These types of plastics are a family of plastics which may be
reheated and reshaped quite a few times. We say the they
have a memory because once heated they will attempt to
return to their original form, unless they have been
damaged or over-stretched.
These types of plastics, once heated and formed into a
shape cannot be reheated and reshaped because a process
called polymerisation has taken place.
1. Select the correct term to fit with the given definition
(Thermoplastic or Thermosetting plastic)
Term: Definition:
These types of plastics, once heated and formed
into a shape cannot be reheated and reshaped
because a process called polymerisation has taken
place.
These types of plastics are a family of plastics
which may be reheated and reshaped quite a few
times. We say the they have a memory because
once heated they will attempt to return to their
original form, unless they have been damaged or
over-stretched.
ITEM: TYPE OF PLASTIC:
Water bottle
Plastic chair
Plumbing pipes
Food containers (take-away)
Pot/Pan handles
Electric wall socket
Shopping bags
2. Determine which type of plastic will be better suited for:
3. Evaluate the given scenario and state the problem, in your
own words.
Usually, you take your food in a plastic bag to school.
Your sandwiches get squashed in your school bag and
sometimes the plastic bag tears resulting in a big mess
in your school bag. Sometimes you take food to school
that needs to be kept warm or cool and then the plastic
bag does not work that well. It is expected of you to
use plastic waste to design and build a suitable
solution.
A process whereby used materials are broken down to raw
material status and turned into new products to be used.
A process whereby previously used products are used for the
same or another purpose than for which it was originally
designed. (Products remain the same and are not altered in any
way through scientific processes)
1. Tabulate the difference between Recycling and Reusing
Recycling Reusing
2. Develop/list 3 ways in which you can reuse 2L
Soda Bottles
ITEM
1.
2.
3.
3. Write a brief statement, providing a solution to
the identified problem (from previous lesson)
identified in the given scenario.
1. Identify the plastic identification code symbols of the given
plastic products
Plastic Product Identification code (number)
Polystyrene take-away container
2L Soda bottle
Shampoo bottle
Dishwashing liquid bottle
Water bottle
Yogurt container
Tomato sauce bottle
2. Sort the given items into different recycling bins by using
their plastic identification codes.
Recycling
Bins
Plastic items
3. List 3 products that can be used for the same purpose as the
product that you have to design and make (container to
carry your lunch in that will keep it warm/cold). Then
tabulate the advantages and disadvantages of each.
Consider things like quality, affordability, availability of
material, appearance and fitness for purpose
E.g. Portable cooler bag
ADVANTAGES DISADVANTAGES
1. Looks pretty 1. Expensive
2. Can keep food cold 2. Not environmentally friendly
3. Closes tightly (doesn’t spill) 3. Difficult to clean after use
Before you start making your product it is important to first
write down what needs to be done to meet the need/solve the
problem. There are four aspects that should be considered:
- What should be done?
Elaborate on your design brief.
- Specifications
List the specifications to ensure that you can comply with all the
requirements that your product should adhere to. E.g. Size, shape, cost,
maintenance, function, safety, appearance, environmental factors,
materials and reliability
- Limitations
Identify any implied limitations
- Time plan
Any project should be completed within a certain time. Establishing a
timeframe is a good way of measuring your progress.
1. State in your own words what exactly it is that you intend to make.
2. You have 5 lesson periods to utilise. Complete the time plan below to
give a rough indication of how you would utilise the allocated time.
Technological Process Stage Number of periods used
4. Proposal
5. Initial idea generation
6. Research
7. Development
8. Planning
9. Make/Manufacture
10. Test/Evaluate
3. Make a list of the specifications of requirements of the product.
1. Develop at least 3 ideas that may be a solution to
the problem that you have identified.
2. Use freehand sketches with captions to illustrate
your ideas.
3. Analyse all of these ideas by listing the advantages
and disadvantages of each.
4. Select one idea/a combination of ideas and justify
your choice.
During the investigation stage (lesson 3) you
did research on various materials; their
properties, uses, etc.
You should search for information that could
help you to solve problems and answer any
questions with regard to problematic aspects.
Example questions that you may have:
- For how long will my product be usable if I use this material?
For instance, water bottles have an expiration date and if this is ignored, the plastic
gives off gases that are very harmful to your health and it could kill you.
- What method should I use to attach the different parts of my product?
This answer will depend on the material you are using.
- If I use glue, which glue would work the best?
For instance, you cannot use Bostik glue on polystyrene – it will start to melt and
completely disintegrate – rather use wood glue.
- It is important to consider such aspects and to do thorough research.
1. List some problematic aspects that still needed to be resolved
with regard to the chosen idea before you can develop it any
further
2. Find the information that you need to resolve these
problematic aspects so that you may develop your chosen
idea into a workable solution.
Now you should model your chosen idea to see if it works and
how it can be improved. There are four aspects that should be
considered:
- Materials:
Begin to identify suitable materials for each part of your product.
Properties to consider are weight, strength, toughness, resistance to
heat/corrosion, colour, conductivity, hardness, appearance, flexibility, etc.
- Size and Shape:
Specify accurate sizes. Ergonomics is a key factor here and should be
considered.
- Appearance:
The overall appearance should be considered, since visual qualities are
important. Different preferences and opinions will affect this factor.
- Safety:
It is important that safety be taken into consideration when any product
is being developed. Proper safety standards should be applied.
1. Develop a working model of your chosen idea.
Take the necessary safety precautions
During this phase, it is time for you to make a
working drawing of your final idea,
complete with details and measurements.
Usually you sketch:
- a first-angle orthographic projection and
- an isometric projection
of your final chosen idea.
1. Sketch your final chosen idea in first-angle orthographic
projection
Front View
Top View
Left View
3. Compile a resource list containing all of the parts, their sizes
and the materials they are made of.
During this stage you are finally ready to start making your
final product.
Remember to keep checking whether you are still on track by
referring back to the design brief and the specifications which
you have identified.
Safety is very important. Think before each step and never rush
– if you do, it is easier to make mistakes.
Record everything you do by taking pictures while you work.
Should you be unsure of anything (especially concerning safety
and how to use any of the tools) do not be afraid to ask for help
before attempting it on your own.
MOULDING PROCESS: EXPLANATION
Extrusion During the manufacture of plastic rods, tubes and
curtain rails plastic is pressed through an opening in
long moulds.
Blow moulding Plastic is blown into moulds to produce a variety of
containers. The containers have a visible seam that
looks as if the two looks as if the two parts were glued
together, as can be seen in bottles and cans.
Vacuum and pressure
moulding
Plastic is heated until it is soft before a sheet of plastic
is sucked in over a mould.
Injection moulding Warm plastic is injected under high pressure in a
mould.
1. Choose one of the moulding processes and write one paragraph
(not more than ½ a page) explaining the process in your own
words.
2. Consider all of the work you have done during all of the previous
lessons. Now, make the product which you have designed.
Remember to keep checking whether you are still on track by
referring back to the design brief and the specifications which you
have identified.
•Why did you choose to evaluate your product based on
these points?
•Do you think that this criteria could also be important?
•Develop a list of aspect that you feel could be improved
upon?
•Suggest ways in which these aspects could be approached
differently in the future?