1. WOOD
Design & Technology Homework
Wood is the most accessible and renewable
material used by humankind during its history.
Today, the consumption of wood exceeds all
other known materials. The industry of various
products made of wood grows continuously.
By Pranav Bisumbher,9R
2. Hardwoods
This type of wood comes fromdeciduous
trees. These trees are seasonaland lose
their leaves during the winter. This means
that they don’tgrow as fast as other trees
and, as a result, they take longer to harvest.
Slow growth results in the wood having a
closer grain. This makes it stronger and
harder. Italso gives better aesthetic
qualities due to the interesting colours and
grain patterns.
The slow-growing natureof hardwoods
makes them moreexpensive. They are less
sustainable.
Hardwood aremainly used in high quality
indoor and outdoor furniture. They are also
used in decorative interior and exterior
joinery within construction such as doors,
window frames, and gates.
Examples of hardwoods include:-
Oak
Mahogany
Teak
Like other hardwoods, mahogany is a
strong wood with a close grain
Wood is used in manufactureof an
artefact (for example, tables, chairs,
furnitureand etc. Wood is also referred as
timber. Thereare three types of woods:
Hardwoods, Softwoods, and
Manufacturedboards. Each of these
different wood types can be used in a
number of different ways.
3. Softwoods
Softwoods like pine grow quickly
and have a wider grain.
Softwoods likepine grow quickly and havea
wider grain.
This type of wood comes fromconiferous,
evergreen trees that grow all year round.
This means that they growquicker than
other types of trees and they can be
harvested more regularly and replaced in a
sustainableway. Due to this there is always
steady supply and they are usually cheaper.
Faster growth results in a grain structurethat is wider and less dense that hardwoods. This
makes softwoods easy to work with but less durable. Softwoodstend to mainly be light in
colour.
The easy availability of softwoods means thatthey tend to be used to make less expensive
furnitureand constructions, such as sheds and timber frames.
Examples of softwoods include:-
• Pine
• Spruce
• Cedar
4. Manufactured boards
Manufactured wooden board is a cheap, strong productthat can be sustainable
Manufactured boards area mechanically engineered formof wood. They offer a number of
different advantages over traditional hard and softwoods as they usea combination of
different sources of woods to create a new material.
Boards can be made in several
different ways such as:-
wood particles and glue
pressed together
a build-up of thin wooden
veneer layers
sandwiches of strips of wood
They can be made fromrecycled
woods and by-products, creating a
cheap, strong product that can look
expensive. Italso can be made
available in large formats that are
more sustainable.
Manufactured boards havea range of
uses and are often used to create
inexpensive flat-pack furniture.
Examples of manufactured boards
include:-
Chipboard
Plywood
Block Board
MDF (MediumDensity
Fibreboard)
Manufacturedwoodenboard is a cheap,
strong product that can be sustainable
5. Box joints
Wood joints
Wood joints are a traditional method of joining timber. There are a range of different
joints that can be used for different situations that provide a variety of levels of
strength and structure. Joints are often glued to make them secure and permanent.
Wood joints are classified into two construction categories:
frame
box
The butt joint is the simplest joint to use as with all
joints, both pieces of wood need to be cut accurately. It
has no mechanical strength of its own and relies entirely
on glue and nails.
The lap joint has a shoulder which gives it little more rigidity
than the butt joint. Like the butt joint it relies on glue and
nails for its strength.
A dowel joint does have mechanical strength, because
the wooden peg (dowel) goes into both pieces of wood.
Glue adds further strength.
A comb joint is an interlocking joint which, when
well-made and glued has a lot of strength.
A dovetail joint is more complicated and difficult
to make than the others described, but if it is well
made and glued, it is very strong.
6. Frame Joints
Frames are used when making stools, hairs or doors. The joints can be made in many ways.
Some of the most common ways areshown below.
The haling joint is the simplest frame joint. It has
no mechanical strength and relies on glue and
screws or wooden peg (dowels) for its strength.
The bridle joint is an interlocking joint, which when
glued is very strong. Itis important to get the thickness
of each piece right so as not to weaken the joint.
The mortice and tenonjoint is the
strongestof all frame joints. Itis also
neater in appearance. When glued
together, none of the joints show. This
type of joint is often found on stools,
chairs and tables.
The dowel joint is a strong joint, especially when
glued. Itis commonly used in industrialfurniture
making. When making dowel joints by hand it can
be difficult to drill the holes accurately. Not only do
they have to be in the correct position but they
have to be straight. If they are not accurate the
joint will not fit together.
