Author
For further details log on website :
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J.W. Wong1,*, W. S. Yeo1, M. Faizal1, S. Hashim2
1 Department of Mechanical Engineering, Universiti Tenaga Nasional, Selangor, Malaysia
2 Department of Bio-Composite, Forest Research Institute Malaysia (FRIM), Selangor, Malaysia
1 Department of Mechanical Engineering, Universiti Tenaga Nasional, Selangor, Malaysia
2 Department of Bio-Composite, Forest Research Institute Malaysia (FRIM), Selangor, Malaysia
ABSTRACT
*Corresponding author’s phone: 014-9291675
E-mail: jianwai410@gmail.com
Date Received: 9th June 2014 Date Revised: 6th August 2014 Date Accepted: 20th August 2014
Date Received: 9th June 2014 Date Revised: 6th August 2014 Date Accepted: 20th August 2014
The influence of various mixing ratios by weight percent of kenaf and acacia (0:100, 10:90, 30:70,
50:50 and 100:0) on the mechanical and physical properties of the particleboard was investigated. The
particleboard was produced by compressive moulding at a temperature of 164 ̊C, pressure of 30kg/m2
and pressing time of 6 minutes. The properties such as modulus of elasticity (MOE), modulus of
rupture (MOR), thickness swelling (TS), water absorption (WA), and internal bonding (IB) were
determined. The results showed that particleboard with 100% kenaf particleboard gave the highest
MOE and MOR which are 2098.16 MPa and 12.46 MPa respectively. However, the properties of MOE
and MOR declined when the content of acacia increased. On the other hand, particleboard consisted of
100% acacia showed the lowest percentage change in TS and WA with only 8.82% and 61.35%
respectively. The non-porous structure of the acacia contributed to this observation. Furthermore, the
results showed high IB of 0.291 MPa was obtained from particleboard consisted of 50% kenaf. In
addition, the weight ratio of kenaf: acacia at 50:50 and 30:70 particleboards gave the best mechanical
properties. Therefore, it is concluded that the particleboard with minimum 30% kenaf met the
requirement by British Standard (BS EN 312:2003), for general purpose.
Keywords: Kenaf; acacia auriculiformis; particleboard
1.0 INTRODUCTION
Wood is a renewable, precious resource of nature that is rich in cellulose fibers. However, the global population growth and economic development have led to high demand of forest resources in manufacturing wood product [1]. It became a significant issue for any developed country such as Western Europe and North America as the present-day forest resources are insufficient to meet with the wood consumption level [2]. To minimize the shortage of wood resources, alternative resources should be introduced in order to reduce the process of destructive logging. Natural fiber, such as kenaf, acacia, bamboo, pine, snegon, sonokeling, mahogany and rattan [3] are some examples and researchers should study the suitability as an alternative. The advantages of these plants are fast-growing, inexpensive, biodegradable, and not causing health problem to the public.
Globally, kenaf is considered as a suitable alternative for wood because it is highly adaptable to various soils and environment, strong resistance, biodegradable and rich in cellulose [4,5]. It is an herbaceous annual of the family Malcaceae that can grow under a wide range of temperature and extensively grown in tropical and subtropical. As a fast-growing species, it can grow more than three meters within three months under moderate ambient temperature. Kenaf fiber can be classified into two parts that are the bast fiber and core fiber with the content of 30% to 70% from the stem respectively. In addition, bast fiber is the outer part of the stem while core fiber is the inner part.
Keywords: Kenaf; acacia auriculiformis; particleboard
1.0 INTRODUCTION
Wood is a renewable, precious resource of nature that is rich in cellulose fibers. However, the global population growth and economic development have led to high demand of forest resources in manufacturing wood product [1]. It became a significant issue for any developed country such as Western Europe and North America as the present-day forest resources are insufficient to meet with the wood consumption level [2]. To minimize the shortage of wood resources, alternative resources should be introduced in order to reduce the process of destructive logging. Natural fiber, such as kenaf, acacia, bamboo, pine, snegon, sonokeling, mahogany and rattan [3] are some examples and researchers should study the suitability as an alternative. The advantages of these plants are fast-growing, inexpensive, biodegradable, and not causing health problem to the public.
Globally, kenaf is considered as a suitable alternative for wood because it is highly adaptable to various soils and environment, strong resistance, biodegradable and rich in cellulose [4,5]. It is an herbaceous annual of the family Malcaceae that can grow under a wide range of temperature and extensively grown in tropical and subtropical. As a fast-growing species, it can grow more than three meters within three months under moderate ambient temperature. Kenaf fiber can be classified into two parts that are the bast fiber and core fiber with the content of 30% to 70% from the stem respectively. In addition, bast fiber is the outer part of the stem while core fiber is the inner part.
According to the previous study, kenaf fiber is found to possess 60.8% and 50.6% of cellulose content
for its bast and core respectively [6]. In terms of application, kenaf is widely used as a cordage crop
and livestock feed for over 6000 years until recent researches which demonstrated its suitability in
building materials, textiles, adsorbent.
On the other hand, acacia is another type of fast-growing species that are similar to the kenaf [7]. Acacia auriculiformis is a fast-growing, twisted, gnarly tree in the family of Fabaceae. It is extensively planted in tropical Asia region, China and Indonesia but lesser in Africa and South America region. Acacia auriculiformis is an evergreen tree which can grow up to 30m tall with the trunk size of 12 m long and 50 cm diameter. It is very adaptable to different soil type including degraded sides and hills. The wood of acacia is diffuse-porous with mostly solitary vessels and it is the reason for it to have survived on poor soil. Good properties of acacia give them excellent dimensional stability, hence is a potential alternative for wood resources [8].
Researchers have studied the particleboard composite with various types of natural fiber. For instance, Juliana and friends [3] have studied the properties of a particleboard by mixing rubberwood and kenaf fiber at the mix ratio of 70:30. In their study, the results showed the suitability of having a lesser amount of rubberwood but it is still less satisfying as a long term solution to tackle the shortage of rubberwood. Therefore, further studies have to be done for other alternatives so that the natural fiber can be utilized effectively and replace wood resources one day.
The objective of this study was to investigate the effect of various weight ratios of kenaf and acacia on the mechanical and physical properties of particleboard. The modulus of rupture, modulus of elasticity, internal bonding, water absorption and thickness swelling were evaluated. The results of each experiment were compared to British Standard (BS EN 312:2003) [9].
2.2 Methods
Figure 1 showed the overall process flow of the particleboards. The manufacturing of particleboard included several main procedures such as refining, screening, drying, forming, cold pressing and hot pressing. The mechanical testing that was carried out were bending, internal bonding, thickness swelling and water absorption test. All the particleboards processes and mechanical tests were available and conducted at FRIM. The target density of the particleboard made was set at 600 kg/m3. The five different ratios of KC:AA mixture by weight percentage at 0:100, 10:90, 30:70, 50:50 and 100:0 were investigated. Three particleboards were made for each category of different weight ratio. Therefore, a total of 15 particleboards was manufactured in this study.
2.2.1 Making of Particleboard
Both kenaf core and acacia wood were chipped and flaked to reduce into particle size. Next, the flakes obtained were screened and segregated to various sizes which consisted of 0.5 mm, 0.8 mm, 1.5 mm and 4.0 mm. In this study, only the particle size of 0.8 mm was selected and used in this work. The particles were kept in the oven at the temperature of 65 ̊C for 48 hours to reduce and obtained homogeneous moisture content.
The kenaf particles and acacia particles were mixed together with urea formaldehyde resin (12 % total material weight), wax (1 % total material weight) and hardener (3 % total resin weight). The hardener used in this study was ammonium chloride to reduce the bonding time during hot press. While, the liquid paraffin was the wax used to achieve a smooth surface. The mixture was placed in a mould for cold pressing for 10 to 17 minutes to achieve uniformity, reducing the particleboard thickness (or compacting the board) and consolidating the resin. Lastly, hot pressing was performed at a temperature of 165 ̊C for 6 minutes with pressure of 90 kg/m2 to stimulate sintering.
On the other hand, acacia is another type of fast-growing species that are similar to the kenaf [7]. Acacia auriculiformis is a fast-growing, twisted, gnarly tree in the family of Fabaceae. It is extensively planted in tropical Asia region, China and Indonesia but lesser in Africa and South America region. Acacia auriculiformis is an evergreen tree which can grow up to 30m tall with the trunk size of 12 m long and 50 cm diameter. It is very adaptable to different soil type including degraded sides and hills. The wood of acacia is diffuse-porous with mostly solitary vessels and it is the reason for it to have survived on poor soil. Good properties of acacia give them excellent dimensional stability, hence is a potential alternative for wood resources [8].
Researchers have studied the particleboard composite with various types of natural fiber. For instance, Juliana and friends [3] have studied the properties of a particleboard by mixing rubberwood and kenaf fiber at the mix ratio of 70:30. In their study, the results showed the suitability of having a lesser amount of rubberwood but it is still less satisfying as a long term solution to tackle the shortage of rubberwood. Therefore, further studies have to be done for other alternatives so that the natural fiber can be utilized effectively and replace wood resources one day.
The objective of this study was to investigate the effect of various weight ratios of kenaf and acacia on the mechanical and physical properties of particleboard. The modulus of rupture, modulus of elasticity, internal bonding, water absorption and thickness swelling were evaluated. The results of each experiment were compared to British Standard (BS EN 312:2003) [9].
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2.0 EXPERIMENTAL DETAILS
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2.1 Materials
The raw materials used in this work were kenaf core, acacia wood and urea formaldehyde
2.2 Methods
Figure 1 showed the overall process flow of the particleboards. The manufacturing of particleboard included several main procedures such as refining, screening, drying, forming, cold pressing and hot pressing. The mechanical testing that was carried out were bending, internal bonding, thickness swelling and water absorption test. All the particleboards processes and mechanical tests were available and conducted at FRIM. The target density of the particleboard made was set at 600 kg/m3. The five different ratios of KC:AA mixture by weight percentage at 0:100, 10:90, 30:70, 50:50 and 100:0 were investigated. Three particleboards were made for each category of different weight ratio. Therefore, a total of 15 particleboards was manufactured in this study.
2.2.1 Making of Particleboard
Both kenaf core and acacia wood were chipped and flaked to reduce into particle size. Next, the flakes obtained were screened and segregated to various sizes which consisted of 0.5 mm, 0.8 mm, 1.5 mm and 4.0 mm. In this study, only the particle size of 0.8 mm was selected and used in this work. The particles were kept in the oven at the temperature of 65 ̊C for 48 hours to reduce and obtained homogeneous moisture content.
The kenaf particles and acacia particles were mixed together with urea formaldehyde resin (12 % total material weight), wax (1 % total material weight) and hardener (3 % total resin weight). The hardener used in this study was ammonium chloride to reduce the bonding time during hot press. While, the liquid paraffin was the wax used to achieve a smooth surface. The mixture was placed in a mould for cold pressing for 10 to 17 minutes to achieve uniformity, reducing the particleboard thickness (or compacting the board) and consolidating the resin. Lastly, hot pressing was performed at a temperature of 165 ̊C for 6 minutes with pressure of 90 kg/m2 to stimulate sintering.
For further details log on website :
http://ijimm.org/upload/papersV1I2/5-Wong_Jian_Wai_et_al.pdf
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