Steps are taken in the preparation of tools used in fabricating parts constructed of composite laminate material. In the process of finishing a part, often a hole is needed to be drilled through the cured part. The drilling of a hole occurs with the cured composite laminate material positioned in the tool in which it was cured. Maintaining the cured composite laminate material in the tool provides stability to the cured composite laminate material which provides improved quality control of the drilling process.
In the process of drilling a hole through the cured composite laminate material, the drill bit will pass through the cured material assuring a complete fully dimensioned hole is positioned through the cured composite laminate material. With the drill bit passing through the cured composite laminate material the drill bit engages a wall of the tool positioned immediately beyond the drilled hole in the cured composite laminate material. As a result of this drilling process a hole is created in the wall of the tool, a tool which is needed to be reused in fabricating another part.
Thus, in preparation of the tool for fabricating another part the hole in the wall of the tool needs to be closed by the fabricator to prevent resin from entering the hole with positioning composite laminate material onto the wall of the tool in reusing the tool. Without closing the hole, resin from the composite laminate material will leak into the hole and create, in reuse of the tool, an unwanted resin nub configuration positioned on the cured part. Should a resin nub result in being positioned on the cured part, the fabricator will need to hand sand the part to remove the resin nub. This process is time consuming and can create potential assembly issues when using the fabricated part such as in the use of the fabricated part in tight tolerances or with creating uneven surfaces on the part resulting in shimming operations needing to be applied.
Fabricators attempt to reduce the occurrences of resin nubs appearing on the cured part with filling the holes which were drilled into the wall of the tool in a previous fabrication of a part with the tool. The fabricator will attempt to fill these holes with the use of a potting compound with applying the compound into the hole to close the hole. Several applications of the potting compound material may be needed with the material drying, shrinking and creating voids at the hole location. In addition, with the tool in re-use containing the composite laminate material, the tool with composite material is placed into an autoclave and the potting compound material used to fill the hole in the wall of the tool can further shrink. As a result, the potting compound can even fall out of engagement with the wall of the tool resulting in resin nubs being positioned on the part at the hole location.
As a result, timely efforts are made by fabricators to close previously drilled holes in walls of tooling in the preparation of that tooling for fabrication of another part. These timely repair efforts may not reliably maintain closure of the hole further requiring hand sanding of the fabricated part at the hole location. This sanding process further presents complications when employing the sanded fabricated part in fabricating an assembly.
USPTO Backgrounds
USPTO Backgrounds