Protective Boundary
Plastic film containment defines the protective boundary that holds stacked materials securely on a pallet while sealing them against environmental moisture. Maintaining stretch wrap integrity ensures that paperboard piles do not absorb ambient moisture or shift physically during transport and warehousing. When the wrap is compromised by punctures or loose layers, the boards inside can warp due to localized moisture changes.
A secure and continuous wrap maintains the structural shape of the pile from the mill to the converter.
Tension Maintenance
Automated wrapping machines apply a calculated pre-stretch to the plastic film, which generates a continuous compression force that secures the pallet. This containment force must be balanced so that it is high enough to prevent sheet shifting but not so high that it crushes the edges of the paperboard. Proper overlap between film layers ensures that the wrap holds together even when subjected to the vibration of transport trucks.
If the tension drops or the film tears, the loss of compression allows the sheets to slide, which can lead to damaged stock.
Climate Shield
Restricting air movement around the paperboard prevents changes in the internal humidity of the sheets. The film acts as a barrier against rain, spills, and high relative humidity in unheated transit warehouses. Keeping the wrap intact until the board is ready for the press ensures the sheets remain flat.
