Macerator blades at a composting plant clogged with biodegradable bags

Paper Sacks

Biodegradable Bags

When bio-plastic is macerated on arrival at a composting plant it cuts into glutinous, sticky ribbons which bind to the blades and has to be manually removed.

Biodegradable Bags, or Bio-Plastic bags, are generally manufactured from a food crop such as corn or potatoes.

Less than a third of a cornstarch liner is actually biodegradable starch. The typical composition of a cornstarch liner is about 60% polyester, 26% starch, 4% ash and 3% water.

When bio-plastic is macerated on arrival at a composting plant it cuts into glutinous, sticky ribbons which bind to the blades and has to be manually removed.

Bio-plastic liners need oxygen and UV to degrade, neither of which is present in anaerobic digestion. Therefore they have to be removed from the food waste before the composting process.

When the liner is removed, it is generally sent to landfill.

Each small cornstarch liner weighs about 6 grams. Therefore if 50,000 households use 3 liners per week that will amount to about 44 tons of waste going to landfill.