Spindle for winding up coreless rolls of a plastic film

摘要

A spindle (10) suitable for winding up coreless rolls (11) of a stretchable plastic film; the spindle (10) comprises a tubular body having a peripheral wall (12) defining at least one internal chamber (14) connectable to a pressurized air source. A plurality of perforations (17) extends from the internal chamber (14) of the spindle (10), through the peripheral wall (12) and a protective layer (19) of hard chrome having a sandblasted outer surface (18) with an average roughness ranging between 6 and 6.5 μm, obtained by dry sandblasting.

主权项

1. A spindle suitable for winding up and frictionless removing rolls of stretchable plastic film, the spindle comprising:
a tubular body having a cylindrical wall provided with a peripheral surface and at least one coaxially extending internal chamber connectable to a pressurized air source; a flash deposition of a hard chrome layer having an average thickness ranging between 8-15 μm on the peripheral surface of the tubular body, said hard chrome layer having an external surface for winding up at least one roll of plastic film; a plurality of perforations which extend from the internal chamber through the wall of the tubular body to the external surface of the layer of hard chrome; and wherein: the external surface of the layer of hard chrome is dry sandblasted and configured with an artificial average roughness value between 6.0 and 6.5 μm to provide a random distribution of micro-path and pressurized lubricating air fluxes between the chrome layer and the plastic film at the removal of a roll.