Hey Mr. Green,
Should you remove the zipper portions of plastic bags prior to tossing them in the recycling bin? Also, can black plastic bags be recycled with other plastic bags? -- Peter in Easton, Connecticut
Plastic bags are recycled to make durable, long-lasting synthetic boards used for decks and fences. When the plastic is heated up to make it gooshy enough to blend with wood waste and other board material, those thick zipper strips don’t soften as much as the flimsy plastic. This can create clumps that gunk up the board-making process. So rip those zips!
As for black plastic bags, it’s best not to recycle 'em, again because of plastic lumber manufacturing. Once pigment is in a plastic, it's impossible to remove; black plastic can discolor synthetic boards, which makes them a lot less attractive to your average homeowner.
Why do they dye bags black in the first place? It’s not to add an air of sophistication to lugging your 12-pack of Bud Lite. The bags are made of recycled plastic already tainted by a petrochemical rainbow, so black dye makes their color consistent.