Understanding thermally induced wrinkling in decorative film laminated sheets

The development of wrinkles in decorative film laminates during processing operations like thermoforming was the focused of this paper so that we may understand the driving factors and develop strategies to overcome. A series of studies looked at the effects of temperature and heating rate on the wrinkling behavior of a commercial black-out film laminated onto metal and plastic substrates. A threshold temperature was identified for our film under which no wrinkles formed, related to the stiffness of its different construction layers. Heating rate was also noted by this study to be an important parameter in wrinkling. It was found possible to exceed the threshold temperature stated above without the occurrence of wrinkling when the heating rate was sufficiently low. The effect is believed to be related to the rate of change in stiffness between the different construction layers in relation to building thermal stresses.