What is photodegradable?
“Photodegradable” means it is decomposed by (direct) sun light, in this case HDPE is oxidised by UV with oxygen.
Photodegradable plastic how does it degrade?
Photodegradable plastic, in our shipping material HDPE, has bonds in its structure that are weakened and broken by sunlight, the exact process is that it is oxidised by active UV light with oxygen. Over time it completely degrades and is resorbed into the biosphere without adverse effects.
HDPE is photodegradable by nature; it’s interesting to note that plastic manufacturers have been attempting to make polymers resistant to UV light degradation, in order to make certain plastic products more durable, especially when exposed to direct UV light (through the addition of carbon black or chemical UV inhibitors). This natural characteristic of HDPE is an advantage for Stone Paper.
The sun’s rays have capabilities in its ultraviolet light (UV light) and infrared radiation which bring about the incorporation of oxygen molecules into the plastic, a process known as oxidation. As more and more oxygen intermingles with the polymer in the plastic, it becomes brittle and easier to break into ever diminishing pieces.
When it fully degrades there are no micro-plastics as the resin oxidizes into 1.4ppm of Nitrous Oxide and 65ppm of CO leaving only calcium carbonate behind. Recent research has concluded there are no halogens present.