BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other advantages and features of the invention, and the manner in which the same are accomplished, will become more readily apparent upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings which illustrate preferred and exemplary embodiments, but which are not necessarily drawn to scale, wherein:
FIG. 1 is a schematic drawing of the prior art CAPRI (controlled atmospheric pressure resin infusion) process;
FIG. 2 is a close-up perspective view of a prior art resin distribution tube used in the CAPRI (controlled atmospheric pressure resin infusion) process;
FIG. 3 is a front sectional view of another prior art distribution tube configuration;
FIG. 4 is a top view of an embodiment of the TIDE (tube induced deformity elimination) process of the invention;
FIG. 5 is a perspective view of an embodiment of the TIDE process of the invention;
FIG. 6 is a front sectional view of the TIDE process of FIG. 5;
FIG. 7 is a perspective view of another embodiment of the resin distribution tube and bagged preform of the TIDE process of the invention; and,
FIG. 8 is a front sectional view of the resin distribution tube of FIG. 7.
DETAILED DESCRIPTION OF THE INVENTION
The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, this invention may be embodied in several different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
Referring to the FIGS., FIG. 4 is a top view of a first aspect of the tube induced deformity elimination (TIDE) process of the invention. FIG. 5 is a perspective view of the first aspect of the TIDE process of the invention. FIG. 6 is a front sectional view of the TIDE process of FIG. 5. The invention provides for a process for elimination of deformations on resin infused composite parts. Referring to FIG. 6, the first step of the process comprises positioning a dry composite preform 100 having a top surface 102 and a bottom surface 104 on a forming tool component 106. The bottom surface 104 of the preform 100 is positioned over a top surface 108 of the forming tool component 106. Preferably, the preform comprises carbon fibers, glass fibers, aramid fibers, or other fibrous materials. More preferably, for high performance uses, the preform comprises carbon fibers. Preferably, the forming tool component is a machined or otherwise formed or molded solid tool having vacuum integrity, such as a mandrel or flat plate. Referring to FIGS. 4 and 5, the process of the invention further comprises the step of arranging resin exit lines 110 in close proximity to the preform 100. The number of resin exit lines is determined by the size and geometry of the composite part being built with the actual number of lines only being restricted by the practical limitation of fabricating and serving a high number of lines, i.e., greater than one hundred (100) lines. Referring to FIG. 6, the process of the invention further comprises the step of placing a permeable release material 112 having a top surface 114 and a bottom surface 116 on the preform. The bottom surface 116 of the release material 112 is placed over the top surface 102 of the preform 100. Preferably, the permeable release material is made of a material comprising permeable thermoplastics, coated woven glasses, coated woven carbons, or other suitable permeable non-bonding materials.
Referring to FIG. 6, the process of the invention further comprises the step of placing a first piece of flow media 118 having a top surface 120 and a bottom surface 122 over the release material 112. The bottom surface of the first piece of flow media is placed over the top surface of the release material 112. Preferably, the flow media comprises plastic mesh, metal mesh, plastic netting, or metal netting. The process of the invention further comprises the step of wrapping a resin distribution tube 124 with a first end 126 of a second piece of flow media 128 and leaving a second end 130 of the of the second piece of flow media 128 extending radially along the length of the tube 124. The resin distribution tube is used to transfer the resin and can also be referred to as a resin inlet line. Preferably, the resin distribution tube is porous and is made of a material comprising nylon, polyethylene, polypropylene, polytetrafluoroethylene, or coiled metal wire. Preferably, the resin distribution tube is a spiral cut tube. The resin distribution tube is wrapped in a piece or strip of flow media, preferably plastic mesh or plastic netting. The second piece of flow media is attached to the resin distribution tube at the first end of the flow media, and the second end of the flow media is free to be fastened or taped to the flow media already coupled to the preform. The second piece or strip of flow media is preferably about three and one-half inches (3½″) wide. A wider strip of about five inches (5″) can be used if two plies of the second piece of flow media are desired to be used to attach the resin distribution tube to the first piece of flow media on the preform. This would allow for a greater volume of resin to flow if that is desired.
As shown in FIG. 6, the process of the invention further comprises the step of coupling a portion 132 of the second end 130 of the second piece of flow media 128 to the first piece of flow media 118 already placed on the preform 100. The process of the invention further comprises the step of placing a vacuum bag layer 134 over the forming tool component 106, preform 100, release material 112, first and second pieces of flow media 118, 128, and resin distribution tube 124, such that the resin distribution tube 124 is retained in a pleat 136 formed in the vacuum bag layer 134 and such that a bagged preform 138 is formed (see FIG. 6). The resin distribution tube 124 is supported in place a distance above the bagged preform 138, and the resin distribution tube 124 is not in physical contact with the bagged perform 138. Preferably, the resin distribution tube is from about 0.5 inches to about 6 inches above the bagged preform. However, the resin distribution tube may also be other suitable distances above the bagged preform as long as it is not touching the surface of the composite part. Preferably, the vacuum bag layer is made of a material comprising nylon film or other material than can withstand the curing temperature of the resin infused into the preform. When the vacuum bag layer is applied during the layup of the preform, the resin distribution tube and flow media are captured in the pleat. The pleat provides a channel to direct the resin and gives stiffness to the resin distribution tube and first and second pieces of flow media when the bagged preform is evacuated. Thus, the vacuum bag layer holds the resin distribution tube in place. The positioning of the resin distribution tube in the pleat of the vacuum bag layer causes the pressure forces of the vacuum bag layer to be around the resin distribution tube rather than in a downward direction toward the preform. This removes the pressure from the preform surface.
The process of the invention further comprises the step of positioning the resin distribution tube 124 above the bagged perform 138, such that the second end 130 of the second piece of flow media 128 contacts the top surface 120 of the first piece of flow media 118 on the bagged preform 138 at an angle less than perpendicular to the bagged preform and indirectly connects the resin distribution tube 124 to the bagged preform and suspends the resin distribution tube above the bagged preform at an angle less then perpendicular to the bagged preform. Preferably, the resin distribution tube is positioned above the bagged preform at an angle of about 45 degrees to the top surface of the bagged preform. The resin distribution tube is connected to the bagged preform by the second piece of flow media which serves as a path for the resin. The process of this embodiment of the invention may further comprise the step, after the last step of positioning the resin distribution tube, of infusing resin into the bagged preform through the resin distribution tube and first and second pieces of flow media and returning an excess resin to a reservoir (not shown). In addition, the process of this embodiment of the invention may further comprise the step, after the infusing resin into the bagged preform, of curing the resin infused bagged preform. Preferably, the temperature for curing the resin infused bagged preform is from about room temperature to about 350 degrees Fahrenheit. However, higher temperature curing resins can also be used with the invention, including thermoset curing resins. The process of this aspect of the invention is carried out via a tube induced deformity elimination apparatus that eliminates surface deformations on resin infused composite parts.
In another aspect of the invention a process is provided for elimination of deformations on resin infused composite parts in which the resin distribution tube 124 is suspended above the preform 100 and is perpendicular to the preform rather than at an angle less than perpendicular to the preform. FIG. 7 is a perspective view of this aspect of the TIDE process of the invention, and FIG. 8 is a front sectional view of the resin distribution tube of FIG. 7. The first step of the process of this aspect or embodiment comprises positioning the dry composite preform 100 having a top surface 102 and a bottom surface 104 on a forming tool component 106, wherein the bottom surface 104 of the preform 100 is positioned over a top surface 108 of the forming tool component 106. The process of this embodiment further comprises arranging resin exit lines 110 in close proximity to the preform 100, placing a permeable release material 112 over the top surface 108 of the preform 100, and placing a first piece of flow media 118 over the top surface 114 of the release material 112. The process of this embodiment further comprises the step of wrapping a resin distribution tube 124 with a middle portion 140 of a second piece of flow media 128 and coupling a first end 126 of the second piece of flow media 128 and a second end 130 of the second piece of flow media 128 to the first piece of flow media 118 already placed on the preform 100, such that each of the first and second ends forms a ninety degree angle to the resin distribution tube. The process of this embodiment further comprises placing a vacuum bag layer 134 over the forming tool component 106, preform 100, release material 112, first and second pieces of flow media 118, 128 and resin distribution tube 124, such that the resin distribution tube is retained in a pleat 136 formed in the vacuum bag layer 134 and such that a bagged preform 138 is formed. The resin distribution tube is supported in place a distance above the bagged preform and the resin distribution tube is not in physical contact with the bagged perform. The process of this embodiment further comprises positioning the resin distribution tube 124 above the bagged preform, such that each of the first and second ends of the second piece of flow media contacts the top surface of the first flow media on the bagged preform and connects the resin distribution tube to and above the bagged preform at a ninety degree angle to the bagged preform. Preferably, the resin distribution tube is from about 0.5 inches to about 6 inches above the bagged preform. However, the resin distribution tube may also be other suitable distances above the bagged preform as long as it is not touching the surface of the composite part.
The process of this aspect or embodiment of the invention may further comprise the step, after the last step of positioning the resin distribution tube, of infusing resin into the bagged preform through the resin distribution tube and first and second pieces of flow media and returning an excess resin to a reservoir (not shown). In addition, the process of this aspect or embodiment of the invention may further comprise the step, after the infusing resin into the bagged preform, of curing the resin infused bagged preform. Preferably, the temperature for curing the resin infused vacuum bag layer is from room temperature to about 350 degrees Fahrenheit. However, higher temperature curing resins can also be used with the invention, including thermoset curing resins. The process of 5 this aspect of the invention is carried out via a tube induced deformity elimination apparatus that eliminates surface deformations on resin infused composite parts.
The TIDE process of the invention eliminates the deformations or mark-offs on the preforms, which become the composite parts, because it moves the resin distribution tube away from the bagged preform surface. By moving the resin distribution tube away from the bagged preform surface, the resin distribution tube is not affected by the downward pressure of the atmosphere. Flow media indirectly connects the resin distribution tube to the bagged preform which allows for free movement of resin without direct contact of the resin distribution tube to the bagged preform and thus eliminates preform deformity that can be caused by direct contact of the resin distribution tube to the bagged preform. The advantages of the invention over known resin infusion processes include production of higher quality composite parts that have a better appearance, require less rework, and are structurally sounder because of the elimination of fiber distortion.
Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Patent Application
20080079193
