First, the polyethylene terephthalate or PET (also called PETE) is heated to dissolve the pelletized substance in purified water. The mixture is then cooled and sent through a spinning machine shaped like an hourglass that heats it to just below its “toughening point”– that is, at this point it will form into a hard plastic with time and pressure in forming molds. From this pile of liquid in molds shaped like test tubes, the hollow-sided test tubes are fused together after they’ve built up enough rigidity. Finally they enter another mold which compresses out all excess air before closing, creating 18 distinct circular forms for each bottle.