2.2.3. Formaldehyde and VOC emission
The formaldehyde emissions from the engineered floorings
bonded with each blend were determined with a desiccator in
accordance with the JIS method using a glass desiccator [18].
The VOC analyzer is a portable device to measure the four main
aromatic hydrocarbon gases: toluene, ethylbenzene, xylene and
styrene. To prepare the samples for the VOC analyzer, the engi-neeredfloorings bonded witheachblend were conditioned at 25
◦
C
and 50±5% in a thermo-hygrostat for 15 days and then cut into 4
pieces of dimensions 50mm×50mm and placed in a 3L polyester
plastic bag thatwas sealed with teflon tape, purged3 timeswithN2
gas, and then filled with N2gas by pulling up the plunger. For the
blank control, an empty bag with N2gas was prepared. The gases
for the VOC analyzer were collected from the 3L polyester plastic
bag in a gas tight (0.5cm
3
) manner after 4 days, placed into the
VOC analyzer and analyzed. This 4-day period was chosen accord-ing to the authors’ previous study for determining the optimum
method for VOC emission test by VOC analyzer