Glass bottles survived typically 25-50 round trips during reuse, sometimes much longer if there was a deposit paid. Plastic as used in milk cartons is extremely

Glass bottles survived typically 25-50 round trips during reuse, sometimes much longer if there was a deposit paid. Plastic as used in milk cartons is extremely easy to spoil causing the recycled batch to be worthless. To avoid this the washing of the material (even after the householder has been required to do so) is done at higher temperature and pressure, with multiple hot, cold and abrasive steps. They have to ensure any food residue, glue, labels and any remnants of the under-cap seal are removed or it's junk[0]. It's significantly more expensive than washing and rinsing glass bottles used to be. [0] http://www.petbottlewashingline.com/pet-bottle-washing-line/ http://www.petbottlewashingline.com/pet-bottle-washing-line/