The fabrication of a film by continuously pumping the polymer through a circular die and filling the tube with air. The volume of air contained within the tube stretches the tube out to the desired width and, in conjunction with the rate at which it is bring pulled away from the die, the desired thickness is created.
Film that is fabricated by continuously pumping the polymer through a circular orifice (die). Once through the die, this polymer is then drawn upward and filled with air, creating a tube. The volume of air contained within the tube stretches the tube or bubble out to the desired width and, in conjunction with the rate at which it is being pulled away from the die, the desired thickness is created.