Continuously extruded micro‐textured polypropylene films

Abstract

The continuous extrusion of micro-textured isotactic polypropylene (i-PP) film and its tribological properties are reported. As analyzed by scanning electron microscopy, a rectangular-semicircular micro-patterned die successfully produced extruded cast-films with hill-like micro-texture. Such films displayed static and kinetic coefficients of friction (COF s and COF k ) values of 0.247 6 0.028 and 0.245 6 0.003, respectively, for a steel fixture sliding along the micro-texture of the film. The equivalent COF s and COF k values for non-textured (NT) films were 0.369 6 0.036 and 0.340 6 0.024, respectively, confirming that textured films displayed a reduction in COF of about 30%. For textured and NT films sliding on textured films, the COF k values were even lower at 0.161 6 0.013 and 0.113 6 0.004, which represents about 20-40% reduction as compared with that for the NT-NT counterparts. Films coated with a silicone lubricant displayed COF s and COF k values of 0.334 6 0.042 and 0.099 6 0.012, respectively, for NT films sliding over lubricated NT films, and 0.426 6 0.031 and 0.063 6 0.006, respectively, for textured films sliding over lubricated textured films. The COF k values for textured/non-lubricated films approach those of NT/lubricated films, indicating that micro-textured polypropylene films may be used in environmentally sensitive applications where lubricants and fluorinated additives may not be used for reducing friction.

Boron Nitride-Filled Linear Low-Density Polyethylene for Enhanced Thermal Transport: Continuous Extrusion of Micro-Textured Films

“…All these methods are batch processes that are too slow and expensive for large-scale production of textured films. In an earlier study [ 33 ], we have successfully demonstrated the processing of neat (unfilled) polypropylene into textured films.…”