► High density polyethylene resin (HDPE) is extruded via the blown film process

to form a tube. The tube is cooled and collapsed into a flat tube.

► After the tube is flattened, it is fed into a multi stage orienter. During orientation,

the film is stretched in the machine direction aligning the polyethylene molecules.

The resulting film is very strong in the machine direction.

► The oriented tube is then annealed and wound up. The annealing step removes

stress in the film and controls shrinkage.

The annealed film retains its high MD strength.

► The next step of the process is spiral cutting. In this step, the flattened, oriented

tube in unrolled, rotated and re-inflated to form a round tube.

► As the film is fed forward and rotated, it is cut on a bias (around 45 degrees) and

wound up. The spiral cut film’s orientation is at 45 degrees to the machine direction.

Step 3: Cross Lamination