easy for residents to dump their "recyclables" into a bin, think they're doing something good, and not think about the business behind it.
Clean cardboard - there's a market for it. Brokers will buy bails of clean cardboard, bails get transported to paper mills and used in the processing and manufacturing of new paper/cardboard products. China's paper mills have increased their standard on how clean it has to be and now they accept less material from the US since most of the US uses single stream recycling that is all mixed up first then sorted inaccurately, so a lot of our paper/cardboard recycling now goes to SE Asia or S. America paper mills instead of Chinese ones. The Canadian and US paper mills take it, but they're at capacity. Regardless, there is a worthwhile market for the efforts to collect/haul clean cardboard, sort it, bail it, and sell it so residents in municipalities don't have to fully pay for double the garbage trucks, drivers, maintenance, sorting equipment and laborers, etc. The Clean Cardboard market is a commodity that goes up and down and can be quite volatile, so it's still a risky business when the price is down and it costs more to collect and sort than what they make selling the bails.
Metals - there's a market for those too, with indexed risky/volatile commodity prices as well. This material can be smelted down and used in the process to make other things at a cost benefit to the buyers and sellers. Again, trash companies who collect, sort, and bail it, have to have brokers to sell it to, who have to have relationships with plants/mills willing to buy it because it's cheaper to mix in used material than buy or mine all new feedstock for whatever they're manufacturing.
Glass- there's no market. Used glass can be "recycled". It can be crushed into sand and used for various purposes. However, the cost for collecting, sorting, and crushing glass far outweighs any price for selling yards of crushed glass and any business out there with a purpose for it can just go buy higher volumes of sand elsewhere for cheaper. Further, as glass containers are dumped in a bin, then dumped in a truck, then dumped at a sorting facility, then run through all the sorting lines, conveyor belts, etc., it breaks into big shards before it's actually crushed, and ruins expensive sorting equipment, making it even worse to "recycle".
Plastics - there's minimal market for it. Some plants will buy bails of certain types of plastics to melt and reuse in their manufacturing processes, but again, volatile commodity market, brokers need to find buyers, any contaminated or dirty material gets sorted and diverted to the landfill, etc.
