Dispenser seals made of Polymers with density < 1.0 that sink in water (specifically PS, silicone, nylon, acetal, thermosets)
Silicone, polystyrene, thermoset plastics, nylon and acetal are expected to sink in the float-sink tank, thereby separating from the PP. They also do not damage or wear cutting machinery in the recycling process. Small amounts of these materials that make it through the float-sink process can be melt filtered from the recycled PP in the extrusion step. However, these materials are lost to the waste stream in the recycling process and are considered less preferable than an alternative floating attachment that is compatible with PP.
Since polyethylene floats in water like polypropylene it is not separated in the reclaimers float-sink tank. When blended with PP it negatively affects the impact properties and can render the material brittle. Although very small amounts of PE, such as that contributed by labels, are regularly accepted by PP reclaimers, closures and dispensers comprising a larger weight percentage of the package have a greater negative affect.
REQUIRES TEST RESULTS
Valves containing Silicone (density and floatability will vary)
Check valves in spray dispensers or pumps may be made of silicone as an alternative to metals. While polymers are generally preferable to metals, the composition of a silicone part may cause it to be incompatible with PP recycling. It should sink in the sink/float system or be compatible with PP if it floats. Companies that are considering such components and are unsure of their compatibility with recycling should ask their suppliers to provide APR test results
Valves or Springs made of Metal
Sortation testing for metal components will result in either a Detrimental or a Renders Non-Recyclable ruling. Dark colors cannot be Preferred at this time.
Metal contamination is highly undesirable in the PP reclaiming process. Metals create wear in process machinery, and increase operation costs and yield loss. While metals sink in the float/sink tank and are therefore easily separable from PP flakes, they contribute wear to size reduction machinery. MRFs and PP reclaimers use magnets, eddy current separators and metal detectors to keep packages with metal components out of the process stream. Any metal components, such as pump springs, valves, safety seals, or lidding that trigger these devices will cause the entire plastic item to be removed from the stream and not recycled.