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Reduced Cost, Repeatable, Improved Property Washout Tooling for Composite Fabrication


TECHNOLOGY AREA(S): Air Platform, Materials/Processes

ACQUISITION PROGRAM: Commander Fleet Readiness Centers (COMFRC)/ Potential Application to V-22,

OBJECTIVE: To develop a process capable of producing a washout tool that can be used in the manufacturing of composite structures using tape placement, Vacuum Assisted Resin Transfer Molding Process (VARTM) and Fused Deposition Modeling (FDM) technology.

DESCRIPTION: High precision composite parts with complex shapes are currently used in aircraft engine applications. To fabricate these parts, washout tooling is required. The currently used material has issues with tolerances, consistency of tooling properties, and time to fabricate the tooling. A process that can more consistently produce the tooling in reduced time will reduce the cost of the resultant component. In addition, the development of an improved tooling processing methodology will open opportunities for many applications that to date are not considered due to the current tolerances that are achievable with current washout tooling manufacturing processes.

Composite materials are gaining increased acceptance as a structural material for Naval applications. Using composite materials for these applications allows both the material and structure to be formed at the same time. As such, using composite materials often allows for part reduction. Additional part reduction can occur using composites if the material can be accurately formed into complex shapes with high tolerances, such as those required for aircraft engine components. One way that this can be achieved is through the utilization of washout tooling. Typically, the washout material is manually poured into tooling and allowed to harden. Depending on the operator, the resulting mandrel can have varying properties and levels of consistency, and the time to produce the mandrel can vary greatly. The development of an automated process that produces the washout tooling with improved dimensional stability and with less time will result in reduced processed composite part cost. The process should produce the washout tooling such that it is highly repeatable (tolerances of +0.005” on thickness and +0.010 on everything else), low cost considering both materials and forming process ($40-$50/part of size 1.5” x 12”x 0.5”), does not require an oven post cure, and with thermal shock and impact resistance equal to ceramics and requiring minimal processing time. The material should be capable being used in autoclave processing with typical processing conditions of 350°F temperature and 100 psi pressure. In addition, the material used for the washout tooling should be environmentally friendly and should not create a hazardous waste stream.

The washout tooling must also provide the appropriate characteristics required for the production of high performance composite structures. In addition to the above mentioned tolerances, it is important that the tooling produces the finished part with the appropriate dimensions. This requires that the washout tooling have the appropriate Coefficient of Thermal Expansion (CTE) such that a finished autoclave cured part meet the tolerances required for the processed component. It should be noted that carbon/epoxy prepreg will be one of the materials that the washout tooling will be required to be compatible with.

PHASE I: Develop and demonstrate material and handling properties to produce proof of concept specimens with properties suitable for use in washout tooling applications, as detailed above. The small business shall demonstrate that the washout tooling material can be easily removed after a component has been processed at 350° F. Finally, since cost is always important, the washout material utilized must not require an oven post cure and temporary storage of washout material shall not require that it be kept under vacuum or be degraded to exposure to ambient air.

PHASE II: Based on the Phase I effort, further develop and demonstrate a repeatable process whereby the small business can produce a soluble rectangular mandrel with dimensions of approximately 1.5” x 12” x 0.5” with tolerances of +0.005” on thickness and +0.010 on everything else. These parts must also demonstrate that they are capable of handling the processing conditions typical of tape placement and autoclave curing. In addition, they need to demonstrate that the process is scalable to 2” x 20” x 0.5”. The small business must next demonstrate the ability to develop and demonstrate the process for manufacturing the soluable tooling with more complex shapes, as determined by the topic sponsor. The shape can include rectangular sections that are out of plane, or circular sections with jogs and protrusions, or foil shapes with complex curvature. In addition, the small business will scale up the processing to be able to produce mandrels with planar dimensions of a minimum 12” x 24 “. The small business must demonstrate that the manufactured component meets the dimensional tolerances established by the Technical Point of Contact (TPOC).

PHASE III DUAL USE APPLICATIONS: During Phase III, quantities of the soluble tooling will be provided to COMFRC, such as Cherry Point as well as NAWCAD Materials Engineering for final evaluation and characterization. In addition, the small business, in collaboration with the Navy monitoring team will address a selected military functional demonstration during Phase III. The final developed process will also transition to an original equipment manufacturer (OEM) where high tolerance washout tooling will be produced for production parts. The commercial aircraft industry would benefit significantly from low cost tooling material that allows for the fabrication of reproducible low cost composite parts by reducing the part count for complex shaped components. The tooling can also be used in Naval platforms (ships, subs) which could benefit from reduced part count and complex composite components.


    • New options for trapped tooling. Retrieved from


    • RTM and VARTM Material Considerations. Retrieved from


  • Introduction of Liquid Resin Molding Project. Retrieved from

KEYWORDS: Soluble Tooling, low cost tooling, tape placement, autoclave curing, washout tool, composite materials

  • TPOC-1: Bill Nickerson
  • Email:
  • TPOC-2: Anisur Rahman
  • Email:

Questions may also be submitted through DoD SBIR/STTR SITIS website.

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