We
use a lot of plastic products on a daily basis. The water bottle is a
prime example. Have you ever wondered how they are made? They are
made by the process of moulding. Plastic granules are used in the
manufacturing process. The process requires a specific moulding
machines and moulds for the creation of a wide variety of plastic
bottles.
Injection
moulding is the most commonly used method. As its name suggests, the
plastic granules are injected in the barrel surrounded by heating
elements. The melted plastic granules are subjected to high pressure
to obtain the required shape. After the cooling process, the final
product is injected with the help of the injection device.
Now,
here comes the twist. Plastic bottles are not manufactured in this
way. They are made with the combination of two moulding methods i.e.
- Injection moulding
- Stretch-blow moulding
Polyethylene
Terephthalate or PET granules are used for the manufacturing process
of plastic bottles. They are manufactured by a chemical reaction
between terephthalic acid and ethylene glycol. Once the PET granules
are manufactured, they are tested heavily for the following
properties before beginning the moulding process:
- Gloss
- Transparency
- Thickness
- Shatter Resistance
- Pressure Resistance
- Permeability
In
the first step of injection moulding, the PET granules are injected
in the moulding machines. They are given a small test-tube shape i.e.
PET Preforms with the help of PET Preform Injection moulds.
These Preforms are then converted into the final bottle in the
stretch-blow moulding phase by stretching and applying high pressure.
The
bottles are tested to ensure they meet the industry standards for
quality purpose. Nowadays, PET Preforms are available separately in
the market by PET
Preforms manufacturers.
Any organization can take advantage by using the pre-designed PET
Preforms. In this way, they will not be required to follow the
two-step moulding process of manufacturing plastic bottles saving
both time and money in the due process.
