Thermoplastic film charged with monocalcic glass microspheres - to prevent the turns sticking together when the film is rolled up

摘要

Adjacent turns in rolls of thermoplastic film are prevented from sticking together by adding monocalcic glass microspheres to the plastic. The microspheres pref. have a mean dia. 10 mu and real density 2.45 (apparent density 1.5). A mixt. contg. 10% of the glass microspheres is added in the proportion of 1-5% to the resin as the film is on the point of being extruded. In contrast with the usual additions of greasy material or of silica, the addition of glass microspheres does not impair the brilliance or transparency of the film.