Ready to Wear
Written by Joan Michel
While performance and comfort of protective equipment have improved, the underlying technological approach of creating an impermeable physical barrier and purifying breathing air through a charcoalbased filter has not changed much from what was available in World War I.
But the state of the art is taking a giant leap forward now as industry commercializes new materials engineered with specific physical properties. Now, industry is integrating protective characteristics into existing materials and equipment and developing ultrathin, high-strength “intelligent” barrier materials that can be integrated into clothing and uniforms for both the military and civilian sectors. Also, advances in non-carbon-based air purification media will eventually allow major design improvements in protective masks.
“Until recently, everything was a big plastic suit bound with tape around the wrists and ankles,” said Agilex Technologies’ chief scientific officer Dr. Darren McKnight, who was involved in the cleanup of the Brentwood, Va., postal facility in the wake of the anthrax incident of October 2001.
In that incident, cleanup of the 700,000-square-foot facility, which was widely contaminated with B. anthrasis spores originating from a letter addressed to then-Sen. Tom Daschle, D-S.D., took months and thousands of man-hours in protective gear.
“We’ve learned that we need to be able to operate through an incident, not just in it,” McKnight said. “This means the suits need to be breathable and unaffected by heat and humidity. You need to be able to use your hands and stay upright on your feet.”
Lightweight, breathable, tough materials that are impervious to all different chemical and biological materials and lowering the total cost of ownership are the two issues driving technology innovation in industry right now, according to McKnight. He foresees a tight-fitting, “Spiderman-type” suit with highly engineered fabric as the protection of the future.
“Big and bulky is where we have gone wrong,” McKnight said. “We are going to have to deal with [an incident like the anthrax attack] again, and we need to be diligent about pushing the technology forward so protective equipment evolves.”
Among the manufacturers working on new types of materials, Wilmington, Del.-based DuPont recently announced the commercialization of its new Nomex On Demand product, a fiber technology that “detects” emergency conditions and automatically expands to trap more air for greater thermal insulation. In emergency conditions, air temperatures can exceed hundreds of degrees, and DuPont’s product is engineered to react and expand when temperatures reach 250 degrees Fahrenheit or higher. While initially available in firefighter gear, DuPont also sees applications for this product in the auto racing industry, wildfire control, oil and gas operations, and the military.
Another firm, c2c Innovations, developed a process to embed chlorine receptors into synthetic fabrics to defend against contamination by biological materials such as bacteria, viruses and toxins. Christopher Leisner, co-founder of the Troy, Mich.-based company, said its Micrillon product improves over time and with use because of how it’s manufactured. Basically, the chlorine receptor sites are introduced at the earliest stage of synthetic fiber production—at the pellet stage, so that the sites sit inside the strands of fiber, not outside the fiber. Washing it with chlorine bleach renews this fabric and replenishes any consumed chlorine at those receptor sites. “Among other things, this science would allow us to bring a new level of disinfection to a surgical suite,” Leisner said. “Once charged, the textile wipe acts as a disinfectant that requires only tap water; no other chemicals are required.”
The product is currently used for janitorial supplies, bed linens, clothing, carpeting and flooring, and face masks, and Leisner said his company was awarded a grant to research usage for the first responder community.
W.L. Gore & Associates, based in Elkton, Md., created a breathable fabric that allows users to wear a protective suit for up to eight hours. This fabric was recently selected as the chemical barrier for the National Fire Protection Association (NFPA)-certified WZ9435 XRT Response Suit made by Blauer Manufacturing, Boston, Mass., and sold to the first responder community. This single-piece coverall, which does not require taping, protects users against NFPA-identified hazards plus additional toxic industrial chemicals and chemical warfare agents.
“Many materials have other industrial applications, and this commercial drive has led to both inventiveness and scaling for production,” said Dr. Charles Bass, Defense Threat Reduction Agency (DTRA) capability area program officer. “In some cases we have been able to leverage this work for [military] chemical-biological protection.”
Last fall, DTRA and the U.S. Army Natick Soldier Center invited industry to submit technology concepts for a novel chemical and biological protective ensemble concept, the Uniform Integrated Protective Ensemble, or UIPE. This will be a completely integrated chemical and biological protective system in which liquid, vapor and aerosol protection is part of the uniform, and respiratory protection is an integrated part of the helmet. The military is looking for concepts that will improve overall mission performance, including reducing the thermal burden, improving human performance, increasing mobility, decreasing weight and bulk, and offering better integration with existing systems. Technologies will be considered for inclusion in a demonstration in fiscal year 2010 that assesses integration with existing boots, gloves, body armor, wrist, neck, helmet, respiratory protection, combat load and communications components.
“In my view, the more revolutionary a chemical and biological system is, the less it is apparent to the user,” said Bass. “In such a system, CB protection would be incorporated into the normal battle dress of the warfighter.”
Bass said that it may be a few years before these concepts make their way into an acquisition program, but elements of the demonstration and supporting science and technology development will likely be employed in chemical and biological ensembles in the near future. In developing such ensembles, added William D. Hartzell, joint project manager of individual protection for the Joint Program Executive Office for Chemical and Biological Defense, the greatest challenge lies in devoting the proper amount of attention to both protection and performance.
“A key part of meeting that challenge is to successfully employ discrete technologies under development now for future integration into mission-tailored ensembles,” Hartzell said. “Understanding the threat is extremely important, and we can’t allow our design and development to be defined as a pursuit of unnecessarily burdensome protection against unrealistic threats.”
When that happens, development programs waste both time and money, he noted. But Hartzell said technologies now under development or expected to be developed soon should allow chemical- biological equipment developers in DoD to achieve the right balance between protection and performance. “The need for high-performance materials is critical, and we are energetically seeking these materials from all sources—academia, industry and government agencies worldwide,” Hartzell said.
Working in the area of novel filtration materials development is Edgewood Chemical Biological Center (ECBC), the Army laboratory at Aberdeen Proving Ground, Md. Carbon is the primary filtration material used in protection systems such as masks, and when impregnated with certain metals, the carbon filter media can protect against a wider range of threats. Researchers at ECBC have been working with industry and academia to develop new filter material that expands the range of threats warfighters can safely counter.
Greg Peterson, chemical engineer at ECBC, said that his main focus is to expand the protection the warfighter gets from his mask, particularly against toxic industrial chemicals (TICs). Reducing the burden in part means reducing the breathing resistance, and to that end “we are always trying to find better materials,” he noted.
Developing new materials is never easy, DTRA’s Bass noted, but government researchers can benefit greatly from academic and industrial research in this field to focus applications on the specific needs of chemical and biological agent protection. One development focus for DTRA, Bass said, has been the metal organic framework (MOF), a new class of nano-structured material that provides adsorption surfaces per unit weight that are much higher than traditionally used adsorbent materials such as activated carbon. Such material can be tailored to target specific classes of chemicals and could significantly enhance protection against chemical and biological threats.
“Of course, the challenge with any new material is to extend performance to conditions outside the laboratory, Bass said. “Our challenge is getting materials such as MOFs to perform well over the full range of environmental conditions, such as temperature extremes, high humidity, dust and other real battlefield conditions.”
Peterson said his team has been working with MOFs that are widely used in the gas storage industry.
“For air purification, they are an immature technology, and it is unclear how commercially viable they are, but we can build them from the ground up and fine-tune the materials at a molecular level,” said Peterson. “For instance, you can identify a target threat and build protection right into your air purification material. This moves us from treating materials such as carbon to making new materials—a big departure from what we’ve done in the past.”
Presently, the current protective ensembles place an undesirable burden on the warfighter—physiologically, cognitively and logistically, according to experts. But Hartzell said the goal is creating equipment warfighters can wear normally but also easily employ in emergencies.
“Although we have significantly advanced beyond the construct of the medieval knight—whose protective armor and chain mail impeded movement and visibility, and required the assistance of a squire to don and doff—our protective equipment still imposes significant physical and psychological burdens on the wearer,” Hartzell said.
So in the case of respirators, Hartzell said the team is developing multi-use materials for incorporation into duty uniforms and specialized head gear that is lightweight and nearly indiscernible to the wearer—even in heightened protective posture. In the future, the equipment might know by itself to go into that emergency mode, modifying itself at the molecular level in response to a threat and providing instant feedback to warfighters on their physiological status and the integrity of their equipment. Conceivably, this “ever ready” ensemble could maintain optimum body temperature and hydration while feeling no more cumbersome than a combat duty uniform, Hartzell said.
Operational issues are driving technological development, said McKnight, given the need for users to quickly suit up in contaminated environments, and to be suited up in something that can handle heat and humidity and lets users breathe properly, stand upright and use their hands.
“You are usually cleaning up a contaminated area with water, and things get slippery,” Hartzell said. “Materials need to be impervious to range of chemical and biological materials. Technology developers need be able to handle all of that and lower the total cost of ownership. Comfort and cost are the two issues driving development.” ♦
JSGPM
One product intended to marry both comfort and protection in defense against contaminants is the joint service general purpose mask (JSGPM), a system consisting of mask, carrier and accessories designed to be compatible with future service equipment. William Hartzell, the joint program manager for individual protection for the Joint Program Executive Office for Chemical and Biological Defense, said the design, development and fielding of the JSGPM broke new ground.
“[It] resulted in a general-purpose, standard-issue joint service mask that reduces the warfighter’s physical burden [and] breathing resistance and provides excellent respiratory and ocular protection,” Hartzell said.
Compared with the legacy M40 mask, JSGPM reduces the on-the-face weight by 21 percent, breathing resistance by 50 percent and exhalation resistance by 55 percent. JSGPM is the first ground mask that will be common across the services, which should significantly reduce the total ownership cost and the logistics burden for the military by only having to support one mask versus service-unique products. JSGPM is in full production with around 100,000 to be fielded by summer. ♦