Paridah Md. Tahir

AGRICULTURE
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INNOVATION
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LIFE
Paridah Md. Tahir
Institute of Tropical Forestry and Forest Products
(INTROP)
Universiti Putra Malaysia, 43400 UPM Serdang
Selangor MALAYSIA
Email: [email protected]
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AGRICULTURE
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INNOVATION
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LIFE
Research team
Adrian C.Y. Choo
Edi Suhaimi
Bakar
NorHafizah Wahab
Zaidon Ashaari
Institute of Tropical Forestry and Forest Products
Universiti Putra Malaysia
Loh Yueh Fong
Yeoh Beng Hoong
Fiber and Biocomposite Centre
Malaysian Timber Industry Board
Nor Yuziah Mohd Yunus
Malayan Adhesives and Chemicals Sdn. Bhd.
Universiti Teknologi Mara
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AGRICULTURE
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INNOVATION
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LIFE
Market Shifts in Europe, USA, Japan
Ø Consumer demand for
sustainable wood products
Ø 1990s: European and
American consumers started
demanding wood products
certified for sustainability.
Ø Much of this was started by
international environmental
organizations such as
Greenpeace and others.
Source: Forest Trends, 2014
AGRICULTURE
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LIFE
Comparison of hardwood and softwood major
products internationally traded
SW logs SW veneer 2%
1%
HW logs
0%
HW plywood
24%
HW veneer
3%
SW lumber
59%
HW flooring
1%
HW molding
3%
HW lumber
7%
Source: Forest Trends, 2014
AGRICULTURE
OPT
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INNOVATION
versus
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LIFE
WOOD
Meranti
logs
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AGRICULTURE
OPT
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INNOVATION
•
versus
LIFE
WOOD
Fibre
Cell wall
Parenchyma
Vascular bundle Woody cells in OPT
(75x)
Woody cells in
tropical hardwood
(175x)
AGRICULTURE
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INNOVATION
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LIFE
OPT STRUCTURE
Outer
Layer
INNER LAYER
OUTER LAYER
Inner
Layer
Vascular bundle
TOP
Parenchyma
MIDDLE
BOTTOM
m.c. ranged
from 60-100%
m.c >300%
OIL PALMTREE
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AGRICULTURE
OPT
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INNOVATION
versus
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LIFE
WOOD
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AGRICULTURE
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INNOVATION
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LIFE
CHALLENGES
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AGRICULTURE
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INNOVATION
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LIFE
ADDRESSING THE
CURRENT ISSUES:
IMPROVED
PROPERTIES
•High adhesive consumption
•Poor in quality compared to
normal plywood
•Require MLHW veneers on
faces
Resin
Treatment
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AGRICULTURE
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INNOVATION
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LIFE
RESIN TREATMENT
1.To enhance the veneer properties
– better surface smoothness, filling small cracks, reduce
resin uptake, easier handling
2. To reduce density variation within veneers
3. To impart strength to plywood
Any thermosetting resin can be used:
PF, UF, MUF
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AGRICULTURE
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INNOVATION
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Resin Treatment Process
1.
2.
3.
4.
5.
Segregate the OPT veneers into outer and
inner veneers
Dry the veneer to 6-8% MC
Treat the veneers with resin by either
soaking, pressure impregnating or using
roller coater
Pre-pressing (between 2 rollers) to squeeze
out the excessive resin. The pressure is set
at 30-40 kg/cm2. MC of treated veneers
should be between 40-60%
Drying of phenolic treated veneers at 60°C
for 2 hours or until reaching the final MC
between ~10-20%
Precuring
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AGRICULTURE
20%
30%
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INNOVATION
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LIFE
40%
30.0
Resin Uptake (%)
25.0
20.0
15.0
10.0
5.0
0.0
10-15%
30-40%
80-100%
Veneer Moisture Content (MC)
Effects of phenol formaldehyde
concentration (20, 30 and 40%) on
the percentage of resin uptake
tested at different veneer initial
moisture contents.
EffectS of PF resin molecular
weight and treatment method on
the percentage of resin uptake.
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AGRICULTURE
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INNOVATION
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LIFE
OPT PLYWOOD PRODUCTION
The resin-procured
veneers are assembled
and hot pressed
Parameters for producing High
grade 5-ply OPT plywood
MC veneers =10-20%
Temperature =140◦
C
Pressing time =25min (Stepwise)
(pressure 20 bar for first 5 min,
followed by 50 bar for next 1520 min)
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AGRICULTURE
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INNOVATION
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LIFE
Hot pressing time for plywood made from
phenolic prepreg OPT veneers
No. of
Ply
Veneer
Thickness
(mm)
Distance to
deepest
glueline
(mm)
Temperature
(⁰C)*
Time needed
per mm1
(min)
Basic
time1
(min)
Total Press
Time2
(min)
(a)
5
(b)
(c)
(d)
3-ply
5
115
1.3
3.25
9.75
140
0.8
2.0
6.0
5-ply
5
10
115
1.3
3.25
16.25
140
0.8
2.0
10.0
7-ply
5
15
115
1.3
3.25
22.75
140
0.8
2.0
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1
Given by the resin manufacturer for respective curing temperature.
2
Total press time, d = (a*b) + c
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AGRICULTURE
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LIFE
A Proposed
Manufacturing Process
for Plywood Made Using
Phenolic Prepreg Veneers
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Process
Manufacturing
process of OPT
plywood
Conventional
plywood
manufacturing
Modified plywood
manufacturing
OPS procurement
P
P
Bucking
P
P
Debarking
P
P
Peeling
P
P
Clipping
P
P
Stacking green veneers
P
X
Pre-pressing
X
P
Drying
P
P
Resin Treatment
X
P
Squeezing
X
P
ReDrying
X
P
Jointing (using hot-melt glue)
P
X
Adhesive spreading
P
X
Assembly
P
P
Cold pressing
P
X
Hot-pressing
P
P
Sizing / Trimming
P
P
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AGRICULTURE
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LIFE
Bending strength (MOR) of OPT
plywood – Conventional method
Stiffness (MOE) of 5-ply OPT
plywood – Conventional method
Mill
A
B
C
D
E
Mill
A
B
C
D
E
PARALLEL
22.2 (2.8)
19.8 (2.4)
17.7 (3.0)
25.3 (3.9)
23.9 (2.6)
PERPENDICULAR
27.3 (1.8)
19.0 (1.8)
23.7 (2.5)
22.4 (3.0)
20.8 (2.8)
PARALLEL
3103 (222)
3111 (199)
2724 (297)
3236 (326)
3392 (246)
Shear Bonding of OPT plywood –
Conventional method
Mill
A
B
C
D
E
Dry
0.38(0.2)
0.21(0.2)
0.35(0.1)
0.28(0.1)
0.71(0.4)
Cyclic Test
0.41
0.23
0.43
1.05
0.25
PERPENDICULAR
3316 (356)
2554 (288)
2542 (400)
2485 (247)
2234 (474)
Unit: MPa
Unit: MPa
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AGRICULTURE
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INNOVATION
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LIFE
Strength and bond integrity of 3-ply PF prepreg OPT
PANEL TYPE
Density
Modulus of
Modulus of
Dry Plywood
WBP Plywood
plywood
g/cm
Elasticity
Rupture
Shear
Shear
3
(MOE)
MPa
(MOR) MPa
MPa
MPa
1.48
1.05
Panel A*
0.65
DIPPING1
5,813
53.4
Panel B*
0.59
4,487
43.0
1.61
1.23
Panel C*
0.66
5,941
55.4
1.98
1.45
Panel D*
0.60
5,914
44.9
1.77
1.13
Panel E*
0.62
6,182
39.3
2.05
0.75
Panel F*
0.62
0.77
Panel G**
0.84
4,626
34.1
2.00
VACUUM IMPREGNATION2
6,537
55.0
-
Panel H**
0.98
5,835
48.2
-
0.46
Panel J**
0.88
5,581
41.7
-
0.36
Panel K*
0.50
ROLLER COATER3
5,569
57.5
1.3
0.7
Panel L*
0.52
4,604
63.5
1.0
0.6
Panel M*
0.49
5,290
58.3
1.3
0.4
0.54
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AGRICULTURE
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INNOVATION
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LIFE
In summary;
PROPERTY
USING CURRENT
PROCESS
MODIFIED
PROCESS DIPPING
MODIFIED
PROCESS IMPREGNATION
MODIFIED
PROCESS – ROLLER
COATER
MOR , MPa
17.7 – 25.3
34.1-55.3
41.7-55.0
57.5-63.5
MOE, MPa
2234 – 3392
4487– 6182
5581-6537
4604-5569
SHEAR, MPa
0.21 – 0.38 (D)
1.48 - 2.05 (D)
-
1.0-1.3 (D)
SHEAR, MPa
0.21 – 0.38
(Cyclic)
0.75-1.45
(WBP)
0.36-0.54
(WBP)
0.4-0.7
(WBD)
0.58
0.62
0.90
0.50
Average
Density, g/cm3
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AGRICULTURE
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Dimensional Stability of phenolic-treated plywood
Untreated OPS plywood> 10%
15-19%
20-24%
Untreated OPS plywood> 25%
25-30%
15-19%
25-30%
5.0
9.0
Water Absorption (%)
Thickness Swelling (%)
10.0
20-24%
8.0
7.0
6.0
4.0
3.0
2.0
1.0
0.0
5.0
50
60
70
Re-drying Temperature (°C)
Fig 1: Effects of phenolic-treated veneer moisture
content during hot pressing on thickness swelling of 3ply OPS plywood at different veneer re-drying
temperature
50
60
70
Re-drying Temperature (°C)
Fig 2: Effects of phenolic-treated veneer moisture
content during hot pressing on water absorption of 3ply OPS plywood at different veneer re-drying
temperature
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Resistance against Decay Fungi
Increased the durability of OPS plywood against
white rot fungi by 62% after 12 weeks exposure
and against termites by 44% (for outer veneers)
after 4 weeks exposure.
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Mean weight Loss
(%)
35
35.65
32.29
30
25
Outer
20
16.05
15
Inner
9.87
10
5
0
Fig 3: Formation of white rot fungi after 12-week
exposure for phenolic-treated and control
specimens taken from plywood made from
inner and outer OPS veneers
UntreatedControl
(Control)
Phenolic-treated
Treated
Fig 4: Mean weight loss (%) of OPS plywood after
being exposed to white rot fungi for 12 weeks
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Resistance against Termites
Day 1
Day 7
Untreated (Control)
Day 28 - control
Day 28 - Phenolic treated
Phenolic-treated
Mean weight loss (%) of OPS
plywood after being exposed to
termites for 4 weeks
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APPLICATION AS CONCRETE
FORMWORK
A
B
C
OPT plywood as concrete formwork
material
A Phenolic-treated OPS plywood;
B Mixed Light hardwood (MLHW) plywood;
C untreated (control) OPS plywood.
The phenolic-treated OPT
plywood can be used in a
tropical outdoor condition for
more than 3 months and
reuse for 5 cycles without any
obvious degradation.
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AGRICULTURE
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INNOVATION
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LIFE
Conclusions
Ø The method used in the study was able to produce high grade OPT
plywood suitable for concrete formwork application
Ø The new method was able to withstand fungi, termites and
dimensional stability significantly better than those of conventional
and, to some extent the commercial MLHW plywood.
Ø Based on a conservative estimation, the cost for producing the
“high-grade palm ply” is relatively higher (6%) for 100% panel
Ø Treated OPT can be used effectively and commercially acceptable
since it generates plywood of comparable performance with that of
MLHW.
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LIFE
WE WOULD LIKE TO THANK THE MINISTRY OF
PLANTATION INDUSTRY AND COMMODITY (MPIC)
AND THE MALAYSIAN TIMBER INDUSTRY BOARD
(MTIB) FOR FUNDING THE PROJECT.
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Testing Procedure BSEN Standard: EN 314-1:
Plywood-Bonding quality-Part 1: Test Method
5.1.1
Immersed for 24 hours in water at temperature 20±3ºC.
5.1.2
Immersed for 6 hours in boiling water followed by cooling water at
temperature 20±3ºC for at least 1 hour.
5.1.3
Immersed for 4 hours in boiling water, then dried in the ventilated drying
oven for 16 to 20 hours and continued Immersed for 4 hours in boiling
water followed by cooling water at temperature 20±3ºC for at least 1 hour.
5.1.4
Immersed for 72±1 hours in boiling water followed by cooling water at
temperature 20±3ºC for at least 1 hour.
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Testing Procedure JAS Standard : Bonding Quality – Type I And
Type II Shear Strength Test (Jas For Plywood : 2008 – Maff
Notification No. 1751)
Type I - Cyclic boiling test
The test pieces is immersed in boiling water for 4 hours and
dried at 60±3°C for 20 hours.
The test pieces are then immersed in boiling water for 4 hours,
and then immersed in water of room temperature to cool
down
Bonding strength test is conducted in wet condition. The
maximum load and wood failure is measured and the shear
strength and average wood failure ratio is calculated.
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