Baling, often spelled bailing, is the compression of sorted recyclable material into dense, strapped blocks called bales. A baling press squeezes loose plastic film, bottles or sacks into a fixed size and ties the block with wire or strap.
Loose plastic is mostly air, so baling is what makes it economical to move. A truck carries several times more baled material than loose material, and bales stack safely in a warehouse. Bales are also the trading unit of the recycling industry: they are graded by polymer, colour and contamination level, and that grade sets the price a recycler pays. Baling normally follows sortation at a collection centre or MRF.
