ABSTRACT
Interest is growing everyday on proper utilization of wood waste resulting partly from poor saw doctoring techniques and lack of skillful machinist for furniture production and engineered wood products. The concept is to mitigate the scarcity of wood raw materials supply. This study seeks to investigate the properties of block-board as engineered wood product made from wood waste of Microbrelinia brazzavillensis, Brachystegia eurycoma, and cedrus atlastica to explore the viability of recovering of under desired dimension of wood for the production of block-boards. The strips were processed and subjected to test to determine the properties of the materials. The strips gotten from three different wood species were used for the fabrication of four samples of block-boards each. The sample specimens from the manufactured boards were tested for both physical and mechanical properties. The test data were subjected to analysis of variance (ANOVA), regression statistics analysis, and pie chart and bar chart analysis in order to test for the level of significance among the obtained parameters. Results showed the mean moisture content (MC) of 10.71%, 10.45%, 9.38%, and 10.86%. Water absorption mean value of 11.99%, 6.60%, 6.38%, and 6.65%. Density of 0.000659g/cm3, 0.000690g/cm3, 0.000715g/cm3, and 0.000662g/cm3. Comprehensive strength value of 0.453N/mm2, 0.409N/mm2, 0.397N/mm2, 0.416N/mm2 static bending: MOE 1265N/mm2 and MOR 85.9 N/mm2 and impact test. Considering the contradictions about property changes in wood, it was presumed that eventually alterations were of little account and may be observed by the effects of other different samples. (i.e difference in density). Therefore, standardized methods were preferred in the study as they are proven to be reliable and allowing comparing the results of recent literature values of wood.
Keywords; Wood, block-boards, wood strips.
TABLE OF CONTENT
Title page i
Declaration ii
Certification iii
Dedication iv
Acknowledgments v
Table of content vi
List of figures x
List of plates xi
List of tables xii
Abstract xiii
CHAPTER ONE:
INTRODUCTION
1.1 Background
of Study 1
1.2 Statement
of Problem 6
1.3 Aim and
Objective of the Study 7
1.4 Justification
7
1.5 Scope
of Study 8
CHAPTER TWO:
LITERATURE REVIEW
2.0 Production
of Engineered Wood Products 9
2.1 Generation
of Wood Waste in Forest Industries 11
2.2 Factors
Responsible for the Volume of Generation of wood waste 11
2.2.1 Imperative
of wood waste management in cross river state 12
2.2.2 Factors
militating against industrial waste utilization 13
2.2.3 Current
methods of wood waste handling in Nigeria 13
2.3 Environmental
Challenges 15
2.4 Wood
Waste Utilization 16
2.5 Sources
of Wood Waste 17
2.6 Characterization
of Wood Waste 19
2.6.1 Macro-structure
of wood 19
2.7 Highlight
of Wood Industries in Nigeria 19
2.7.1 The pulp
and paper industry 19
2.7.2 Sawmill industries
20
2.7.3 Furniture
industries 22
2.7.4 Plywood mill
23
2.7.5 Particle
board mills 23
2.8 Special
Issues in Plywood and Particle Board Operations 24
2.8.1 Mechanical
behaviour 24
2.8.2 Influence
of density 25
CHAPTER THREE:
METHODOLOGY
3.1 Study
Areas 27
3.2 Materials
29
3.2.1 Equipment
29
3.3 Methods
29
3.3.1 Processing
of wood strips and plywood 30
3.3.2 Assembling
of wood strips for the core 30
3.3.3 Sorting 31
3.3.4 Assembling
of surfaces 31
3.3.5 Gluing 31
3.3.6 Planning
32
3.3.7 Filling 32
3.3.8 Sanding 32
3.3.9 Conditioning
32
3.3.10
Finishing 32
3.4 Tests
Carried Out on the Block-boards 33
3.4.1 Determination
of moisture content 33
3.4.2 Density 33
3.4.3 Determination
of water absorption 34
3.5 Mechanical
properties determination 34
3.5.1 Compressive
strength test 34
3.5.2 Impact
load test 35
3.5.3 Static
bending test 36
3.6 Statistical
Analysis 36
CHAPTER FOUR:
RESULTS AND DISCUSSION
4.1 Introduction
38
4.2 Physical
Properties 38
4.2.1 Results
of moisture content 38
4.2.2 Result
of density 49
4.2.3 Water absorption
50
4.3 Mechanical
Properties 60
4.3.1 Compressive
strength result 60
4.3.2 Static
bending test result 63
CHAPTER FIVE:
SUMMARY, CONCLUSION AND RECOMMENDATION
5.1 Summary 66
5.2 Conclusion
66
5.3 Recommendation
67
References
Appendices
LIST
OF FIGURES
1: Show the
Map of Cross River State indicating the study Areas. 28
4.1: Results
of the moisture content of Zebra presented in bar-chat. 40
4.2: Results
of the moisture content of Zebra presented in pie-chat. 40
4.3: Results
of the moisture content of Achi presented in bar-chat. 42
4.4: Results
of the moisture content of achi presented in pie-chat. 42
4.5: results
of the moisture content of cedar presented in bar-chat. 44
4.6: Results
of the moisture content of Cedar presented in pie-chat. 44
4.7: Mixed
sample of A, B & C presented in bar-chat. 46
4.8: Mixed
sample of A, B & C presented in pie-chat. 46
4.9: Water absorption of zebra wood presented in
bar-chat. 52
4.10: Water absorption of zebra wood presented in
pie-chat. 52
4.11: Water absorption of achi wood presented in
bar-chat. 54
4.12: Water absorption of achi wood presented in
pie-chat. 54
4.13: Water absorption of cedar wood presented in
bar-chat. 56
4.14: Water absorption of Cedar Wood presented in
pie-chat 56
4.15: Mixed sample of A, B & C presented in
bar-chat 58
4.16: Mixed sample of A, B & C presented in
pie-chart 58
LIST
OF PLATES
1: Assembling of wood strips 37
2: Application of glue 37
3: Processing of wood strips and plywood sheet 37
LIST OF TABLES
4.1 (A): Result
of moisture content of block-board made from zebra
microbrelinia brazzavillensis 39
4.2 (B): Result
of moisture content of block-board made from achi 41
4.3: Result
of moisture content of block-board made from cedar 43
4.4: Sample
D. mixed samples of A, B, and C 45
4.5: Analysis
of Variance of Moisture content of the block board 47
4.6: Standard error of moisture content of
block-board 48
4.7: Result for Density Determination of Sample A, B, C,
and D 49
4.8:
Result 0f ANOVA One-Sample Statistics 50
4.9: Result
of water absorption of Zebra-wood (Microberlinia
brazzavillensis) 51
4.10: Result
of Water Absorption of Achi-Wood (Brachystegia
eurycoma) 53
4.11: Water
of absorption cedar-wood (cedrus) 55
4.12: Mixed
Sample of A (Microberlinia
brazzavillensis), Sample B 57
(Brachystegia eurycoma), Sample C (cedrus)
4.13: Result of ANOVA of Water Absorption of the
Specimens. 59
4.14: Compressive
strength of block board made from Micobrelinia
spp 61
4.15: Compressive strength of block-board made from Brachystegia spp 61
4.16: Compressive strength of block board made from Cedrus 62
4.17: Result
of compressive strength of block-board made from three species 62
4.18 Summary
of bending test result for orientation 1 and 2. 64
CHAPTER
1
INTRODUCTION
1.1 BACKGROUND OF STUDY
The Nigeria forest resources industry
was among the key sectors that contributed grossly in the Nigeria economy
within 1960’s to early 1970’s. At this time, the exportation of wood base
resources or products and agricultural produce provide above 70% of the Country
Gross Domestic Products (GDP). Though, the plethora oil discovery within 70’s
result to the gregarious utilization of round wood for export, up to the time
of prohibition in 1976. The excessive utilization of wood resources has
affected greatly the growth of the forest resources industry. This factor
mentioned and many other related factors such as lack of technical know-how,
obsolete or aged equipment’s, etc. has militated against the fortune of the
country’s forest industry.
According to (Aribisala, 1993)., the
current public or general forest estate gained within 1900 and 1970 covered
about 11% or 100,000km of the total land area of the country. It’s revealed
that only 26% thereabout of this land covered the high forest area. It is
further estimated that more additional 90,000km2 of high forest is
available outside the forest reserves. This noticeable resource in Nigeria
dated back or as far as 1792 has served as the mainstream or engine of
development and propelled economic activities when pit sawing operation
activities commenced, followed by the establishment of a power sawmill in the
Delta region in 1902. These advancement or growth
result to excessive exploitation of wood base forest resources for domestic
industries utilization and export with substantial increase. Wood export peaked
in 1950’s with log and sawn wood and subsequently, veneer and plywood. This
trend was maintained and sustained in the 1960 and early 1970’s. However, by
mid, 1970; the toll of intensive exploitation started showing. The volume of
wood export which peaked at 700,000m3 in 1964 decreased steadily to
290,000m3 in 1970 (Aribisala, 1993).
Among the factors that led to the
reduction in forest resources availability is intensive exploitation of the
resources. As far back as 1899, the perspective planning for economic
development was to exploit forest resource (Adeyoju, 1975). The revenue from
forestry grew at 4.1%, 8.0% and 28.8% between 1950-1960, 1960-1970 and
1970-1980 respectively (Aribisala, 1993). The report witnessed the development
of a virile forest products industry made up of well-structured sawmills, wood
based panel industries, match factories and pulp and paper industries. The
development of the forest sector is characterized by mechanical processing of
timber into sawn wood, veneer and plywood. This promoted the vast growth of the
economy by making positive contributions to raw material production and supply
for construction, furniture and packaging.
Wood remains virtually the most
predominant material used for construction and energy generation until the last
half of the 19th century (Douglas, 1995). People used timber in the
construction of houses, barns, fences, bridges, furniture items, material
instrument.
Engineered wood products (EWP) have
become very abundant in new homes and other structures.
These products are very popular
compared to standard sawn lumber because they are generally simple to install
and have several engineering and architectural advantages, such as longer spans
and smaller sizes. In fact, EWP often carry a more desirable economic impact on
a building project than standard milled wood, due to their ease of installation
and therefore reduced labor costs.
Additionally, engineered wood
products also has a longer design life, as the products are not subject to rot
or other similar atmospheric or environmental effects to the same extent as
their organic natural counterparts. Unfortunately, the adhesives they are made
with tend to be made using formaldehyde based resins. Throughout their extended
design lives from manufacture to disposal, they emit formaldehyde and other
volatile organic compounds (VOCs). The manufacturing processes for these
products are also much more complicated than standard grade lumber milling, and
they require high energy and resource inputs. Some of the EWP available to the
building industry are actually made of other materials from standard milling or
veneering, such as particle board, oriented strand board (“chip board”) and
parallel strand lumber beams.
Wood
is one of nature’s gifts to mankind. Products that have over the years been
made from wood fiber include all kinds of paper and board materials, cabinets,
decorative works, moldings, beautiful furniture construction materials, sports
equipment, parts for weaving and knitting mills, flooring, home building, rayon
and other fibers, tanning chemicals and thousands of other products that touch
our lives daily. However, as a result of population explosion and other factors
leading to an increased demand for wood for various purposes, solid wood is
becoming increasingly scarce. The combined effects of deforestation, shrinking
forest stock and high consumption are resulting in an escalating problem which
should be of both local and international concern (Frihart, 2004).
Hence,
the use of wood has to be controlled to ensure its continued availability for
human consumption and one of the ways through which this control can be ensured
is to find and make use of technological methods of reducing or minimizing
wastes in the wood industry. Currently, there is significant wastage of timber
at every stage of its production, from harvesting, through the primary and
secondary processing. Timber from products or old buildings that could be re-used
is often thrown away (Frihart, 2004). One of the ways through which wood
products could actually be re-used is through the production of Wood plastic
composite especially from off-cuts, sawdust, shaving, undesired size and
undesired dimension, for the production of wood based panel products. Wood plastic composite as an engineered wood
product offers opportunities to produce large degree of curved shapes for
unlimited flexibility in design with a corresponding increase in mechanical and
physical properties. Statistics obtained from Cross River State Forestry
Commission show that about 30% of the log from the forest is regarded as waste
right from primary and secondary stages of wood conversion due to poor silvicultural
practice, poor knowledge of forest inventory and mapping, unskillful machinist
in all the stages of wood conversion and inadequate saw doctoring technology in
Nigeria saw mill. (Forestry Commission, CRS. 1992).
Approximately 85% of the
ligno-cellulosic material used for particleboard, chipboard, fibre board,
cement board and composite production is obtained from wood species. The rest
consists mainly of seasonal crops such as flax, bagass, cereal straw and hemp.
(Adewole, 2012). This high demand of wood material is what actually interests
the researcher to create a template where, wood material will be utilized up to
94% of log harvest from Nigeria forest for sustainable forest conservation
program.
The
world economy has undergone rapid changes during the past decades with the
advent of global competition to an extent that almost every enterprise is
affected by it. Nigeria’s industrialization policy has always focused on
development and utilization of locally available raw materials.
In
the past, Nigeria was rich in forest resources in terms of its relative
contribution to the economy. However, the real Gross Domestic Product (GDP)
declined steadily from 42% in 1960s, to about 1.8% in 1985, 1.31% in 1995 and
stood at about 1.2% in 1998 (CBN,1999). The observed trend in the performance
of the sector requires urgent attention since the sector is crucial to the
supply of forest products to industries such as sawmills, ply mills, paper
mills, etc. All these wood based industries contribute immensely to the
Nigerian economy (Adeweumi, et al,
2004). As a result of this, a new material for structural building has been
developed. This is known as structural composite lumber (SCL); the wood waste
consists of used lumber, branches of trees and other wood debris for
construction and gubbing activities. Structural composite lumber consists of
laminated veneer lumber (LVL), parallel strand lumber (PSL), laminated strand
lumber (LSL) and thick oriented board (TOB). Wood remains virtually the most
predominant materials used for construction and energy generation until the
last half of the 19th century (Douglas, 1995). People used timber in
the construction of houses, barns, fences, bridges, furniture items, and
musical instruments. In contemporary times, wood is still widely used for
construction purposes.
Wood
waste generated at residential and commercial wood frame construction sites
offer a greater potential for reuse because of ease of separating the wood
during various stages of construction. Wood waste is commonly encountered in
the environment due to the prevalence of lumber, pulp and paper industries, log
rafting, bark stripping, and other wood processing activities, often resulting
in wood waste entering the mill and urban environment. In some places, wood
waste has been deposited in cities, towns and roadside.
There
is evidence of huge wastage of resources during processing operation. These may
be due to one or the combination of the following factors, inefficient
operators, crooked logs, pile of slabs, half processed materials, rejects and
saw dust (R.M.R.D.C, 1991). During saw milling operations, slabs, edging, trims
and saw dust produced in extracting lumbers from round logs are considered as
positive output.
According
to Warsta (1978) the amount of residue depends on the species of the log, the size
and shape of the log, the condition of the sawing machine, the competence of
the machine operator and the required conversion specification.
Nigeria
Institute for Social and Economic Research (NISER) defines wood residue as the
pieces of material that are lost from the process of harvesting, up to when the
final product (planks) have been taken, hence, residue may be regarded as
negative product of wood processing. That notwithstanding, the wood residue in
the saw mill is an important raw material in other industries. Onosode (2006)
reported that the presence of defect in logs greatly affects the quality,
volume of plank yield and volume of residue.
The
term forest management is applied in situations where integrated coordinated
series of actions are directed towards the achievement of specific objectives.
Forest management is a process which effectively integrated the biological,
social and economic factors which influence the decision leading towards the
implementation of one or more specific objectives. Forestry deal with the overall
administrative, economic, legal, social, technical and scientific aspects
related to natural and planted forests. It implies various degrees of
deliberate human intervention to maintain the ecosystem and its function in order
to favor specific valuable species or group of species for production of goods
and services. The Environmental and Development Commission (1987), clearly
recognized the necessity for a broad approach to sustainability.
1.2 STATEMENT OF PROBLEM
The forest area of Cross River State
is known to constitute about 90% of Nigeria’s remaining primary rainforest
(FAO, 2000; Kehinde and Awoyemi, 2009). However, the forest has been decreasing
at an alarming rate.
Currently the demand for wood as an
engineering material for the production of various wood base products has
militated a high level of deforestation thereby causing climatic change. In the
wood based industries, there is a lot of waste recovering such as saw dust, off
cut, stump etc. Due to the demand and increasing population, proper utilization
of waste should be encouraged to meet the need of human in other to combat the
rate of depletion of forest resources by converting the wood waste to wealth.
Studies of recycling wood wastes for block-board are still very rare in the
literature (Chamma, 2004). The production of block-board becomes a good option,
especially for smaller pieces which are usually discarded into landfills.
1.3 AIM AND OBJECTIVES OF THE STUDY
Considering
the significant volume of wood and wood-based products generated as waste, the
focus of this research is aiming at utilization of timber waste from saw mill
for the production of useable block boards.
The
objectives of this research are listed below;
1.
To manufacture block
boards from wood species selected within study area.
2.
To determine the physical
properties of the manufacture boards, viz Moisture Content (M.C), Density, and
Water Absorption Test.
3.
To determine, the mechanicals
properties of the boards; Compressive Strength, Impact, and Static Bending
Test.
4.
To compare the properties
of the manufactured boards with known boards in use.
1.4 JUSTIFICATION
It is common knowledge that wood is
the most multipurpose raw materials the world has ever known. The decline of
forest resource and the problem of global warming have led to serious shortages
of the forest resources for mankind. This study seeks to develop appropriate
techniques for processing the wood waste materials into value added, useful and
marketable products. This will provide solution to the problems of economic
underutilization and ecological damage.
When
the wood waste materials are used for engineering wood products production such
as plywood, block board, etc, the following advantages in utilization will be
achieved viz: convenience in use, ease of handling, high market value etc.
The
felling of trees and sawing into timber in the forest lead to huge amount of
waste wood and this is left unused at the sites which otherwise would have been
sawn and re-sawn in the mill to recover as much sawn timber as possible for
each tree. In the mill where proper conversion takes place, developed sawing
pattern is applied to achieve maximum yield from every log.
1.5 SCOPE OF STUDY
The study is limited to southern
senatorial districts of Cross River State, Nigeria, Precisely Akim Timber
Market in Calabar Municipal Local Government Area. The study covers the production of blockboard
from wood waste of Microbrelinia brazzavillensis, Brachystegia eurycoma, and Cedrus. And it will examine certain properties
which include Mechanical and Physical properties of the products.
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