What are the Differences Between Cast Stretch Wrap and Blown Stretch Wrap?
The primary difference between these two types of Stretch Wrap Film is the process in which they are created and manufactured. These differences also make a big impact on the usability and price of the film.
Creation of Cast Stretch Wrap
The cast process is essentially the same as blown, with beads of resin being fed into a heated barrel and forced through a narrow slotted die. This 'sheet' of film the die produced is then fed along a rolling path that has been cooled, which solidifies the film. It is then brought through the final stages of production and made into large rolls. This method is much faster than the blown extrusion method and also costs less, as more can be produced per man-hour.
is the most common type of film produced by this method.
Creation of Blown Stretch Wrap
Beads of resin are fed through a heated machine that has a circular die. The heated resin is forced through the die and then blown out vertically into a bubble. As this formed bubble finishes the process of being transformed into rolls of stretch film, it is cooled by the surrounding air. This type of film generally costs more to make because the output per hour is less than with cast films. Our blown
film is a common example of this type of film. It has a much higher rating than our cast hand film for holding power and puncture resistance.
That's a Wrap!
Rocket Industrial offers a variety of stretch wrap options. If you have questions on the best type of stretch wrap to use for your application,
We will find the optimal packaging solution for you based on your needs and goals.