Machine direction orienter MDO

Different methods are used. An online ordinary common blown or cast film line uses a machine direction orienter (MDO) on the front end of biaxially oriented film heated chamber extrusion line. If only the machine direction is to be stretched, a series of precision controlled heated rolls can be used. Film is fed through a series of rolls where it is sequentially heated, drawn around rolls that increase in rotational speed providing the stretching action, annealed around larger diameter roll(s), and cooled on a final roll(s). 

---