be easily handled by a human during subsequent operations. However, it will be understood that the meter, cut to length and material handling station400may be configured to cut the airdam web216to form an airdam with any desired length. While the method of making an airdam has been described using one strip of peel ply and two strips of tacky putty, it will be understood that a substantially similar method applies to an airdam having one strip of tacky putty and one strip of peel ply. Referring again toFIG. 9, in the case that only one strip of tacky putty is desired, the payout and lamination station200could be easily modified by removing the tacky putty supply roll payout204and tacky putty backing rewind208and making the recessed portions236,238substantially correspond to the width and thickness of the one strip of tacky putty228.

The embodiments described above may provide for a variety of benefits including that a method of making an airdam according to the innovation allows for the repeatable manufacturing of airdams without deformation allowing for a more consistent curing process resulting in reduced scrap and higher quality composite work pieces. It may also reduce labor costs and increase efficiency by eliminating the need for human assistance during manufacturing.

To the extent not already described, the different features and structures of the various embodiments may be used in combination with each other as desired. That one feature may not be illustrated in all of the embodiments is not meant to be construed that it may not be, but is done for brevity of description. Thus, the various features of the different embodiments may be mixed and matched as desired to form new embodiments, whether or not the new embodiments are expressly described. All combinations or permutations of features described herein are covered by this disclosure.

This written description uses examples to disclose the innovation, including the best mode, and also to enable any person skilled in the art to practice the innovation, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the innovation is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims