PROBLEM – Fabricate a non-structural duct in a quick, clean, and efficient process without an autoclave or washout tooling.
OPPORTUNITY – Create an oven cure solution that will produce a high-quality composite duct with a reusable Smart Tool.
SOLUTION – A Smart Tool that acts as a bladder during cure was combined with a OML cure mold to create an oven cure process that consolidates the composite laminate during cure and creates a high-quality duct with cost savings of 19% and an 81% reduction in cycle time.
Washout Tooling Process
The previous process of using washout tooling to create a mandrel to layup on was dirty and laborious. From beginning to end, it took 60 hours to fabricate a duct, with nearly 6 hours of touch time.
Technicians would start by cleaning up the casting tool, removing excess plaster and debris from the previous cycle. Next, they mix the plaster and pour it into the mold, waiting 24 hours for it to cure. After cure, technicians disassemble the casting mold and rework any damage, voids, or blemishes.
After repair, the plaster mold is sanded to create a smooth surface. Next, release tape is applied to the surface, followed by the prepreg, then breather.
The laid up mandrel is then vacuum bagged and placed in an autoclave for a 6 hour cure. After debagging, the mandrel is soaked in water for 24 hours to soften the washout material. Next, the washout material is manually removed from the duct, and then the composite duct is washed, trimmed, and finished.
Smart Tooling Process
The Smart Tooling process is fast, clean, and efficient. The Smart Tool that acts as a bladder has its release film pre-applied, allowing the layup process to begin right away. Because the Smart Tool is rigid at layup, you can apply prepreg directly to the released Smart Tool.
Once finished, the laid up Smart Tool is placed into the cure mold, sealed with a pressurized bag placed through the inside of the Smart Tool, then placed in an oven for a 6 hour cure cycle. As the cure temperature ramps up, the Smart Tool becomes elastic and the inner bag is pressurized to apply force on the laminate to drive out air and excess resin.
Because it was desired by the customer to eliminate an autoclave for cure, the duct will have both a smooth outside mold line (OML) and a smooth inside mold line (IML) after it is cured.
Once the cure is complete and the temperature is ramping down, but is still above the transition temperature of the Smart Tool, the mold is opened and the Smart Tool is extracted from the trapped geometry composite part. Elastic Smart Tools can be extracted with low-force from the cured composite duct.
After extraction, the still elastic Smart Tool is placed into a pre-heated form mold, a vacuum bag is pulled through the Smart Tool and sealed to the ends of the mold, vacuum is pulled to reset geometry, and it is left to cool so it can begin the next cycle.
Smart Tools reduce cycle time by 81%, labor cost by 14%, and material cost by 33%, netting a payback of only 7.3 months. If the customer had requested we use a Smart Tool mandrel solution and stayed in the autoclave, the payback would be only 1.7 months.
The dirty, time consuming, and tedious process of washout was eliminated and replaced by the simple and elegant Smart Tooling process.
Smart Tooling provides formable, reusable tooling solutions for manufacturing composite parts with complex geometries for the aerospace & defense industry. Smart Tools improve quality, reduce labor hours, decrease consumables, and increase throughput – essentially, Smart Tools enable the manufacturing of composite parts better, cheaper, and faster.
Smart Tooling’s Shape Memory Polymers are designed to be aerospace-grade RIGID epoxies at room temperature, and highly FLEXIBLE elastomers when heated, eliminating the need for expensive, laborious, tedious, dirty, and challenging solutions such as melt-out foam, metal breakdown tools, rubber bladders, or washout tooling.
We also deliver comprehensive solutions. We offer total solutions for the manufacture of your composite part, including custom tooling engineering and design, fabrication of molds, Smart Tooling fabrication, initial composite part manufacturing, custom standard operating procedures, onsite start-up support and training, and any future training if required.
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