Recycling of PVC plastisols

In addition to the factors cited previously, which could modify flow properties and gelation and fusion processes of PVC plastisols, the presence of recycled PVC particles could also provoke relevant changes, as previously reported, because of addition to fresh plastisols of preprocessed PVC particles with different particle sizes (four different fractions with diameters below 0.500 mm) in concentrations ranging from 0 to 10 wt%. 

Recycled PVC particles drastically increase the shear viscosity (even more when they contain fractions of smaller particles) as shown in Table 10.5 (viscosity of fresh plas-tisol at 2.1 Pa.s increased to 28.3 Pa.s when 10% recyclate with finest fraction was added). The viscosity of these plastisols was unstable (after 24 hom plastisol with 10% recycled PVC had viscosity of 781 Pa.s because recycled particles were either swollen or dissolved by the plasticizer). With lower content of recycled PVC, viscosity increases and aging process are not so prominent, but changes in viscosity are also observed. 

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