What are Heat Stabilizers?
Heat stabilizers are additives that are intended to shield polymers from the degrading effects of heat at the time of processing or use.
Role of
Heat Stabilizer in PVC processing
Polyvinyl chloride or PVC has a maximum operating temperature of around 60°C (140°F). At this temperature, the heat distortion of PVC begins. As PVC starts getting heated up to 170°, hydrogen and chlorine are eliminated i.e. HCl (autocatalytic dehydrochlorination) is released as decomposition initiates. A chain reaction starts as unstable molecules appear and stimulate the next HCl loss.
Thermal Degradation of PVC
So what exactly do the heat stabilizers do to improve the resistance of PVC compounds to heat or high temperatures?
In simple words, heat stabilizers neutralize hydrogen chloride, replace weakened carbon-chlorine bonds and prevent oxidation to safeguard the vinyl product.
Thus, heat stabilizers play a major role to prevent the degradation of PVC compounds.
Types of Heat Stabilizers for PVC
Calcium-Zinc based Stabilizers
Calcium-Zinc-based Stabilizers are new generation stabilizers that are gaining importance in the PVC market. Calcium Zinc Stabilizers mainly consist of Calcium Stearate, Zinc Stearate, organic and inorganic non-toxic co-stabilizers, and internal and external lubricants. They are usually available in flake or powder forms.
Let`s dive deeper to understand some of the major features of these non-toxic stabilizers.
Benefits of Calcium Zinc based Stabilizers
-Non-toxic and eco-friendly stabilizer
-Core stabilizers provide initial colour sufficient for PVC processing. -Co-stabilizers are used to give excellent whiteness and long-term stability.
-NOVISTA Calcium-Zinc stabilizers are performance-oriented and particularly provide excellent long-term retention of colour, outstanding mechanical properties, and a high level of the weathering resistance.
-Compatible with all other types of stabilizer
-No issue of staining
