composite temporary web 100 through the perforations 130 and create apertures 160 on the resulting permanent film 150 the film 150 is cooled by ambient air and the vacuum 140 but also may be cooled by other available alternatives there are three basic components that are desirable for practicing this method the fibrils 30 the lower temperature polymer melt 70 used to form the composite temporary web 100 which captivates the fibrils and the higher temperature polymer melt 126 used to form the final permanent film 150 the fibrils 30 are preferably composed of material having the highest melting point fibrils 30 can be derived from natural fibers such as cotton cellulosics from pulp animal hair or synthetic fibers from polyethylene polypropylene nylon rayon and other materials the lower temperature melt polymer 70 must be comprised of the lowest melting point material finally the higher temperature melt polymer 126 used to form the permanent film 150 must have a melting point above the temporary web 39 s melting point yet below the fibril 39 s melting point melting point separation of at least 10 u00b0 f and preferably around 20 u00b0 f has been shown to be successful a greater separation is of course desirable because the selection of fibrils 30 prevents the fibrils 30 from melting or distorting by the thermal load of the other melt polymers 70 126 the composite temporary web 100 will effectively u2018 disappear u2019 into the face of the higher temperature melt polymer 126 during formation of the permanent film 150 while maintaining fibril integrity it is.