Two years ago the company began to use an unusual process, called the “sandwich bale”, to collect waste material at its stores and distribution centres for recycling.

The compactor then produces a “sandwich” which is easier to handle and transport, says Jeff Ashby of Rocky Mountain Recycling, who invented the process for Wal-Mart.

Sandwich plate production process is complex, therefore, relatively in the delivery time is not long, the price will be slightly higher than the double-sided circuit board products.