ULTS
Unrestricted Linear Thermal Film Shrinkage Apparatus
Thermal shrinkage testing apparatus for liquid immersion, compliant with ASTM D2732, with 8 simultaneous sample hol...
Thermal Film Shrinkage
Thermal shrinkage is the dimensional reduction that a plastic film or sheet undergoes when heated to a temperature higher than its operating temperature. This phenomenon is directly linked to the internal stresses “locked” within the material during the extrusion or stretching process: upon heating, the polymer chains tend to relax and return to their equilibrium configuration, resulting in measurable contraction in the machine direction (MD) and transverse direction (TD) relative to the processing direction. Controlling thermal shrinkage is critical in the flexible packaging industry: in applications such as shrink wrap, shrinkage is a desired functional property; in other uses, excessive or uneven shrinkage can compromise the material’s flatness, causing problems in printing, lamination, or thermoforming processes.