What is this difference between cast stretch wrap and blown stretch wrap?
You may be wondering what the difference is between cast stretch film and blown stretch film. So, what is the difference?
Well, the difference is the way they’re made.
Cast stretch wrap is manufactured when molten plastic resin is extruded horizontally through a flat die to create a sheet of material. The material is then passed over chilled rollers, which cool the film rapidly before trimming and rolling.
Cast stretch film is usually very clear and has good puncture resistance. It’s also low noise when it’s unwound from a roll.
In contrast, blown stretch wrap is made when molten plastic resin is extruded vertically through a circular die. This creates a bubble, and the air in the bubble slowly cools the film. The film is then flattened and made into tubes or cut to make rolls of stretch wrap.
Blown stretch film isn’t as clear as cast film. However, it has excellent puncture resistant and can offer high holding power. You may be able to identify blown stretch wrap by the high noise it produced when unwound.