Physical and Mechanical Properties of Randu and Angsana Impregnated with Polystyrene
ISBN : 978-979-96348-6-3
PROCEEDINGS OF THE FIRST INTERNATIONAL SYMPOSIUM OF
INDONESIAN WOOD RESEARCH SOCIETY
“Contribution of Scientific Profession Society on the Development of
Wood Science and Technology in Indonesia”
2nd – 3rd November, 2009
IPB INTERNATIONAL CONVENTION CENTER
BOGOR, INDONESIA
Supported by
Directorate General of Higher Education
Ministry of National Education
Edited by
Wahyu Dwianto
Ari Kusumaningtyas
Cover Design by
Teguh Darmawan
Published by
Indonesia Wood Research Society
Scientific Committee
Editor-in-Chief
Dr. Wahyu Dwianto, M.Agr.
Editorial Boards
Bogor Agricultural University
Prof. Surjono Surjokusumo
Prof. Yusuf Sudo Hadi
Prof. Wasrin Syafii
Prof. Fauzi Febrianto
Prof. Imam Wahyudi
Dr. I Nyoman J. Wistara
Dr. I Wayan Darmawan
Indonesia Institute of Sciences
Dr. Subyakto
Dr. Sulaeman Yusuf
Dr. Myrtha Karina
Mulawarman University
Prof. Sipon Muladi
Dr. Rudianto Amirta
Gadah Mada University
Dr. Sri Nugroho Marsoem
Hasanuddin University
Prof. Musrizal Muin
Universiti Putra Malaysia
Dr. Edi Suhaemi Bakar
International Peer Reviewers
Japan Wood Research Society
Prof. Yuji Imamura
Prof. Toshiaki Umezawa
Prof. Kohei Komatsu
Research Institute for Sustainable Humanosphere
Kyoto University
Uji, Kyoto 611-0011, Japan
Korean Wood Research Society
Prof. Nam-Hun Kim
Insttute of Forest Science
Department of Wood Science and Engineering
College of Forest and Environmental Sciences
Kangwon National University
Chunchon 200-701, Korea
Published by
Indonesia Wood Research Society
Wood Quality Enhancement
Fixation of Agathis and Gmelina Densified Woods at Radial Direction and
Observation of their Anatomical Structure - Atmawi Darwis, Imam Wahyudi and
Wahyu Dwianto
71
Physical and Mechanical Properties of Randu and Angsana Impregnated with
Polystyrene - Rudi Hartono, Sucahyo, Yusuf Sudo Hadi and Jasni
79
Wood Constructions
Acacia mangium Shear Modulus Based on ASTM D198-05a (2008) and Modulus of
Elasticity Curve - Indah Sulistyawati, Naresworo Nugroho, Surjono Surjokusumo and
Yusuf Sudo Hadi
83
The Reliability of LVL-CFB Shearwall Structure Due to Pseudo Dynamic Cyclic Load Maryoko Hadi
90
Bamboo Connection Design (An advanced Research) - Gina Bachtiar, Naresworo
Nugroho and FM. Farida
96
Possibility of Javanese Traditional House Reconstruction Using Laminated Veneer
Lumber (LVL) - Yulianto P. Prihatmaji
100
Wood Composites
Biocomposites of Polypropylene or Polylactic Acid Reinforced with Sisal or Bamboo
Micro Fibers - Subyakto, Euis Hermiati, Dede Heri Yuli Yanto, Nanang Masruchin,
Fitria, Kurnia Wiji Prasetiyo and Ismadi
106
Static Bending Strength of Meranti Merah (Shorea spp) LVL Bonded by PVAc - Isna
Yuniar Wardhani
111
Termite Resistance of Oriented Strands Board (OSB) Made of Small Diameter Fast
Growing Species - Arif Nuryawan, Bud Diman Gea, Muh.Yusram Massijaya and
Yusuf Sudo Hadi
116
The Properties of Oil Palm Fronds Cement-Bonded Board - Dede Hermawan
121
Effects of Some Factors on Veneer Volume Recovery - Benoni Kewilaa
124
Wood Entomology and Preservation
Distribution and Identification of Subterranean Termites of Macrotermes gilvus
Hagen in Dungus Iwul Sanctuary, Bogor, Indonesia - Niken Subekti
139
Identification of Wood Destroying Beetles Attacking Log and Timber - Ira
Taskirawati, Astuti Arif and Ayu Astrianingsih R.
142
Physical and Mechanical Properties of Randu and Angsana
Impregnated with Polystyrene
Rudi Hartono1, Sucahyo2, Yusuf Sudo Hadi2 and Jasni3
1 Department
of Forest Product Technology, Faculty of Agriculture,
North Sumatera University, Jl. Tridharma Ujung No. 1 Kampus USU,
Medan, North Sumatera 20155, Indonesia
2 Department of Forest Product Technology, Faculty of Forestry
Bogor Agriculture University
3 Forest Product Research and Development Centre
Forestry Research and Development Agency (FORDA)
Ministry of Forestry
Abstract
The aim of this research was to know the physical and mechanical properties of Randu (Ceiba pentandra
Gaertn) and Angsana (Pterocarpus indicus) polystyrene. Clear specimens were used with dimension 2 x 2 x 30 cm
with MC 7 %. Replication of wood sample was three. Samples were divided into 3 treatments; there were control,
soaked and vacuum-pressured. Three of each species were soaked by styrene monomer liquid for 3 days. The others
were put in tank and given treatment by vacuum at 600 mm Hg for 30 minutes, then Pressured at 10 kg/cm 2 for 30
minutes. After that, woods were wrapped by aluminum foil and dried with temperature 60oC for 24 hours to make
polymerize, then conditioned in the room for 2 weeks.
The result showed that average of polymer loading by soaking on Randu wood and vacuum-pressure were
32.20% and 92.43%, respectively. While by soaked on Angsana wood and vacuum-pressure were 22.20% and
68.71%, respectively. There were increasing in density, stability of dimension, hardness, modulus of elasticity (MOE),
modulus of rupture (MOR) and compression parallel to grain.
Key words : Polystyrene, Randu, Angsana, physical and mechanical properties.
Introduction
Industrial Plantation Forest has being developed for additional supply of log in Indonesia, and fast growing
species were dominantly planted. . These species have a great contribution, not only improvement of damage forest
productivity, but also to balance of supply and demand for wood industry. The disadvantage of fast growing species
has inferior physical and mechanical properties and more susceptible attacked by biodeterioration than the ordinary
structural wood.
Many methods that can use to improve wood qualities. One method is modifying wood properties with
impregnation particular chemical agents into the wood, such as polystyrene. Some researchers mentioned that
polystyrene can improve the physical, mechanical properties and also the wood durability.
Lawniczak (1993) mentioned that polystyrene impregnated wood produced by a thermal polymerization
process has been used on an industrial scale in Poland. Lawniczak and Kozlowski (1993) stated that polystyrene
bamboo with 20 % weight gain increased MOR 60 % in dry condition and 300 % in wet condition, decreased two third
water adsorption, and more resistant to fungal attack. Furthermore Lawniczak (1995) studied another research, the
inner part of coconut wood was impregnated with polystyrene using heat as catalyst, and the products had equal
properties with outer part of coconut wood and more resistant to fungal attack.
Bakraji et.al (2000) mentioned that wood polymer composite with styrene that is gamma-radiation-induced
can increase polymer loading 18-54 % and the compression strength with compression strength factor (Cf) between
1.04 – 1.15 on poplar, cypress, white willow, swamp mahogany and walnut. Furthermore Baysal et.al (2006)
mentioned that styrene can weight gain 203.7 ± 18.1 %, increase anti swelling efficiency (ASE) 72.6 ± 7.4 % and
wood density from 0.52 to 0.94, decrease water absorption from 250.4 ± 15.3 % to 35.7 ± 3.5 %, and also increase
MOE and MOR properties.
Wood Quality Enhancement - The First International Symposium of IWRS
79
Impregnation of polystyrene is possible to improve wood of fast growing species, such as to Randu and
Angsana Wood. The purpose of this research was to know the physical and mechanical properties of the polystyrene
wood.
Methods
Wood Preparation
The wood species were used for physical and mechanical test were Randu (Ceiba pentandra Gaertn) and
Angsana (Pterocarpus indicus). The small clear specimens sized 2 cm x 2 cm x 30 cm were used for the test.
Samples were divided into three treatments; there were control, soaked and vacuum-pressure. Three of
each species were soaked by styrene monomer liquid for 3 days. The others were put in tank and given treatment by
vacuum at 600 mm Hg for 30 minutes, then Pressure at 10 kg/cm2 for 30 minutes. After that, woods were wrapped by
aluminum foil and dried with temperature 60oC for 24 hours to make polymerize, then conditioned in the room for 2
weeks.
Physical Properties Test
Some physical properties test were moisture content, density and polymer loading. The formula of physical
properties test were
a. Polymer loading
Polymer loading = {(BP–BK)/BK} x 100 %
BK: weight of control wood; and BP: weight of treatment wood
1.
Moisture Content = {(BA-BKT)/BKT}x 100%,
BA: weight prior to the test; and BKT: weight oven dry
2.
Density = BKU/VKU (g/cm3)
BKU: weight to the air dry condition; and VKu: volume to the air dry
Mechanical Properties Test
Some mechanical properties test were modulus of rupture (MOR) and modulus of elasticity (MOE), hardness
and compression parallel to grain. The formula of mechanical properties test :
1. Modulus of Rupture (MOR) = (3 PL)/(2 bh2) kg/cm2
2. Modulus of Elasticity (MOE) = (PL3)/(4 ybh3) kg/cm2
3. Compression parallel to grain = P/A kg/cm2
4. Hardness = P/A kg/cm2
Where
P = max load/force (kg),
L = span length,
b = wide (cm)
h = height (cm)
y = deflection (cm),
A = area (cm2),
Results and Discussions
Physical Properties Polystyrene Wood
After polymerization process with heat, the average of polymer loading of Randu woods could be described
as follows, soaking and vacuum-pressure were 32.20 % and 92.43 %, respectively. While average of polymer loading
of Angsana woods, soaking and vacuum-pressure were 22.20 % and 68.71 %, respectively.
The moisture content of wood polymer decreased with treatments, both on randu and angsana. The other
hand, density increased with treatments, as shown in Table 1.
Wood Quality Enhancement - The First International Symposium of IWRS
80
Table 1. Average of physical properties of Randu and Angsana.
Polymer Loading
Moisture Content
Variable
(%)
(%)
Density
(g/cm3)
Randu
Control
-
13,86
0,24
Soaking
31,20
12,59
0,31
Vacuum-pressure
92,43
11,72
0,45
Control
-
11,63
0,47
Soaking
22,20
10,20
0,61
Vacuum-pressure
68,71
9,90
0,81
Angsana
Impregnation of polystyrene into woods, such as lumen, vessel, void spaces inside cell walls, decreased
hydrophobic properties. Therefore, the moisture content in the wood decreased due to increasing polystyrene in wood.
Furthermore, impregnation of polystyrene caused increasing of density, both on randu and angsana woods.
Impregnated Polystyrene into Randu was higher than Angsana, because density of randu is lower (0.2
g/cm3) then Angsana (0.4 g/cm3). Generally wood with low density has big pore, thin cell walls, big lumen, and also low
extractive content. They could make more permeable (Pandit, 1996)
Mechanical Properties Polystyrene Wood
Average of mechanical properties of this research i.e. MOE, MOR, hardness, MOR, MOE and compression
parallel to grain shown in Table 2.
Table 2. Average of mechanical properties of Randu and Angsana
Compression parallel
Variable
to grain
MOR
MOE
Hardness
(kg/cm2)
(kg/cm2)
(kg/cm2)
(kg/cm2)
Control
124,69
225,48
16336,71
108,67
Soaking
128,42
227,37
16416,81
113,33
Vacuum-pressure
138,26
271,59
18825,22
133,33
Control
431,69
944,95
67865,66
331,33
Soaking
441,86
951,71
68217,67
341,00
Vacuum-pressure
444,81
969,29
69925,48
352,33
Randu
Angsana
Table 2 shown that vacuum-pressure treatment has the highest value for all parameter respond, after that
soaking treatment Vacuum-pressure treatment has the high value, because high pressure in tank can force
polystyrene enter into wood, then made bonding with wood structure. Therefore, wood strength will increase.
Conclusions
1.
2.
3.
From discussions above, it could be concluded that:
Wood with low density is easier to be entered polystyrene than high density.
Impregnation polystyrene could increase physical and mechanical properties.
Vacuum-pressure treatment force polystyrene enters to woods, those cause vacuum-pressure treatment is
better than soaking treatment.
Wood Quality Enhancement - The First International Symposium of IWRS
81
References
Bakraji, E.H., N. Salman, and H. Al-Kassiri. 2000. Gamma-radiation-induced wood–plastic composites from Syrian
tree species. Journal of Radiation Physics and Chemistry 61 (2001) 137–141
Baysal, E., M.K. Yalinkilic, M.Altinok, A. Sonmez, H. Peker and M. Colak (2006). Some physical, biological,
mechanical, and fire properties of wood polymer composite (WPC) pretreated with boric acid and borax
mixture. Journal Construction and Building Materials (article in Press)
Lawniczak, M. 1993. Method of production of the composite bamboo polystyrene elaborated in Poland. Presented at
International Bamboo Festival and First National Bamboo Convention, Bandung, Indonesia, 25-28 November
1993.
Lawniczak, M and R. Kozlowski. 1993. Chosen properties of composite bamboo polystyrene. Presented at
International Bamboo Festival and First National Bamboo Convention, Bandung, Indonesia, 25-28 November
1993.
Lawniczak, M. 1995. Effect of the density of Cocos nucifera wood on the quality of produced wood polystyrene
composite. Folia Forestalia Polonica, Seria B, Zeszyst 25, p. 29-41.
Pandit, I.K.N. 1996. Anatomi, Pertumbuhan dan Kualitas Kayu. Bidang Studi ilmu Pengetahuan Kehutanan, Fakultas
Pascasarjana IPB.
Wood Quality Enhancement - The First International Symposium of IWRS
82
PROCEEDINGS OF THE FIRST INTERNATIONAL SYMPOSIUM OF
INDONESIAN WOOD RESEARCH SOCIETY
“Contribution of Scientific Profession Society on the Development of
Wood Science and Technology in Indonesia”
2nd – 3rd November, 2009
IPB INTERNATIONAL CONVENTION CENTER
BOGOR, INDONESIA
Supported by
Directorate General of Higher Education
Ministry of National Education
Edited by
Wahyu Dwianto
Ari Kusumaningtyas
Cover Design by
Teguh Darmawan
Published by
Indonesia Wood Research Society
Scientific Committee
Editor-in-Chief
Dr. Wahyu Dwianto, M.Agr.
Editorial Boards
Bogor Agricultural University
Prof. Surjono Surjokusumo
Prof. Yusuf Sudo Hadi
Prof. Wasrin Syafii
Prof. Fauzi Febrianto
Prof. Imam Wahyudi
Dr. I Nyoman J. Wistara
Dr. I Wayan Darmawan
Indonesia Institute of Sciences
Dr. Subyakto
Dr. Sulaeman Yusuf
Dr. Myrtha Karina
Mulawarman University
Prof. Sipon Muladi
Dr. Rudianto Amirta
Gadah Mada University
Dr. Sri Nugroho Marsoem
Hasanuddin University
Prof. Musrizal Muin
Universiti Putra Malaysia
Dr. Edi Suhaemi Bakar
International Peer Reviewers
Japan Wood Research Society
Prof. Yuji Imamura
Prof. Toshiaki Umezawa
Prof. Kohei Komatsu
Research Institute for Sustainable Humanosphere
Kyoto University
Uji, Kyoto 611-0011, Japan
Korean Wood Research Society
Prof. Nam-Hun Kim
Insttute of Forest Science
Department of Wood Science and Engineering
College of Forest and Environmental Sciences
Kangwon National University
Chunchon 200-701, Korea
Published by
Indonesia Wood Research Society
Wood Quality Enhancement
Fixation of Agathis and Gmelina Densified Woods at Radial Direction and
Observation of their Anatomical Structure - Atmawi Darwis, Imam Wahyudi and
Wahyu Dwianto
71
Physical and Mechanical Properties of Randu and Angsana Impregnated with
Polystyrene - Rudi Hartono, Sucahyo, Yusuf Sudo Hadi and Jasni
79
Wood Constructions
Acacia mangium Shear Modulus Based on ASTM D198-05a (2008) and Modulus of
Elasticity Curve - Indah Sulistyawati, Naresworo Nugroho, Surjono Surjokusumo and
Yusuf Sudo Hadi
83
The Reliability of LVL-CFB Shearwall Structure Due to Pseudo Dynamic Cyclic Load Maryoko Hadi
90
Bamboo Connection Design (An advanced Research) - Gina Bachtiar, Naresworo
Nugroho and FM. Farida
96
Possibility of Javanese Traditional House Reconstruction Using Laminated Veneer
Lumber (LVL) - Yulianto P. Prihatmaji
100
Wood Composites
Biocomposites of Polypropylene or Polylactic Acid Reinforced with Sisal or Bamboo
Micro Fibers - Subyakto, Euis Hermiati, Dede Heri Yuli Yanto, Nanang Masruchin,
Fitria, Kurnia Wiji Prasetiyo and Ismadi
106
Static Bending Strength of Meranti Merah (Shorea spp) LVL Bonded by PVAc - Isna
Yuniar Wardhani
111
Termite Resistance of Oriented Strands Board (OSB) Made of Small Diameter Fast
Growing Species - Arif Nuryawan, Bud Diman Gea, Muh.Yusram Massijaya and
Yusuf Sudo Hadi
116
The Properties of Oil Palm Fronds Cement-Bonded Board - Dede Hermawan
121
Effects of Some Factors on Veneer Volume Recovery - Benoni Kewilaa
124
Wood Entomology and Preservation
Distribution and Identification of Subterranean Termites of Macrotermes gilvus
Hagen in Dungus Iwul Sanctuary, Bogor, Indonesia - Niken Subekti
139
Identification of Wood Destroying Beetles Attacking Log and Timber - Ira
Taskirawati, Astuti Arif and Ayu Astrianingsih R.
142
Physical and Mechanical Properties of Randu and Angsana
Impregnated with Polystyrene
Rudi Hartono1, Sucahyo2, Yusuf Sudo Hadi2 and Jasni3
1 Department
of Forest Product Technology, Faculty of Agriculture,
North Sumatera University, Jl. Tridharma Ujung No. 1 Kampus USU,
Medan, North Sumatera 20155, Indonesia
2 Department of Forest Product Technology, Faculty of Forestry
Bogor Agriculture University
3 Forest Product Research and Development Centre
Forestry Research and Development Agency (FORDA)
Ministry of Forestry
Abstract
The aim of this research was to know the physical and mechanical properties of Randu (Ceiba pentandra
Gaertn) and Angsana (Pterocarpus indicus) polystyrene. Clear specimens were used with dimension 2 x 2 x 30 cm
with MC 7 %. Replication of wood sample was three. Samples were divided into 3 treatments; there were control,
soaked and vacuum-pressured. Three of each species were soaked by styrene monomer liquid for 3 days. The others
were put in tank and given treatment by vacuum at 600 mm Hg for 30 minutes, then Pressured at 10 kg/cm 2 for 30
minutes. After that, woods were wrapped by aluminum foil and dried with temperature 60oC for 24 hours to make
polymerize, then conditioned in the room for 2 weeks.
The result showed that average of polymer loading by soaking on Randu wood and vacuum-pressure were
32.20% and 92.43%, respectively. While by soaked on Angsana wood and vacuum-pressure were 22.20% and
68.71%, respectively. There were increasing in density, stability of dimension, hardness, modulus of elasticity (MOE),
modulus of rupture (MOR) and compression parallel to grain.
Key words : Polystyrene, Randu, Angsana, physical and mechanical properties.
Introduction
Industrial Plantation Forest has being developed for additional supply of log in Indonesia, and fast growing
species were dominantly planted. . These species have a great contribution, not only improvement of damage forest
productivity, but also to balance of supply and demand for wood industry. The disadvantage of fast growing species
has inferior physical and mechanical properties and more susceptible attacked by biodeterioration than the ordinary
structural wood.
Many methods that can use to improve wood qualities. One method is modifying wood properties with
impregnation particular chemical agents into the wood, such as polystyrene. Some researchers mentioned that
polystyrene can improve the physical, mechanical properties and also the wood durability.
Lawniczak (1993) mentioned that polystyrene impregnated wood produced by a thermal polymerization
process has been used on an industrial scale in Poland. Lawniczak and Kozlowski (1993) stated that polystyrene
bamboo with 20 % weight gain increased MOR 60 % in dry condition and 300 % in wet condition, decreased two third
water adsorption, and more resistant to fungal attack. Furthermore Lawniczak (1995) studied another research, the
inner part of coconut wood was impregnated with polystyrene using heat as catalyst, and the products had equal
properties with outer part of coconut wood and more resistant to fungal attack.
Bakraji et.al (2000) mentioned that wood polymer composite with styrene that is gamma-radiation-induced
can increase polymer loading 18-54 % and the compression strength with compression strength factor (Cf) between
1.04 – 1.15 on poplar, cypress, white willow, swamp mahogany and walnut. Furthermore Baysal et.al (2006)
mentioned that styrene can weight gain 203.7 ± 18.1 %, increase anti swelling efficiency (ASE) 72.6 ± 7.4 % and
wood density from 0.52 to 0.94, decrease water absorption from 250.4 ± 15.3 % to 35.7 ± 3.5 %, and also increase
MOE and MOR properties.
Wood Quality Enhancement - The First International Symposium of IWRS
79
Impregnation of polystyrene is possible to improve wood of fast growing species, such as to Randu and
Angsana Wood. The purpose of this research was to know the physical and mechanical properties of the polystyrene
wood.
Methods
Wood Preparation
The wood species were used for physical and mechanical test were Randu (Ceiba pentandra Gaertn) and
Angsana (Pterocarpus indicus). The small clear specimens sized 2 cm x 2 cm x 30 cm were used for the test.
Samples were divided into three treatments; there were control, soaked and vacuum-pressure. Three of
each species were soaked by styrene monomer liquid for 3 days. The others were put in tank and given treatment by
vacuum at 600 mm Hg for 30 minutes, then Pressure at 10 kg/cm2 for 30 minutes. After that, woods were wrapped by
aluminum foil and dried with temperature 60oC for 24 hours to make polymerize, then conditioned in the room for 2
weeks.
Physical Properties Test
Some physical properties test were moisture content, density and polymer loading. The formula of physical
properties test were
a. Polymer loading
Polymer loading = {(BP–BK)/BK} x 100 %
BK: weight of control wood; and BP: weight of treatment wood
1.
Moisture Content = {(BA-BKT)/BKT}x 100%,
BA: weight prior to the test; and BKT: weight oven dry
2.
Density = BKU/VKU (g/cm3)
BKU: weight to the air dry condition; and VKu: volume to the air dry
Mechanical Properties Test
Some mechanical properties test were modulus of rupture (MOR) and modulus of elasticity (MOE), hardness
and compression parallel to grain. The formula of mechanical properties test :
1. Modulus of Rupture (MOR) = (3 PL)/(2 bh2) kg/cm2
2. Modulus of Elasticity (MOE) = (PL3)/(4 ybh3) kg/cm2
3. Compression parallel to grain = P/A kg/cm2
4. Hardness = P/A kg/cm2
Where
P = max load/force (kg),
L = span length,
b = wide (cm)
h = height (cm)
y = deflection (cm),
A = area (cm2),
Results and Discussions
Physical Properties Polystyrene Wood
After polymerization process with heat, the average of polymer loading of Randu woods could be described
as follows, soaking and vacuum-pressure were 32.20 % and 92.43 %, respectively. While average of polymer loading
of Angsana woods, soaking and vacuum-pressure were 22.20 % and 68.71 %, respectively.
The moisture content of wood polymer decreased with treatments, both on randu and angsana. The other
hand, density increased with treatments, as shown in Table 1.
Wood Quality Enhancement - The First International Symposium of IWRS
80
Table 1. Average of physical properties of Randu and Angsana.
Polymer Loading
Moisture Content
Variable
(%)
(%)
Density
(g/cm3)
Randu
Control
-
13,86
0,24
Soaking
31,20
12,59
0,31
Vacuum-pressure
92,43
11,72
0,45
Control
-
11,63
0,47
Soaking
22,20
10,20
0,61
Vacuum-pressure
68,71
9,90
0,81
Angsana
Impregnation of polystyrene into woods, such as lumen, vessel, void spaces inside cell walls, decreased
hydrophobic properties. Therefore, the moisture content in the wood decreased due to increasing polystyrene in wood.
Furthermore, impregnation of polystyrene caused increasing of density, both on randu and angsana woods.
Impregnated Polystyrene into Randu was higher than Angsana, because density of randu is lower (0.2
g/cm3) then Angsana (0.4 g/cm3). Generally wood with low density has big pore, thin cell walls, big lumen, and also low
extractive content. They could make more permeable (Pandit, 1996)
Mechanical Properties Polystyrene Wood
Average of mechanical properties of this research i.e. MOE, MOR, hardness, MOR, MOE and compression
parallel to grain shown in Table 2.
Table 2. Average of mechanical properties of Randu and Angsana
Compression parallel
Variable
to grain
MOR
MOE
Hardness
(kg/cm2)
(kg/cm2)
(kg/cm2)
(kg/cm2)
Control
124,69
225,48
16336,71
108,67
Soaking
128,42
227,37
16416,81
113,33
Vacuum-pressure
138,26
271,59
18825,22
133,33
Control
431,69
944,95
67865,66
331,33
Soaking
441,86
951,71
68217,67
341,00
Vacuum-pressure
444,81
969,29
69925,48
352,33
Randu
Angsana
Table 2 shown that vacuum-pressure treatment has the highest value for all parameter respond, after that
soaking treatment Vacuum-pressure treatment has the high value, because high pressure in tank can force
polystyrene enter into wood, then made bonding with wood structure. Therefore, wood strength will increase.
Conclusions
1.
2.
3.
From discussions above, it could be concluded that:
Wood with low density is easier to be entered polystyrene than high density.
Impregnation polystyrene could increase physical and mechanical properties.
Vacuum-pressure treatment force polystyrene enters to woods, those cause vacuum-pressure treatment is
better than soaking treatment.
Wood Quality Enhancement - The First International Symposium of IWRS
81
References
Bakraji, E.H., N. Salman, and H. Al-Kassiri. 2000. Gamma-radiation-induced wood–plastic composites from Syrian
tree species. Journal of Radiation Physics and Chemistry 61 (2001) 137–141
Baysal, E., M.K. Yalinkilic, M.Altinok, A. Sonmez, H. Peker and M. Colak (2006). Some physical, biological,
mechanical, and fire properties of wood polymer composite (WPC) pretreated with boric acid and borax
mixture. Journal Construction and Building Materials (article in Press)
Lawniczak, M. 1993. Method of production of the composite bamboo polystyrene elaborated in Poland. Presented at
International Bamboo Festival and First National Bamboo Convention, Bandung, Indonesia, 25-28 November
1993.
Lawniczak, M and R. Kozlowski. 1993. Chosen properties of composite bamboo polystyrene. Presented at
International Bamboo Festival and First National Bamboo Convention, Bandung, Indonesia, 25-28 November
1993.
Lawniczak, M. 1995. Effect of the density of Cocos nucifera wood on the quality of produced wood polystyrene
composite. Folia Forestalia Polonica, Seria B, Zeszyst 25, p. 29-41.
Pandit, I.K.N. 1996. Anatomi, Pertumbuhan dan Kualitas Kayu. Bidang Studi ilmu Pengetahuan Kehutanan, Fakultas
Pascasarjana IPB.
Wood Quality Enhancement - The First International Symposium of IWRS
82