of deflection of the springs 132 it is contemplated that the core mounting structures 134 include journaling openings 141 which include respective internal cylindrical surfaces the end portions 120 126 of the cores 116 118 are engaged within respective journaling openings 141 and are rotatable relative thereto each of the end portions 120 126 may include a retaining element not shown to prevent substantial relative axial movement relative to the respective core 116 118 between the cores 116 118 and the supply roll supports 106 108 in other words a retaining element may be disposed on each end portion 120 126 to prevent axial movement of the core mounting structures 134 on the end portions 120 126 outwardly past the retaining element in this manner the cores mounting structures 134 may be prevented from sliding out of engagement with the cores 116 118 likewise the cores 116 118 may be prevented from sliding out of openings 114 the apparatus 10 of the embodiment shown in fig5 is configured such that as the supply substrates 110 112 are unwound from the supply rolls 102 104 during for example a laminating process the supply rolls 102 104 are simultaneously pulled toward one another by the biasing structure 130 as such the supply rolls 102 104 maintain.