Why can all #1 and #2 plastics be recycled?
The symbol on the bottom of a container only tells you about the type of resin used to make the product. Even though the plastic resin in a milk jug and a butter tub may be the same, the molding process to make them is quite different. A milk jug is blow molded, like blowing a bubble, and a butter tub is injection molded, like stamping two forms together with the plastic between them. To use each molding technique, different chemicals must be added to the plastic resin to make it melt and flow correctly. These added chemicals make the resins incompatible in most recycling processes because they no longer melt at the same rate. Melting is an important phase of the plastics recycling process. The biggest recycling end markets are for the blow-molded containers since we generated so many more of them than any other type.
