How do you make plastic bottles?

Question

No jokes!

Answer 1

Hot liquid plastic resin is poured into molds.  Polyethylene, polypropylene, acrylic, nylon variations, for instance.  In some instances, the resin is cold and sets like adobe, by dehydration of the liquid carrier.

Answer 2

the answer above is completely wrong for this application

Here's the process skipping how plastic is made:

plastic resin (looks like beads) is poured in a machine called a blow molder through a hopper that holds the resin. The plastic beads go into the machine and a s***w inside turns, conveys, shears, and heats the plastic until it melts. once it is molten, the plastic is extruded through a die  downwards and what comes out is called the parison. the parison looks like a hollow tube, and then two mold halves are forced together and clamps the bottom of the parison together and an air pin goes into the mold and blows the parison outwards into the shape of the mold and creates a bottle. the parison is cut from the top and the mold opens. the bottle pops out. then excess material is trimmed and it's ready to go.

A very basic description of the process.