by seyoum kelemwork hailepsasir.upm.edu.my/52/1/1000548923_t_fh_2005_7.pdfkeputusan menunjukkan...

1

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


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


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


(Internal examiner)

Associate Professor. Mohd.Saleh Jaafar PhD

Head of Department

Civil Engineering

Faculty of Engineering


(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


(Chairman)

Wong Ee Ding , PhD

Faculty of Forestry


(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.


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.


5.2.2 Evaluation of Orientation Error! Bookmark not defined.



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.


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.




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.


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


2. 8 The requirements for regular high performance particleboard for humid

condition Error!


3. 1 General characteristics of Y. alpina bamboo grown in different sites Error!


3. 2 Culms merchantable length and number Error! Bookmark not defined.

21

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!


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!


3. 8 Buffering capacity of bamboo from different ages and growing sites Error!


3. 9 Values of contact angles among culm surfaces of different age groups Error!


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!


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!


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


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!


4. 5 Effects of growing sites on water absorption of bamboo particleboards Error!


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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