Most plastics aren't actually recyclable. This is because it is difficult to separate the plastic from the other parts, like aluminum, paper, or non-recyclable plastic labels. 
Plastics like food containers are also rarely recycled due to being low-quality. 
Misleading recycling symbols also cause unrecyclable plastics to contaminate batches. Only recycling symbols with numbers can be recycled. However, most numbers rarely are. This is because they are difficult for most recycling plants to recycle. 
Number 1, or polyethelene terephthalate (PETE), is the most commonly recycled plastic. Most drink bottles, as well as polyester, are made from it.
Number 2, or high-density polyethylene (HDPE), is also commonly recycled. Liquid containers and plastic bags are the most common forms. However, plastic bags are more difficult to recycle, as they can clog recycling equipment. 
Number 3, or polyvinyl chloride (PVC), is very diverse. It is used to make records, food wrap, bottles, and piping. However, even in recyclable forms, it is difficult to recycle, so it is rarely accepted by recycling plants.
Number 4, or low-density polyethylene (LDPE), is mainly used for packaging material, as well as squeeze bottles. It is only sometimes recycled, depending on the municipality.
Number 5, or polypropylene (PP), is used for microwavable food containers, bottle caps, yogurt containers, and more. It is commonly recycled.
Number 6, or polystyrene (PS), is most well known in the form of styrofoam. It is mainly used for food containers, cups, and lids. It is rarely recycled due to difficulty. 
Number 7, or other, includes various types of plastics, including nylon and acrylic. It used to make a variety of things such as drink containers and squeeze bottles. However, due to being such a broad category, it is rarely recycled. 
Of the 6.3 billion tons of plastic waste generated between 1950-2015, 79% was landfilled or released into the environment, 12% was incinerated, and only 9% was recycled. 
Of the 9% recycled in the U.S., half of this was handled by China and Hong Kong.
However, most of this was contaminated with food or dirt, or was non-recyclable, and had to be landfilled in China. 
Due to growing environmental and health concerns, China banned imports of American recyclables in 2017.
This caused an increase in imports to Malaysia, Vietnam, and Thailand, who also had to restrict imports in 2018 for the same reasons. 
That year, the equivalent of 68,000 shipping containers of plastic recycling was exported from the U.S. to developing countries that mismanage more than 70% of their own plastic waste, including Thailand, Malaysia, Vietnam, Indonesia, Senegal, and Turkey.
Workers in these countries are extremely underpaid, making as little as $6.50 a day, an inhumane amount, to sort plastic. 
Overall, this current system may bear economic losses of $120 billion per year.