AO: Vitamins for Your Plastics

“An apple a day keeps the doctor away.”

Supplying your body with good nutrition promotes better health. Supplying your plastics with “good nutrition” will also help keep them in good health. Colortech masterbatches can supply this nutrition to your product in the form of Antioxidants (AO).

Polymers are subject to degradation by many invisible enemies like UV radiation, oxygen, and heat. Plastics are made up of very long chain molecules. When UV light strikes a plastic object, those chains can start to break, causing the plastic to discolor and even lose the physical properties that make them so useful. In the worst cases, they can even become brittle and fall apart.

Antioxidants should be used when processing conditions require long residence times, high temperatures, or utilize reground or reprocessed material. AO’s are a plastic recycler’s weapon to preserve the quality of their recycle streams and a manufacturer’s tool to be used in regrind or reprocessed flash and trim. Added benefits include increasing the number of times a material can be recycled/reprocessed into a new product, producing less waste, and saving money.

Red flags that indicate additional AO is needed include charred resin, black specs, gels, and discoloration. AO is consumed throughout processing, so if these warning signs pop up, the resin being used may need more stabilization.

The chemistry of an AO dictates how it protects the polymer. The two major types, primary and secondary, are typically used in combination to target different stages of the process.

  • Primary antioxidants stabilize a polymer both during extrusion and during use. For example, if a product is destined for use where long term heat exposure is expected (such as under the hood applications for automotive parts), you will see the primary AO’s shine.
  • Secondary antioxidants protect the polymer against the conditions found when extruding in a high heat environment.
  • A blend of primary and secondary AO’s will be key to protect your product during processing, use, and recycling.

AO’s are great at preventing damage from oxidation, but they cannot repair previously damaged polymer chains. It is because of this phenomenon that products intended to be recycled should include AO when they are initially created.  An ounce of prevention is truly our only option!

Contact a Colortech Sales Representative for more information about how our Antioxidant products can help you. Our Technical Service team will help select the right package for your needs. For other stabilization necessities, please ask us about our UV & AO combination products.


Joseph Swann

Technical Services Representative