lab report adherend

TABLE OF CONTENTS

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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

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.


- 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.


- 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.


- 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.


- 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.


- 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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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.

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