Vinyl polymers reprocessing

Since the plastics are produced from petrochemicals derived from hydrocarbons, the motivation to reuse, recycle, or reprocess for energy recovery is primarily driven by an interest in conservation of petroleum resources. Economic factors are also important, but the potential saving of landfill space is more a perception rather than a reality [9]. Most of the categories of vinylic polymers discussed in this chapter are melt-formable, that is, they are thermoplastic materials, rather than nonmelting or thermosetting as are several of the condensation polymers discussed in Chapters 20 and 21. Thus,... 

Once the plastic has been separated into its various types, it can be recycled by reprocessing. More commonly, some recycled polymer is added to virgin polymer, although this may limit the application of the resulting material. For example, poly(vinyl chloride) containing 25% recycled resin is available, but only for applications in which it does not come into contact with food. 

Addition polymers, such as vinyls, acrylics, fluoroplastics, and polyolefins, can hardly be reprocessed except that, if they are sorted, they maybe converted into powder by grinding operation and mixed with respective virgin resins for remolding into finished goods or, in some cases, blended with other resins using suitable compatibilizers to make useful end-products of commercial value. 

We should especially consider the question of the influence exerted by thermal stabilizers on the reprocessing process. As is well known, the reprocessing of polyvinyl chloride and vinyl chloride copolymers is hindered by the fact that in these polymers the temperature of transition to the viscous-fluid state, as a rule, exceeds the temperature of the begin-... 

Poly ethyleneterephthalate - PET- and Poly(vinyl chloride) - PVC - are two of the most frequently encountered polymers in post-consumer plastics. In particular, these polymers can be used for manufacturing the same products (bottles, for example) and therefore are often found in the same stream, even when the collection is done with separation. The recycling of PET and PVC is usually carried out by separating them and reprocessing the two homogeneous polymers. Indeed, the heterogeneous recycling of two polymers is at present almost impossible because of many problems ... 

The melt processing of postconsumer waste is not limited to PET, and this process can also be applied to PP, PE and poly(vinyl chloride) (PVC) products that can be reprocessed in to pellets and fibres with ease. Alongside direct polymer-to-web production, staple fibres produced from recycled products are readily available and are commonly formed into nonwovens. 

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