Prestretch is the process that allows stretch film to be stretched before (pre) being applied to a load. The film threads past two rollers (Primary and Secondary) in which the second rollers’ rotational speed is faster than the first, thus stretching the stretch film between the two. The better machines are equipped with a mechanism allowing the stretch film to be pre-stretched. The more the machine film is pre-stretched, the lower is the usage. In addition, it is important that the stretch film maintains its original width. The so-called “neck down” is to be minimal. A lower usage of machine film is not only good for your wallet also for the environment. When a machine is not equipped with a pre-stretch mechanism, pre-stretched film can be used. Though the cost of this film is higher but due to its low consumption it becomes cheaper. Depending on the product to be wrapped a choice must be made between “cast” or “blown” stretch film. Quality wise “blown” film is better. The puncture resistance is greater which is especially useful when it comes to sharp edges which may be present. The recovery ability of this machine film is also longer retainable. Strength : « As you stretch the film , the tensile strength of the film increases so it is significantly (2X) stronger once you pass the point of permanent deformation.