The preform production is of virtual importance for the manufacturing fiber-
reinforced composites. The distribution and orientation of the individual fibers in the
preform significantly affect the mechanical properties of the later composites. This
paper presents the techniques for preparing random (non-oriented) and unidirectional
(UD) preforms for coconut fiber-reinforced composites. The experimental results
confirm that the length and the state (wet or dry) of coconut fibers in the random (non-
oriented) preforms affects the mechanical properties of random coconut fiber-
reinforced composites. The effects of techniques of random preform preparation on
the mechanical properties of composites were investigated for various fiber volume
fraction. It was found that the preforms prepared from wet coconut fibers show higher
and more stable properties. On the other hand, the research also presents a technique
to prepare straight coconut fibers for UD preform production. Several parameters such
as composite processing method, experimental conditions of chemical treatment were
examined for UD preform based composites.