Plastics in processing step is exposed to high temperature, its structure may be broken to make free radicals. To prevent that radicals spread out and affect in large section should use antioxidant to stop that free radicals.
After processing step, plastic products usually contact oxidation source (ex. Oxygen in atmosphere), so their structures are broken by oxidation processes. Preventing the oxidation processes of Antioxidant helps to increase life time of products.
Antioxidant is used bring some advantages, such as:
Making plastic structure is more stable, so plastics keep their properties.
Preventing the discoloration during processing and using time.
increasing the life time of final products
Antioxidant has to use for some cases:
Process in high temperature and in long cycle time
Products is used in long time (for more than 2 years).