Six species of wood in light, medium and heavy hardwood category. Characteristics of the wood such as color, shape of pore, density range etc. The physical properties of wood that affect adhesive bonding

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TABLE OF CONTENTS
CONTENTS PAGE
TABLE OF CONTENTS 1
ACKNOWLEDGEMENT 2
INTRODUCTION 4
Lab manual 6
Six species of wood in light, medium and heavy hardwood
category.
8
Characteristics of the wood such as color, shape of pore,
density range etc.
10
The physical properties of wood that affect adhesive bonding 17
DISCUSSION AND CONCLUSION 20
REFERENCES 23

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In the name of Allah, Most Gracious, Most Merciful. Alhamdulillah, with His
Blessings we have successfully completed this lab report. Of identifying and classifying the
adherence.
First and foremost, I would like to express my sincere appreciation to my subject
lecture Mrs Ainul Munirah binti Abdul Jalil for guiding and encourage us in this laboratory
work. Thanks a lot to her for giving us the knowledge, sharing the experience and providing
guide line finishing this report.
Besides, I also wish to express our appreciation to our friends who assist and always
lend a hand when needed and provide valuable input to improve many elements in this study
through their informal suggestions and ideas. They also give an opinion while we keep
finding the best reference for this report.
A thousands thanks also to all the staff for helping us in conducting the equipment
and conducting the testing in laboratory work. Also thank to our group members Nur Isfarina
binti Ismail, Suraya binti Yusof, Hanis Afiqah binti Idrus and Izzah Azimah binti Noh for
giving to give the energy and full cooperation in making this laboratory work become
smoothly.
Last but not least, our deepest gratitude goes to my family for their never-ending
support, love, trust and encouragement,

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An adherend is a substrate held to another substrate by an adhesive. Adhesion is the
state in which two surfaces are held together by interfacial forces, which may be valence
forces, interlocking action, or both. Valence forces are forces of attraction produced by the
interactions of atoms, ions, and molecules that exist within and at the surfaces of both
adhesive and adherend. Interlocking action, also called mechanical bonding, means surfaces
are held together by an adhesive that has penetrated the porous surface while it is liquid, then
anchored itself during solidification.
Because adhesives bond by surface attachment, the physical and chemical conditions
of the adherend’s surface are extremely important to satisfactory joint performance. Wood
surfaces should be smooth, flat, and free of machine marks and other surface irregularities,
including planer skips and crushed, torn, and chipped grain. The surface should be free of
burnishes, exudates, oils, dirt, and other debris.
The bond ability of wood is not only affected by the surface properties of wood
adherends but also by wood’s physical properties, particularly density, porosity, moisture
content, and dimensional movement.
Moreover, for this subject FUR464, we make some research and provide data by
identify six different species of wood and their characteristics such as color, shape of pore,
density range and others. The species of wood are classify by category of the adherence,
(heavy, medium or light weight density). The six different species of wood that we are
choose is Merbau (Intsia palembanica) and Balau merah (Shorea collina) for heavy
hardwood, Kulim (Scorodocarpus borneensis) and Mata Ulat (Kokoona coriacea) as a
medium hardwood and for light hardwood is Jelutong ( Dyera costulata) and Pulai ( Alstonia
angustiloba).
At the end of this report, we will have knowledge about why difference species will
affect the bonding strength when using adhesive.

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ADHERENCE
Objective : To identify and classify the adherence.
Procedure :
1. Find any six species of wood in light, medium and heavy hardwood category.
2. Identify the species of wood and list the characteristics of the wood such as color,
shape of pore, density range etc.
3. By using the same adherence, classify the category of the adherence, (heavy, medium
or light weight density) and (specific gravity group of adherence –SG1, SG2, SG3,
SG4, SG5, SG6) etc.
4. Discuss why difference species will affect the bonding strength etc. when using
adhesive.

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SIX SPECIES
OF WOOD IN THREE
CLASSES:
LIGHT, MEDIUM
AND
HEAVY HARDWOOD

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HEAVY HARDWOOD
1. Merbau (Intsia palembanica)
2. Balau merah (Shorea collina)
MEDIUM HARDWOOD
3. Kulim (Scorodocarpus borneensis)
4. Mata ulat (Kokoona coriacea)
LIGHT HARDWOOD
5. Jelutong ( Dyera costulata)
6. Pulai ( Alstonia angustiloba)

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THE
CHARACTERISTICS OF
THE WOOD
BASED ON IT CLASSES

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HEAVY HARDWOOD
1. Merbau (Intsia palembanica)
 Color/appearance :
- Has an orangish-brown color when freshly cut, which ages to a darker reddish-
brown.
- Has small yellow deposit (these yellow deposits are soluble and can cause
staining)
 Grain/texture :
- Grain is straight to interlocked
- Texture is coarse, with a moderate natural luster
 End grain/shape of pore
- Diffuse-porous ; large to very large pores, very few
- Aliform shape of pore (winged or lozenge) and confluent
 Density range
- 515-1040 kg/m3
(32-65 lb/ka3
)

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2. Balau merah (Shorea collina)
 Color/appearance :
- Heartwood is red-brown or purple-brown in color when freshly cut, weathering to
a dark brown
 Grain/texture :
- Grain is straight to interlocked often giving rise to stripe figure.
- Surface is rather dull without luster.
- Texture is rather coarse but even.
 End grain/shape of pore
- Diffuse-porous ; medium to large pores
- Have many tyloses
- Aliform shape of pore (winged or lozenge) and confluent
 Density range
- 800-850 kg/m3
(50-55 lb/ka3
)

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MEDIUM HARDWOOD
3. Kulim (Scorodocarpus borneensis)
 Color/appearance :
- Heartwood reddish-brown to dark purplish-brown towards the centre.
 Grain/texture :
- Hard to cut if against the grain.
- Texture medium fine and evenly.
 End grain/shape of pore
- Indistinct, vessels moderately small to medium-sized, solitary but more often in
radial multiples of 2-3(-6).
- tyloses mostly well-developed, occasionally with white deposits; parenchyma
moderately abundant.
- Apotracheal diffuse and diffuse-in-aggregates; rays very fine to moderately fine,
visible with a hand lens; ripple marks absent.
 Density range
- 835 kg/m3
(52 lb/ka3
)

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4. Mata ulat (Kokoona coriacea)
 Color/appearance :
- Yellow brown with pinkish spot
 Grain/texture :
- Hard to cut if against the grain.
- Texture very fine and evenly.
 End grain/shape of pore
- Single pores, medium and more.
- Concentric layer of parenchyma.
 Density range
- 880-1040 kg/m3
(55-65 lb/ka3
)

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LIGHT HARDWOOD
5. Jelutong ( Dyera costulata)
 Color/appearance :
- White color for fresh cut and turns pale yellow.
 Grain/texture :
- Straight grain.
- Slightly really smooth cut against the grain.
- Texture medium fine and evenly.
 End grain/shape of pore
- Single pores, medium size of pore with no tyloses and deposit.
 Density range
- 415-495 kg/m3
(26-31 lb/ka3
)

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6. Pulai (Alstonia angustiloba)
 Color/appearance :
- White cream color of wood.
- Zig zag appearance along tangent surface.
 Grain/texture :
- Smooth solitary grain.
- Slightly really smooth cut against the grain.
- Texture medium fine to medium coarse.
 End grain/shape of pore
- Single pores, medium size of pore and normally have 2-9 vessels in one series.
- no tyloses and deposit
 Density range
- 464 kg/m3
(29 lb/ka3
)

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THE
PHYSICAL PROPERTIES
OF WOOD
THAT AFFECT
ADHESIVE BONDING

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1. Density or Specific Gravity (SG)
Density or specific gravity is one of the most important physical properties of
wood. Density is the mass or weight of wood divided by the volume of the specimen
at the given moisture content. Thus unit for density are kg/m3
or lb/ka3
. In hardwood,
density is depending not only on fibre wall thickness but also on amount of void space
occupied by vessel and parenchyma.
The glue-bond quality required for the species listed and for other species
falling within the density range given the solid wood substances of all species has
about same specific gravity, but in high-density species less of the volume in capillary
structure of dry wood is occupied by air. As moisture is added to the wood, the air
space decreases. When wood of different species is examined with the naked eye, the
ratio of wood substances to air species not readily seen.
2. Wood pores and vessel
Different wood species may influence the bond lines of adhesives. The
porosity and the pore size distribution were analysed as a function of the respective
position. The pores will completely bind together if the neighbouring pores during
adhesion have bigger spaces or large diameter sizes of pores or vessel. The
penetration of the adhesive to the adherence which have larger diameter of pores may
conclude the strength of wood bonding. It is also can be explained in easy words by;
before the adhesive turn to solid, it is in liquid form and travel along the pores and
adhesive may penetrate easily in form of size of pores.
Less, medium or more pores with small sizes may affect the bonding strength
between the adhesive with the adherence. Small sizes of pore which evenly appear in
adherence may conclude the good result in bonding strength in adhesion. It can be
explain when the adhesive penetrate in the pores or vessel evenly its will grip the
whole surface of adherence during the process.

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3. Grain and texture
The term of grain and texture are commonly used rather loosely in connection
with wood. Grain is often used in reference to the relative sizes and distributions of
cells, as is fine grain and coarse grain; this use of grain is roughly synonymous with
texture. Grain is also used to indicate the orientation of the cells of axial system (fibre
direction), as in “along the grain”, straight grain, spiral grain and interlocked grain.
The texture of wood by different direction may influence the bonding strength
in adherence. Two term of direction; along the grain and against the grain. Many light
hardwoods may be easily to cut by against the grain compared to the heavy or
medium hardwood. The explanation maybe same as the sizes of pores but the shape of
grain may conclude the dissimilar of bonding result.

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The difference species will affect the bonding strength when using adhesive because
for each type of wood has a different characteristic based on their density, texture of surface,
porous and others.
For the heavy hardwood species, Merbau has air dry density from 515-1040 kg/m3
(32-65 lb/ka3
) meanwhile the red balau has 800-850 kg/m3
(50-55 lb/ka3
). This is classifying
as high density woods. The medium hardwood species, Kulim (Scorodocarpus borneensis)
has range density from 835 kg/m3
(52 lb/ka3
) meanwhile Mata ulat (Kokoona coriacea) has
880-1040 kg/m3
(55-65 lb/ka3
). This is classify as moderate density woods and for the light
hardwood species, Jelutong ( Dyera costulata) has range density from 415-495 kg/m3
(26-31
lb/ka3
) and Pulai ( Alstonia angustiloba) has range from 464 kg/m3
(29 lb/ka3
). This is
classifying as low density woods.
The high density woods have thick walls and small lumen volumes, whereas low
density woods have thin walls with large lumen volumes. The strength of wood is directly
related to its density because thick-walled cells are capable of withstanding much greater
stress than are thin-walled cells. A high density wood which is Merbau and Red Balau are
difficult to bond because of thicker cell walls and less lumen volume, adhesives do not
penetrate easily, so important mechanical interlocking of adhesives is limited to one or two
cells deep. Much greater pressure is required to compress stronger, stiffer, high density wood
to bring contact between wood surface and adhesive.
Texture and grain may influence the bonding strength of the adhesion. Based on the
observation of the different species, the level of coarseness of wood may influence the
bonding strength. On the other words, if the wood is very coarse surface it may help in the
bonding strength in adhesion. As example, the texture of Merbau wood has very coarse
surface and the Red Balau has medium coarse surface. The adhesive may not easily shear
during gel time because of the coarseness of the wood would grip the entire surface which
spread by adhesive. It is different to the smooth surface wood which is tending to shear or
sliding easily during gel time. For the Mata Ulat species, it has more grain but has fine
texture. Even though, it has fine texture, the appear of more grain could help in improve their
bonding strength. Besides that, for the Jelutong and Pulai species has a smooth surface
texture which is highly cause shear during the binding process. Refer from the result,
Jelutong and Pulai not recommended as the adherend for the high strength bonding in
adhesion.

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Size of pores and vessel and number of pores appear in wood may also affect the
bonding strength of the adhesion. Inference for the size of pores; Merbau and Red Balau has
the larger pores appear in wood which is more high strength of adhesive bind the adherence
together. The liquid form of adhesive are allow travel along the pores and adhesive may
penetrate easily in form of size of pores. Besides, the number pores appear in wood also
affect the entire bonding strength of adhesion. For the Kulim species it has many pores and
vessel from moderately small to medium-sized, it’s solitary but more often in radial
multiples. Many pores appear should could result high strength of wood bind process. For the
Jelutong species, it has medium size of the single pores which is not evenly appear in the
radial surface. This may give the less bonding strength result of adhesion.

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24. 24
Lopez, D. T. 1981. Malaysian Timbers – Red Balau. Malaysian Forest Service Trade
Leaflet No. 45. The Malaysian Timber Industry Board and Forest Research
Institute Malaysia, Kuala Lumpur. 7 pp
Menon, P. K. B. 1986. Uses of Some Malaysian Timbers. Revised by Lim, S. C.
Timber Trade Leaflet No. 31. The Malaysian Timber Industry Board and
Forest Research Institute Malaysia, Kuala Lumpur. 48 pp.
Menon, P. K. B. 1997. Struktur Dan Pengecaman Kayu Kayan Malaysia. Forest
Research Institute Malaysia, Kuala Lumpur. 53 pp.
Jabatan perhutanan. 1984. Peraturan Pemeringkatn Kayu Keras Gergaji Malaysia...
Lembaga Perindustrian Kayu Malaysia, Kementerian Perusahaan Utama. 8 pp.
FRIM. Forest Product Technology Division. Common Commercial Timbers of
Peninsular Malaysia.