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Introduction to Materials for Making
Year 7 Design and Technology
By Keith Galea
Short Description:
By following this lesson students will be introduced to Materials and their use in Design and
technology activities. Various materials are used in many everyday items and have both
advantages and disadvantages, as well as different properties, let’s discover together.
Keywords to lookout for in part 1:
Resistant materials; properties: strength, softness, flexibility, hardness, weight, density;
What are Materials?
In Design & Technology we discover how different
materials are used in the real world. We can learn by
seeing these materials, reading about them, working
them properly and hopefully also use them to create
interesting projects.
We call these useful materials…
Resistant Materials
Now let’s look at some of the materials we will learn about:
(Other useful materials, which are not listed here like glass, ceramics, fibers, marble, granite, plaster, etc., will be covered further on.)
WOOD
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What makes a Material different from another?
We all have used things made of these materials in our life but these are only general words and there are thousands of different types from each of these. It’s useful to know what an object is made of sometimes because then we can match it to other objects and this could also help us to choose which is best.
But how can we know if a material is better than another? For example metal is stronger than plastic so why do we have plastic toys? Is metal better?
… You can see that for a toy the strength is not the most important feature. One prefers that a toy is soft, light and also colourful for example. That is why every material has different properties.
Properties of materials are characteristics that materials have and that help us compare similar or different materials together.
The following are few examples of some characteristics that materials could have.
Where do materials come from?
One way to look at materials is by making a distinction (group them) by their origin being either:
Natural OR Man-Made
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Natural- Naturally found materials
Some materials are found in nature and these were always available to us, as long as humans could harvest or extract these like rock, wood, sand, wool, clay, and others.
Technology made it possible to extract materials and prepare them to be used in the required needs of human activity. An example is wood, where before the discovery of metals to make sharp tools, we could only use it in its natural shape and form. When tools like saws and blades were available, humans could shape wood to neater standard forms and build better products with it.
The following is a list of some Materials that are initially found in nature and how these are extracted to become more useful:
A short, but very interesting overview of how humans developed materials through history can be seen now by going back to the Teleskola lesson: (2 min)
Materials
Source
Extraction
Minerals –
Stone, Marble, sand
Earth/
mines/sediments
Collection, cutting or
blasting
Wood – various
types
Trees
Collection, cutting or
shaving.
Raw Metals
Earth/mines
Mining and Industrial
forging
Textiles- Natural
fibres
Natural- Living
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Man-made Materials
Man-made Materials are Engineered so that they have the properties that are required. Man-made materials still originally come from natural materials, but these are modified through technological or chemical processes.
You can find that a material like wood can be found in either man-made or natural state. For example a plank of wood is natural as it is simply cut from a tree and shaped to a required size. However if wood is engineered it will be cut and glued in layers, like plywood, grained in particles and compressed like chipboard or similar variations. Some materials are changed also at a molecular level, where the position or different quantities of certain atoms is designed to obtain the properties needed.
In metals we can expect every material to be modified from their original mineral state. Metals are not only given new form and shape but will be modified by heat treatments so that the properties of that same material are selected both before producing the material and even later during manufacturing.
For plastics its is safe to say that these are all manmade materials but some examples of natural materials, for example pasta and dough are very similar in properties to synthetic plastics. However, these still are man-made since they do not occur in nature as they are and are still the result of human intervention. Synthetic Plastics are made in a lab by a process called polymerisation. The chemicals used to make plastics are mostly derived from chemicals and consist of a mixture of carbon and hydrogen. The mixture will determine how flexible, soft, hard and resistant is a plastic. There are over a thousand types of plastics.
Textiles are also man-made materials. The fibres used to make yarn to make fabrics are obtained from both natural and synthetic sources. Some come from plastics but others like cotton may come from plants. However, textiles are always man-made and can offer many options of properties.
Materials and the Environment
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Glossary
Refer to the below keywords when reading the full info in this document. Knowing such keywords helps to be able to understand technology.
Keyword Meaning
Harvest When a material needs to be grown
Extract When a material is embedded in another and needs to be separated to collect
Standard form The common shape of a materials found for sale Engineered Designed and produced using science and technology
State Its current type
Layers Each piece stacked on another is a layer Plywood A man-made wood with many layers of thin wood
sheets glued together grained Shredded material to very fine pieces particles Fine pieces of material small like dust chipboard
A manmade wood board with large and small particles of wood compressed in glue. (Similar to a
cereal bar) Molecular level
Molecules are smaller than particles, but similar. At molecular level you look at how to particles and
atoms come together in a material. Heat treatment Modifying properties of a material by using heat
manufacturing When materials are turned to useful parts and products
Synthetic When a material is made from non-natural sources Polymerisation The process to turn chemicals into plastics
fibres The little strands of materials that later may become a yarn
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Further Resources and links:
Current Middle School syllabus Learning outcomes associated with this lesson:
Year 7:
I can identify and work with a range of materials; list their main
properties, to produce an artefact.
Further exercises and reading on materials:
Worksheets and more exercises from www.technologystudent.com:
http://www.technologystudent.com/designpro/matintro1.htm
Lesson tasks:
See the resources attached to this lesson and try out one of the following Tasks:
-on mini D&T tasks: see task documents in the resource secti-on.
Mini Task #1 – Materials Quiz. Open Materials Quiz sheet. Or follow this link:
https://forms.office.com/Pages/ResponsePage.aspx?id=O3ivQUNSKEy3pGcsC57e0v9EMUDLlR ZOqAAwySkELrZURTBGSkpKR1UxU1pCMFhENlU1SUlLUUFONC4u
