What is photodegradable?
Stone Paper is Photodegradable.
This means it is decomposed by (direct) sunlight. Photodegradable plastic, in this case HDPE which we have in our Stone Paper notebooks and envelopes, has bonds in its structure that are weakened and broken by sunlight, the exact process is that it is oxidized by active UV light with oxygen.
Over time it completely degrades and is resorbed into the biosphere without adverse effects. This natural characteristic of HDPE is an advantage for Stone Paper.
Is Stone Papeer biodegradable?
No it is not. For that we would need to add bacterias, which we don't.
HDPE more information around
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).
With the last decade’s environmental awareness and ecologically minded efforts, more and more environmentalists’ pressure has been exerted on numerous government officials, to choose better plastic for products which may end up in nature, so as to reduce and eventually eliminate harming nature because of our laziness or convenience. It’s interesting to note that laws have been passed requiring plastic rings connecting beverage cans to be either, bio, photo, or chemically degradable.
Up to now, after many tests, the conclusion that spontaneous chemical plastic degradation does not seem feasible has been reached. Thus, photodegradation was explored, namely in plastics which are sensitive to UV degradation.
HDPE’s relatively quick photodegradation (the speed of course depends on the amount and thickness of HDPE; stone paper has a very low percentage and is not in bulky form) makes it a good environmentally minded choice.