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SUITABILITY OF Yushania alpina FOR ORIENTED PARTICLEBOARD
By
SEYOUM KELEMWORK HAILE
Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia, in
Fulfilment of the Requirement for the Degree of Doctor of Philosophy
2
February 2005
DEDICATION
Dedicated to my mother the late Yesharege Zerfu, my brother the late Ashagrea Deme
and my elder sisters Teseme and Negat
3
Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfilment of the
requirement for the Degree of Doctor of Philosophy
SUITABILITY OF Yushania alpina FOR ORIENTED PARTICLEBOARD
By
SEYOUM KELEMWORK HAILE
February 2005
Chairman: Associate Professor Paridah Md Tahir, PhD
Faculty: Forestry
Highland bamboo (Yushania alpina) and lowland bamboo (Oxytenanthera abyssinica)
are widespread in Ethiopian. Both covering approximately 1 million hectare of land. No
commercial importance has been found for these lignocellulose materials. It is thus the
main objective of this study is to determine the suitability of Yushania alpina for the
manufacture of oriented particleboard.
Yushania alpina from three major bamboo growing areas, namely Ambo, Bore and
Masha of three age groups of bamboo (one, two and three year-old) were used for this
study. The effects of bamboo growing sites and age variation on mensurational attributes
(i.e., culm basal diameter, culm wall thickness, culm volume and weight) and on basic
properties (i.e., moisture content, density, anatomical characteristics, buffering capacity
and wettability of bamboo) were statistically analyzed using completely randomized
design. The analysis indicated that mensurational attributes and basic properties of vary
with respect to growing sites, ages and culm height.
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Homogenous, three-layered oriented from fine particle sizes, three-layer oriented from
coarse particle sizes and three-layered oriented conventional (a mixture of fine and
coarse particles) bamboo particleboards were manufactured using 10% urea-
formaldehyde resin to evaluate the effects of particleboard processing parameters such as
board density, particle size, particle orientation and particle layering on mechanical
properties and dimensional stability. The completely randomized design with factorial
experiments was used in the analysis.
The results show that the mechanical properties and dimensional stability of homogenous
boards made from three-year old bamboo varied among the growing sites. Age of
bamboo did not show significant effects on strength and stiffness properties of
homogenous bamboo particleboards. It was also found that the internal bond strength of
bamboo particleboards decreased as the bamboo gets older whilst thickness swelling
increased.
The modulus of rupture (MOR) and modulus of elasticity (MOE) of three-layered
oriented bamboo particleboards produced from fine particle sizes and three-layered
oriented bamboo particleboards produced from coarse particles were significantly
affected by particle alignment and sizes. Both types of particleboards made from fine and
coarse particle sizes and parallelly aligned to the longitudinal axis of the boards had
superior strength (about 15%) compared to random oriented boards. Similar
comparisons of the MOE between oriented and random boards showed that MOE of
parallelly aligned boards to the longitudinal axis of the boards was higher by 28% and
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37%, respectively for both fine and coarse particle size oriented boards than those of
random boards. The internal bond strength, thickness swelling and water absorption of
oriented bamboo particleboards showed insignificant variation with particle alignment.
However, boards made from fine particle sizes gave 35% higher IB strength and 12%
dimensionally stable oriented boards than those made from coarse particle. The screw
withdrawal resistances of oriented bamboo particleboards were affected by particle
alignment and particle size. Boards made from coarse particles that were randomly
oriented particles had superior screw withdrawal resistance than that made from fine
particles.
The properties of three-layered conventional oriented bamboo particleboards were
affected by the density profile of the boards. As fine particles at face layer was increased
from 20% to 30% (based on the weight of the board) the MOR and MOE of the boards
increased from 27 MPa to 41 MPa and 4.9 GPa to 6.1 GPa, respectively. The thickness
swelling (TS) decreased from 7.5 to 5.8 % and the internal bond (IB) strength increased
from 0.60 MPa to 0.69 MPa. The presence of high amount of fine particle at the face
layers and high internal bond strength increased significantly screw withdrawal
resistance.
In general, vertical density profile has significant impact on strength and stiffness
properties of three-layered boards. Three-layered boards that have steeper density
gradient (higher average face layer density and low core density) have high strength and
stiffness properties than three-layered boards which have relatively more uniform density
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profile. Regression equations of three-layered boards relating the proportion of fine
particles on the face layer to coarse particles in the core layer may be used to predict the
MOR, MOE, IB strength and TS of three-layered particleboards produced in this study.
Generally, the strength and dimensional stability of particleboards manufactured from
Yushania alpina bamboo met the ISO standards ISO/DIS 16978, ISO/DIS 16984 and
ISO/DIS 16983 for high performance general purpose particleboards.
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Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai
memenuhi keperluan untuk ijazah Doktor Falsafah
KESESESUAIAN PAPAN SERPAI BERORIENTASI DARI SEPSIS BULUH
Yushania alpina
Oleh
SEYOUM KELEMWORK HAILE
Februari 2005
Pengerusi: Profesor Madya Paridah Md Tahir, PhD
Fakulti: Perhutanan
Buluh tanah tinggi (Yushania alpina) dan buluh tanah rendah (Oxytenanthera) tersebar
luas di Ethiopia. Kedua-dua spesis ini merangkumi kawasan vegetasi yang luas yang
mana lebih dari 1 juta hektar. Walau bagaimanapun, tidak ada kepentingan komersil
didapati pada bahan lignoselulosa ini. Oleh itu, objektif kajian ini adalah untuk
menentukan kesesuaian buluh ini untuk pembuatan papan serpai berorientasi.
Batang Yushania alpina daripada tiga kawasan utama pertumbuhan buluh seperti Ambo,
Bore dan Masha dan batang daripada tiga kumpulan umur (1, 2 dan 3 tahun) digunakan
dalam kajian ini. Kesan daripada kawasan pertumbuhan buluh dan perbezaan umur
terhadap sifat pengukuran (contohnya, diameter pangkal batang, ketebalan dinding
batang, isipadu batang dan berat) dan sifat asas (contohnya, kandungan lembapan (MC),
ketumpatan, sifat-sifat anatomi, kapasiti penahan dan kebasahan buluh) dianalisis
menggunakan rekabentuk rawak lengkap. Analisis menunjukkan bahawa sifat
pengukuran dan sifat asas Y. Alpina berbeza pada kawasan pertumbuhan, umur dan
ketinggian batang.
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Papan serpai buluh sama jenis, tiga lapis berorientasi daripada patikel bersaiz halus, tiga
lapis berorientasi daripada partikel bersaiz kasar dan tiga lapis berorientasi biasa
(campuran partikel bersaiz halus dan kasar) dibuat untuk menilai kesan parameter
pembuatan papan serpai seperti ketumpatan panel, saiz partikel, orientasi partikel dan
lapisan partikel terhadap sifat mekanikal dan kestabilan dimensi. Rekabentuk rawak
lengkap dengan eksperimen faktorial digunakan dalam analisis ini.
Keputusan menunjukkan bahawa sifat mekanikal dan kestabilan dimensi panel sama jenis
diperbuat daripada buluh berumur tiga tahun berbeza dengan kawasan pertumbuhan.
Umur buluh tidak mempunyai perbezaan bererti pada sifat kekuatan dan kekakuan papan
serpai buluh sama jenis diperbuat daripada kumpulan umur yang berbeza. Kekuatan
dalaman (IB) papan serpai buluh juga didapati menurun apabila buluh semakin tua
manakala pengembangan ketebalan (TS) meningkat.
Modulus Kehancuran (MOR) dan Modulus Kekenyalan (MOE) papan serpai buluh tiga
lapis berorientasi daripada partikel bersaiz halus dan papan serpai buluh tiga lapis
berorientasi mempunyai perbezaan bererti pada susunan dan saiz partikel. Papan serpai
buluh tiga lapis berorientasi diperbuat daripada partikel bersaiz kasar dan halus serta
disusun selari dengan pada paksi membujur panel mempunyai nilai kekuatan lebih
kurang 15% berbanding dengan panel yang mempunyai partikel yang disusun secara
rawak. Perbezaan yang sama didapati pada modulus kekenyalan (MOE) antara panel
berorientasi dan rawak menunjukkan bahawa kekakuan panel yang disusun selari pada
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paksi membujur panel masing-masing meningkat lebih kurang 28% dan 37% untuk
partikel bersaiz halus dan kasar panel berorientasi berbanding panel rawak. Kekuatan
dalaman (IB), pengembangan ketebalan (TS) dan penyerapan air (WA) papan serpai
buluh berorientasi menunjukkan tidak ada perbezaan bererti dengan susunan partikel.
Namun, panel yang dibuat daripada saiz partikel halus memberikan kekuatan dalaman
(IB) 35% lebih tinggi dan 12% lebih tinggi untuk kestabilan dimensi panel orientasi
daripada partikel bersaiz kasar. Panel yang diperbuat daripada partikel kasar yang mana
disusun secara rawak mempunyai ketahanan pengeluaran skru yang lebih tinggi
berbanding partikel halus.
Sifat papan serpai buluh tiga lapis berorientasi biasa adalah dipengaruhi oleh profil
ketumpatan panel. Apabila partikel halus pada permukaan lapisan meningkat daripada
20% kepada 60% (berdasarkan pada berat panel), modulus kehancuran (MOR) dan
modulus kekenyalan (MOE) panel masing-masing meningkat daripada 27 MPa kepada
41 MPa dan 4864 MPa kepada 6114 MPa. Pengembangan ketebalan (TS) menurun
daripada 7.5 kepada 5.8% dan kekuatan dalaman (IB) meningkat daripada 0.600 MPa
kepada 0.685 MPa. Kehadiran lebih banyak partikel halus pada lapisan permukaan dan
kekuatan dalaman (IB) yang tinggi juga mempunyai kesan yang bererti pada ketahanan
pengeluaran skru.
Secara amnya, profil ketumpatan tegak mempunyai perbezaan bererti pada sifat kekuatan
dan kekakuan panel tiga lapis. Panel tiga lapis mempunyai kecerunan ketumpatan yang
tinggi (purata ketumpatan permukaan lapisan tinggi dan ketumpatan tengah rendah)
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mempunyai sifat kekuatan dan kekakuan yang tinggi berbanding panel tiga lapis yang
mana mempunyai profil ketumpatan yang seragam. Persamaan regresi panel tiga lapis
mungkin digunakan untuk meramal modulus kehancuran (MOR), modulus kekenyalan
(MOE), kekuatan dalaman (IB) dan pengembangan ketebalan (TS) papan serpai tiga lapis
mengandungi partikel halus dalam lapisan permukaan daripada 20% kepada 40%.
Amnya, kekuatan dan kestabilan dimensi papan serpai diperbuat daripada buluh Yushania
alpina mencapai piawaian ISO/DIS 16978, ISO/DIS 16984 dan ISO/DIS 16983 untuk
pelaksanaan papan serpai untuk tujuan am.
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ACKNOWLEDGEMENTS
First and foremost I would like to express my sincere gratitude and appreciation to my
supervisory committee chairman Associate Professor Dr. Paridah Md Tahir for her
indispensable guidance and supervision. Her insight, constant support, encouragements,
and advice throughout the research work were invaluable. Special thanks is extended to
my co-supervisor Dr. Wong Ee Ding helping me to sort through my numerous doubts,
questions, and her constructive comments throughout my research work and during the
preparation of this thesis. Many thanks to Associate Professor Dr. Zaidon Ashari for all
his assistance at several stages of my research work and his encouragements and advice.
My sincere thanks extends to my co-supervisor Dr.Rahim Sudin from Forest Research
Institute Malaysia (FRIM) allowing me to use board processing workshop and testing
facilities in his laboratory besides his encouragement and advices in my research work. I
also wish to express my appreciation to all his staff members. The author expresses
sincere thanks to graduate students and staff of forest production department in UPM,
Mr.Harmaen, Puan Halimah, Stephanie and Hafizah. I also want to acknowledge all
Ethiopian graduate students in UPM, who helped me immensely through moral support.
Special thanks are offered to Dr. Mekasha, Mandefro, and Abayneh who took time from
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their own research to assist me in my works. I would also like to express my gratitude to
Ethiopian agricultural research organization (EARO) for sponsoring this study.
Appreciation and thanks extend to Dr. Sissay Feleke and Dr.Kassahun Embaye for
valuable discussions and suggestions given at the beginning of this study. My sincere
thanks extend to my colleagues Ayshesim Tebeje and Kinfe Tesfaye for their assistance
in harvesting and drying, of bamboo culms in Ethiopia. Most important, I would like to
thank my elder sisters Amelework, Teseme and, Negat, and many other friends and
relatives for their continuous support and encouragement.
Last but not least I would like to express a very special appreciation to my wife Azeb
Legesse, and children Habeake, Arseima and Abeselom for their countless sacrifices to
be left away, their relentless love, patience, and understanding during my stay in
Malaysia.
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I certify that an Examination Committee met on February 18 2005 to conduct the final
examination of Seyoum Kelemwork Haile on his Doctor of Philosophy thesis entitled
“Suitability of Ethiopian highland Bamboo for Oriented particleboard ’’ in accordance
with Universiti Pertanian Malysia (Higher Degree) Act 1980 and Universiti Pertanian
Malysia (Higher Degree) regulation 1981. The committee recommended the candidate to
be awarded the relevant degree. Members of the examination Committee are as follows:
Associate Professor Mohd. Zin bin Jusoh Faculty of Forestry
Universiti Putra Malaysia
(Chairman)
Fauzi Febrianto PhD
Faculty of Forestry
Universiti Putra Malaysia
(Internal examiner)
Associate Professor. Mohd.Saleh Jaafar PhD
Head of Department
Civil Engineering
Faculty of Engineering
Universiti Putra Malaysia
(Internal examiner)
Professor. Shuichi Kawai PhD Faculty of Agriculture
Institute for sustainable Humanoshere
Kyoto University
Kyoto Japan
(External examiner)
GULAM RUSUL RAHMAT ALI,PhD
Professor /Deputy Dean
School of Graduate Studies
Universiti Putra Malysia
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Date:
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This thesis is submitted to the Senate of Universiti Putra Malaysia and has been accepted
as fulfilment of the requirement for the degree of Doctor of Philosophy.
The Members of Supervisory Committee are as follows:
Associate Professor Paridah Md Tahir, PhD
Faculty of Forestry
Universiti Putra Malaysia
(Chairman)
Wong Ee Ding , PhD
Faculty of Forestry
Universiti Putra Malaysia
(Member)
Rahim Sudin, PhD
Forest Research Institute Malaysia (FRIM)
Kepong, Kuala Lumpur
(Member)
AINI IDERIS, PhD Professor/Dean
School of Graduate Studies
Universiti Putra Malysia
Date:
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DECLARATION
I hereby declare that the thesis is based on my original work except for quotations and
citations which have been duly acknowledged. I also declare that it has not been
previously or currently submitted for any other degree at UPM or other institutions.
SEYOUM KELEMWORK HAILE
Date:
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TABLE OF CONTENT
PAGE
DEDICATION 2
ABSTRACT 3
ABSTRAK 7
ACKNOWLEDGEMENTS 11
DECLARATION 16
LIST OF TABLES 20
LIST OF FIGURES 23
LIST OF PLATES Error! Bookmark not defined.
LIST OF ABBREVIATIONS Error! Bookmark not defined.
CHAPTER
1 INTRODUCTION Error! Bookmark not defined. 1.1 Background Error! Bookmark not defined.
1.2 Objective Error! Bookmark not defined.
2 LITERATURE REVIEW Error! Bookmark not defined. 2.1. Bamboo Resources and Availability Error! Bookmark not defined.
2.3 Basic Properties of Bamboo Error! Bookmark not defined.
2.3.1 Wettability of Bamboo Error! Bookmark not defined.
2.3.2 Buffering Capacities of BambooError! Bookmark not defined.
2.4 Particleboard Error! Bookmark not defined.
2.4.1 Particle Geometry Error! Bookmark not defined.
2.4.2 Particle Orientation Error! Bookmark not defined.
2.4.3 Density Variation Error! Bookmark not defined.
2.5 Resin Types Error! Bookmark not defined.
2.5.1 Urea-Formaldehyde Error! Bookmark not defined.
2.5.2 Melamine-Formaldehyde Error! Bookmark not defined.
2.6 The Potential and Utilization of Bamboo in EthiopiaError! Bookmark not
defined. 2.7 Bamboo Particleboard Error! Bookmark not defined.
2.7.1 Testing and Evaluation of bamboo particleboardError! Bookmark
not defined. 2.8 Conclusion Error! Bookmark not defined.
3 SELECTED MENSURATIONAL ATTRIBUTES AND BASIC PROPERTIES
OF ETHIOPIAN HIGHLAND BAMBOO Error! Bookmark not defined. 3.1 Introduction Error! Bookmark not defined.
3.2 Materials and Methods Error! Bookmark not defined.
3.2.1 Raw Material Sources and Sampling SitesError! Bookmark not
defined. 3.2.2 Field Procedure Error! Bookmark not defined.
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3.2.3 Determination of Culm Solid Volume Error! Bookmark not
defined. 3.2.4 Determination of Selected Anatomical PropertiesError! Bookmark
not defined. 3.2.5 Determination of Moisture contentError! Bookmark not defined.
3.2.6 Determination of Basic DensityError! Bookmark not defined.
3.2.7 Determination of pH and Buffer CapacityError! Bookmark not
defined. 3.2.8 Determination of surface wettabilitry Error! Bookmark not
defined. 3.2.9 Statistical Analysis Error! Bookmark not defined.
3.3 Results and Discussion Error! Bookmark not defined.
3.3.1 Mensurational Attributes of Y.alpina Error! Bookmark not
defined. 3.3.2 Basic Properties of Y.alpina Error! Bookmark not defined.
3.4 Conclusion Error! Bookmark not defined.
4 EFFECTS OF SITE AND AGE ON PROPERETIES OF PARTICLEBOARDS
MADE FROM ETHIOPIAN HIGHLAND BAMBOOError! Bookmark not
defined. 4.1 Introduction Error! Bookmark not defined.
4.2 Material and Methods Error! Bookmark not defined.
4.2.1 Sample Preparation Error! Bookmark not defined.
4.2.2 Preparation of Bamboo ParticlesError! Bookmark not defined.
4.2.3 Board Manufacturing Error! Bookmark not defined.
4.2.4 Sample Sizing and ConditioningError! Bookmark not defined.
4.2.5 Board Evaluation Error! Bookmark not defined.
4.2.6 Experimental Design and Statistical AnalysisError! Bookmark
not defined. 4.3 Result and Discussion Error! Bookmark not defined.
4.3.1 Particle Recovery and AnalysisError! Bookmark not defined.
4.3.2 Effects of Site on Properties of Bamboo Particleboards Error!
Bookmark not defined. 4.3.3 Effect of Age on Properties of Bamboo Particleboards Error!
Bookmark not defined. 4.4 Conclusion Error! Bookmark not defined.
5 EFFECT OF PARTICLE ORIENTATION ON PROPERTIES OF BAMBOO
PARTICLEBOARD Error! Bookmark not defined. 5.1 Introduction Error! Bookmark not defined.
5.2 Materials and Method Error! Bookmark not defined.
5.2.1 Board Manufacturing Error! Bookmark not defined.
5.2.2 Evaluation of Orientation Error! Bookmark not defined.
5.2.3 Board Evaluation Error! Bookmark not defined.
5.2.4 Experimental Design and Statistical AnalysisError! Bookmark
not defined.
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5.3 Result and Discussion Error! Bookmark not defined.
5.3.1 Effects of Particle Orientation and size on Bending and Stiffness
Strength Properties Error! Bookmark not defined.
5.3.2 Effects of Particle orientation and size on Internal Bond and Screw
Withdrawal Resistance Error! Bookmark not defined.
5.3.3 Effects of Particle orientation and size on Thickness Swelling and
Water Absorption Error! Bookmark not defined.
5.4 Conclusion Error! Bookmark not defined.
6 EFFECTS OF FACE TO CORE PARTICLE SIZE RATIOS ON THE
PROPERTIES OF THREE-LAYEREDORIENTED BAMBOO
PARTICLEBOARD Error! Bookmark not defined. 6.1 Introduction Error! Bookmark not defined.
6.2 Materials and Method Error! Bookmark not defined.
6.2.1 Board Manufacturing Error! Bookmark not defined.
6.2.3 Board Evaluation Error! Bookmark not defined.
6.2.4 Experimental Design and Statistical AnalysisError! Bookmark
not defined. 6.3 Result and Discussion Error! Bookmark not defined.
6.3.1 Effects of Face to Core Ratio on The Properties of Three-Layered
Bamboo Particleboard Bonded With Urea-Formaldehyde Resin
Error! Bookmark not defined. 6.3.2 Properties of Three-Layered Oriented Particleboard Bonded with
Melamine-Urea-Formaldehyde Resins Error! Bookmark not
defined. 6.3.3 Strength Properties of Three-Layered Oriented Particleboard
Bonded with Melamine-Urea-Formaldehyde Resins under Wet
Condition Error! Bookmark not defined.
6.4 Conclusion Error! Bookmark not defined.
7 OVERALL CONCLUSIONS AND RECOMMENDATIONError! Bookmark
not defined. 7.1 Conclusion Error! Bookmark not defined.
7.2 Recommendation Error! Bookmark not defined.
BIBLIOGRAPHY Error! Bookmark not defined.
APPENDICES Error! Bookmark not defined.
BIODATA OF THE AUTHOR Error! Bookmark not defined.
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LIST OF TABLES
Table Page
2. 1 Comparisons of fibre between some species of bamboo and woodError! Bookmark
not defined.
2. 2 Comparisons of Density between some species of bamboo andError! Bookmark
not defined.
2. 3 General characteristics of the Ethiopian natural bamboo forestsError! Bookmark
not defined.
2. 4: Forest products produced in Ethiopia during the year, 1993-1998Error! Bookmark
not defined.
2. 5 Forest products imported into Ethiopia during the year, 1993-1998 Error!
Bookmark not defined.
2. 6 The requirements for regular furniture grade particleboard for dry condition
Error! Bookmark not defined.
2. 7 The requirements for regular high performance particleboard for dry condition
Error! Bookmark not defined.
2. 8 The requirements for regular high performance particleboard for humid
condition Error!
Bookmark not defined.
3. 1 General characteristics of Y. alpina bamboo grown in different sites Error!
Bookmark not defined.
3. 2 Culms merchantable length and number Error! Bookmark not defined.
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3. 3 Effects of bamboo growing sites on mensurational attributesError! Bookmark not
defined.
3. 4 Effects of bamboo age on mensurational attributesError! Bookmark not defined.
3. 5 Correlation coefficient of bamboo mensurational attributes with age Error!
Bookmark not defined.
3. 6 Effects of site and age on culm weight and culm wall thicknessError! Bookmark
not defined.
3. 7 pH values of Y. alpina from different age groups and growing sites Error!
Bookmark not defined.
3. 8 Buffering capacity of bamboo from different ages and growing sites Error!
Bookmark not defined.
3. 9 Values of contact angles among culm surfaces of different age groups Error!
Bookmark not defined.
3. 10 Average values of contact angles among culm surfaces of three- -year old
bamboo from three growing sites. Error! Bookmark not defined.
4. 1 Types of homogenous particleboards manufactured from three bamboo growing
sites Error! Bookmark not defined.
4. 2 Types of homogenous particleboards manufactured from three age-
groupsof bamb Error! Bookmark not defined.
4. 3Specification of urea formaldehyde resin Error! Bookmark not defined.
4. 4 The specimen sizes dimension and number Error! Bookmark not defined.
4. 5 Flaking recovery of Y. alpina Error! Bookmark not defined.
22
4. 6 Screen analysis of Y. alpine from three bamboo growing sites and Error!
Bookmark not defined.
4. 7 Comparison of properties of homogenous particleboard from Y.alpina
with some hardwood and bamboo particleboardsError! Bookmark not defined.
5. 1 Types of aligned and random particleboards manufactured for testing Error!
Bookmark not defined.
5. 2 Calculated particle alignment used in the studyError! Bookmark not defined.
5. 3 Specimen dimension and number for property evaluatedError! Bookmark not
defined.
5. 4 Mean comparisons of internal bond, screw withdrawal, thickness swellin and
water absorption Error! Bookmark not defined.
5. 5 Comparison of properties of oriented and random Y.alpina particleboards
with some hardwood and bamboo particleboardsError! Bookmark not defined.
6. 1 Specification of UF and MUF resins Error! Bookmark not defined.
6. 2 Experimental parameters used in the study Error! Bookmark not defined.
6. 3 Mean comparisons ofmechanical properties and dimensional stability
of three-layered oriented Y.alpina particleboa Error! Bookmark not defined.
6. 4 Comparison of properties of three-layered oriented particleboard from
Y.alpina with some hardwood and bamboo particleboardsError! Bookmark not
defined.
6. 5 Wet and dry strength values of MUF boards Error! Bookmark not defined.
23
LIST OF FIGURES
Figure Page
3. 1 Three Major Yushania alpina growing areas in Ethiopia Error! Bookmark not
defined.
3. 2 Surface wettability tester Error! Bookmark not defined.
3. 3 Effects of culm height and growing sites on vascular bundles distribution
Error! Bookmark not defined.
3. 4 Effects of culm height and growing sites on fibre sheath coverageError! Bookmark
not defined.
3. 5 Effects of culm age, height and growing sites on the initial moisture
content Error! Bookmark not defined.
3. 6 Effects of culm age, height and growing sites on densityError! Bookmark not
defined.
3. 7 Titration of bamboo extracts solution with acid (0.1N, HCl)Error! Bookmark not
defined.
3. 8 Titration of bamboo extracts solution with alkali (0.1N, NaOH)Error! Bookmark
not defined.
3. 9 Relation between contact angle and time on outer, middle and inner surfaces
of the culm Error! Bookmark not defined.
4. 1 Effects of growing sites on MOR of bamboo particleboardsError! Bookmark not
defined.
24
4. 2 Effects of growing sites on MOE of bamboo particleboardsError! Bookmark not
defined.
4. 3 Effects of growing site on IB strength of bamboo particleboardsError! Bookmark
not defined.
4. 4 Effects of growing sites on thickness swelling of bamboo particleboards Error!
Bookmark not defined.
4. 5 Effects of growing sites on water absorption of bamboo particleboards Error!
Bookmark not defined.
4. 6 Effects of age on MOR of bamboo particleboardError! Bookmark not defined.
4. 7 Effects of age on MOE of bamboo particleboardError! Bookmark not defined.
4. 8 Effects of age on IB strength of bamboo particleboardError! Bookmark not
defined.
4. 9 Effects of age on thickness swelling of bamboo particleboardError! Bookmark not
defined.
4. 10effects of age on water absorption of bamboo particleboard Error! Bookmark
not defined.
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