Why don manufacturers of plastic containers make their caps out of the same type of plastic as the containers?
Manufacturers choose which of the seven primary types of plastic they want to use for each of their products based on the characteristics of each type of plastic and the use for which the product is intended. For example, most plastic beverage containers are transparent because people like to see what is inside, but not all plastics can be made transparent. And while it may be necessary or at least acceptable for the main container of a beverage to be a soft plastic, it would cause problems if the cap was also soft because it would soon wear down from repeated use and start leaking–a development which would rapidly cause customers to switch brands. When designing containers and choosing the plastic type, manufacturers are usually interested in only a few specific concerns primarily cost per unit, durability, marketability, and whether the material can be safely used with the product it will be containing. Recyclability is a secondary concern for most manufacturers, unfortunately, unle
