5
Conclusions and Recommendations

When high-performance carbon fibers were first developed in the 1960s, their high cost (as much as $400 to $500 per pound) limited their applications to high-value military aerospace and space systems. The results of early military composite development programs may be seen today in systems fielded by each of the military services. For example, more than 350 parts of the F-22 Raptor, accounting for 25 percent of its structural weight, are carbon-epoxy composites.1 Further, the developmental Joint Strike Fighter will be between 25 and 30 percent composite by weight. The Army now uses carbon-thermoplastic composites in high-volume production of sabots for the M829A3 munition.

FINDINGS AND CONCLUSIONS

Fiber Supply

The 2004 worldwide capacity of carbon fibers (SAF based and textile precursor based) was expected to be more than 70 million pounds. Consumption was expected to be more than 40 million pounds and increasing. In this changing market, it appears that each carbon fiber supplier has targeted specific market segments and is building facilities and directing product portfolios to support its chosen strategies. Although some producers have indicated that the high cost of adding new facilities is a barrier to increasing capacity, DuPont, Honeywell, Dyneema, Toho, and Toray are all adding capacity in the United States. This added capacity will help to meet the anticipated shortage of carbon fiber produced with SAF precursor and meet the demand for organic fiber for military and homeland security applications.

Significant investment has been made over the past 4 to 5 years in capacity for p-aramid and PE fibers. Some of this capacity has been developed for military products, but most is targeted toward nonmilitary applications. Current expansion is targeted to meet the military needs for soldier protection and homeland security. An important aspect of this continuing investment is an M5 pilot plant start-up planned for 2005. This new M5 capacity will enable ballistic and structural performance evaluation to be conducted on full-scale components.

Fiber Demand

As the fiber industry matured during the 1980s and costs began to decrease, a variety of commercial applications for high-performance composites emerged, including sporting goods, commercial aircraft, and various industrial applications. As a result, DoD usage, which dominated U.S. requirements in the 1970s and 1980s, became a smaller part of the total market. In 2003, the historic and unsustainably low prices observed for carbon fibers were $5.25 per pound for a standard-modulus (32

1  

Composites are commonly denoted by their fiber-matrix composition. A carbon-epoxy composite will consist of carbon fibers in an epoxy matrix.



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High-Performance Structural Fibers for Advanced Polymer Matrix Composites 5 Conclusions and Recommendations When high-performance carbon fibers were first developed in the 1960s, their high cost (as much as $400 to $500 per pound) limited their applications to high-value military aerospace and space systems. The results of early military composite development programs may be seen today in systems fielded by each of the military services. For example, more than 350 parts of the F-22 Raptor, accounting for 25 percent of its structural weight, are carbon-epoxy composites.1 Further, the developmental Joint Strike Fighter will be between 25 and 30 percent composite by weight. The Army now uses carbon-thermoplastic composites in high-volume production of sabots for the M829A3 munition. FINDINGS AND CONCLUSIONS Fiber Supply The 2004 worldwide capacity of carbon fibers (SAF based and textile precursor based) was expected to be more than 70 million pounds. Consumption was expected to be more than 40 million pounds and increasing. In this changing market, it appears that each carbon fiber supplier has targeted specific market segments and is building facilities and directing product portfolios to support its chosen strategies. Although some producers have indicated that the high cost of adding new facilities is a barrier to increasing capacity, DuPont, Honeywell, Dyneema, Toho, and Toray are all adding capacity in the United States. This added capacity will help to meet the anticipated shortage of carbon fiber produced with SAF precursor and meet the demand for organic fiber for military and homeland security applications. Significant investment has been made over the past 4 to 5 years in capacity for p-aramid and PE fibers. Some of this capacity has been developed for military products, but most is targeted toward nonmilitary applications. Current expansion is targeted to meet the military needs for soldier protection and homeland security. An important aspect of this continuing investment is an M5 pilot plant start-up planned for 2005. This new M5 capacity will enable ballistic and structural performance evaluation to be conducted on full-scale components. Fiber Demand As the fiber industry matured during the 1980s and costs began to decrease, a variety of commercial applications for high-performance composites emerged, including sporting goods, commercial aircraft, and various industrial applications. As a result, DoD usage, which dominated U.S. requirements in the 1970s and 1980s, became a smaller part of the total market. In 2003, the historic and unsustainably low prices observed for carbon fibers were $5.25 per pound for a standard-modulus (32 1   Composites are commonly denoted by their fiber-matrix composition. A carbon-epoxy composite will consist of carbon fibers in an epoxy matrix.

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High-Performance Structural Fibers for Advanced Polymer Matrix Composites Mpsi) fiber and $17 per pound for an intermediate-modulus (42 Mpsi) fiber. The DoD market was just under 10 percent of the total U.S. market and 4 percent of the world market. Military usage is a decreasing share of the total U.S. carbon fiber market—from 43 percent in 1989 to 9 percent in 2003. Because the military usage in the total market is ever smaller—currently less than 4 percent of the world market—the installed integrated capacity in North America is adequate to supply all projected DoD needs for the next decade. In addition, the fiber modulus and strength properties of current production meet DoD's performance requirements for the near term. For the suppliers, this increasingly tight market is expected to lead to pricing structures that could support sustainable reinvestment. For the buyers, in cases where DoD relies on a sole source, prices could remain high. Significant demand from DoD combined with a technological design shift toward lighter-denier products is expected to strain existing capacity for structural organic fibers. Additional military and homeland security applications are also emerging. In particular, the demand for organic fibers is currently high to satisfy the military's need for body armor and crew protection kits for tactical vehicles. This demand is predicted to remain high for 2 years and then decrease gradually. Fiber Technology A few companies continue to invest in new carbon fiber technologies. This investment has been primarily in process improvements and better manufacturing controls to decrease variability and reduce cost rather than to improve properties. Because of this trend, any change in carbon fiber properties is expected to be evolutionary, not revolutionary. Any impact of new lower-cost technology is at least 10 years away. In the organic fiber area, M5 fiber has the potential to become a commercial fiber with a step improvement in functionality, especially to address the need for optimized structural and ballistic properties of interest to DoD. M5 has the potential to meet the future structural and ballistic needs of the Army. Existing fibers, such as Kevlar, have good ballistic properties but poor properties in compression. M5 could be an enabling technology for a new generation of soldier protection systems. Finally, although significant progress has been made in improving fiber and matrix properties and reducing material costs, similar progress has not been achieved in manufacturing technology and innovative design to lower the cost of composite structures. Composite processing remains a major opportunity for improvement. CONCLUSIONS AND RECOMMENDATIONS Accelerating technology transition has been identified as a key target. One method to speed new fiber technologies to market, especially for such new fibers as M5® or nanocomposite fibers, would be for DoD to provide a guaranteed initial purchase order if the pilot product meets specified property and price requirements. In the near term, DoD should provide significant funding to purchase M5 fiber and rapidly evaluate its properties and applications. Cost reduction has been identified as a key target. A clearly significant way to reduce fiber costs over the next 10 years is to reduce or modify the aerospace specifications and qualification process. The DoD should review existing and new qualifications and material specification documents and reduce testing and quality requirements where possible. To reduce acquisition costs, all major DoD programs that use fiber or prepreg should have two qualified sources. To reduce manufacturing costs in aircraft structures, DoD should invest in manufacturing technology and innovative design concept development. Promising ways to improve dimensional tolerance and reduce processing variability include investment in new continuous process controls that would contribute to controlling fiber structure and purity, prepreg properties such as fiber weight per unit length, and overall property variability.

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High-Performance Structural Fibers for Advanced Polymer Matrix Composites To reduce manufacturing costs across all DoD applications, DoD should initiate a program with university-industry-government participation. Promising manufacturing and design concepts should be assessed, including vacuum-assist resin transfer molding (VARTM) to replace more costly manufacturing processes. Virtual manufacturing and simulation should play an important role in accelerated insertion of materials and processes into DoD systems. Research in automation using simulation, sensing, and control systems should be pursued to advance this process from prototype to a production-ready process. Improved understanding has been identified as a key target. The DoD should take a lead in developing a better design methodology that incorporates variability and stochastic aspects of local properties into lifetime models. DoD personnel should use this improved understanding to develop new design allowables and parameters that prevent overdesign of parts and overspecification of fiber properties. The DoD should aid in developing a better understanding of new promising technologies in such areas as micron-scale fibers with nanoscale structure and new sizings with the ability to maximize structural and ballistic properties.