2.3. Volume fraction of fiber and Orientation of fibers
The composites were fabricated with 10%, 20%, 30%, 40% and 50% fiber and ground nut shell in the ratio of
1:1 as in volume fractions. The treated fibers were taken with required volume fractions laid into the mold of same
size 300 mm x 300 mm x 5 mm and care is taken to ensure that the fibers are pressed to form the size of the mold.
Then the top mold is closed and bolts are tightened. Then the mold is transferred to a compression press and placed
under pressure for about an hour such that it compresses and forms a thin laminate shape. Orientation is termed as
the alignment of fiber in the mould along with the resin mix. This also defines the properties of composites to be
fabricated. In this work, the discontinuous fiber mat has oriented in longitudinal axis and discontinuous single fiber
materials are in random orientation.
3. Fabrication process
Considering factors such as type of reinforcement and matrix materials, size, shape, quantity and cost, there are
many specialized processes available. The most commonly used process is the hand layup method. The set-up for
hand lay-up technique is shown in figure 3. The mould used for the composite is made of mild steel with stainless
sheet placed in the inner surface. A de-bonding agent (mansion wax) is applied before curing of resin on the
stainless sheet and the composite specimen is casted in the mould. The inner cavity dimension of the mould is
300mm x 300mm x 5mm. The hand lay-up method is a simple and the most widely used for FRP fabrication
process. This process comprises of applying resin on the either side of natural fibre knitted pad with usage simple
tools brush and roller. The fiber is arranged in discontinuous method in the steel plate and it is compressed by the
help of bolt. After 15 minutes the bolt are released and the mat form fiber is taken out carefully without any damage.
The fiber are arranged in such a way that there is no gap in-between the fiber, If there is any gap in the fiber
arrangement the resin is filled by the gap so as to manage the strength. Measure the weight of the fiber using
weighing scale. Then 1:5 of resin and hardener is added and mixed using the jar. Then the steel plate was cleaned
with acetone and wax is applied in the inner side of the plate finally resin is poured and steel plate was compressed
by tighten the bolt and nut. After 24 hrs the bolt was released and the laminates are taken carefully without any
damage. Specimens are cut for testing as per ASTM standards.