Page 54 - Kutnar, Andreja, et al., eds., 2015. Proceedings of the 1st COST Action FP1307 International Conference - Life Cycle Assessment, EPDs, and modified wood. University of Primorska Press, Koper.

surface
roughness
was
changed
with
the
coating
application.
For
both
methods
the
aging
of

the
treated
samples
showed
less
variation
in
surface
roughness
as
compared
with
the
control.

Figure
1:
Colour
changes
of
wood
of
Pinus
sp.
exposed
to
two
weathering
treatments.
Two
finishes

are
compared
with
control
specimens.

In
the
colorimetric
assay
it
is
observed
that
the
samples
showed
similar
behaviour
for
the
L
*
and

b
*
parameters
in
both
natural
and
accelerated
weathering
treatments
(Figure
2).
After
240
hours

of
exposure
in
the
climatic
chamber
the
photo
degradation
was
similar
to
the
180
days
of
natural

weathering.
Only
the
parameter
a*
showed
different
results.

Table
1:

Roughness
changes
of
wood
of
Pinus
sp.
exposed
to
natural
and
accelerated
aging.

Average
Roughness
Ra
(µm)

Weathering
in
the
natural
(days)
Climatic
chamber

(hours)

0
180
0
240

Finish
1
2.46
8.07
2.77
8.51

Finish
2
2.52
3.88
2.82
4.13

Control
wood
4.99
13.92
4.92
9.98

Figure
2:

Colour
changes
of
parameters
L*,
a*
and
b
of
Pinus
sp.
wood
with
different
finishes.

The
results
of
the
240
hours
accelerated
aging
test
showed
a
similar
photo
degradation
compared

to
natural
exposed
wood
(180
days).
This
study
revealed
that
accelerated
weathering
are

satisfactorily
similar
results
to
natural
weathering
in
southern
Brazil.

References

ASTM
G
154
(2000),
American
Society
for
Testing
and
Materials,
Standard
Practice
for
Operating

Fluorescent
Light
Apparatus
for
UV
Exposure
of
Non-­‐metallic
Materials.

Acknowledgement:

The
authors
would
like
to
thank
CNPq-­‐Brazil,
PhD
scholarship
DGE
(246018/2012-­‐7),
the
CNPQ/CAPES

(014/2012),
Federal
University
of
Pelotas,
and
University
of
the
Basque
Country
for
financially
supporting

this
work.

42