Properties of Rice Straw fibreboard Bound with Recycled Low Density Polyethylene (LDPE)

Properties of Rice Straw fibreboard Bound with Recycled Low Density Polyethylene (LDPE).

ABSTRACT

The environmental impact of deforestation and the non biodegradability of synthetic polymer as a major product of household waste, necessitate the need to look into agricultural residue and low density polyethylene (LDPE) as an alternative source of raw material for the production of fibreboard panels.

This study investigated the properties of fibreboard made from Rice Straw (as main matrix) and LDPE (as filler material and binder), with a view to establishing their suitability for use as panels in the Construction Industry. The composite were produced using the dry blend/hot press method.

Processed Rice Straw was mixed with shredded LDPE from sachet water at 20%, 30%, 40%, and 50% replacement levels, based on the dry weight of the straw. The mixed material was pressed at an optimum temperature and pressure of 170oC and 1.4N/mm2 respectively in Moore’s Hydraulic Press machine.

Ten test samples of nominal size 200mm x 200mm x 6 mm were produced at each replacement levels. The test samples were evaluated for both physical and mechanical properties according to the relevant standards.

The results showed that the density ranged from 800kg/m3 to 1000 kg/m3. The mean value for surface absorption was observed to increase from 149mm for samples with 20% replacement level to 200mm for samples with 50% polymer content.

As the concentration level of LDPE increases, it was generally observed that both thickness swell and moisture absorption decreases in value from 31% to 4% and 57% to 24% respectively.

The bending strength properties showed a non linear behavior with the lowest mean value of 20N/mm2 for samples with 20% replacement level and the highest mean value of 43N/mm2 for samples with 30% Polyethylene content.

The Internal Bond property was observed to vary from 1.07N/mm2 to 3.07N/mm2 for samples with 20% and 50% replacement levels respectively.

Similar trend was observed with regards to the screw holding properties. The screw holding properties vary from 720N to 1220N for samples with 20% and 50% polymer content respectively.

However the result on bending stiffness was observed to be unsatisfactory. The maximum mean value recorded for the samples at 30% replacement level was 2279N/mm2, which was 16% lower than the 2700N/mm2 specified by BS 622-5: 2003.

The study concluded that samples with 30%, 40% and 50% Polyethylene replacement levels met the requirements set out by BS 622-5: 2003. It was therefore recommended that fibreboards made with these materials can be used for interior furniture works, wall paneling and ceiling board.

TABLE OF CONTENTS

Content Page
Title page – – – – – – – I
Declaration – – – – – – – II
Certification – – – – – – – III
Acknowledgement – – – – – – – IV
Abstract – – – – – – – V
Table of Content – – – – – – – VI
List of Figures – – – – – – – X
List of Tables – – – – – – – XI
List of Plates – – – – – – – XII
List of Appendices – – – – – – – XIV
Abbreviations and Symbols – – – – – – XV

CHAPTER 1: INTRODUCTION

1.1 Background of the Study – – – – – – 1
1.2 Statement of Research Problem – – – – – 4
1.3 Justification for the Study – – – – – 5
1.4 Aim and Objectives – – – – – 6
1.5 Scope and Limitation of the Study – – – – – 6
1.6 Research Methodology – – – – – 7

CHAPTER 2: LITERATURE REVIEW

2.1 Boards – – – – – – – – – 9
2.2 Fibreboards – – – – – – – – 13
2.2.1 Definition – – – – – – – – 13
2.2.2 Basic Processes in the Manufacture of Fibreboard – – – 13
2.2.3 Origin and Development of Fibreboard Plants – – – 14
2.2.4 Types of Fibreboard – – – – – – – 15
2.2.5 Applications of Fibreboard – – – – – – 16
2.2.6 Advantages and Disadvantages of Fibreboards – – – 16
2.3 The Rice Plant – – – – – – – – 18
2.3.1 World Rice Production- – – – – – – 20
2.3.2 Rice production in Nigeria – – – – – – 22
2.3.2 Uses of Rice – – – – – – – – 23
1.4 The Rice Straw – – – – – – – 24
1.4.1 Uses of Rice Straw – – – – – – – 26
1.4.2 Properties of Rice Straw as Material for Board Making – – 28
2.5 Plastics – – – – – – – – 29
2.5.1 Definition and Characteristics- – – – – – 29
2.5.2 Development of Plastics – – – – – – 31
2.5.3 Types of Plastics – – – – – – – 32
2.5.3.1 Thermoplastics – – – – – – – 33
2.5.3.2 Thermosetting Plastics – – – – – – 34
2.6 Polyethylene – – – – – – – – 34
2.6.1 Properties of Polyethylene – – – – – – 37
2.6.2 Classification and Uses of Polyethylene – – – – 38
2.6.2.1 Ultra High Molecular Weight Polyethylene (UHMWPE) – – 38
2.6.2.2 High Density Polyethylene (HDPE) – – – – – 38
2.6.2.3 Cross Linked Polyethylene (PEX) – – – – – 39
2.6.2.4 Medium Density Polyethylene (MDPE) – – – – 39
2.6.2.5 Linear Low Density Polyethylene (LLDPE) – – – – 40
2.6.2.6 Low Density Polyethylene (LDPE) – – – – – 40
2.6.2.7 Very Low Density Polyethylene (VLDPE) – – – – 41

CHAPTER 3: MATERIALS AND METHODS

3.1 Materials and Processes – – – – – – 42
3.1.1 Chipping, Washing, and Soaking – – – – – 43
3.1.2 Cooking, Felting and Drying – – – – – – 44
3.1.3 Washing, Shredding and Sieving of Polymer Material – – – 46
3.1.4 Blending of Material – – – – – – – 48
3.1.5 Mat Formation- – – – – – – – 50
3.1.6 Pressing – – – – – – – – 50
3.1.8 Conditioning – – – – – – – – 51
3.1.9 Process Flowchart – – – – – – – 54
3.2 Test of Specimen – – – – – – – 55
3.2.1 Determination of Density – – – – – – 55
3.2.2 Bending Strength (Modulus of Rupture) and Bending Stiffness (Modulus of Elasticity in Bending) Test  56
3.2.3 Tensile Strength Parallel to Surface of Board Test- – – – 58
3.2.4 Tensile Strength Perpendicular to Surface of Board (Internal Bond) Test 61
3.2.5 Lateral Nail Resistance Test – – – – – – 62
3.2.6 Nail Head Pull-Through Test – – – – – – 63
3.2.7 Screw Withdrawal Test – – – – – – 63
3.2.8 Surface Absorption Test – – – – – – 65
3.2.9 Swelling in Thickness and Water Absorption Test – – – 67

CHAPTER 4: RESULTS, ANALYSIS AND DISCUSSIONS

4.1 Preamble – – – – – – – – 70
4.2 Bending Strength (Modulus of Rupture) and Bending Stiffness – 70
4.3 Tensile Strength – – – – – – – 72
4.4 Screw Withdrawal – – – – – – – 75
4.5 Nail Resistance – – – – – – – 76
4.6 Surface Absorption – – – – – – – 77
4.7 Swelling in Thickness and Water Absorption – – – 79

CHAPTER 5: SUMMARY, CONCLUSIONS AND RECOMMENDATIONS

5.1 Summary of Findings – – – – – – – 82
5.2 Conclusions – – – – – – – – 83
5.3 Recommendations – – – – – – – 83
References – – – – – – – – – – 85
Appendices – – – – – – – – – – 90

INTRODUCTION

1.1 Background of the Study

Studies have shown that factors such as environmental, health and economic implications of residues and/or “wastes” from agricultural and wood processing outfits have necessitated the need for their use for the production of value-added products (Hussaini and Zubairu 1997; Erakhrumen, 2006; Mamza and Kambai 2008).

This need
has led to series of research efforts spanning decades on composite materials based on plant fibres. An example is the production of different types of composites boards from various types of materials particularly from those considered residues or “waste” (Erakhrumen, et al 2008).

Researches on a wide variety of agricultural residues and/or “wastes” including those from animals and lesser known or lesser utilized vegetal materials from different regions of the world including Nigeria for composite boards production have been carried out (Erakhrumen, et al 2008; ,), among which is fibreboard making (Petruzzi, 2001; Christianson,2009).

BS EN 7916: (1998) defines fibreboard as panel material with a thickness of 1.5mm and greater, manufactured from lignocellulosic fibres with application of heat and/or pressure. The bond is derived from either the felting of the fibres and their inherent adhesive properties or from a synthetic binder added to the fibres.

REFERENCES

Amaza P. S. and Maurice D C (2005) “Identification of Factors that Influence Technical Efficiency in Rice Based Production Systems in Nigeria”. Presentation at workshop on policies and strategies for promoting Rice
production and food security in Sub-Saharan Africa, Cotonou, Benin, 7- 9 Nov 2005 FAO (2005)

Apeh A.J. (1999) “The use of Rice Straw in the production of Compressed Straw Slabs” (unpublished) An MSc thesis submitted to the Department of Building, Ahmadu Bello University Zaria. Nigeria 1999.

ASTM C208 – 08a ‘Standard Specification for Cellulosic Fiber Insulating Board’ American Society for Testing and Materials, West Conshohocken, PA, USA 1998

ASTM C209 – 08a ‘Standard Specification for Cellulosic Fiber Insulating Board’, American Society for Testing and Materials, West Conshohocken, PA, USA 1998

ASTM D1037- 99 ‘Standard Test Methods for Evaluating Properties of Wood- Base Fiber and Particle Panel Materials’ American Society for Testing and Materials, West Conshohocken, PA, USA 1999

Brandrup J. and Immergut E.H, “Polymer Handbook” 2nd Edition John Wiley and Son,
New York 1975