| abstract |
This invention relates to abrasive compositions useful in preparing purge compositions for purging plastics processing equipment comprising: (A-1) at least one abrasive powder comprising a major amount of calcium carbonate; (A-2) at least one organic rosin material; and (A-3) at least one surfactant. The abrasive compositions of the present invention further may comprise at least one viscosity reducing organic diluent. The purging compositions of the present invention comprise (A) a minor amount of the abrasive composition of the invention, and (B) a major amount of at least one polymer or resin. These purging compositions allow fast and effective purging of processing equipment. These compositions may also be reused, i.e., used for more than one purging operation, and they may be recycled by incorporating the used purge composition into a polymer which is identical to or compatible with the polymer (B) of the purge composition. The invention also relates to a method of purging plastics processing equipment utilizing the purging compositions described herein. |