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PVC, the most predominant member of the large family of vinyl polymers is among
the most versatile and widely used thermoplastics. The unique combination of
properties of pve has been responsible for tremendous potential it posseses both for
industrialas well as for domestic applications.
In this research study an effort was made to understand the behaviour of pve when
exposed to weathering characteristics. Theory of degradation and characteristics of
stabilizermechanisms and systems were studied before undertaking the research work.
Research work was carried out on an industrial scale in a pve leather cloth
manufacturing plant, to replace a Pb stabilizer system in the skin white formulation.
Pb stabilizersystem was replaced for two reasons.
(l) Yellowing of the material when exposed to environment. Pb stabilizers are prone
to sulfide staining. PbS is black in colour and as a result, Pb stabilized systems
prone to discolour.
(2) The greatest deterrent to the use of Pb stabilizer is their toxicity. There is no
doubt that Pb stabilizers are toxic and as a result the use of these stabilizers have
been restricted in many applications in many countries. Sn stabilizer system which does not disco lour and is non toxic, was introduced to the
formula to replace the existing Pb stabilizer system. Several process changes had to
be made to incorporate the new stabilizer system to overcome the processing problems
associated with the use of Sn stabilizers. This new stabilizer system intoduced and the new formula developed is currently being
used successfully to produce white colour PVC leather cloth in this factory for
commercial purposes. This new formula developed by introducing a Sn stabilizer is environmentally friendly
and has a significant advantage over Pb stabilized systems in reducing harmful,
hazardousand toxic effects.
