On the difficulties in manufacturing of luffa fibers reinforced bio- composites and variations in their dynamic properties

Defects in raw bio materials such as luffa plant effect the characteristics of the composites of these materials. These defects results in structural differences and large scattering mechanical properties such as density, damping and elasticity modulus. There are difficulties during the manufacturing of the composites from bio materials inherent to their nature. The major problems and restrictions encountered with the use of green luffa materials as reinforcement are studied in this study. First, the structural differences in the raw luffa plants are presented and the difficulties in their manufacturing are discussed. After that, the variations in measured modal parameters of luffa composites such as natural frequencies and loss factors and mechanical properties such as density and elasticity modulus are presented. Some solutions are provided to minimize the problems in manufacturing and identifying properties of luffa composites. The results show that the luffa composites can be produced with similar properties without any special selection of fibers to homogenize the batches of fibers for controlling the defects. However, a preliminary selection of fibers is required if the mechanical or dynamic properties of the luffa composites are desired to have small variations.