Novel Tooling Technique Cuts Cost and Time of Manufacturing Parts

April 1, 2008

Imagine being able to mold and manufacture parts the size of a bedroom in just two days. A system for composite fabrication, based on a material that has been nicknamed "engineered quicksand," provides such fast and inexpensive tooling to both the aerospace and transportation industries.

2Phase Technologies (Dayton, NV), with funding from the Missile Defense Agency (MDA), has developed a reconfigurable tooling system (RTS™) that enables composite shops to quickly mold and replicate tools and parts on one platform at a fraction of the cost incurred when using conventional tooling approaches.

The company was awarded $820,000 in MDA funding through Small Business Innovation Research (SBIR) Phase I and II contracts between 2003 and 2006. The contracts focused on the manufacture, modification, and redesign of rocket motor casings using 2Phase's reconfigurable tooling approaches. The result was a tooling solution that allowed a motor case with precision-located features to be manufactured quickly and inexpensively over a lightweight mandrel that could be removed quickly and simply after the fabrication was complete.

2Phase's system has advantages in cost, speed, and scalability over competing rapid-tooling approaches. The company expects the overall manufacturing cost of a generic 4 × 4' rapid tool to decrease tenfold from $5,000 to $500, while providing improved tool performance. Using a unique replication process to create tools from a master model or original part is the key to the cost savings. Speed is also a factor, with the total turnaround time from master to mold to finished product being one to two days, as compared with the several weeks to months required to fabricate tooling for composites using conventional methods.

Scalability is also key, and the RTS can make use of large tool beds — which can vary in size depending on the customer needs — currently ranging from roughly 2 × 3' to 6 x 9'. The company already has built concept tool beds that can handle the fabrication or replication of parts more than 65' long. For the U.S. Army, it also has designed tool beds that have successfully replicated the hood of an M35 truck and the cargo-bay door of a Black Hawk helicopter.

2Phase's system is commercially available in its fourth iteration, the RTS 4000. The customer base for the equipment is expected to be aerospace and transportation manufacturers who need rapid, low-cost, and very large original or replacement parts.

How it Works

The RTS machine design in no way resembles a conventional tooling system. Its tool bed is a large, deep, flexible tray filled with a slurry of 2Phase's unique "engineered quicksand" — a "state-change material" composed of a ceramic powder mixed with a water-soluble inorganic binder solution — and covered by a thin, flexible silicone membrane.

To replicate a part, the master is placed on the membrane and covered by a vacuum cap. The air around the master is evacuated and the master sinks into the slurry mix, which exactly conforms to the part's shape. Using the controls and pumps of the system base station, the machine then withdraws the liquid from the "quicksand" and rapidly hardens it to a firm, chalk-like consistency. The entire process takes just 15 to 30 minutes, and in many cases, the solidified mix can then be used as a tool for low-temperature composite molding. If a harder, more durable tool is required, the mold is then heated up to temperatures as high as 400°F to remove the last of the liquid and harden the mix to a ceramic-like state. The process of fully hardening the tool takes between six and eight hours.

In this form, the tool can be removed from the tool bed and used to mold composites by processes such as autoclave curing or vacuum thermoforming. When the fabrication of the composite part is complete, the tool can be used again or, even if fully hardened, can be reconfigured to make another type of part. To reconfigure the tooling material, the water-based binder mixture is reintroduced, dissolving the inorganic binder, and the solidified state-change material is reliquified. The tool bed is thus returned to its original slurry state, allowing the shop to begin work on another tooling project.

The RTS 4000 comes with a hefty price tag of about $250,000 per machine. While the cost may be prohibitive for some smaller composite shops, large composites users like the aerospace industry should find the price reasonable. A single system can quickly allow production or replication of many different composite pieces and thus replace numerous tools that can cost up to $100,000 each.

Where it Stands

With continued development, 2Phase anticipates that the technology will provide aerospace and transportation manufacturers a means of creating faster, less-expensive products or repairs with conventional or high-temperature composites. In some or many applications, 2Phase officials believe their technology may replace altogether tooling materials and approaches currently used.

2Phase now is looking for customers as well as joint-development partners willing to invest to embed the RTS technology into their applications.

More Information

For more information on the RTS machine, click here  . (Source: MDA TechUpdate, Missile Defense Agency, National Technology Transfer Center Washington Operations)

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