2.2. Samples preparation
Samples of PVC and WF-PVC were prepared according to the
compound formulation shown in Table 1. All of the components
were mixed in the two-roll mill for 3 min; the temperature was
controlled between 155
◦
C and 160
◦
C. Then they were shaped
into 4.0 ± 0.1 mm thick sheets by the hot-press molding machine
at 160
◦
C for 5 min. Finally, they were cut into models with
100 mm × 100 mm × 4 mm dimensions for CONE testing.
2.3. Cone calorimeter testing
FTT cone calorimeter was manufactured in the U.K. According
to ISO 5660-1 standard, all data were taken from the FTT cone
calorimeter at heat flux of 50 kW m
−2
. All samples were laid on
a horizontal sample holder and were protected from bending or
expanding by a stainless steel grid during the heating process.