Performance of sustainable flax yarn reinforced polyester laminate : exploratory study

Abstract EN

Green composites become very considerable in the new investigations and research because of its potential in replacing polymers and metals in some industrial applications.

replacing polymer parts with green composite in vehicle’s interior parts is an important application.

in this study, physical and mechanical efficiencies of using long flax yarns-made of short discrete fibers were used to produce natural yarn reinforced polyester (NYRP) laminate.

single-layer (lamina), samples made of polyester matrix and reinforced with flax-yarn fabric, was investigated in this study.

in order to examine the manufacturing process effect, both hand layup and compression molding techniques-at different packing pressures-were used to produce different NYRP laminae.

tension and flexure testes were applied to measure the main mechanical properties of different produced NYRP laminae.

in addition, two main fiber’s orientation zero degree (00) and 45 degrees off axis (450) were considered during testing to investigate the fiber orientation’s effect.

microscopic images showed good fibers distribution and resin-fibers impregnation across hand layup and compressed NYRP laminae for many specimens, while some fiber’s impregnation / distribution defects were observed for other specimens in addition to few air bubbles in resin.

generally, stiffening of polyester is the main significant role of adding flax-yarn fabric to polyester reaching 3.3 folds under tension and 2.2 folds under flexure depending on the manufacturing process and fiber-loading directions.

however, early premature mode’s failure-due to the observed defects-lower bounded the strengthening, ductility and toughness gains of the NYRP laminates compared to pure polyester.

as the possible defects have sensitive effect during the assessment of single-layer laminate’s performance, further current study is considering multi-layer influence on the performance of NYRP composites.

the initial results of the later further investigation show significant enhancement in stiffness, strength, maximum strain and accordingly modulus of toughness of eight layers (0)8 NYRP laminate compared with the explored single-layer (0).