Additives are substances blended into a plastic to change how it looks, processes or performs. Common examples are pigments, UV stabilisers, antioxidants, slip agents, fillers such as calcium carbonate, and impact modifiers.
In recycling, additives matter twice. Those already present in waste plastic, such as colour masterbatch or fillers, decide what the recyclate can be used for, which is why sorting by colour and grade comes first. Recyclers also add fresh stabilisers or compatibilisers during compounding to restore properties lost through heat and use, so that recycled granules run reliably on a converter’s machines.
