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

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February 2005

DEDICATION

Dedicated to my mother the late Yesharege Zerfu, my brother the late Ashagrea Deme and my elder sisters Teseme and Negat

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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% ureaformaldehyde 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 2 3 7 11 16 20 23 Error! Bookmark not defined. Error! Bookmark not defined.

DEDICATION ABSTRACT ABSTRAK ACKNOWLEDGEMENTS DECLARATION LIST OF TABLES LIST OF FIGURES LIST OF PLATES LIST OF ABBREVIATIONS CHAPTER 1

INTRODUCTION 1.1 Background 1.2 Objective

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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.

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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.

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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 APPENDICES BIODATA OF THE AUTHOR

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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!

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not defined. 2. 3 General characteristics of the Ethiopian natural bamboo forestsError!

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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

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condition

2. 7 The requirements for regular high performance particleboard for dry Error! Bookmark not defined.

condition

2. 8 The requirements for regular high performance particleboard for condition Bookmark not defined.

humid Error!

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

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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

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not defined. 3. 7 pH values of Y. alpina from different age groups and growing sites

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age-

4. 3Specification of urea formaldehyde resin

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4. 4 The specimen sizes dimension and number

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4. 5 Flaking recovery of Y. alpina

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4. 6 Screen analysis of Y. alpine from three bamboo growing sites and

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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

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6. 2 Experimental parameters used in the study

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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

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LIST OF FIGURES Figure

Page

3. 1 Three Major Yushania alpina growing areas in Ethiopia Error! Bookmark not defined. 3. 2 Surface wettability tester

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3. 3 Effects of culm height and growing sites on vascular bundles Error! Bookmark not defined.

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 content Error! Bookmark not defined.

moisture

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 of the culm Error! Bookmark not defined.

surfaces

4. 1 Effects of growing sites on MOR of bamboo particleboardsError! Bookmark not defined.

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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!

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not defined. 4. 4 Effects of growing sites on thickness swelling of bamboo particleboardsError! 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!

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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! not defined.

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