Cleaning material for extruders

Abstract

The invention relates to a cleaning composition for apparatus for processing thermoplastic melts, which composition essentially comprises discrete particles capable of plastic deformation and made from a thermoplastic (A) with a melting point above 200° C. and with a crystallinity of not more than 50%, and comprises an amorphous or semicrystalline thermoplastic (B) with a processing temperature below the melting point of the thermoplastic (A). The proportion of the thermoplastic (A) is from 1 to 95% by weight and that of the thermoplastic (B) is from 5 to 95% by weight. The total of the percentage proportions by weight of (A) and (B) is always 100% or less. The discrete particles made from the thermoplastic (A) and capable of plastic deformation have a very effective cleaning action, while the amorphous or semicrystalline thermoplastic (B) acts as a liquid or flowable carrier for the particles, which are made from the thermoplastic (A) and/or contamination which has been released, and are capable of plastic deformation.

Dependencies are inferred from the claim text.