Evaluation of surface treatment and fabrication methods for jute fiber/epoxy laminar composites

Low fiber volume fraction and uncertain void content are continuing problems in natural fiber composites with continuous reinforcement. This study addresses these problems through the optimization of the Vacuum Infusion (VI) fabrication process for use with jute fabric reinforcement. The effects of reinforcement weave architecture, surface treatment, and fabrication method on the performance of jute fiber/epoxy laminated composites are subsequently characterized. Alkali and silane surface treatments were applied to enhance the fiber/matrix bonding. Wicking tests showed silane coupling produced jute yarn with zero water wicking and increased epoxy wicking. Extension of this treatment to reinforcing fabrics significantly reduced the moisture absorption of jute/epoxy composites. Constituent analysis showed traditional hand‐layup fabrication method results in composites with unacceptably high void content. For this reason, the VI method was employed and optimized. The addition of pre‐compaction and deadweight compaction steps resulted in composites having a near‐zero void content and a very good fiber volume fraction. Mechanical testing showed that the studied surface treatments improved tensile modulus in jute/epoxy composites, regardless of reinforcement architecture. Unidirectional preforms increased tensile strength and modulus due to reduced fabric crimp. POLYM. COMPOS., 35:310–317, 2014. © 2013 Society of Plastics Engineers