Potentiality of Abaca Fiber As Engineering Structural Materials

Abstract

Related to the importance of selectivity to natural fibers that can be used and qualify as one of the raw material composite engineering substitute for Fiber Reinforced Plastics (FRP) or Fiber Reinforced Metals (FRM), one plants that have the potential of fiber and volume growth is very abundant, namely abaca. This research aims to clarify scattering in tensile strength of an abaca single fiber through statistical approach and to search a way of suppression in the scatter with intention that abaca fibers can be used as a raw material for engineering structural components. Tensile test specimens were prepared from fiber samples from two different areas, East Aceh and North Aceh, Indonesia. Specimen gauge length is 25 mm, then as the holder of a fiber made of paper (20mm x 100mm), where the specimen size for fiber tensile test in accordance with JIS standard K-760. Diameter the specimen fibers obtained varied from 0.060 mm to 0.140 mm. The tensile strength of abaca fiber varies in the wide range from 100 MPa to 900 MPa. Coefficient of variation was calculated for East Aceh abaca fibre 0.32 and North Aceh abaca fibre 0.35. It was examined whether Weibull distribution or log-normal distribution could well express scatted experimental results. The results showed that both the distribution types could well express the experimental probabilty density, but log-normal distribution could be more rational for expression of biologial and chronological effects. To reduce scattering of tensile strength, pre-screening concept was proposed. Pre-screening test was proposed here for one of the methods and the effectiveness was examined using experimental results on tensile strength of virgin and surviving fibers after the pre-screening test. It was indicated that three-parameter log-normal distribution could well characterize the experimental results, and the threshold tensile strength in three-parameter log-normal distribution could be related to allowable stress for strength design.