Black pigment for recyclable plastic packaging

Consumers, environmental organizations, politicians and industry are increasingly taking action to reduce microplastics. Reusing plastic waste as a raw material also contributes to this, but requires that the different plastics be separated according to type first. The iron oxide Bayferrox 303 T helps to increase the recycling rate for plastic packaging, which is still far too low around the world.
The black pigment Bayferrox 303 T for coloring black plastic reflects 20 percent of near-infrared radiation (NIR). This enables plastics to be identified efficiently and cost-effectively with the aid of NIR detectors like those used for sorting waste. Plastic packaging colored with carbon black, on the other hand, as is used in large part today, does not reflect any radiation and therefore cannot be detected in sorting plants. 
In automated recycling plants, near-infrared detection (NIR spectroscopy) is used to quickly sort plastic waste into different types. To this end, infrared cameras are installed above the conveyor belts in most cases. However, black plastic packaging such as foils cannot be identified correctly by the optical sensors due to its color and consequently cannot be sorted. Unlike the carbon black pigments often used in the plastics industry, Bayferrox 303 T reflects infrared radiation, thus allowing identification with the aid of NIR detectors. As a result, black plastic items such as packaging films or trays can be better identified with the iron-manganese mixed oxide and sent for recycling.

Nowadays, three types of pigments are principally used to color plastic packaging. In terms of quantity, carbon black is the pigment most frequently used for black packaging materials, as it is available at low cost on the market and exhibits high color strength. But it does not reflect infrared radiation and items made with it remain virtually invisible in sorting plants. Thus large quantities of plastic packaging cannot be sent for recycling.

Complex inorganic colored pigments (CICPs) and manganese ferrites, of which the latter are far more cost-effective, are high-quality alternatives to carbon black thanks to their property profiles – because they reflect infrared light. The iron-manganese mixed oxide Bayferrox 303 T also offers color strength that is 20 percent higher than comparable pigments. 

Reduced magnetic properties prevent false alarms

What’s more, thanks to its special manufacturing process, Bayferrox 303T has extremely low magnetic value making it ideal for coloring plastic packaging. Magnetizable pigments can trigger false alarms during quality control processes in the food industry, for example, disrupting production as a result. After all, metal detectors cannot distinguish between pigments and pieces of metal in an edible item. This is why metal contaminants must be avoided in both the masterbatch and the packaging. 

Compared to other standard manganese ferrites, the magnetism of Bayferrox 303 T has been reduced by more than 50 percent,” says Bartolucci. Thus, false alarms in production can be avoided and a higher degree of process reliability can be achieved due to fewer interruptions.
Usage of Cookies
We would like to use cookies to better understand you use of this website. This enables us to improve your future experience on our website. Detailed information about the use of cookies on this website and how you can manage or withdraw your consent at any time can be found in our Privacy Statement.

OK Other Settings