How tanks are manufactured?
 Tanks are manufactrued using a process known as ROTO MOULD.


Rotomoulding is a process through which you can manufacture desired shape plastic tanks.

 These plastic tanks are used for storing water on the top of buildings and offices, In manufacturing of pesticide spraying tanks in Agricultural industries.

Suppose you want to manufacture a tank for storing water at your terrace which is of complex shape as below.

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How will you manufacture it?
You will require to manufacture a mould for it.
The rotomould must be perfectly designed keeping in mind all the shrinkage tolerances and premould parts.

Once the mould is manufactured then the process becomes easy. You just need to fill up the mould with plastic resin.

The mould is then mounted on Rotomould machine.

The biaxial roto moulding machine is then rotated with the plastic resin melting inside it at high temperature.

As the machine rotates the mould biaxially , A very fine uniform thickness shape similar to mould gets developed.

This process is continued for specific time period.

Then the mould is allowed to cool down at room temperature.

And finally your desired shape tank has been manufactured.

As the material is plastic and the process used is melting the resin at high temp. The material used to manufacture the roto mould is cheap as temperature are low to melt the plastics.

Here is video of roto moulding you can watch over and can understand with more clarity.