JEC COMPOSITES MAGAZINE - Issue #42 - July/August 2008 - 41

Thermoplastics wood was combined with polymers. This discovery led to advanced engineered wood systems. The researchers analysing the effects of Hurricane Andrew in South Florida expected to find that wind pressures had simply overcome wood’s ability to resist. Actually, they learnt that joints were also a problem. This is a critical area for construction that could be improved by using reinforced polymers. The ASC Laboratory initially developed material systems using fibreglass and thermosetting polymers. While they made the structures much stronger, they were also expensive and unfamiliar to the people building homes and commercial structures. This led to hybrid wood products and new techniques for assembling joints. traditional military tent frame. Requiring no tools, the MBPS can be used by as few as four soldiers to up-armour a 6 x 10 m tent in less than an hour. Centre for composites Research on engineered wood continued and soon prompted the Laboratory to set up the Advanced Engineered Wood Composites (AEWC) Centre. This laboratory helped formalize the research and development process and provided resources. A breakthrough of sorts came when the AEWC Centre was asked to help develop a modular ballistic protection system (MBPS) to protect military troops from blast and fragmentation threats in mobile tent camp environments. The Centre worked under contract and in partnership with the Natick Soldier Research, Development & Engineering Centre. The challenge was to balance threat protection capabilities, ease of deployment and cost. The system needed to be highly mobile while remaining quick and easy to assemble. It also needed to withstand a specific blast force and fragmentation threat, in addition to having a reasonable cost structure. As the system was intended for use in hot environments, the offgassing of materials containing styrene would have been a problem. That led the AEWC Centre to look into reinforced thermoplastics, such as the tapes from Polystrand, Inc. Soldiers can armor a 20’ x 32’ tent in less than 30 minutes A final generation of the MBPS was shown at Composites & Polycon 2007, the trade show and conference hosted by the American Composites Manufacturers Association. The MBPS won both the Best of Show and People’s Choice Awards for Composites Excellence (ACE). The MBPS was developed with military use in mind but the material concept can potentially be used in any situation where blast protection or energy absorption of wind forces is needed for temporary structures, i.e. in homeland Fig.4: Wood and reinforcedsecurity, police, prison and thermoplastic composite panels can provide both blast and storm private security applications. protection Testing shows great strength The MBPS tests demonstrated the high strength and resilience of the reinforced thermoplastic and wood composite system. Not only did the structures remain intact after blast testing, but video made it possible to carefully examine the panel performance during blast overpressure. Panels with reinforced thermoplastics were able to bend and recover while their wood counterparts came apart after a relatively small amount of pressure. Tests performed at the AEWC Centre showed that reinforced thermoplastic and wood composites absorbed energy two to six times better than unreinforced wood structures. In the bending mode, the composite panels were found to absorb six to seven times more Reinforced thermoplastic tapes made with glass fibers and resin Nowadays, the cost of such materials is reasonable and the manufacturing process is capable of large-scale, volume production. There is no inherent roadblock to adding any capacity whatsoever for the system. In collaboration with its partners, the Centre was able to develop wood and reinforcedthermoplastic composite panels that can be mounted inside a Blast testing showed reinforced thermoplastic and wood composites have great strength and ductility No42 July-August 2008 / JEC Composites Magazine 41

JEC COMPOSITES MAGAZINE - Issue #42 - July/August 2008

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #42 - July/August 2008