The 10 wt% and 15 wt% FT sheets were prepared likewise using
appropriate amount of natural rubber latex, 1.68 mL and 2.52 mL,
respectively. (The 5 wt% sheet means the sheet contains 5% by
weight of latex. When less than 5 wt% of latex was used the sheet
was too thin and not sufficiently strong enough to withstand the
vacuum suction resulting in a cracked sheet. On the other hand,
for higher than 15 wt% of latex, the sheet showed low activity as is
illustrated in Section 3.2.1.)