POLYMER SEGREGATION PROCESS

摘要

The present invention provides a method enabling segregation of the various ingredients making up the polymer based products into component product streams and collection of these component streams so as to form individual product streams. Thus, according to this invention there is provided a process for purposefully segregating polymer-polymer and polymer-additive mixtures. The process for segregating the various combinations of components may be advantageously used on the one hand for the production of separate product streams from a mixture of polymers or polymer-additives in, for example, recycling of waste plastic based products, or on the other hand, in the production of polymer-polymer or polymer-additive layered structures exhibiting preselected spatial segregation of the various components. In its simplest form, the polymer segregation part of the process consists of a tube added to an extruder. During segregation, polymer layers containing different blend compositions are formed. Operating conditions are selected to enhance differences in viscosity between polymer components. This includes addition of low viscosity grades of one of the polymer components present to encourage migration of that component to the high shear region of the flow. Segregation may occur in either the extruder or in a tube added onto the end of the extruder, or in both. Preferential segregation of additives into one or more of the polymer layers can also be effected. Addition of components which attract the additives to be segregated provide a method of segregating a wide variety of additives.