(1) Fine selection to remove impurities
Impurities such as metal and ceramics must be removed from the glass bottle reclaimed material because glass container manufacturers need to use high purity raw materials. For example, a metal cover or the like in the cullet may form an oxide that interferes with the operation of the furnace; ceramics and other foreign materials form defects in the production of the container.
(2) color selection
Recycling colors is also a problem. Because colored glass cannot be used in the manufacture of colorless flint glass, only a 10% green or flint glass is allowed to be produced when producing amber glass. Therefore, the cullet after consumption must be color-selected by hand or machine. Broken glass can only be used to produce light green glass containers if it is used directly without color picking.