If you use industrial feedstock of known characteristics quality control is much easier than if you use glass that might include window glass, coloured glass of

If you use industrial feedstock of known characteristics quality control is much easier than if you use glass that might include window glass, coloured glass of a colour you don’t want, random chips of ceramic, etc. Recycling of one time glass doesn’t work that well in Germany, look at wine bottles. What works well is reuse of bottles, both glass and plastic, and having big deposits on bottles, big enough that people are motivated to bring them back to the store to redeem the deposit.