The Effect of Stretch Wrap Prestretch on Unitized Load Containment

摘要

There are three main factors affecting the stability of a palletized load that is unitized by a stretch wrapping mechanism - the type of unitized load, wrapping configuration and shipping method. The wrapping configuration is typically determined on the basis of the type of unitized load and shipping method. For this study, the aforementioned components were referred to as the package, the product and the distribution environment. This study was designed to observe and understand the interactions between each of the components of the stretch wrap system. Prior to stretch wrapping a pallet of product, the film is elongated or prestretched. The elastic nature of the stretch wrap forces the film to conform to the palletized load. It is hypothesized that the containment force that the stretch wrap applies to the palletized load contributes to improved load containment. Hence, the objective of this study was to determine the existence of a correlation between percentage prestretch to change in containment force and load containment. For the study, a range of prestretched unitized loads were subjected to International Safe Transit Association 3E distribution testing. Simultaneously, the containment force was monitored during the period of distribution testing. Subsequent to distribution testing, the load dispersion was quantified. The data obtained from this test suggested that there is no correlation between percentage prestretch and change in containment force or load containment.