Armor applications are growing with the development of new markets and new composite materials. #aramidfiber #braiding #carbonnanotubes
TEAM Inc. (Woonsocket, RI) custom jacquard looms facilitate the cost-effective production of 3-D woven preforms through computer control of up to 7,000 individual warp fibers at a time. The loom can weave mixed polymer matrix composite (PMC) preforms with various fibers up to 2 inches/51 mm thick (see the picture below). Compared with traditional laminated composite armor, PMC preforms are usually infused with polyester resin to create armor with excellent multi-strike performance. Source: TEAM Inc.
TEAM's preform thickness can reach 2 inches/51 mm.
When the IronHorse 5-ton truck was hit by an improvised explosive device in Iraq, the truck passengers walked away unharmed. The vehicle has been retrofitted with ArmorCore bulletproof fiberglass panels provided by Waco Composites (Waco, Texas). After the explosion, the armor was dismantled and reused in another vehicle. Source: Waco Composites
Result: SM Carbon/S-Glass Source: TEAM Inc.
Result: Various hybrid power sources: TEAM Inc.
Protecting government buildings and their occupants from security threats is a growth area for bulletproof products. ArmorCore bullet-proof fiberglass panels from Waco Composites are integrated into the woodwork of the judge's bench and the structure of the court clerk's seat and witness stand. Source: Waco Composites
Continued concerns about infrastructure security threats are driving the growth of new markets and applications for armor and other ballistic materials. In order to maximize performance and minimize costs, suppliers and manufacturers of these products are increasingly turning to designs that not only integrate multiple materials, such as ceramics, steel, and composite laminates, into a single armor solution, And it is taking advantage of combining carbon, aramid, glass and other fibers in preforms and prepregs to form multiple forms of reinforcement in composite materials. These hybrid composite materials take advantage of the unique advantages provided by each material. Armor manufacturers are also taking full advantage of the development of nanotechnology to improve the performance of composite materials. HPC investigated the growing anti-revulsion community and found some of the latest product developments that illustrate trends.
Riley Solutions Inc. and NanoRidge Materials Inc. of Houston, Texas have jointly launched what may be the first commercial armor application constructed with carbon nanotube-reinforced composite materials. The carbon nanotubes (CNT) provided by NanoRidge are dispersed in a ceramic fiber fabric in a heated and pressurized reaction vessel. The carbon nanotubes are attached to the fibers, forming connections between the various layers of the fabric, thereby imparting strength in the z direction. The laminated fabric is injected with epoxy or polyurethane resin containing additional carbon nanotubes in a hot press or autoclave. As a direct result of the use of nanotubes, panels of any length or thickness can be made and reported to have improved strength-to-weight ratios and enhanced back deformation characteristics. According to John Tidrow, President of Riley Solutions, proprietary processes and materials have been developed for many years. In addition to ceramic fibers provided by Superior Technical Ceramics (St. Albans, Vt.), a variety of other fibers are used in these panels, including aramid fibers and high molecular weight polyethylene (HMWPE) fibers from DSM Dyneema (Geleen, The Netherlands), “The process of manufacturing cost-effective carbon nanotube-reinforced armor involves adjusting every individual component of the composite material, from fiber to fabric to resin,” he said.
Riley Solutions opened a new manufacturing plant in January, and Tidrow stated that the first commercial application will be a panel for military aircraft. When the plane takes off or landed, these panels will provide bulletproof protection for the flight deck and other sensitive areas that are vulnerable to light weapons. The fabric can be cut into shapes, allowing the company to easily customize the panel size. For example, a panel is 3 inches/76.2 mm thick at one end and 7 inches/177.8 mm thick at the other end, and the length is only 10 inches/254 mm. Tidrow said the company is also working with a large armor manufacturer to commercialize lightweight, nanotube-reinforced composite body armor inserts into panels.
Historically, designers of bullet-proof materials prefer tough but expensive aramid, high-density polyethylene, etc., to traditional E glass because it is too brittle and has no bullet-proof ability. But Waco Composites Co. (Waco, Texas) now produces bulletproof fiberglass panels sold under the trade name ArmorCore. These panels are designed to provide ballistic and ballistic protection specified in eight of the nine levels of the Underwriters Laboratories (UL) bulletproof equipment safety standard UL 752 (see Table 1, page 40). Company President Wayne Hampton (Wayne Hampton) said that these panels are made of alkali-free glass woven roving and injected with "proprietary additives, fillers and performance-enhancing resin systems." Panels are sold in a variety of sizes, the most common being 4 feet x 8 feet (1.2mx 2.4m), and the thickness ranges from 0.25 inches/6.35 mm (meeting Class 1 requirements) to 1.4375 inches/36.51 mm (for class) 8 Protection . The panel is pressed into a heated platen in a process similar to that used to make plywood.
Waco Composites was founded in 1995 and initially entered the market with ArmorCore panels that meet UL 752 Class 1 to Class 4 standards. The product line is mainly aimed at federal, state, and local judicial agencies, following government requirements to build all ballistic materials for judge seats. Although benches are still one of the company’s core markets for panels, Hampton reports that, in the past five years, the company’s sales of panels used in high-rise building security for wall-mounted applications have increased by 10% annually. Tornado shelters and other structures. It is worth noting that the security room helped protect the crew of an oil tanker flying the British flag and prevented the hijacking attempt by Somali pirates in the Arabian Sea in January this year.
"When the jet hit the Pentagon's wing on September 11, we installed some level 3 [0.4375 inches/11.1 mm thick] panels on the inner walls of the Pentagon," Hampton said. "After the accident, determining that the panel helps limit damage." Since then, the company has worked on the entire interior and exterior walls of the Pentagon, as well as numerous US federal buildings, including those occupied by the Treasury, FBI, and CIA. Provide a panel. Hampton. The exterior walls are reinforced with panels that meet UL 752 Class 4 (1.375 inches/34.9 mm), Class 5 (1.5 inches/38.1 mm), or Class 8 (1.4375 inches/36.5 mm). These panels are most often installed as structural wall panels, and then drywall is used to cover interior or exterior wall facing bricks or other cladding materials. Hampton said the company also provides armor kits to military departments for upgrading armored combat vehicles, helicopters and naval vessels. "In the past seven years, we have helped 3,500 Hummers upgrade their armor," he reported.
Hampton said that Waco Composites is providing ArmorCore panels as a peeling liner in the construction of an armor system that can provide protection against 0.50 caliber armor-piercing projectiles. DefBar Systems LLC (Lebanon, Missouri) manufactures and sells 0.50 caliber products as part of its registered trademark Zouline series of opaque armor, designed for vehicle, construction and aviation applications. The armor system combines parabolic ceramic striking tiles and 2.5 inches/63.5 mm thick ArmorCore panels, and weighs approximately 29.5 lb/ft2. When the projectile hits the parabolic tile, it will deviate from the target and dissipate its energy.
Elsewhere, Fiber-Tech Industries Inc. (Washington Court Building, Ohio) plans to launch a bulletproof panel designed to meet UL 752 Level 1 and Level 2 requirements sometime this year. Fiber-Tech President Terry Keegan said that if the test is successful, the new product will target the bulletproof protection of commercial buildings, such as banks and court buildings. Keegan said these panels will be made of woven E glass and thermosetting resin. This product represents the company's second attempt to enter the rebound market. "In 2008, we evaluated some ballistic panels, but the price of this product is too high for today's market," Keegan said. "This time, we plan to qualify for a more competitive product." The company also produces fiberglass reinforcement panels for the transportation, construction and agricultural markets. The company uses alkali-free glass produced by Owens Corning Composites (Toledo, Ohio) and PPG Industries (Pittsburgh, Pennsylvania)
Historically, 3-D weaving has been used to make thick and complex preforms. When these preforms are injected with resin, they can produce strong, high-strength parts for aerospace, military, and other industries that require high performance. However, these same characteristics and characteristics also make 3-D preforms suitable for cost-effective production of panels and components for heavy armor applications.
TEAM Inc. (textile engineering and manufacturing company, Woonsocket, RI) uses customized jacquard looms to manufacture glass, carbon and other fiber mesh, woven fabric polymer-based composites ( PMC) Prefabs (6.35 mm to 50.1 mm). PMC preforms are usually injected with polyester resin through the traditional vacuum assisted resin transfer molding (VARTM) process. Aaron Tomich, project manager of TEAM Inc., said that manufacturing similar preforms through traditional methods requires laminating 40 or more layers of fabric. Compared with 3-D, the resulting 2-D multilayer laminate has multiple hits. The ballistic performance is inherently poor. D Weaving preforms. “From a structural point of view, the fibers of the woven preforms we produce are oriented in the x, y, and z planes, which imparts excellent ballistic resistance and prevents the structure from delamination on impact,” Tomic said. "Compared with 2-D laminates, the excellent multi-strike performance of 3-D woven preforms is very obvious." TEAM uses S-2 Glass from AGY (Aiken, SC) and carbon fiber provided by Hexcel (Dublin, CA). The company also uses Nextel high-temperature ceramic fibers from 3M (St. Paul, Minnesota) to make preforms. The ceramic preform is then poured into molten metal to form a metal matrix composite (MMC), which is used as the back of the armor.
According to Tomich, TEAM Inc. is providing PMC hybrid (multi-fiber) and single-fiber preforms, as well as MMC preforms, to the US Army to evaluate "several new tank-like vehicle platforms" for armor. The project is part of the Army's plan to reduce and reduce the cost of next-generation armor solutions, and hybrid prefabs can help in both aspects. The company's custom looms are computer-controlled up to 7,000 individual warp fibers at a time, facilitating the rapid, cost-effective production of hybrid preforms. In turn, the independent control of the fibers allows designers to freely mix and match fiber types to achieve the required ballistic performance at a lower cost.
For example, TEAM produces 1 inch/25.4 mm thick preforms composed of 10% carbon fiber and 90% S glass by volume. Compared with preforms of the same thickness made entirely of S glass, this design is optimized Cost and weight (see illustration, page 38). In addition, Tomich said the company is looking for ways to replace S glass with E glass in the design of hybrid preforms. The cost of E glass is one-tenth of that of S glass, and its strength and rigidity are low. However, this shortcoming can be made up for by nominally using high-density polyethylene, aramid or carbon fiber in the design.
Another 3-D fabric weaver, 3TEX Inc. (Cary, North Carolina), produces 3-D woven and woven preforms on custom looms that are manufactured entirely in-house. The company's bulletproof material series, branded as 3WEAVE, is made with reduced crimping (bending at the warp/weft intersection), which can damage the fiber and reduce the performance of the fabric. The thickness of the fabric sold ranges from 0.02 inches to 3 inches (0.51 mm to 76.2 mm). 3TEX product manager Don Wigent said that the company has been selling preforms with a thickness of 1 inch/25.4 mm or larger in large quantities. The preforms can be stacked to build extra-thick armor sections, ranging from 6 inches to 12 inches (152.4 mm to 304.8 mm).
Currently, the company's prefabs are used in various heavy armor applications, such as armored doors, floors, and panels for military vehicles and naval vessels. 3TEX also produces thinner preforms for body armor insert panels. Wigent reports that the company also has an ongoing plan with the US Department of Homeland Security to develop and manufacture composite panel systems for ballistic protection of interior and exterior walls of government buildings.
3TEX’s custom looms can use aramid fiber (Kevlar from DuPont Conservation Technology in Richmond, Virginia), glass fiber (E-glass from PPG Industries and S-2 Glass from AGY), high molecular weight polyethylene ( HMWPE) manufactures hybrid preforms with fibers from DSM Dyneema and carbon fibers from Hexcel and Toray Carbon Fibers America (Flower Mound, Texas). Wigent said the resulting preform has "up to 20 discrete layers sewn together from top to bottom with z-directed fibers." Given a specific level of ballistic performance, cost and weight optimization drive the design of the hybrid preform. In addition, the company's computer-controlled loom enables designers to quickly change the fabric structure to meet the requirements of different applications. Wigent insists that the technology can be used to customize the thickness and stiffness of discrete areas of preforms and create armor with gradients in the width and length of the structure.
Tomich of TEAM Inc. believes that the application of 3-D woven hybrid preforms may grow. "From a commercialization point of view, I think the most interesting thing is that the blending achieved through 3-D weaving may allow us to drastically reduce costs while maintaining the same performance and weight as other designs," he said. For armor designs that include tile finishes and composite backings, Tomich claims that in terms of performance and weight, 2-D laminate backings are currently used.
The U.S. Army is conducting final testing of its next-generation soldier helmet, called the Enhanced Combat Helmet (ECH). The helmet is expected to be released this year and includes a carbon fiber inner cage, overmolded by a preform made of Spectra ultra-high molecular weight polyethylene (UHMWPE), which is made by Honeywell Advanced Fibers and Composites ( Colonial Heights, Virginia). According to reports, the design of ECH is 10% more bulletproof than the previous generation helmet Advanced Combat Helmet (ACH) it will replace with a lighter weight. The helmet is made of DuPont Kevlar and phenolic resin ( See "Editor's Choice"," under "Learn More" on the right).
Although ECH has improved, designers and suppliers are already looking for ways to make better helmets and have achieved some tangible results. Once again, the new hybrid structure shows the greatest potential for achieving the two often contradictory goals of improving ballistic performance and reducing weight and cost.
Researchers from DuPont Protection Technologies conducted Taguchi-style experimental design tests to evaluate the economic and bulletproof benefits of different combinations of fibers, resins, fabric densities, and processing conditions for helmet design. The survey covered a wide range of helmet types with different designs to meet the standards used in military and non-military applications.
Therefore, DuPont introduced a new design for multi-purpose (military and non-military) helmets at the American Army Association (AUSA) trade show in 2010. The helmet includes a ballistic core (composed of the company's new aramid fiber grade Kevlar XPH 170), sandwiched between the inner and outer shell, with polyvinyl butyral (PVB) supplied by Lewcott (Millbury, Massachusetts) Phenolic Resin. DuPont senior research assistant Jeffrey Hanks said that through trial commercial prototypes with a number of helmet manufacturers, the helmet is about 20% lighter than ACH. Hanks said that the commercialization of lightweight, low-cost, mixed-material helmets depends on the development of new resins. "When designing a helmet made of mixed materials, you often find yourself having to solve compatibility issues related to the resins and processing conditions required for different materials," Hanks said. He reported that DuPont is conducting internal research and working with suppliers to find and produce resins compatible with various fibers and fabrics.
Dana Granville, a composites engineer at the U.S. Army Research Laboratory (Adelphi, Maryland), said that the use of modeling and simulation tools has been improved, such as finite element analysis (FEA), which can simulate micro-scale resin/fiber interactions until The large laminate scale may allow designers to create a shopping list of performance goals and then build armor and multifunctional structures for specialized applications of the US Department of Defense (DoD). "Computational materials science will greatly help us understand how to make composite materials before making expensive investments in tools and process equipment," Granville said.
Armor Designs Inc. (Phoenix, Arizona) is using an advanced computational manufacturing technology called Volume Controlled Manufacturing (VCM) to achieve this goal. VCM is a proprietary technology based on the reverse FEA method, which combines design and manufacturing processes to optimize advanced composite structures for specific performance requirements. The engineer enters the specific ballistic performance level, weight or density limit, size and other parameters. The VCM software specifies a design and automatically generates the material structure, processing conditions and CNC processing path of the laminate.
Phil Clement, CEO of Armor Designs, stated that the company uses VCM to manufacture the lightest National Institute of Justice (NIJ) level 4 body armor panels on the market. The board is not used with soft armor vests, including ceramic finishes and UHMWPE fabric backing. The company also produces body armor panels that meet the NIJ level 3 and 3A protection standards. Clement reports that customers of these license plates include European military departments and police agencies in the United States and other parts of the world.
AGY recently expanded its composite armor product portfolio with two new S glass fibers (trademarks Featherlight and Quicksilver). Manufacturers are using this new fiber in an ongoing reinforced armor project aimed at enhancing the ballistic protection of improvised explosive devices (IED) and explosively formed projectiles (EFP). These fibers will also help reduce the weight of military vehicles in service in Iraq and Afghanistan. According to reports, Featherlight glass fiber provides 5% to 10% protection than standard AGY S-2 glass composite armor, making it possible for armor designers to create armor with the same ballistic performance and lighter weight. Quicksilver S-1 fiberglass is designed to be a stronger and stiffer alternative to E-glass fiber in armor applications, where weight reduction is not important. Both fibers are suitable for a variety of manufacturing processes, including compression molding lamination, thermoforming, and 3-D weaving.
NP Aerospace Ltd. (Coventry, UK) is using AGY's S-2 glass in the components of the company's advanced composites demonstration vehicle. The shell of the demonstration pod is designed with the AGY HJ1 armor system, which is also an important part of the CAMAC lightweight composite armor system registered by NP Aerospace. The CAMAC system has been used as the core ballistic and explosion protection system for the full range of vehicles provided by NP Aerospace.
In the past two years, DSM Dyneema's plant in Greenville, North Carolina has substantially expanded its production capacity. This is a direct result of the increased demand for Dyneema UHMWPE for bulletproof products purchased by the U.S. military and law enforcement agencies. result. The company's unidirectional rigid ballistic composite material HB26 recently achieved commercial application for the first time in a helmet used by the Denver Police Department (Denver, Colorado). These helmets are manufactured by Protech Armored Products (Pittsfield, Massachusetts) and are reported to be 15% lighter than comparable aramid fiber reinforced helmets.
The security threats to people, aircraft, ships, vehicles and buildings are unlikely to decrease in the future. In addition, more than 10 years of field tests on the battlefields in Iraq and Afghanistan have highlighted the urgent need for lightweight armor, especially in terms of vehicle mobility and fuel efficiency. Although the conflict in Iraq has eased, the battlefield comparison of armor design will continue to promote armor development in the next few years. These circumstances should ensure that composite materials will continue to play a key role in the development of new bulletproof products.
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