Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/20/2007
Publication Date: 11/26/2007
Citation: Alcock, M., Boyko, S., Foulk, J.A. 2007. Performance of flax mat to replace E-glass in panels produced using traditional thermoset resin infusion methods. Proceedings of the 6th Canadian-International Composites Conference, August 14-17, 2007, Winnipeg, Manitoba, Canada. p.1-12.
Interpretive Summary: The objective of this article is to assess flax fibers and their use in composites. The USDA Flax Fiber Pilot Plant exists for the utilization and testing of natural fibers. Composite panels were produced with approximately 17 to 20% flax fiber on a volume basis. Flax panels performed well in the acoustic, operating temperature, and chemical exposure tests. The water immersion tests demonstrated that flax did absorb more water than glass while the flammability test demonstrated a decreased resistance for flame spread. Poor composite results were found for tensile, flexural, and impact strength properties. Work continues to address a weak fiber to resin bond demonstrated from SEM imaging.
Technical Abstract: The purpose of the project was to assess the capability of non-optimized, commercially producible flax fiber to be fabricated into composites using a polyester thermoset resin and manufacturing methods common to industry. Flax composite panels were manufactured using a disposable bag resin infusion process which produced a fiber volume of 17 to 20%. The panels were tested, along with hand lay-up glass panels of similar fiber volume, to determine the following properties: tensile and flexural strength, tensile and flexural modulus, acoustic damping, chemical resistance, temperature effects, impact toughness, flammability and moisture absorption. The flax panels performed well in the acoustic, operating temperature and chemical exposure tests, demonstrating an improved ability to dampen noise on a per-weight basis, no visible degradation following exposure to hot and cold temperature cycles, as well as a resistance comparable to glass for three chemical agents: benzene, 10% ammonia solution and diesel fuel. The water immersion test demonstrated that the flax did absorb more water than the glass. However, there was no measurable swelling, and the difference in uptake was minor for the short duration test. The flammability test for the flax panels showed a decreased resistance to flame spread as compared to glass. The flax panels displayed inferior results for the tensile, flexural and impact strength properties, where performance was often less than that of neat resin. SEM images were taken of the tensile fracture surfaces and indicated that a weak fiber/matrix bond may have been responsible for the poor performance.