Methods for stiffening portions of flexible material

The method for stiffening a flexible workpiece comprising the steps of depositing a layer of fast crystallizing synthetic linear polymer resin substantially free from side chains in molten condition on a transfer surface member, said transfer surface member being at a temperature controlled relative to its heat take-up capability and to the temperature and heat conductivity of the deposited molten resin rapidly to bring the deposited resin at the interface with the surface of said member to a temperature for rapid crystallization, the temperature of said transfer surface member being below the crystallization temperature of said resin but being sufficiently high to avoid supercooling of said resin, solidifying resin by crystallization from molten state at said interface of the resin with said transfer surface member leaving substantially all of the remainder of the thickness of said resin layer in soft molten condition, pressing the resin layer between said transfer surface member and the surface of said workpiece within a time after deposition of said resin on said transfer surface member during which portions of said resin layer away from said interface remain molten with a viscosity low enough for wetting adhesive engagement with and flow into conformity with the surface of said workpiece and separating said transfer surface member from said resin layer at a time when crystallized resin has formed adjacent said transfer surface member to an extent sufficient to preserve the integrity of the layer of resin during separation.