some plastic products |
There are different advantages as same
as some disadvantages when we are using plastic for product designing.
Advantages
- No corrosion
- Light weight
- Low processing temperature (compare to the metal)
- Low energy requirement for processing
- High strength can be achieve if needed
- Non toxic, non smell, non taste etc
Disadvantages
- Plastic has temperature dependent characteristics
- Less dimension stability
If we are going to design a plastic
product we have to consider about some factors. They are application of the
product, service life, service temperature, environment concerns and other
specific customer requirements.
Now a day’s some commercial plastics are
there widely used for product design.
It is generally milky white brittle
material which can easily crack. It has different classifications according to
its density and branching. LDPE (low density polyethylene), HDPE (high density polyethylene),
LLDPE (linear low density polyethylene) are the most common and important types
of them. Mainly they are used for film and packaging applications.
More ductile material than polyethylene
and it is not easily cracked. It has good resistance to fatigue. Mainly used in plastic furniture applications.
Polyvinyl chloride (PVC)
Generally there are two types called
UPVC (un-plasticizer) and PPVC (plasticizer). Each one has different properties
and different applications as follows.
PPVC
|
UPVC
|
Relatively
soft
|
Relatively
hard
|
Used
for cable insulation, soft bottle squeezed etc.
|
Used
for piping, roofing, doors, window frames etc.
|
Polystyrene (PS)
It has good resistance to water, but swells
in solvents. It is brittle, not strong and cheaper material. Generally used for
packaging and food containers like yogurt containers.
Nylon
Nylon has high strength as same as dimension
stability. Generally used for cloths and mechanical engineering applications like aircraft
propellers, gear wheels.
When we design a plastic product we
have to consider about different modes of deformations can be happen in plastics.
Some of them are tension, compression, torsion, simple shear, bending. They will
discuss in detail future.