Fig. 2 shows an example of the flotation results
for the PVC particles recovered from pine oil
bottles; the same plastic as used in contact angle
measurements. A poor flotation recovery (lo-15%
in 8 min flotation) of the PVC particles, which
were treated for 30 min with hot 2 wt% NaOH
solution before flotation, characterized the experiments
involving the PVC recovered from pine oil
bottles. In comparison, over 90% recovery was
obtained for a PVC/PET mixture with ordinary
PVC particles treated in an alkaline solution.