Unpigmented (Natural) PP
Natural material has the highest value as a recycled stream since it has the widest variety of end-use applications. It is the most cost effective to process through the recycling system.
Translucent and opaque colors
PP is commonly colored so volumes and markets exist for colored material and it is economical to process.
Optical brighteners are not removed in the recycling process and can create an unacceptable fluorescence for next uses of recycled PP. It is difficult to identify material with this negative effect until extremely late in the recycling process where a great deal of added cost has been imparted into a material of low value due to the additive.
REQUIRES TEST RESULTS
Colors with an L value less than 40 or an NIR reflectance less than or equal to 10 percent
Sortation testing for dark colors will result in either a Detrimental or a Renders Non-Recyclable ruling. Dark colors cannot be Preferred at this time.
There is no mechanical property inherent in dark PP that makes it unrecyclable. The problem lies in sorting and the physics behind polymer identification. NIR (near-infrared) sorting technology used in MRFs is not capable of identifying many dark polymers since the colorant absorbs light. There are dark shades that may be detected by NIR, and a PP label of a different color on a package might aid in detection by NIR. It is not feasible to use manual sorting to separate one dark polymer from another since they cannot be distinguished by sight.
Although the APR encourages and anticipates development in capturing dark plastics at the MRF this technology is not widely available today. It should be noted that dark colors used in industrial items fall outside the scope of the design guide since they are not typically collected through curbside collection that is the focus of this guidance. Non-NIR sortable PP, if collected in a source separated or postindustrial stream, can be reclaimed.
Recent innovations in both black colorants and sortation technology have created the possibility of sortable black PP containers. However, markets for black PP containers remain limited for curbside material as referenced above. Therefore, testing results are limited to Detrimental and Non-recyclable only.
Sortable colorants are commercially available. Companies that are considering such colorants and are unsure of their compatibility with recycling should ask their suppliers to provide APR test results. An item may meet the technical specifications for sorting, but may still not be considered recyclable in many communities.