Salale University

College of Agriculture and Natural

Resources

Department of Forestry

Course Title: Wood processing (Fors4105)

Instructor: Lamesa Abera

01/19/2025 1
 CHAPTER ONE
WOOD PRODUCTS
Introduction
Definition of Wood
 Wood is a raw material of plant origin. It is found in the
trunks of trees, which grow every year.
 Wood is a renewable, ecological and organic good. It has
been used since the origins of humanity until nowadays to
produce furniture, buildings, boats, etc.
 To classify a wood as hard or soft depends on the seeds
that the tree produces.
 A wood will be classified as a hardwood if the seeds that
the tree produces have a coating: softwood if the seeds
don’t have any type of coating and are instead dropped to
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the ground and left to the elements.
Wood based composite
• Wood based composite products are products
made from lumber, veneer, wood particle or
strands of fiber bundles, chemical using adhesive
to form a composite products.
• Wood based composites products are made
through a series of mechanical and chemical
processing lines or using several types of
composite processing machines.
• The most common types of commercial wood
based composites are:-
 Glue-laminated boards
 Plyboards
 Particle board
 Wood plastic boards
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
 Types of Wood products
1. Lumber
• Comes from trees that have been turned into planks or
boards.
•Lumber is commonly used in structural materials, but is
also used in cabinetry, furniture and flooring and
pallets.

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 2. Veneer
•Veneer refers to thin slices of wood and
sometimes bark that typically are glued onto core
panels (typically, wood, particle board or
medium-density fiberboard) to produce flat panels
such as doors, tops and panels for cabinets, parquet
floors and parts of furniture. They are also used in
marquetry. Plywood consists of three or more layers
of veneer.

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3. Laminated Veneer Lumber (LVL)
•Made of wood veneers that are compressed together
with resins and glues.
• LVL is a high density engineered wood product used
in framing. LVL is very strong, but has only one
strength axis, because its veneers are stacked with
the grain running in the same direction.

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4. Chipwood:- also sometimes referred to as
Particle Board or Low Density Fibreboard.
•It is made by mixing small wood particles with
epoxy resin, which are pressed together under
intense heat and pressure to produce a rigid board,
typically with a smooth surface.
•Chipboard is available in a variety of densities to
suit different needs and uses, including low,
medium and high-density varieties.
•The lower densities are fairly soft and pliable, while
the higher-density chipboards are more rigid and
can be used for more heavy-duty applications.

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5. Plywood
 It is made up of thin layers of wood called veneers of
different thickness and glued together to get the desired
product.
 The name 'ply' refers to plywood and the most common
type is 3-ply(number indicates layers used) which is
strong, durable, and more decorative than plywood with
more plies, recommended for interior uses.
 As the number of layer increases, its strength and
durability increases and use for exterior purposes like
roofing, where they can withstand heavy wind and
damages.
 Plywoods have several benefits to builders, since they
are made by binding resin and wood fiber sheets to
form a composite material whose “cross graining”
property provides dimensional stability and makes the
strength of the panel consistent in all directions.
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 Plywood

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6. Medium density fiberboard (MDF)
•MDF is made by breaking down hardwood and softwood
pieces into fibers, which are combined with wax and resin
binders, and formed into panels by applying high
temperatures and pressure.
•A dense composite wood fibers are glued together to form
this fibreboard.
•It is commonly used, which is less expensive, stronger and a
good alternative to plywood.
•We need to handle carefully the finished product to avoid
cracks and splits.
•It is usually denser than plywood, and is denser than
oriented strand board, but just like OSB, there are grades
that can withstand water and weather and other grades that
cannot.
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 Medium density fiberboard (MDF)

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7. Glue laminated timber
• Glue laminated timber(glulam) is an engineered
stress-related products that consists of two or
more layers of lumber glued together.

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 8. Cross-laminated timber (CLT)
•This wood panel product is made from gluing
together layers of solid sawn lumber.
•It is strengthened by layering each board
perpendicular to the next and glued on the wide
faces of each board.
•The thicknesses of the panels can easily be
increased, which makes it a design-flexible
material.
• It can be a good insulator, since it’s made of
multiple layers of wood.

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9. Pulp and paper
• Pulp is a lignocellulosic fibrous material
manufactured from raw materials containing
cellulose fibers, such us wood, recycled paper,
and non-wood material.
• Whereas paper is a felted sheet formed on a fine
mesh from cellulose fibers.
• Pulp and paper are manufactured from
mechanical or chemical breakdown of raw
materials containing cellulose fibers mainly
derived from wood.
• Since modern life needs usage of paper every
day, the demand for paper is increasing with
population and modernization.
•01/19/2025
Worldwide cellulose pulp is produced from14
 paper

Pulp

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Application and used of wood products
Glue laminated boards
1)For structural construction
a)Residential b) commercial
c) Industrial d) Beams
e)Ceiling f)Doors
g)windows and etc
2)Transportation and mining
a)Bridge b)rail way sleepers c)pallet containers
d) Retention wall of construction site
3) Furniture and cabinet making
a) Office furniture
b) Household furniture
c) Restaurant/hotel furniture
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d) Recreational/garden furniture
4) For machinery and vehicle parts
a) Ship and boat panufacturing
b) Pulp and paper mill parts
c) Sugar mill machine parts
d) Leather mill machine parts
Uses of plywood
 Container manufacture
 Bottom boards of truck and buses
 Decorative furniture
 Boat making
Uses of Medium density fiber boards(MDF)
 Doors and Celling
 Vehicle dashboards
 Furniture
 Partitions and Interior decoration and etc
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 CHAPTER TWO
Classification of Wood Processing Machineries and Equipment’s

 Wood working machine are divided into three classes:

1. Single purpose machine

2. Special purpose machine

3. Multipurpose machine

1. Single purpose machine: are machine types used

for single job operation type like sizing, surfacing,
molding, shaping, drilling and finishing.

2. Special purpose machine: Are machine types used

for manufacturing of windows, doors, and glue
laminated products.
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3. Multi-purpose machine: Are machine types used for
several types of operation like ripping, cross cutting,
boring and shaping.

 Measure wood working machines used for furniture and

glue laminated manufacturing purposes are divided into
the following categories.

1. Sawing /sizing machines: used for cutting and ripping.

e.g. cross cut machine, band saw, radial arm saw

2. Planning machines: For minimizing the thickness of

lumber. e.g. thicknesser, edge surfacer

Shaping/molding machines. E.g. shaper, Lath machine

3.01/19/2025 19
4. Boring/mortising Machines- for drilling

5. Joining/assembling machines: - used for hold and fasten

different components of furniture and glue laminated products
together.

6. Finishing Machines; - Used for smoothing various types of wood

products and to apply finishing material for protection decorative.

Eg. Sanding machine, brushing and polishing machine, coating or

painting machine

7. Grinding machines: is the process of removing metal by the

application of abrasive which are bounded to form a rotating wheel.

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 Measure Equipment Types in Wood working
Machines

Most of wood working machine have the following types of

similar common equipment’s.

1)Electric motor: - electric motors provide energy for wood

working machines. Electric motors used in wood working
machine may have single and double face currents.

2)Gear –Box: - Gear box in wood working machines are

used to increase torque while reducing speed or the prime
mover output shaft especially for feed mechanism.

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 Measure Equipment Types in Wood working
Machines cont….
3) Pulleys: - A pulley is a drum and may have a groove b/n angles
around its circumference. A pulley is a wheel that designated to
transmit power from source to the required application using belts
along its circumference.

Types of pulleys : a) Groove b)Flat and c)Teeth

4) Belts:- Is a loop of flexible material used to link two or more

rotating shafts or pulleys mechanically. Belts may used as a source of
motion to transmit power efficiently.

Belt types: a) Flat, b) round, c) V- belt, d)timing belt, e) multi

– groove belt, and f) Ribbed-belt

5) Bearings: - A device that allows constrained relative motion

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between two or more parts typical rotation or movement.
 Chapter Three
Wood sawing/sizing machine

o There are three types of sizing machine:-

1) Radial arm saw

2) Circular saw

3) Band saw machine

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 Radial arm saw Machine

o It is one of the single multipurpose wood working machines

that used to cut long and rough lumber to the required length.
o This machine can be square rough lumber to the required

length, by using circular saw blade mounting on horizontal arm

that can slide from front to back.
o It has suspended blade, motor carriage on yoke which slide

along horizontal arm.

o The yoke allowed the head to tilt for bevel cut and to swivel for

rip cuts.
o Mounting arm on pivoting column allowed rising and lower the

column changed the blade depth of the cut.

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 Main Equipment of Radial arm saw

1. Track arm: - For moving back and forth of head

2. Yoke: - For tilting and swiveling the head
3. Column: - For supporting the whole mechanism
4. Saw blade with guard: - For cross-cutting
5. Electric motor with pulley:-To supply energy and
transmit power
6. Guide fences: - For cross cutting work pieces precisely
7. Anti-kick back and safety device:-For protection of an
operate from injuries
8. Table and bed: - For supporting the machine and
perform the operation.

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Operational procedures
oThe radial arm saw can cut long sizes of lumber into the
required length by moving the saw blade over the lumber
remains stationary on the saw table.
oThe radial arm saw machine the operation consists of work
pieces cut by putting the rotating blade over work piece, which
makes the cutting operation fully visible to the operator.
oIn addition of cross-cutting radial arm saw can be used for
cutting bevels, miter, dados and rabbet from molding.
oA cross cut blade which have knifes like shaped is to cut across
the grain so as to cut the fiber rather than rip them. Radial arm
Saw can cut up to 600mm wide and 150mm thick rough
lumber boards.
o The saw speed of such machine may have up to 300
revolutions per minute and the motor can be within the range
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of 2.2 to 3.2 kilowatt.
 Radial arm saw Machine

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 Safety rules of radial arm saw machine

1)Use always secure blade guards

2)Your hands should not reach around and over moving blade
3)Keep always blades sharp and clean
4)The blades should have low and negative hook angles
5)Use always handles for pulling or pushing the saw blade
over the stock.
6)Always double check to be sure that the hand holding stock
against the fence is clearly away from the path of the blade
7)Use feather board and pushing stick has necessary
8)Wear and use all safety protection during operation

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 2.Circular saw machine

Definition and uses

o Circular saw machine is one of the most frequently

used in wood working machine.

o It can be used for ripping, cross cutting, dados and

rabbet making using different sizes of saw blades

o This machine also used for sizing of wood based

boards like ply boards, MDF and particle
boards.

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 Sizes of circular saw blade

a) The sizes of the saw blades to remount on the

machine are 250mm, 300mm, 400mm and
500mm. The greater the diameter of the saw blades,
the larger is the saw machine.
b) The work pieces on this machine should not be less
than 350mm in length and 300mm in width. The total
electric power of this machine can be ranges from 3-
15kilowatt.
c) Circular saws used for sizing wood based boards
have special long and wide tables equipped with
roller and fences.
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 Depending on the arrangement of saw blade

circular saw machine may have the following

functions:-

1) Ripping: - Used for sawing along the grain of

the fiber of the wood that is diving wide lumber into

several narrow pieces.

2) Cross-cutting:- Used to saw across the grain

of wood that is diving to several shorter Pieces.

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 Main Equipment of Circular saw Machine
1)Saw blade: - Circular saw blade which are disks on the
rim of which teeth are cut. Saw blade are made from
either high speed steel or tungsten carbide.
a) The saw blade with diameter of 200-800mm and from 1-
5.5mm thick can be used for ripping.
b) The saw blade with diameter of 160-250mm and from 1-
5.5mm thick can be used for cross-cutting.
c) To avoid sticking the saw blade should be set alternately
0.3-0.5mm right and left at 1/3 height of the teeth for
ripping.
d) From 0.5-0.7mm should be set for cross- cutting
e) Saw blades used for ripping and cross cutting can be
normal or carbide tipped blades.

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 Main Equipment of Circular saw
Machine cont..
2)Arbor:- Is spindle or shaft to that the saw blade is mounted
3) Table: - Table that made from cast iron is used to support all
operation processes
4) The blade guards:-Is used as protection devices over the
rotating blade
5) Rip fence:- The rip fence is the rail which is fitted to the blade
along the slide wood on the saw blade. The fence is used in guiding
the work pieces is determined the accuracy of the cut during the
process of making rip cut.
6) The on/off switch:- Switch is mounted at the front of the
machine that used to start up and stop the machine.
7) Blade elevation control:- Is used to adjust the height of the saw
blade to the desired depth of cut.
8) Splitter:- Splitter is a riving knife that vertical projection located
behind the saw blade, it is slightly narrow in width than the blade and
located directly in line with the blade. Splitter prevents the material
being cut from rotated blade and protects kick back.
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01/19/2025
Circular saw machine 34
 Operational Procedures

o A circular saw machine is a type of wood working

machine which have saw blade made from high
speed steel or tungsten carbide and used for
ripping of wood.
o Circular saw may use for the following types of
operation: -
(1) Cross-cutting (2) Ripping (3)
Cutting dados
(4) Angular cutting and (5) Sizing of wood
based boards
o All the above mentioned operations can be
performed by moving the pieces of lumber against
rotating protruded blade.
o01/19/2025
Rough lumber may push against the saw blade 35by
 Safety rule of Circular saw machine
1)Your hands should not be reach around and over moving

blades.

2)Do not feed the work pieces faster than the saw can accept.

3)Avoid kick back or when the blade catches the work pieces and

violently throw it back to the front of the saw towards the

operator.

4)Never stand in direct line between the blade and the fence

where ripping narrow stock.

5)Use blade guard and pushing stick during operation

6)Use sharp and clean blades always

7)Wear
01/19/2025 all appropriate safety protection 36
 3. Band Saw Machine
Definition and Uses
o one of the most important types of wood working machine that has
blade with continuous band of metal with teeth along one edge
to cut lumber.
o The band usually moves or rides on two wheels rotating in the same
plane. At the result of evenly distributed louds uniform cutting can
produce on band saws.
o Band saw can be used to saw irregular shapes, circle and to rip
straight pieces.
o The minimum radius of the curve that can be cut on particular saw is
determined by width of the band and its lateral flexibility.
o Band saw can accommodate a wide surface of lumber and has less
waste due to smaller curve or cutting sizes.
o A band saw machine is equipped with lower and upper wheels that
used for clock wise rotation of the blades. The blade can cut pieces of
lumber
01/19/2025 continuously down stroke. 37
 Main Equipment of band saw machine

1)Band saw blade:- The narrow band saw blade usually

rides on two wheels rotating in the same plane. Band saw
blades can be classified based on the width of the blade and
the type of teeth that the blade have. Depending on the
width of the blade, band saw blades are divided into:-
a)Narrow type blade: - Is used to cut very small radius of
curves. The width of the blade ranges from 15-75mm. It
can also use to make sharp curves.
b)Wide type blade:- Used for making curves having large
diameter and also used for ripping and re- sawing operation.
2) The Band Wheel: - The band saw consists of two large
wheels around which a continuous band of steel with cutting
teeth is driven.

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 a)Upper wheel: - Is not power driven and runs free
during operations.
 The upper wheel they also tilted back and fourth to
the center the blade on the wheels.
 To protect the teeth of the saw blade, thin rubber tire
cover rim of the wheels. The upper wheels also
adjusted up or down to put tension on the saw blade.
b) Lower wheel:- Unlike the upper wheel the lower
wheel is powered by electric motor and does not tilt
on its axis and also it does not move up and down, its
permanent in its position.
 Like upper wheel the rim of the wheel is covered by
rubber tire to prevent damage of the blade and also
avoid blade breakage.
01/19/2025 39
3) Blade tension Wheel:- The tensioning wheel can be used
for accurate cutting and avoid blade breakage.
4) Throat width. It is the distance from the top of the table to
the bottom upper guide assemblies. The width of the throat
limits the maximum thickness of the stock that the machine
can cut.
5) Blade guide assemblies:-Blade guide assemblies are
found above and below the table of the band saw to prevent
saw blades and it is dived into:-
a)Rear blade guide:- is located at the back of the blade. It
prevents the blade from being pushed of the wheel during
machining.
b)Side guide wheel:- located either side of the blade and
used to control side wheel movement of the blade during
machining and thus avoiding twisting and breakage of the
blade.
01/19/2025 40
6)Table: Used to support the work during machining.
Table may be tilted, this enables to make to cut the
required angles.
 There is slot in the table from the center of the edge for
moving and replacing the saw blade.
7) Metal insert:- Is soft metal which is used to cover the
opening of the slot on the table.
 Soft metal is used to insert the blade.
8) Wheel guards:- Thin sheet of metal which is used to
cover the band saw wheel and are used during operations.
9) Fence: - Is used for guiding the stock during machining
10) Control switch: - Used to start and stops the matter
11) Dust chute:- Used to remove dusts from the
machine

01/19/2025 41
 Band saw machine
01/19/2025 42
Operational procedure of band saw machine
 Irregular shapes, curves, and holes can be cut by band
saw using free hands following the lay out without the use
of guiding devices such as fences, jigs, and wooden blocks
etc. Straight cutting can be done on band saw using guide
fences or lay out by free hands.
Safety of band saw machine
1. Keep the saw blade sharp and clean
2. Always use stick for pushing
3. Do not use excessive force when pushing pieces of wood.
4. Do not use excessive tension to avoid blade breakage
5. Do not remove saw dust or cutting from the table by hand
or with compressed air. Use stick or brush.

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 Chapter 4
Wood products planning, shaping, drilling,
molding & tenoning machines
Definition and uses: Wood Planning machines are
used for removing several lumber defects like twist,
warp, scratch and other irregularities for uneven
surface of rough lumber. As a result of removal of these
irregularities the lumber surface will become straight
level and smooth.
 There are two types of machine to perform this
operation
1) Jointer/edge surface
2) Thicknesser
01/19/2025 44
1. Jointer/edge surface:- The jointer machine frame
are made cast iron that used to carry the cutter head drive,
an electric motor rear and front tables between which the
cutter head revolving.
Jointer machine may have the following main
components.
1. Table: - jointer has two tables the rear and front. The
front table is larger than the rear table to provide accurate
jointing. Tables are adjusted so that the rear table should
level with the cutter at the height will the front table
should be lowered by the thickness of the west to be
removed.
2. Electric Motor: - the total input of electric power for
jointer can be from 4-10kw.
3. Cutter head:- Cutter head may have 2-4knives which are
secured on knife folder and protrude 1-2mm above the
chip breaker lip. The cutter head may have speed from
01/19/2025 45
4000-5000rpm.
4. Fence:- the fence of jointer is support and
guides the work piece being feed into the machine.
It set or adjusted vertically 900 to the machine table
for operations. It can be also tilted to vary angles
usually up to 450 both ways forward and backward
from vertical positions.
5. Safety guard:- the safety guard of the jointer is
used to protect the operator from injuries may
cause by cutter head.
6. Pushing blocks:-Is used to press and push the
stock over the cutter to plan the stock properly.

01/19/2025 46
Operational procedure
 The jointer machines used for flattening or surfacing of the
wide faces of the board and squaring the edge of the boards.
•To perform this operation, the operator examines both pieces
of the stock and placed on concave side of the stock on the
front table.
•Then by holding tightly the stock with his left hand he can
push into the cutter head without jerks by his right hands.
•The operator must use pushing block when he pushing wide
surfaces. The work piece is should be surfaced until perfect
edge or surface will be obtained.
•The quality of surface operation is checked by fitting the
machine surface or edge to each other. If no light can be seen
through the joint the surface are properly planned.
•The machine can surface the work pieces up to 630mm wide
is 01/19/2025
the maximum cutting depth of 6mm. 47
 Safety rules of jointer machine
1. Always keep the knife sharp, dull knife tend to cause
kick back or poor planning
2. Avoid vibration that may allow kick back
3. Never adjust the fence while the jointer is running
4. Cut with the grain, never plain against the grain
5. Do not try to cut too heavy cut
6. Always put the guard in place to cover the cutter head
7. Keep your fingers at least 100mm away from the cutter

01/19/2025 48
 2. Thicknesser

Definitions and uses:- The thicknesser planer or thicknesser is

used to plane boards to the required thicknesses.
 It is a machine type that revolving cutter head set above adjust
table on which material is pressed under the cutter head by
powered rollers.
 It can smooth one or both surface of pre-planned boards on
jointer machine and it can also use to create boards of that have
un even thickness throughout their length and flat on both
surface.
 There are two types of thicknesser planers
1) Double thicknesser
2) Single thicknesser
 Double thicknesser: Have two cutter head and plane both surface
of boards at the same time while single thicknesser have only
01/19/2025 49
one cutter head and can planed only one surface at a time
 Main Equipment of thickness planer

1. Table:-Is the part of which the work piece riding during machining.
Table is adjustable in height relative to the cutter head to control the
resultant thickness of the board.
2. Feed mechanism:-The feed mechanism of thicknesser planer is the
part which moves the stock through the machine thus advancing the
stock to the rotating cutter head and moving away the stock after it has
been planed.
3. Cutter head: the cutter head is a heavy steel and cylinder cutter
knives are mounted on it.
4. Pressure bar: is used to hold the stock down to prevent vibration
during planning. There are two types of pressure bars the rear and front
bars.
5. Anti kick back: - is a device used to prevent possible kickbacks of the
stock during operations
6. Thicknesser control handle: - thickness control handle is used to
adjust the table in the height for controlling the thickness of the stock
being planed.
7. 01/19/2025
Feed control level:- is used to regulate the rate of feed of the stock
50
being planed from slow to fast
 Operational procedure

 In thickness planer the board is feed into the

machine until it makes contact with the feed rollers
which grips the boards and draw it into the machine
and past under a rotating heads.
 The knives remove an amount of material on the
way through and out feed rollers pulls the boards
through and eject it from the machine at the end of
the pass.
 In thicknesser planer it is necessary to start with
the board that has at least one perfect flat reference
face during planning.

01/19/2025 51
Safety rules of thickness planer

1. Always keep knives sharp. Dull knives tens to

cause kickback or poor planning.
2. Do not try to cut more than 2mm once.
3. Do not use high feed speed for all types of woods.
4. Cut with the grain, never plain against the grain
5. Use always exhaust fans for dust collections
6. Use always safety tools during operations

01/19/2025 52
 Wood shaping/ molding machine
Definition and uses
 Shaping machine are used to plane and
mold surface of lumber into varies shaper for
joining and decorative purposes.
 There are three types of shaping machines:-

1.Spindle shaper
2.Tenoning
3.Lath machine

01/19/2025 53
1. Spindle shaper
o It is machine type designed for making decorative
and curved irregular or regular edges of the stock.
o This machine is one of the most dangerous to
operate due to high speed of rate.
o The speed of rotation of this machine may from
4000-10000 revolution per minute (rpm).
o This machine is available in single spindle and
multi spindles with power feed mechanism.

01/19/2025 54
 Main equipment of spindle shaper
1. Spindle:-is a vertical shaft on which the cutter head are
mounted. It can raise and lower to provide various positions
for the cutter. Its diameter determines the size of the shaper
and the speed rates.
2. Fence: - is part which is used to guide the work during
machining and it has two parts the rear and front fences
3. Cutter: - Are made of alloy steel and are various shapes. The
common types of cutter are the clamp type and solid wing
cutter
4. Table: - Is made of cast iron and supports the fences for
guiding the work pieces.
5. Spindle height adjustment wheel: - Is used to move the
spindle up and down together with driving mechanism.
6. Spindle lock: - Is used to lock the spindle in place after it has
been adjusted.
01/19/2025 55
Operational procedures

o The operator places the work piece with its fence of the table and
holding the edge to be shaped against the fence and push to the
cutter head.
o The work should be feed gently with uniform pressure against the
fence.
o Plane edges are shaped against the guide fence. Curved edges are
shaped against collar using hemp lets.
Safety rules of spindle shaper
1. Adjust appropriate feed speed specially when flat and open face
knives are used
2. Use safety guards and wear all safety tools during operations
3. Do not back up and work because it may throw out of your hand
4. See that the knives are exactly the same height and width
5. See that the spindle is free before turning on the power
6. Do not take your attention of the work and the machine for one
instant
7.01/19/2025
Do not attempt to shape smaller pieces of wood 56
2. Tenoning Machine

Definition and uses

o Tenoning is used to cut tenons from 100-160mm long and

up to 50mm thick.

o It is also used to cut mortise from 100-125mm long, 80-

125mm wide and 50mm thick.

o Tenoning machines may be single ended and double

ended cutter heads.

o Single end cutter head is used to cut one side of tenon at

a time and double end tenon cut two side of tenon at a

time.
01/19/2025 57
Main equipment of tenoning machine
1. Cast iron frame or table:- Used to carry sadle with cutter
head and electric motor.
2. Sadles:- Used for vertical, horizontal and angular movements
3. Cutter heads:- Used for holding cutter or tenons and
mortizes
4. Rail:- Used as a ways for sliding rollers
5. Electric motor:- Is used to supply power for cutter heads
6. Hydroualic power carriage:- Carriages help to move rollers
7. Guide fence:- Is help to set strictly the work piece
perpendicular to the direction of the fed.

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Operational procedures
o The machine can perform tenon and mortise job on work
pieces of 2200mm long to 250-700mm wide and 75mm thick.
o The dimension of the tenon cuts are up to 100mm in length
and not less than 6mm in thickness.
o The minimum distance between the tenoning shoulder should
be 200mm. Tenon machine may have 1.5 to 16m/minute feed
speed.
Safety rule of tenoning Machine
1. The work piece should be tightly placed on the carriage and
secure with pressure device
2. The carriages should be feed to the cutting speed heads
gently at the constant speed.
3. Fit tightly the cutter on the heads properly
4. Use safety guards and wear safety clothes during operations
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3. Lathe Machine

Definition and uses

 A lathe machine is one of the oldest wood working tool or

machine that used for turning pieces of wood on its axis to

produce various cylindrical and circular shapes. The work pieces

is rotated and the cutting tools moved relative to the job.

 Wood items like tool, drawer handles, turned table, chair

legs, bowls, lamp holders, flower vases, musical

instruments and other turned items are produced on the lathe

machine.

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Main Equipment of lathe machine
1. Bed:- Is the main structure of the lathe machine that used to

carry head stock, tail stock, electric motor, tool rests and other

attachments used for turnings

2. Head stock:- Is the main part of lathe machine that carry the

electric motor with pulley, gear box used for turning work pieces.

3. Tail stock:-The counter point to the head stock is called tail

stock. Its adjustable devices that help to hold the work pieces

during turning.

4. Tool rest:- Is used to support the turning tools during operation.

It can slide along the blade and locked securely in any location.

5. Locking
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handle:- Used for control guard and switch 61
01/19/2025 62
Operational procedures
o The material can be held in place by either one or two
centers at least one of which can be moved horizontally
to accommodate varying length of material.
o The other work holding method includes clamping the
work about the axis of rotating using chuck or collets or
face plate using clamps.
o The rotating speed of spindle is controlled by variable
speed motor or by stepped pulleys. Speed ranges from
340 to 3200 revolution per minute.
o Slow speed is used to rough down large cylinders
whereas high speed is used for finishing operations.
The general rule to remember is the large stock to be
turned on the lathe, the slower speed of the lathe.
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Safety rules of lathe machine
1. Wear safety face shield and ear protection to protect your self
2. Before the lathe is turned on, ensure that all clamps and
fittings are secure and that the work piece is free form.
3. Hold tools firmly with both hands against the two tests.
4. Use the stock securely on the face plate or between the
centers
5. Use sharp well maintained chisels and gouges
6. Select speed that is appropriate for the job
7. Adjust tool rest so that they are parallel and as close as
possible to the stock
8. Remove the tool rest when sanding or polishing

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 Chapter 5
Finishing Machines

•Wood finishing refers to the process of refining, protecting or

covering a wooden surface.

•Wooden surface is normally coated with finishes such as paints,

lacquers, drying oils varnishes or stains.

•The process starts with surface preparation, that is covering the

wood defects using wood filler and sanding works.

•Surface coating helps to protect the wood substrate from dirt,

moisture, fungal attack, weather and scratches.
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•In wood furniture manufacturing, surface coating is the final process
where it is called “finishing”, while the coating material used is called
“finish”.

•Finishing is regarded as one of the most important phases in

furniture processing that will give value to the final product.

•Wood finishes are chosen based on factors such as types of wood,

preparation time, cost, protection against weathering and the
product’s final appearance.

• Essentially, another factor that need to be considered is the final role

of the furniture, whether it is for indoor or outdoor usage.
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•Finishing machine are divided into three major categories.
I. Sanding machine
II. Brushing and polishing machine
III. Coating or painting machine

1. Sanding machine:- Are used for wood surface smoothing and

removal of surface defects. Depending up on the application and
design the sanding machine can be classified as follows:-
Narrow sander:- for sanding narrow pieces and curved surfaces.
Wide belt sander:- Used for smoothing flat surfaces with stationary
table and manual pressing of the sand belt over work pieces.
Drum sander:- Used for smoothing both sides of wide surface of the
boards with the help of feed motor moving.
Dick sander: - used for sanding curves, circle and irregular shape
products.
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•The belts for sanding are made of canvas or paper to which an
abrasive of glass silicon or other material of high hardness is
applied.
•Depending up on the grit size the sand paper is divided into
numerous grades.

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 Operational procedure of sanding machines
•The drum sander may use chain and rollers for their feed mechanism

•Work piece up to 125mm wide and not less than 460mm long and up
to 130mm thick can sand on drum sander.

•The work pieces are feed in to the machines at the rate 4-12.5m/min.

•Sanding can be done manually either by hand or with the help of

machines such as wide belt sander, vibrator or random-orbital sander.

•When hand-sanding a flat surface, a wooden or sanding block is used

to hold the sand paper rather than holding it directly with a hand as
shown in Figure 4(a).
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•This is to prevent an undulant wooden surface at the end of the
sanding process.

•Electric sanding machines like in Figure 4(b) are power tools that
make sanding easier and faster.

•However, extra precaution must be taken not to burn or over

sanding the surface. When sanding into corners, a detail sander
may be helpful.

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Figure 4: (a) Hand-sanding and (b) power tool sanders 70
 2. Brushing
 Brushing is a traditional technique to apply paint or other wood
finishes.
 It is the easiest way and suitable for small scale finishing works
such as for antique or small size furniture.
 This method requires patience because it is time consuming.

 For a good result, it is advisable to use a good quality brush and

high quality finish.
 Oil based finishes would not work well with latex brushes.
Similarly, water based finishes will not work well with oil
brushes.
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 Figure 5: shows common brushes used for wood finishing.

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painting
o The use of roller to apply finishes is easier, fast and economical.
o Paint roller can cover much larger flat surface area efficiently as
compared to brushes.
o Its simple design consists of a roller cover and a roller frame.
o Foam and fabric type rollers are commonly found in the market.
o The roller frame can be reused or replaced depending on the
need.
o Paint is transferred to the roller by rolling it in a flat paint
container and then rolled onto the surface to be painted with
medium and uniform pressure.
o However, paint roller is only suitable for flat surface.

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 4. Coating/ painting machines
 Coating of stain, lacquers, varnish and other finishing material are
applying on wood products by semi- automated and fully automated
coating lines.
 Spraying is the most commonly used industrial wood coating method in
Ethiopia for mass production.
 Spraying the aid of spraying installation and spray guns using air
pressure up to 0.3mpa at a distance of 200-300mm from the surface to
be finished.
 After application of coating the work piece are dried in drying
chambers.
 Spray finishing is a widely used technique in the furniture industry.
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Although it adds up to the cost due to maintenance and spare parts.
Spray finishing has many advantages
 This technique is able to give smooth and uniform layer of finish
on the final product.
 It is way quicker than brushing and can save time, finishes and
labour.
 Spraying may be easier than brushing; however special knowledge
is necessary before doing it.
 Most importantly is knowing the right tools and equipment to

protect the wooden surface.

•Spraying requires some practice before getting a satisfying
result
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 Factors that need to be considered are such as the;-
 Distance of the spray gun’s nozzle from the substrate
nozzle position,
 Spraying angle, the movement of the spraying tool,
shape of the item or surface, right air pressure
 Correct handling and time interval between layers.

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 Spray Gun Nomenclature

• When buying and using a spray gun, basic knowledge of its features
can be helpful in order to operate it properly.

• It is therefore imperative to learn the components and its

terminology so that the spray gun can be used efficiently. The spray
gun nomenclature is shown in Figure 9.

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01/19/2025 78
 Two common types of spray guns
1. Suction feed spray guns work by bringing the pressurized air over the
finish and draw it out through the nozzle.

• It is suitable for a large scale finishing works.

• The finish is placed below the trigger in a fairly big container and that
helps for a comfortable and stable handling.

2. Gravity feed spray guns are suitable for smaller batches of finishing
works.

• The material container is located on top of the spray gun that allows the
finish to flow down into the nozzle by gravity force.

• The air only serves to carry the finish to the substrate; therefore lesser
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air pressure is needed.
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 Chapter 6
Wood Products Joining and Assembling Machines

Definition and uses

 Joining and assembling machine are a machine types those can
be used to hold or fasten different components of furniture,
glue laminated products together by surface attachments.
 Various types of adhesives and several types of wood joints are
widely used for joining or fastening in the operation of joining
and assembling machines.
 Long term loading physical and chemical changes should not
affect intimate contact of each components bonding.
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 Material necessary for Joining Wood Components
1. Adhesive:- any substance that is capable of holding materials together
in a functional manner by surface attachment that resists separation.
 It is the most important raw material for joining wood components in
joining and assembling machines.

2. Adhesion:- Defined as the state in which two surface are held together by
interfacial forces, which may consist of valence force ,interlocking actions.
 In the performance of adhesive joints, the physical and chemical
properties of the adhesive are the most important factors.

3. Adherened:- Defined as the material/wood being held together by an

adhesive.
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Types of Adhesive
1. Bio based adhesive
2. Thermoplastic(synthetic polymer) and

3. Thermosetting

 Bio-based adhesives;- Are natural polymeric materials that act as

adhesives, have high molecular weight, and are biocompatible
and biodegradable polymers used to join two surfaces.

 Bioadhesives may consist of a variety of substances, but proteins

and carbohydrates feature prominently.

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2. Thermoplastic glue:- Are a long-chain polymer that soften and flow on heating, then
harden again by cooling.
 They generally have less resistance to heat and moisture and long term static
common glues live.
 Polyvinyl acetate emulsion
 Elastomeric
 Contracts
 Hot – melts

3. Thermosetting glue:- Make excellent structural adhesives because they

undergo irreversible chemical change, and on re-heating, they do not soften
and flow again.
 They form cross-linked polymers that have high strength ,resistance to
moisture and are rigid to support high long term static loads without
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Examples are:-
 Phenol formaldehyde
 Melamine formaldehyde
 Urea formaldehyde
 Resorcinol formaldehyde
 Isocynate
 Epoxy

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 Equipment’s and machines used for Joining
 The following types of equipment’s and machines may use
for joining furniture and glue laminated products.
1. Various types and sizes of clamps
2. Glue mixer and spreader
3. Guillotine for veneer cutting
4. Veneer joining machine
5. Hot pressed machine
6. Cold press and special purpose automatic assembling
machine

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1. Various types and sizes of clamps

 Clamps are fastening device those used to join two or more

glued wooden components together by applying pressure.

 When joining glued components by clamp there should be

stationery clamped to avoid movements of joint components
and helps for proper drying of glue at least from 4-24hrs
depending on the glue type.

 Most of clamps are operated manually for joining wood

components.

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 Clamp types
a) Bar clamp:- are sliding type of clamp used for joining edge
and surface on the bench top
b) Bench clamp:- it is used for holding work pieces on the
bench top
c) Cardellin clamp:-is a jaw style clamp that clamps round
square or rectangular tubing or on to flat objects.
d) C-clamp or G-clamp:-Is used for joining small work pieces.
e) Flooring clamp:-Is used to clamp up floor boards.

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2. Glue spider
 Is a machine type used to make and spread glues uniformly on

the surface of joints.

 Adhesive should be distributed with an adequate amount of

uniform thickness over the bonding area.

 Adhesive can be spread by hand with brush, rollers of bed

extruders.

3. Veneer joining machines

 Is a type of machine used to join narrow piece of veneer to

produce wide surface veneer used for wide boards.

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 4. Hot press machine
 Is a machine type used for to over lay veneer, plastics, aluminum
sheets, formica and impregnated paper products on surface of
large wood based boards such as plastic boards, medium density
fiber boards, plyboards, and strand boards.
 Hot presses are used a high pressure and temperature for
polymerizing thermosetting adhesive in the wood cells.
 It forces adhesive to penetrate into the wood structure for more
effective mechanical interlocking.
 The extent of temperature in hot press may ranges from 80-
140oc and the extent of pressure applied vary from 12-40kg/m2.
 Hot pressing times vary from 2-15minutes and up to 30 minutes.

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5. Cold press
o Are machine types used to join wood joints and overlay wood
based boards using thermoplastic adhesives.
o The applied pressure may depend on the type of the products.
o Temperature is not applied in cold press and pressing time varies
from 15min-24 hours.
o Pressure is applied with either a mechanical or hydraulic system.
6. Special purpose automatic assembling machines
 Are machine types used to join windows, doors, chairs, tables
and other cabinet products.
 The machines are operated by semi or full automatic pneumatic
and hydraulic systems.

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 Chapter 7
Panel sizing and drilling machines

Panel sizing machines

o Circular saw machine is one of the most frequently used in

wood industry for panel sizing.

o This machine used for sizing of wood based boards like ply
boards, medium density fiber boards and particle boards.

o It can be used for ripping and cross cutting, using different

sizes of saw blades

o Circular saws used for sizing wood based boards have special
long and wide tables equipped with roller and fences.

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 Main equipment of panel sizing machines
1) Table:-Table that made from cast iron is used to support all
operation processes
2)Arbor:-Is spindle or shaft to that the saw blade is mounted
3) The blade guards:-Is used as protection devices over the rotating
blade
4) Rip fence:- The rip fence is the rail which is fitted to the blade
along the slide panel on the saw blade. The fence is used in guiding
the work pieces is determined the accuracy of the cut during the
process of making rip cut.
5) The on/off switch:- Switch is mounted at the front of the machine
that used to start up and stop the machine.
6) Blade elevation control:- Is used to adjust the height of the saw
blade to the desired depth of cut.
7) Splitter:- Splitter is a riving knife that vertical projection located
behind the saw blade, it is slightly narrow in width than the blade and
located directly in line with the blade. Splitter prevents the material
being cut from rotated blade and protects kick back .
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 Operational procedure of panel sizing machine
o Panel sizing machine(circular saw) is a type of wood working
machine which have saw blade made from high speed steel or
tungsten carbide and used for ripping of boards.
o Panel sizing machine may use for the following types of
operation: -
1. Cross-cutting panel boards
2. Ripping of panel boards
3. Angular cutting of panel boards
o All the above mentioned operations can be performed by
moving the pieces of lumber against rotating protruded blade.
o Panel board may push against the saw blade by hand or
feed motor. The depth of cut is varied by moving the blade
up and down.
o The higher the blade protrudes the table, the dipper cut that is
made
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 Safety rule of panel sizing machine
1) Your hands should not be reach around and over moving blades.

2) Do not feed the work pieces faster than the saw can accept.

3) Avoid kick back or when the blade catches the work pieces and

violently throw it back to the front of the saw towards the

operator.

4) Never stand in direct line between the blade and the fence

where ripping narrow stock.

5) Use blade guard and pushing stick during operation

6) Use sharp and clean blades always

7) Wear all appropriate safety protection

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 7.1.2 Panel Drilling Machines
Definition of Drilling Machine
o A drilling machine is a tool that is used to create cylindrical holes or
other shapes in a material such as metal, wood, or plastic.
o It is a versatile machine that has a rotating drill bit that is designed to
penetrate the material and create a hole of a specific size and depth.
o Drilling machines are commonly used in factories, workshops,
construction sites, and other settings where precise and efficient hole-
making is required.
o Overall, drilling machines play a crucial role in a variety of industries
and are essential tools for creating accurate and precise holes.
What is Drilling Process?
o Drilling is a material-removing or cutting process in which the tool
uses a drill bit to cut a hole of circular cross-section in solid materials.
o This is the most common machining process, around 75% of all metal
cutting material removed comes from the drilling operation.
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Functions of Drilling Machines
Drilling machines are very versatile and can be used to create holes of
all types and geometries, as shown below.
1. Drilling: The main function of a drilling machine is to create holes
in a variety of materials, such as metal, wood, and plastic. The drill
head of the machine rotates a drill bit at high speeds to cut through
the material and create the hole.
2. Tapping: Some drilling machines can be equipped with a tapping
attachment that allows the machine to create threads in a hole.
3. Counter boring: A counter boring attachment can be used to
enlarge the top of a hole to a specific diameter.
4. Counter sinking: A countersinking attachment can be used to
create a conical recess at the top of a hole to allow the head of a
screw or bolt to be flush with the surface of the material.
5. Reaming: A reaming attachment can be used to smooth and
enlarge the inside of a hole to a precise diameter.
6. Boring: A boring attachment can be used to enlarge an existing
hole to a specific diameter.

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 Main Parts of A Drilling Machine
Here are the main parts of a typical drilling machine
1. Base:- This is the bottom portion of the machine, which provides stability
and support for the rest of the components.
2. Column:- This is the vertical part of the machine that connects the base to
the table. It typically contains the spindle and other internal components.
3. Table:- This is a horizontal platform that the material to be drilled is placed
on. It is usually adjustable, allowing the operator to move it up or down to
control the depth of the hole.
4. Spindle:- This is the rotating shaft that holds the chuck and drill bit. It is
driven by a motor and is responsible for turning the drill bit at the desired
speed.
5. Chuck:- This is a clamping device that holds the drill bit in place. It is typically
operated by a key or lever and allows the operator to change out drill bits as
needed.
6. Drill Head:- This is the part of the machine that contains the motor and other
components responsible for driving the spindle and turning the drill bit. It is
usually mounted on a sliding mechanism that allows it to be raised and
lowered.
7. Controls:- These are the buttons, levers, and dials that allow the operator to
start and stop the machine, adjust the speed and torque of the drill, and
control other functions.
8. Other components of a drilling machine may include a coolant system, a
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work light, and a chuck key.
 Parts of Drilling
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 Types of drilling Machines

 Based on the functions, structures, uses, and material of

the work piece, the types of drilling machines are various.
The most common types of drilling machines used in machine
shops are:-
1. Portable drilling machine
2. Sensitive drilling machine
3. Gang drilling machine
4. Multi-spindle drilling machine
5. Upright drilling machine
6. Radial drilling machine
7. CNC drilling machine
8. Deep hole drilling machine
9. Micro drill press
10.Turret type drilling machine

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1.Portable drilling machine 2. Sensitive drilling machine

3. Gang drilling machine 4. Multi-spindle drilling machine

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 6. Radial drilling machine
5. Upright drilling machine

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 Operational procedure of drilling machine

• To use a drilling machine, the material to be

drilled is placed on the table of the machine,
and the drill bit is secured in the chuck.
• The drill head is then lowered onto the
material, and the spindle is rotated to turn
the drill bit.
• The operator can adjust the depth of the hole
by moving the table up or down, and can
control the speed and torque of the drill using
controls on the machine.
• Some drilling machines also have a coolant
system to help keep the drill bit cool and
lubricated while it is in use.
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 Chapter - 8
Grinding Machines
Saw blades, knives and Cutters Grinding Machines

Grinding Machine:- is the process of removing metal by the application of

abrasive which are bonded to form a rotating wheel.
•The grinding machine is used for roughing and finishing flat, cylindrical, and
conical surfaces; finishing internal cylinders or bores; forming and
sharpening cutting tools; snagging or removing rough projections from
castings and stampings; and cleaning, polishing, and buffing surfaces.
•When moving abrasive particle contact the work piece they act as tiny
cutting tool, each particle contact the work piece they act as tiny cutting
tool, each particle cutting a tiny chips from the work piece.
•The grinding machines supports and rotates the grinding abrasive wheel
and often support and position the work piece in proper relation with the
wheel.
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•Grinding machines in wood industries are used to sharpen:-
1. Normal saw blades
2. Carbide saw blades
3. Shaper knives
4. Band saw blades
5. Jointer and thicknesser planer knives
6. Drill bit and chain mortizers
7. Lathe gouges
8. Other countless cutting tools in wood industries
Operational procedure of grinding machines
There are three operational procedures in grinding machines
9. Clearing by wire wheels
10.Cylindrical or conical work piece and
11.Surface grinding work piece.
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I. Clearing by wire wheels:- A wire wheel which is mounted on utility grinding
machine is used for cleaning operations such as removing rust, paint or dirty from
metal objects.
 To clean objects with wire wheel place the object firmly against the wire wheel.
Work the object back and fourth across the face the wheel until all traces of rust
paint or dirty are removes.
II. Cylindrical or conical work piece grinding:- Cylindrical grinding is the practice of
grinding cylindrical or conical work piece by revolving the work piece in contact with
the grinding wheel.
 The work piece and the wheel are set to rotate in opposite direction at the point of
the contact. These grinding methods is used to sharpen saw blades, drill bits and
gouges
III. Surface work piece grinding:-The surface grinding machine is used for grinding flat
surfaces.
 The work piece is supported on a rectangular table which moves back and forth and
reciprocates beneath the grinding wheel.
 Grinding flat surface is characterized by a large contact area of the wheel with the
work piece, as opposed to cylindrical grinding where a relatively small area of
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contact is present.
 Coolant:- The coolant is directed over the point of contact between
the grinding wheel and the work. This prevents distortion of the work
piece due to uneven temperature by the cutting action. In addition,
coolant keeps the chips washed away from the grinding wheel and
point of contact, thus permitting free cutting.
Safety rules of grinding machine
1. Wear goggles for all grinding machine operations
2. Never operate grinding wheel at speeds in excess of the
recommended speed
3. Never adjust the work piece or work mounting device when the
machine is operating
4. Do not exceed recommended depth of cut for the grinding wheel or
machine
5. Remove work piece from grinding wheel before turning machine off.
6. Use proper wheel guards on all grinding machine.
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